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Anatomy & Physiology
Key Terms For Final Exam
Term | Definition |
---|---|
Anatomy | the study of normal structure of various body organs and their locations |
Appendicular Skeleton | is composed of bones of the limbs |
Autonomic Nervous System | specialized areas and bundles of cardiac cells initiate each heartbeat; the rate of the heartbeat is controlled by. |
Axial Skeleton | is composed of bones located on the axis or midline of the body. |
Cardiac Cycle | refers to the series of events happening during one heartbeat |
Central Nervous System | consists of accumulations of nerve cell bodies, nerve fiber (axons), and supporting cells in the brain and spinal cord |
Dental Formula | places the teeth in the upper arcade in the numerator position and the teeth in the lower arcade in the denominator position. |
Endocrine Glands | the ductless glands that secrete directly into the bloodstream (pituitary glands, thyroid, testes, ovaries, adrenal gland). |
Endocrine System | consist of glands in various parts of the body that secrete minutes amount of chemical substances called hormones directly into the bloodstream, rather than the ducts. |
Exocrine Glands | secrete substances through the ducts, can be simple with a single duct ( sweat glands), or compound with a branching duct system (mammary glands). |
General Senses | are distributed generally throughout the body over the entire skin surface |
Gestation | the time from fertilization of the ovum to delivery of newborn |
Integumentis | the outer covering of the body that consists primarily of the skin, hair, claws or hooves and the horns. |
Lymphatic System | a vascular system that serves to return excess tissue fluid to the blood vascular system. |
Parturition | the primarily effect of oxytocin, the second hormone stored in the posterior, are to promote uterine contractions and milk let-down from lactating mammary glands. |
Physiology | describes the mechanism and steps of the body and its various components function |
Reproductive System | is different from other body systems, the main function of reproductive system is to help maintain the species |
Skeletal Muscle | it moves the skeleton; it is under conscious control and its cells, at the microscopic level, have striped or striated appearance. |
Endocrine Glands | the ductless glands that secrete directly into the bloodstream (pituitary glands, thyroid, testes, ovaries, adrenal gland). |
Endocrine System | consist of glands in various parts of the body that secrete minutes amount of chemical substances called hormones directly into the bloodstream, rather than the ducts. |
Exocrine Glands | secrete substances through the ducts, can be simple with a single duct ( sweat glands), or compound with a branching duct system (mammary glands). |
General Senses | are distributed generally throughout the body over the entire skin surface |
Gestation | the time from fertilization of the ovum to delivery of newborn |
Integument | the outer covering of the body that consists primarily of the skin, hair, claws or hooves and the horns. |
Lymphatic System | a vascular system that serves to return excess tissue fluid to the blood vascular system. |
Parturition | the primarily effect of oxytocin, the second hormone stored in the posterior, are to promote uterine contractions and milk let-down from lactating mammary glands. |
Physiology | describes the mechanism and steps of the body and its various components function |
Reproductive System | is different from other body systems, the main function of reproductive system is to help maintain the species |
Skeletal Muscle | it moves the skeleton, it is under conscious control and its cells, at microscopic level, have striped or striated appearance. |
Smooth Muscle | is found mainly in internal organs, its cells do not show any stripes or striated under magnification, it is involuntary muscle because it is not under conscious control |
Special Senses | sensory receptor are concentrated in certain areas rather than being generally distributed |
Tissues | depends on the health of the cells that make them up and the organs that are part of, and so on up the line. |
Urinary System | the many metabolic reactions that take place in the body's cells that generate a variety of chemical by-products which consist of two kidneys, two ureters, the urine bladder and the urethra. |
Epithelial Tissue | covers the interior and exterior surfaces of the body, lines body cavities and forms glands. |
Connective Tissue | holds the different tissues together and provides support, contains fewer cells and more fiber than epithelial tissue. |
Adipose Connective Tissue | consists of collections of lipid-storing cells which refers to as fat, represents the body's storage supply of excess nutrients. |
Loose Connective Tissue | is found throughout the body wherever cushioning and flexibility are needed, commonly found beneath the skin and around the blood vessels, nerves and muscles. |
Dense Connective Tissue | has the same components as loose connective tissue but is much more densely packed, has fibers arranged in parallel bundles, this type of tissues regularly arranged and it makes up tendons which attach muscles to bones and ligaments. |
Cartilage Connective Tissue | consists of a few cells called chondrocytes, various types and amounts of fibers embedded in a thick gelatinous, intercellular substance, the matrix. |
Elastic Connective Tissue | contains large numbers of elastic and collagen fibers, giving it more flexibility than the other two cartilage types, it makes up parts of the larynx and most of the ear flap ( pinna). |
Bone Connective Tissue | is second only to the enamel of teeth in its hardness, composed of a few cells the osteocytes embedded in a matrix that has become mineralized through the process called ossification. |
Skeleton | the framework of bones that supports and protects the soft tissues of the body |
Long Bones | have two extremities (epiphyses) and a shaft (diaphysis), contains a medullary cavity filled with a bone marrow. |
Bone Marrow | contains stem cells which produce the blood cells. |
Flat Bones | are expanded in two directions to provide maximum area for muscle attachment, and examples of flat bones are the scapula, skull bones, and pelvis. |
Small Bones | are cuboidal or approximately equal in all dimensions; are located at complex joints such as the carpus and hock joint; examples of small bones are the carpal and tarsal bones. |
