click below
click below
Normal Size Small Size show me how
Anatomy
Exam I- Lecture 2: The Integument
Question | Answer |
---|---|
Integument | 1. largest most extensive organ systems in body 2. composed of all 4 tissue types 3. outer shell entirely dead |
Integumentary system | 1. skin + related structures 2. prevents desiccation, reduce threat, excrete water, receieve/convert sensory info |
Keratin | tough protective substance |
Keratinization | 1. process by which cell substance expires 2. gives keratinocytes ability to rub off or exfoliate daily |
Layers of skin | Epidermis, Dermis, Hypodermis |
Dermis | layers separated by epithelial basement |
Where is Hypodermis located | found below dermis, composed of adipose tissue |
List the cells of the epidermis | 1. Keratinocytes 2. Melanocyte 3. Langergans cells 4. Merkel cells |
Keratinocytes | 1. produce keratin |
Melanocyte | 1. pigment production 2. found in deeper layers of skin 3. makes melanin -> dark pigment stored in membrane bound granules (melanosomes) |
Langerhans cells | 1. macrophage specific to the epidermis 2. Originates in the bone 3. Phagocytize microinvaders and stimulates other cells of the immune system |
Merkel cells | 1. epidermal-dermal junction 2. assoc w/ sensory nerve 3. aid in touch sensation 4. half-dome shape of sensory nerve + merkel cells= merkel disk |
Merkel disc | Half-dome shape of sensory nerve + merkel cells |
List the layers of epidermis | 1. Stratum germinativum 2. Stratum spinosum 3. Stratum granulosum 4. Stratum lucidum 5. Stratum corneum 4. |
Stratum germinativum | 1. deepest layer 2. aka stratum basale 3. single row of keratinocytes attached to epithelial basement membrane 4. actively engaged in cell div 5. merkel cells, melanocytes, keratinocytes found here |
Which cells are found in the Stratum germinativum | merkel cells, melanocytes, keratinocytes |
Which layer of epidermis is the deepest layer | Stratum germinativum |
Which cells of the epidermis originate in the bone | Langerhans cells |
Which cells of the epidermis aid in touch sensation | Merkel cells |
Which layer of epidermis is known as the spiny layer | Stratum spinosum |
Which layer of epidermis is the clear layer | Stratum lucidum |
Which layer of epidermis is outermost and dominates the epidermis | Stratum corneum |
Stratum spinosum | 1. spiny layer 2. cell layers held together by desmosomes 3. infrequent divisions seen 4. Langerhans in greater abundance |
Stratum granulosum | 1. 2-4 layers of flat diamond-shape keratinocytes 2. cytoplasm fills with keratohyaline & lamellated granules 3. dramatic degeneration of nucleus 4. lamellate granules have waterproofing glycolipids and transported to periphery of cell |
Which cells of the Stratum granulosum are known as waterproof cells | Lamellate granules |
Stratum lucidum | 1. clear layer 2. thick skin most skin lacks this layer, dead cells 3. Keratogranules with intracellular tonofilaments to form keratin fibrils |
Stratum corneum | 1. outermost layer 2. dominates epidermis 3. 3 quarters of total epidermal thickness: 20-30 layers 4. remnants of keratinocytes |
How many layers of epidermis of the hairy skin | 3 instead of 5 |
List the layers of epidermis of the hairy skin | 1. stratum basale 2. stratum spinosum 3. stratum corneum |
Tylotrich hairs | 1. important in touch perception 2. tactile hair 2. tactile elevations (epidermal papillae) |
Dermis | 1. 2 layers 2. binds superficial epidermis to underlying tissues 3. composed of dense irregular CT 4. structural strength of the skin 5. Hair follicles, nerve endings, sm muscle, blood vess, lymphatic channels |
List the layers of dermis | Papillary layer & Reticular Layer |
Papillary layer of dermis | 1. beneath epithelial layer 2. loose CT w/ loosely woven fibers & ground substance 3. dermal papillae 4. mesissners corpuscles |
Dermal papillae | 1. In papillary layer of dermis 2. rise up into epidermis 3. cements the epidermis and dermis together |
What cements the epidermis and dermis together and where is this structure located? | Dermal papillae; located in papillary layer of dermis |
Meissner's Corpuscle | Pain & touch receptors; found in papillary layer of dermis |
Reticular layer of dermis | 1. dense irregular CT 2. 80% of dermis 3. binding & see dermal folds |
Hypodermis | 1. thick layer 2. loose layer of areolar tissue rich in blood, lymphatic vessels, nerves 3. pacinian corpuscle 4. permits skin to move free over underlying bone & muscle |
What is the thick layer the resides below the dermis | hypodermis |
pacinian corpuscle | 1. touch receptor 2. heavier pressure than meissner's corpuscle 3. found in hypodermis |
Special features of the integument | 1. pigmentation 2. paw pads 3. planum nasale 4. Ergots and chestnuts 5. cutaneous pouches in sheep |
Langerhans cells are found in abundance in which epidermis layer | Stratum spinosum |
Which epidermal layer is composed of 20-30 rows of keratocyte "remnants" | Stratum corneum |
Dermis is composed of dense irregular CT, what is included in this | collagen, elastic, reticular fibers |