Irregular Bones | are bones with an irregular shape such as vertebrae |
Sesamoid Bones | are tiny bones found along the course of the tendons, reduce friction and change the direction of a tendon; examples of sesamoid bones are the patella and fabella. |
Pneumatic Bones | contain air spaces to make the skeleton lighter. |
The Skull | composed of many bones, most of which are held together by immovable joints called sutures; can be divided into bones of the cranium and the face bones which extend in a rostral direction from the cranium. |
The Spinal Colum | is composed of a series of individual bones called vertebrae. |
The Vertebrae | form a long, flexible tube called vertebrae canal, protects the spinal cord, are divided into five groups and each vertebrae is numbered with each group from cranial to caudal. |
The Cervical Vertebrae (C) | are in the neck region, the first cervical vertebrae (C1) is the atlas that forms a joint with the skull. |
The Thoracic Vertebrae (T) | are the dorsal to the chest region and form joints with the dorsal end of the ribs. |
The Lumbar Vertebrae (L) | are dorsal to the abdominal region, are fairly large and heavy because they serve as the site of attachment for the large sling muscles that support the abdomen. |
The Sacral Vertebrae (S) | in the pelvic region are fused together into a solid structure called the sacrum which forms a joint with the pelvis. |
The Ribs | support and help form the lateral walls of the thorax and chest. |
The Sternum | forms the ventral portion of the thorax, composed of a series of rodlike bones called sternebrae, the manubrium sterni is the first ( cranialmost) sternebrae, the xiphiod process is the last (caudalmost); often used as external landmarks on the animal. |
The Scapula | the shoulder blade |
The Phalanges | are the bones of the digits equivalent to human fingers. |
The Pelvis | is composed of three pairs of bones that are fused in the adult animal, the ilium, ischium and pubis. |
The Femur | the long bone of the thigh region, the head of the femur forms a ball portion of the hip joint and the greater trochanter is the site of the attachment for the powerful gluteal (rump) muscles. |
The Patella | or kneecap is the largest sesamoid bone in the body, helps distribute the force of quadriceps femoris muscle, the main extensor muscle of the stifle joint |
The Tibia | the main weight-baring bone of the distal leg |
The Tarsus | is equivalent to the human ankle and consists of two rows of short bones |
Fibrous Joints | hold bones together but do not allow movement at the joint site. |
Cartilaginous Joints | allow slight rocking movement |
Synovial Joints | allow free movement between bones in several directions and usually have smooth articular surfaces covered by articular cartilage and fibrous joint capsule |
Six Potential Joint Movements | flexion, extension, adduction, abduction, rotation and circumduction. |
Flexion | bending of the limb, decreases the angle between two bones |
Extension | straightening of the limb, increases the angle |
Adduction | moves the extremity toward the median plane |
Abduction | moves the extremity away from the median plane |
Rotation | is a twisting movement of a part on its own axis |
Circumduction | is a movement in which the distal end of an extremity describes a circle. |
Articular Surface | is a surface in which a bone forms a joint with another bone, usually smooth and is often covered with a layer of hyaline cartilage. |
Condyle | large, convex, articular surface usually found on the distal ends of long bones that make up the imbs |
Foramen | is a hole in a bone through which blood vessels and nerves usually pass |
Fossa | is a depression of a bone usually occupied by a muscle or tendon |
Facet | is a flat and smooth articular area such as the surface of a tarsal or carpal bone |
Bone Head | is a spherical articular projection usually found on the proximal ends of some limb bones |
The Neck | a bone is the often-narrowed area that connects a bone head with the rest of the bone |
A Process/Tuber/Tubercle/Tuberosity/or Trachanter | is a lump or bump on the surface of a bone, usually the site where the tendon of a muscle attaches to a bone; the larger the process the more powerful the muscle that attaches at the site. |
The Skin | is the largest body organ which consists of two main layers; the superficial epithelial layer (epidermis), and the deep connective tissue layer (dermis). |
Epidermis Layer | is composed of keratinized, stratified squamous epithelium; the surface layer of the epidermis dries out and is converted to a tough horny substance called keratin which also makes up the bulk of hair, claws, hooves and horns (antlers). |
Dermis Layer | skin is composed of collagen, elastic and reticular fibers; it contain s hair follicles, sebaceous glands, sudoriferous glands and arrector pili muscles; in addition this layer also contains various sensitive nerve endings and blood vessels. |
Sebaceous Glands | are oil glands of the skin, they secrete oily sebum which helps waterproof the skin and keep it soft and pliable. |
Sebum | is secreted directly onto the shafts of hairs in the hair follicles. |
Sudoriferous Glands | are the sweat glands which primarily help cool the body. |
Hypodermis or Subcutis | is a layer of loose connective tissue just below the dermis which connects the skin to underlying muscles; also contains some fat cells |
Claws and Hooves | are horny structures that cover the distal ends of the digits; are composed of parallel bundles of keratinized cells organized into an outer wall and a bottom sole. |
Circulatory System | is primarily a transport system in the body; transports a variety of substances throughout the body such as cells, antibodies, nutrients, oxygen, carbon dioxide, metabolic waste and hormones. |
Two Main Divisions Are? | the blood vascular system and lymphatic system. |
Blood Vascular System | consists of a closed system of tubes through which a fluid connective tissue is propelled by a muscular pump |
Fluid Connective Tissue | is blood, the tubes are blood vessels, and the pump is the heart. |
Three Types of Blood Vessels Are? | arteries, capillaries, and veins. |
Arteries | carry the blood away from the heart to the capillaries; are large near the heart and gradually branch into smaller and smaller vessels as they course throughout the body |
Capillaries | are composed of a single layer of endothelium and permit substances to move freely between the extracellular fluid ( fluid surrounding cells) and blood. |
Vein | contain tiny one-way valves along their length, assisted by movement of muscles in the area that help propel the blood back toward the heart. |
Systemic Circulation | the blood moves from the heart to the body tissue and back to the heart; the aorta ( largest and main artery) originates from the left ventricle of the heart and carries oxygenated blood to various body tissue. |
Pulmonary Circulation | the blood moves from the heart to the lungs and back to the heart again |
Heart | is a muscular two-way pump that propels blood around the body and receives it back; it consists of dense accumulations of cardiac muscle cells and connective tissue organized into two side by side pumps that together are composed of 4 chambers. |
The 4 Chambers Of The Heart Are? | two atria (right and left atrium) and two ventricles ( right and left ventricles) |
Right Atrium | lies above the right ventricle and receives CO2 rich blood from the cranial and caudal venae cavae |
Left Atrium | lies just above the left ventricle and receives oxygenated blood form the pulmonary veins; it is separated from the right atrium and the interatrial septum. |
Right Ventricle | receives blood from the right atrium through the right atrioventricular opening (AV opening), which is guarded by a tricuspid valve. The pulmonary artery originates from the right ventricle, and its opening is guarded by pulmonary semilunar veins. |
Left Ventricle | receives blood from left atrium through the left atrioventricular opening which is guarded by a bicuspid valve or mitral valve. The aorta originates from the left ventricle and its opening is guarded by aortic semilunar valves. |
Diastole | the relaxation of the heart chamber to receive the blood |
Systole | the contractio of the heart chamber to pump the blood into body tissues and lungs. |
Blood | is specialized connective tissue composed of fluid and cellular portions; the fluid portion is plasma and the cellular portion is composed or red blood cells, white blood cells and platelets. |
Plasma | is composed of 91% of water, 7% of protein molecules and 2% of other substances and electrolytes; it serves tp suspend the blood cells and dissolve the many substances that are transported in the blood. |
Fibrinogen | is one of the proteins in plasma; is converted through a complex series of steps to strands of fibrin. |
Fibrin Strands | form a meshwork that traps the rest of the cellular components and forms what is recognized as a blood clot; this blood-clotting process serves to obstruct leaking blood vessels temporarily and minimize blood loss caused by injury. |
Red Blood Cells (RBCs) | are also called erythrocytes, are the most numerous of the blood cells, typically numbering in the millions per microliter of blood. |
In Mammalian Species | RBC's do not normally contain nucleus and are shaped like biconcave discs resembling tiny pillows. |
In Birds, Reptiles And Fish | they are normally nucleated and elliptical. |
The Protein Hemoglobin | gives erythrocytes their red color, also gives them the ability to carry large amount of O2 to the body's cells. |
White Blood Cells (WBCs) | are also called leukocytes, typically number in the tens of thousands per microliter of blood; are divided into granulocytes ( neutrophils, eosinophils and basophils), and agranulocytes (lymphocytes and monocytes). |
Difference Between Granulocytes And Agranulocytes? | granulocytes have stainable granules in their cytoplasm; agranulocytes lack cytoplasmic granules. |
Granulocytes | play a role in natural defense and adaptive defenses |
Eosinophil And Basophils | release specific chemicals to help activate other aspects of the immune system |
Neutrophils | also play a major role in the immune system |
The Respiratory And Urinary Systems | contain groups of neutrophils, referred to as resident neutrophils that act as scavengers and function phagocytize foreign substances. |
Phagocytosis | litterily means "cell-eating"; the neutrophils engulf the antigen and then release chemicals that damage the foreign agent. |
Monocytes | act in a manner similar to phagocytic neutrophils and are often referred to as tissue macrophages and are capable of phagocytosis and antigen processing and presentation |
Lymphocytes | are the primary cellular components of antibody-producing systems |
T lymphocytes | are involved in assisting in full activation of B lymphocytes, although B lymphocytes can be activated without this interaction |
B lymphocytes | are responsible for the creation and secretion f antibody that is specific for a certain antigen |
Humoral immunity | the production of a specific antibody that is secreted into the body fluids or humors |
Cellular immunity | is a protective immune process that involves the activation of phagocytes, antigen-sensitized cytotoxic T cells and the release if cytokines and chemokines in response to antigen. |
Antibodies | are protein molecules produce by a certain subgroup B lymphocytes when they are presented with a substance that is recognized as foreign ( the antigens); also referred to as immunoglobulins |
Fetal circulation | a fetus developing in the uterus leads a parasitic existence. |
The placenta | is the life support system of the fetus that makes this possible |
The fetus | is connected to the placenta by the umbilical cord |
The umbilical vein | carries nutrient- rich, freshly oxygenated blood from the placenta to the fetus |
The fetal heart | then pumps the blood throughout the developing fetus where the blood releases its nutrients and O2 ; picks up wastes and CO2. |
The umbilical arteries | return the waste filled blood to the placenta, where it exchanges its waste for nutrients and O2. |
The Foramen ovale | is a hole in the interatrial septum of the heart, the wall between the left and right atria which allows some of the blood returning from the systemic circulation to flow from the right atrium directly into the left atrium bypassing the lungs. |
Patent Ductus Arteriosus (PDA) | is a common congenital abnormality in dogs when the ductus arteriosus fails to close and persists even after birth. |
The ductus venosus | connects the portal sinus to the posterior vena cava, diverting the blood away from the liver until birth. |
Lymphatic system | is a vascular system that serves to return excess tissue fluid to the blood vascular system |
12 Cranial Nerves | facial, hypoglossal, glossopharyngeal, vestibulocochlear, abducens, trigeminal, olfactory, accessory, vagus, trochlear, oculomotor, optic. |
Lymph Capillaries | begin peripherally as blind ended vessels that pick up excess fluid called lymph and move it toward the thorax |
Lymph Capillaries continued (1) | the small lymph vessels merger to form larger vessels; these larger lymph channels contain one-way valves similar to those in vein. |
Lymph Capillaries continued (2) | combined with movements; these one-way valves help propel the lymph to the thorax, where it is deposited back into the blood stream. |
Lymph Nodes | contain large accumulations of one type of blood cell, lymphocytes, organized into collections called lymph nodules. |
Lymph Nodes Continued | filter the lymph, removing debris and foreign invaders, and produce antibody producing cells that are important components of the body's defense mechanism |
Lymph Nodules | found in areas of the body other than lymph nodes |
Lymph Nodules continued (1) | the spleen which is responsible for blood storage contains large accumulations of lymph nodules |
Lymph Nodules continued (2) | the thymus is a lymphoid organ located in the caudal cervicocranial thoracic region |
Lymph Nodules continued (3) | it is of importance primarily in young animals as it helps jump start the immune system and then gradually shrinks and disappears around the time of sexual maturity |
Lymph Nodules continued (4) | accumulations of lymph nodules are also found in the tonsils, and scattered in the lining of the intestines. |
Primary Function of Respiratory System | is to allow exchange of O2 in oxygenated blood for CO2, which is produced as a waste product by the cells |
Secondary Function of Respiratory System | vocalization ( barking, mooing ect…), body temperature regulation and acid-base regulation |
Respiratory System Is Composed Of: | Upper Respiratory Tract & Lower Respiratory Tract |
Upper Respiratory Tract | Tip Of The Nose, Nasal Passages, Pharynx/Throat, Larynx - valve that controls air way to the lungs and Trachea- at the caudal aspect it divides into the right and left bronchi, which enter the lungs |
Pharynx | back of the throat that leads to the trachea or esophagus |
Larynx | voice box which vibrates; is a short irregular tube of cartilage and muscle that connects the pharynx with the trachea. |
Trachea | windpipe that divides into left and right bronchi which enters the lungs |
Lower Respiratory Tract | bronchi and alveoli |
Respiratory Mechanisms | the process of external respiration depends on physical mechanisms that allow air to move in and out of the lungs, and on control systems that set limits on and adjust the process |
Thorax | the area located between the neck and diaphragm |
Inspiration on inhaling | is the process of drawing air into the lungs |
The Diaphragm | is a dome-shaped, sheet-like muscle that completely separates the thoracic cavity from the abdominal cavity |
Oxygen | diffuses from the alveoli to the blood in the alveolar capillaries |
Carbon Dioxide | diffuses in the other direction, from the blood of the alveolar capillaries to the alveoli. |
Expiration | occurs as muscular contractions compress the thoracic cavity and elastic lung tissue returns to its original shape, expelling air from the lungs. |
Control of Breathing | two systems control the process of respiration, a mechanical control system and a chemical control system |
Mechanical Control System | sets normal limits on inspiration and expiration to allow rhythmic, resting respiration. |
Chemical Control System | monitors the chemical composition of the blood; if it senses fluctuations of O2 and CO2 levels of pH, it initiates adjustments in respiration necessary to restore normal values. |
Digestive System | converts food eaten by an animal into nutrient compounds that the body cells can use for metabolic fuel. |
Digestive System continued (1) | consists of a tube running from the mouth to the anus, with accessory digestive organs attached to it. |
Digestive Systems of Carnivores | (meat eaters) such as dogs and cats is much simpilar, which depend on enzymes to break down easy-to-digest animal source nutrients through the process of enzymatic digestion. Therefore no large fermentation vat is needed. |
Digestive Systems of Omnivores | (species eating a mixed diet), such as pigs are somewhat intermediate depend on primarily on enzymatic digestion, with a minor amout of microbial fermentation occurring in their large intestines. |
Mouth | where found is chewed and mixed with saliva in preparation for swallowing. |
The Four Canines (C) | if present are located at the rostral lateral corners of the mouth adjacent to the incisors |
The Premolars (PM) | are the rostral cheek teeth |
The Molars (M) | are the caudal cheek teeth |
Esophagus | is a musclular tube that connects the pharynx with the stomach |
Stomach | is an enlarged chamber in which swallowed food is mixed with hydrochloric acid and digestive enzymes |
Small intestine | Duodemum( first short segment), Jejunum (longest segment), Ileum ( shortest segment). |
Large Intestine | Cecum (first), Colon (longest), Rectum (last)-carries feces to the anus to discharge from the body |
Anus | the caudal opening to the outside world |
Nervous System | is a complex communication system of the animals body |
Unconscious functions | heart rate, breathing and blinking |
Conscious functions | holding breaths and swallowing rapidly |
Neurons or Nerve cells | are specialized cells that respond to stimuli and conduct impulses from one part of the cell to another |
Two type of fiber like processes extend from the cell bodies of neurons: | dendrites and axons |
Dendrites | are often multiple and they conduct impulses received from other neurons toward the nerve cell body |
Axons | are usually single and they conduct impulses away from the cell body to other neurons of the effector organs such as muscle cells |
The junction of an axon with another nerve cells is called | synapse |
Neurons have three physical unique characteristics: | they do not reproduce, their processes are capable of limited regeneration if damages and they have an extremely high oxygen requirement. |
Since they do not reproduce, if injured the damage is: | permanent |
The high oxygen requirement | makes them the most delicate cells in the body |
The dendrite and axon process sometimes regenerate as: | long as the nerve cell body is intact |
The suffer permanent damage if | deprived from the blood for more than a few minutes |
This is why CPR must begin within a few minutes | after cardiac arrest if there is to be any chance for full recovery |
The 3 main divisions of the nervous system | 1. Central Nervous System, 2. Peripheral Nervous System and 3. Autonomic Nervous System |
Central Nervous Systen | consists of nerve cell bodies, never fibers and supporting cells in the brain and spinal cord |
Anatomy of the central nervous system | brain and spinal cord |
Grey matter | area containing nerve cell bodies |
White matter | containing large accumulations of nerve fibers. |
Cerebrum | two hemispheres, largest, most rostral part of the brain, the surface area is increased by a system of folds termed by the gyri and grooves termed by the suici |
the cerebral cortex or outer layer of the cerebrum consists of | grey matter |
the medulla or inner layer of the cerebrum consists of | white matter |
the functions of the cerebrum are | complex and poorly understood; it is the center of higher learning, thinking and reasoning, and initiation of responses to sensory stimuli |
Cerebellum | located just caudal to the cerebrum, wrinkled appearance |
Cerebella cortex | is grey matter |
Inner medulla | is white matter |
Directly by the cerebrum is | coordination, adjust and generally fine tune movements |
Brainstem | forms a stem to which the cerebrum, cerebellum and the spinal cord are attached |
Functions: | maintain vital functions of the body; respiration, body temperature, heart rate, gastrointestinal tract functions, blood pressure, appetite, thirst and sleep-wake cycles. |
Severe damage usually results in: | immediate death |
Spinal Cord | caudal continuation of the brain stem; spinal nerves exit and enter the spinal cord between each set of adjacent vertebrae |
Spinal Cord Continued: | they carry information to and from the peripheral portion of the nervous system. |
Peripheral Nervous System | consists of cord like nerves that run throughout the body- the nerves are actually bundle of axons that carry impulses between the central nervous system and the rest of the body. |
Spinal Nerves | originate as two roots, the dorsal root and ventral root on either side of the spinal cord. |
The Brain | consisting of the cerebrum, cerebellum and brainstem is housed in the skull |
The lobes of the brain are | frontal lobe, parietal lobe, occipital lobe and temporal lobe. |
Autonomic Nervous System | the self governing portion of the nervous system which operates independently of conscious thought |
Consists of two parts | sympathetic and parasympathetic |
Sympathetic | fight or flight response; HR increase, RR increase, BP increase, Pupils dilate, Air passageways in lungs dilate, digestive tract activity decreases and raised hackles |
Parasympathetic | resting and digesting; HR decrease, BP decrease, pupils constrict, digestive tract activity increases. |
Muscular System | general function of the muscular system is to move the body internally and externally. |
The 3 distinctively different types of muscles in the body are: | Cardiac muscle, Skeletal muscle and Smooth muscle |
Skeletal Muscle | moves the skeleton |
Cardiac Muscle | found only in the heart, AKA involuntary striated muscle |
Smooth Muscle | found mainly in internal organs |
Sensory System | the body monitors its internal and external environment with senses |
The five senses are | hearing, smell, taste, touch and sight. |
General Senses | distributed generally throughout the body or over the entire skin surface; modified nerve endings. |
The tactile sense or sense of touch | perceives mechanical contact with the body |
The temperature sense | is a thermal sense that perceives hot and cold |
The position of the limbs is | monitored by the kinesthetic sense, a mechanical sense that provides information on the position of the joints and the relative force exerted by muscles and tendons |
Pain can be set off by | overloads of mechanical, thermal or chemical stimuli |
Special Senses | sensory receptors are contracted in certain areas, rather than being generally distributed |
Gustatory Sense | taste |
Olfactory Sense | smell |
Auditory Sense | hearing |
Vestibular Sense | balance |
Visual Sense | sight |
The vestibule impulses | carry information to the brain about changes in the position and inner ear motion of the head |
Semicircular canals | are three fluid filled canals of the semicircular shape on each side of the head |
The resulting impulses | carry information to the brain about rotary motion of the head |
Eye Anatomy | globe, cornea, sclera, anterior chamber, iris and posterior chamber |
Globe | outer covering gives its eyeball its shape |
Cornea | clear window where light rays enter through the eye |
Sclera | makes up the rest of the outer layer of the globe referred to as the white of the eye |
Anterior Chamber | full of aqueous humor and is produced by cells caudal to the iris |
Iris | muscular diaphragm that controls the size of your pupil |
Eye Anatomy Continued: | lens, ciliary body, vitreous humor |
Lens | biconvex, elastic, crystalline structure responsible for the process of accommodation, focusing light rays on the photoreceptors cells in the caudal portion of the eye to allow for near and far vision |
Ciliary Body | contains the muscles responsible for changing the shape of the lens as required tp focus light rays |
Vitreous humor | transparent gelatinous substance where light rays pass through on their way to the photoreceptor containing layer, the retina. |
Retina | where visual images are formed, complex multilayered structure that lines most of the interior of the eye caudal to the lens |
Composed of photoreceptors cells termed | rods and cones, and several layers of nerve cell bodies, and synapses that integrate and relay information from the receptor cells to the brain |
Rods | are long and narrow, and are more sensitive to light than cones |
Rods do not detect | color or detail well, they are receptors for dim light vision |
Cones | dectect color and detail |
The area of the retina at which nerve fibers converge to form optic nerves is called: | the optic disc |
The optic disc | is the blind spot of the eye |
Accessory organs | the conjunctiva, the eyelids and lacrimal apparatus, medial canthus and lateral canthus |
The Conjunctiva | thin membrane that lines the underside of the lids and covers the outer aspect of the eyeball |
The eyelids | are dorsal (upper) and ventral (lower) folds of skin by conjunctiva that cover and protect the eye when the animal blinks or sleeps |
Lacrimal apparatus | responsible for the production of tears |
Endocrine System | consists of glands in various parts of the body that secrete minute amounts of chemical substances called hormones directly into the bloodstream rather than through the ducts |
Hypothalamus | is part of the brainstem, produces two hormones which are called releasing factors and inhibiting factors. |
Pituitary Glands | is often called the master endocrine gland because many of the hormones it produces direct activity of other major endocrine glands. |
The two separate pituitary glands are: | anterior and posterior pituitary glands |
Anterior Pituitary Glands | produces and releases six hormone |
The six hormones are | growth hormone (GH), prolactin, thyroid stimulating hormone (TSH), follicle stimulating hormone (FSH), luteinizing hormone (LH), and adrenocorticotropic hormone (ACTH) |
Growth hormone | stimulates growth in young animals |
Prolactin | effects only females which helps initiate and maintain milk secretion in the mammary glands |
Thyroid Stimulating Hormone | stimulates the thyroid gland to produce and release hormones |
Follicle Stimulating Hormone | in females stimulates production of follicles in the ovaries, in males it stimulates production of spermatozoa in the testes. |
Luteinizing Stimulating Hormone | in females it promotes ovulation of a mature ovarian follicle and the follicle's conversion into a corpus luteum; while in males it simulates the testes to produce testosterone. |
Posterior Pituitary Glands | does not produce any hormones but stores and releases two hormones produced in the hypothalamus |
The two hormones | are antidiuretic hormone (ADH) and oxytocin |
Antidiuretic hormone | also called as vasopressin causes the kidneys to conserve water producing more concentrated urine. |
Oxytocin | are to promote uterine contractions at parturition and milk let-down from a lactating mammary gland. |
Nictitating Membrane | is a plate of cartilage covered by conjunctiva located medially between the eyelids and eyeball in some species |
Thyroid Gland | consists of two lobes that may or may not be connected; produce two hormones thyroxine (T4), and calcitonin. |
Thyroxine | produces effect similar to that of growth hormone, it is necessary for normal growth and helps regulate metabolism in the cells of animal of any age |
Calcitonin | regulates the blood calcium level and is secreted when blood calcium levels are abnormally high |
Parathyroid Glands | are several small nodules located in, on or near the thyroid gland; the effects of the hormone that they produce, parathormone, oppose those of calcitonin |
Parathormone | acts to regulate the blood calcium lever and is secreted when blood calcium levels become too low |
Adrenal Glands | are located near the kidneys; they consists of two parts, the cortex and the medulla |
The adrenal cortex-the outer part of the gland | produces three groups of hormones- glucocorticoids, mineralocorticoids, and sex hormones |
The adrenal medulla-the inner part of the gland | produces two hormones that are similar to each other, epinephrine and norepinephrine |
Glucocorticoid Hormones | are the basis for cortisone-type drugs |
Their primary effects are | to increase the blood glucose level through a number of mechanisms, decrease inflammation and affect the metabolism of fats (mobilization), proteins (catabolism), and carbohydrates (glucose production). |
Mineralocorticoid Hormones | primarily aldosterone work mainly in the kidneys to promote the retention of water and sodium; which the body cannot tolerate in large amounts |
Sex Hormones | both estrogens and androgens are produced in the adrenal cortices of both sexes; the amounts produced are relatively minor |
Adrenal Medullary Hormones | the hormones of the adrenal medulla, epinephrine and norepinephrine are released under control of the sympathetic nervous system as part of the body's fight or flight response |
The Pancreas | is mainly an accessory digestive organ that serves as an exocrine gland and as an endocrine gland. |
The exocrine part of the pancreas contains | acinar cells that produce enzymes; these enzymes are released into the duodenum through pancreatic ducts. |
The endocrine part of the pancreas mainly contains | small nodules of endocrine cells, the islets of Langerhans. |
Two hormones produced in the islets are | insulin and glucagon |
Insulin | is necessary for the body's cells to use glucose for fuel; it prevents abnormally high blood glucose levels and allows glucose to enter the cells for use |
A defect in insulin secretion or action leads to | diabetes mellitus, characterized by abnormally high blood glucose levels and many metabolic difficulties |
Glucagon | the other pancreatic hormone has the opposite effect and tends to increase the blood glucose level. |
Gonads | are the sex cell-producing organs |
The male gonads are | the testes |
The female gonads are | the ovaries |
The main hormone produced in the testes is | the male sex hormone testosterone |
Leydig cells | produce testosterone at a fairly level throughout the year |
Sertoli cells | very small amount of female sex hormone estrogen is produced in the testes |
The two main hormones produced in the ovaries are | estrogen and progesterone |
Levels of the hormones produced by the ovaries | fluctuateb in a cyclical fashion linked to the development of follicles and corpora lutea. |
Under the stimulation of FSH from the pituitary glands | follicles develop in the ovaries |
Estrogen | is responsible for the signs of heat or estrus after LH form the pituitary glands has caused the follicle to rupture and release its ovum, it stimulats the empty follicle to develop into a solid corpus luteum which produces progesterone |
Progesterone | is necessary for the maintenance of pregnancy |
if the animal is pregnant | the corpus luteum is retained |
if the animal is not pregnant | the corpus luteum lasts for only a short time and then regresses |
Urinary System | is the primary means whereby waste products are removed from the blood |
Kidneys | the left and right kidneys are located in the dorsal part of the abdominal cavity, just ventral to the most cranial lumbar vertebrae |
The right kidney of the horse is | heart-shaped |
Bovine kidneys | have a lobulated appearance |
Blood and lymph vessels, nerves and the ureter | enter and leave the kidneys through an indented area, the hilus |
The hilus | a rough-appearing outer cortex is wrapped around a smooth-appearing inner medulla |
The area deep to the hilus region is | the renal pelvis- the funnel-like beginning of the ureter |
The work of the kidneys is | done at microscopic level in tiny waste disposal units called nephrons |
Depending on the animal's size | each kidney may contain form several hundreds to several million nephrons. |
Each nephron | is a tube with several bends |
This tube has different names because | the shape and function of its cells changes as it passes through different levels of the kidney matrix |
The Nephron (tubule) has the following parts: | renal corpuscle, proximal convoluted tubule, loop of Henle, distal convoluted tubule, and collecting tubule. |
Renal corpuscle | are blood filters located in the renal cortex |
Each renal corpuscle is | composed of glomeruli surrounded by a Bowman's capsule |
Glomeruli | are tufts of capillaries interposed between the arterioles entering and leaving the renal corpuscle |
Bowman's capsule | a saclike structure which is a blind end of each tubule surrounds the glomerulus |
Cells of glomerulus and Bowman's capsules together | make a filtration membrane which is highly permeable. |
From the proximal convoluted tubule | the contents pass to the loop Henle which dips deep into the renal medulla |
Collecting tubules of all nephrons drain urine | into the renal pelvis- the funnel-like opening of the ureter in the kidney |
Ureters | muscular tubes that conduct the urine by smooth muscle contractions; from each renal pelvis, urine is transported to the urinary bladder |
The ureters enter | the bladder at oblique angles forming valve like openings that prevent backflow of urine into the ureters as the bladder fills. |
Urinary Bladder | is a muscular sac that stores urine and releases it periodically to the outside in a process called urination |
The kidneys | constantly produce urine |
As urine accumulates in the urinary bladdle | the bladder enlarges and stretch receptors in the bladder wall are activated when the volume reaches a certain point |
A spinal reflex | then initates contraction of the smooth muscle in the bladder wall. |
A voluntarily controlled sphincter muscle | around the neck of the urinary bladder enables conscious control of urination |
Urethra | is a tube that carries urine form the urinary bladder to the outside of the body |
In females | it is relatively short, straight and wide; and has a strictly urinary function |
In males | it is relatively long, curved, and narrow, and serves both urinary and reproductive functions |
The male reproductive system | is organized to produce male reproductive cells and transmit them to the female. |
Its main components are | the testes, epididymis, vas deferens, accessory sex glands and penis |
The testes are | the male gonads |
Their functions include | production of the male reproductive cells (spermatozoa)and male sex horomes |
Before birth | the testes develop in the abdominal cavity |
At or soon after birth | they descend through slits in the abdominal muscles called inguinal rings into a sac of skin called the scrotum |
The scrotum | houses the testes and helps regulate their temperature |
To produce viable spermatozoa | the testes must be maintained at a temperature slightly lower than body temperature |
The cremaster muscle | a muscle in the scrotum acts to raise or lower the testes to adjust their temperature |
Pampiniform Plexuses | a network of veins surrounding the cranial part of the testes also helps lower the temperature of arterial blood coming to testes |
Spermatogenesis | occurs in the seminiferous tubules |
Each U-shape tubule | is connected at both ends to efferent ducts |
When the development of spermatozoa is complete in the seminiferous tubules | the spermatozoa move through the efferent ducts into the epididymis |
Epididymis | a single large tortuous convoluted tubule lying on the surface of the testis |
Spermatozoa | are stored here until ejaculation; if spermatozoa are not expelled from the epididymis, they die and are absorbed |
Vas Deferens | muscular tube that carries spermatozoa and the fluid in which they are suspended to the urethra for emission as a component of semen |
The accessory sex gland | found in all common mammals is the prostate gland |
The seminal and bulbourethral glands | are present only in certain species |
Each is responsible for | adding components of semen to the spermatozoa that are delivered by the vas deferens during ejaculation |
The penis | is the male organ of copulation |
It consists of roots | which attach it to the brim of the pelvis |
Brim of the pelvis | a body, which consists primarily of erectile tissue, and the glans- which is the distal free end of the penis that is richly supplied with sensory nerve endings |
The erectile tissue | is composed of spongy networks of vascular sinuses surrounded by connective tissue |
Erection | the result is engorgement and stiffening of the penis. |
Ejaculation | the reflex expulsion of semen from the urethra occurs in two rapidly successful stages. |
First | spermatozoa and seminal fluids are moved into the urethra |
Second | semen is expelled from the urethra by rhythmic contractions of muscles surrounding the urethra. |
Female Reproductive System | is organized to produce female reproductive cells accept male reproductive cells spermatozoa, allow one sperm cell to unite with each female reproductive cell; then shelter and nourish the resulting developing fetuses until birth. |
The organs of the female reproductive systems are: | the ovaries, oviducts, uterus, cervix, vagina and vulva |
Ovaries | are the female gonads; produce female reproductive cells (ova) and hormones. |
Flattened Follicular Cells | a single layer surrounds the immature ova |
Particular Follicle Cells | when activated the follicle cells become more cuboidal and multiply to form layers around the ovum |
Mature Follicle Cells | is a large, blister like structure that protrudes from the surface of the ovary; as it develops the follicle secretes increasing amounts of estrogen, which causes physical and behavioral signs of heat, or estrus. |
Ovulation | is characterized by the physical rupture of the follicle surface |
The collapsed follicle | a fluid of antrum which rushes out and carries the ovum with it |
Corpus Hemorrhagicum (CH) | after ovulation the collapsed follicle fills with blood then is converted quickly |
The corpus luteum (CL) | starts producing progesterone which is necessary for the maintenance of pregnancy |
The oviducts | partially surrounding each ovary but not physically connected to it; are convoluted, tubular extensions of the uterus; each oviduct is flared to form the funnel like infundibulum which catches ova as they are released from the follicles. |
The uterus | is a hollow, muscular organ that is continuous with the oviducts cranially and opens, via the cervix, into the vagina caudally; consists of two cranial uterine horns that unite in a caudal uterine body |
The cervix | is a powerful smooth muscle sphincter that functions to close off the lumen of the uterus from the lumen of the vagina most of the time; the only time the cervix is relaxed and partially dilated are at breeding and parturition. |
The vagina | is the canal from the cervix to the vulva; it receives the erect penis during copulation and is the birth canal for the newborn at parturition |
The vulva | is the external portion of the females genitalia |
The estrous cycle | is composed of four or five stages, depending on the species and whether the animal is polyestrous (cycles repeatedly) or monstrous (cycles only once during breeding season). |
The stages of estrous are: | anestrus, proestrus, estrus, metestrus and diestrus |
Anestrus | is the period of ovarian inactivity with no behavioral signs of heat or estrus |
Proestrus | under the influence of gonadotropin-releasing hormone (GnRH) produced in the hypothalamus, FSH released from the pituitary, acts on the ovary, and causes initial follicle development; which these growing follicles produce estrogen. |
Estrus | is the period of true heat during which the female allows mating. |
Metestrus | is the short stage during which the female may still attract males but no longer allows mating |
During this stage | ovulated follicles, metamorphose into corpora lutea which begin to secrete progesterone |
Diestrus | is a stage of ovarian activity without signs of heat. |
Bitches | the bitch (female dog) is a seasonally monstrous animal with a definite anestrous period between cycles |
Most bitches come into season | approximately once every 6 to 7 months |
Bitches reach puberty at | 6 to 24 months of age with an average of 10 to 12 months; small breeds usually reach puberty earlier than large dogs |
They release their eggs at a: | predetermined time in their cycle after the appropriate hormonal change. |
The queen on the other hand | is an induced ovulator meaning coitus (mating) is necessary to stimulate ovulation. |
The queen is a | seasonally polyestrous animal; if not induced to ovulate she will have several cycles of sexual behavior before being bred and induced to ovulate or having the follicles regress |
Queens | is a female cat that is different from other animals discussed earlier in that the others are spontaneous ovulators and are seasonally polyestrous animal. |
The cycle lasts approximately | 14 days and is composed of 1 to 2 day of proestrus, 3 to 6 days of estrus (heat), and approximately 7 days of metestrus before proestrus occurs again |
Pacitation | the final maturation process |
Cleavage | single cell divides into two cells, the two cells to four and so on |
The zygote | begin the process of cell divisions as the cells lining the oviduct slowly move it distally toward the uterus |
The blastocyst | hallow ball of cells which is ready to implant itself into the wall of the uterus |
Following implantation the placenta | the life support system of the developing fetus, develops. |
The placenta | a multilayered fluid-filled sac in which the embryo develops; it attaches to the uterine wall so that its blood vessels and the uterine bood vessels are intertwined. |
The first trimester | is the period of the embryo, when the newly implanted zygote is getting itself organized and developing its life-supporting placenta |
The second trimester | is the fetal development period, when all the various parts of the fetus are taking shape and differentiating from each other |
The third trimester | is the period of fetal growth |
Parturition | is divided into three stages |
Stage 1 | is preliminary to expulsion of the fetus; during this stage the uterine muscles undergo rhythmic contractions which reposition and advance the fetus toward the cervix |
Stage 2 | is the stage of expulsion of the fetus from the birth canal |
Stage 3 | parturition is characterized by expulsion of the placenta |
After delivery of the fetus | the dam rests and begins to care for the newborn |
The mammary glands | are specialized skin glands that produce secretions essential for nourishment of the newborn |
The process of milk production | called lacation begins toward the end of pregnancy |
Colostrum | has a laxative effect on the newborn and is important in transferring antibodies from the mother to the offspring . |
Suckling or milking | stimulates continued production of milk |
Sensory stimulation of the teat or nipple | either by the offspring's suckling or by milking causes continued production of the hormones necessary to support lactation. |
Stimulation of the teat or nipple | causes immediate release of oxytocin from the posterior pituitary gland |
Oxytocin | has the effect of squeezing milk out of the alveoli and small ducts of the mammary glands into the large ducts and sinuses where the newborn can extract it by suckling |
Milk let-down | is the immediate effect of suckling or milking |
Cessation of suckling or milking | results in the cessation of milk production; the mammary gland dries up. |
The pinna | ear flap; is a cartilaginous funnel that collects sound waves and directs them medially into the external auditory canal |
The tympanic membrane | is a thin connective tissue membrane that is tightly stretched across the opening into the middle ear |
The cochlea | is a fluid filling space shaped like a hollow spiral snail shell |
Corti | is a organ shaped like a ribbon and contains the receptor cells for hearing |
Semicircular canals | are three fluid filled canals of semicircular shape on each side of the head |
The vestibule consists of | two fluid filled spaces in each inner ear that contain patches of sensory epithelium on their floor. |