What is present in Dermis | 1. hair follicles 2. nerve endings 3. glands 4. smooth muscle 5. blood vessels 6. lymphatics 7. fibroblasts 8. adipocytes 9. macrophages |
Special feature of the integument: Pigmentation | 1. more granules present, the darger the pigmentation 2. keratocytes arrange melanin on side of cell with most sun exposure 3. protects keratocytes from exposure to UV rays 4. Melanocyte-stimulating hormone controls granule dispersion |
When is there no pigmentation | if granules concentrated around nucleus of melanocyte |
When does pigmentation become macroscopically apparent | As granules move into cellular extensions and into surrounding tissue |
Hypophysis | Controls MSH (melanocyte-stimulating hormone) |
Paw Pads | 1. thick layers fat & CT 2. outer surface is thickest & toughest in body 3. 5 layers but Strat corneum biggest 4. conical papillae covers whole pad 5. exocrine sweat glands & lamellar corpuscles 6. respide on carpal pads, metatarsal pads, digital pad |
Planum Nasale | 1. Top of nose: cats, dogs, sheep, pigs 2. made of 3 epidermal layers: stratum germinativum, spinosum, corneum 3. aglandular except in sheep, pigs, cows 4. pigmented, thick 5. start corneum 4-8 cell layers 6. deep grooves 3. 4. |
Which epidermal layers are absent in planum nasale | Stratum lucidum & granulosum |
Planum nasolabiale | muzzle of cows and horses |
Ergots | 1. smaller, overlooked borruid in long caudal hairs of fetlock 2. Vestigs of 2nd & 4th digit |
Chestnuts | 1. Dark brown inside of leg at carpus 2. Vestiges of carpal & tarsal pad of first digit |
Ergots & Chestnuts | 1. Dark horny structures on equine 2. horse walks on third digit |
Cutaneous pouch in Sheep | 1. infoldings of skin 2. infraorbital, interdigital, inguinal 3. fine hairs, sebaceous & oil glands 4. secrete fatty yellow substance, dries & sticks to skin when dry |
Hair is formed in 3 concentric layers, list them | 1. medulla 2. cortex 3. cuticle |
Shaft (hair) | portion visible about the skin |
Root (hair) | burined within the skin |
hair follicle | anchor, invagination of epidermis extending from skin surface |
hair bulb | deepest part of hair follicle |
What is the deepest part of hair follicle | hair bulb |
papilla | base of bulb, mound of dermal cells papilla |
root hair plexus | web of sensory nerve endings |
compound follicles | 1. multiple hair strands emerge from single epidermal orifice 2. primary hair: guard/cover hair 3. secondary hair: satellite hair |
Function of hair | maintains body temp, camouflage |
Hair Color | 1. pigment in cortex & medulla 2. Darker achieved with large amts melanin 3. White: cortex loses pigment entirely & medulla completely filled with air |
How many types of maleanin do dogs and horses produce? | Horse: 1 Dog: 2 |
Pheomelanin | yellowish & reddish colors |
Tyrosine melanin | brown black colors |
List the types of hair | Primary, Secondary/wool type, Tactile (sinus) hairs |
Primary Hair | 1. straight or arched 2. thicker & longer than secondary hairs 3. dominant hairs in follicle |
Secondary/wool type | 1. softer & shorter 2. wavy or bristled in dogs |
Tactile (sinus) hairs | 1. sensory endings 2. whiskers 3. presence of large blood sinus -> located in CT portion of follicle |
Arrector pili muscles | 1. allows hair to stand when cold or scared, beyond normal implant angle 2. is small smooth muscle 3. innervated by sympathetic nervous system |
Sebaceous glands | 1. in dermis 2. store oily liquid substance made of glycerides & FFA 3. antibacterial & antifunga; props 4. released when arrector pili muscle contracts 5. white semiliquid -> sebum 6. sheep-> make lanolin |
Sweat Glands | 1. sudoriferous glands 2. found all over body 3. 2 types: Eccrine & Apocrine |
Name the types of sweat glands | Eccrine & Apocrine |
Eccrine sweat glands | 1. Excretory portion is simple, coiled tube located in dermis or hypodermis 2. empty onto surface of skin thru long duct 3. dogs -> only found in deep layer & tissue of foot haps |
Aprocrine sweat glands | 1. coiled excretory portion buried in dermis or hypodermis 2. single excretory duct 3. empty into hair follicles |
Tail glands | 1. oval region at dorsal base of tail 2. assist with recognition & ID of indiv animals 3. coarse, oily hairs 4. apocrine & sebaceous glands large in region |
Anal Sacs | 1. expressed when animal frightened or defecates 2. located 5 to 7 o'clock relative to anus 3. connected to lateral margin of anus via single duct 4. lined w/ sebaceous & apocrine glands |
Claws | 1. pigmented 2. outer coverings of distal digits 3. keep good traction 4. only retractable in cats |
Dewclaws | 1. evolutionary remnants of digits 2. In dog it's 1st digit 3. In cow, sheep, pig medial & lateral dewclaws 2nd & 5th digits |
Dewclaw is which digit in dog | 1st |
Dewclaw is which digit in cow, sheep, pigs | 2nd & 5th |
What bones are present in dewclaws of pigs | Metacarpal & Phaland |
Hoof | 1. Horny outer covering digits of some animals 2. aka ungula 3. weightbaring hooves are 3rd & 4th digit |
What do you call hoofed animals | ungulates |
Claws & hooves rest on underlying sensitive tissue called what? What is it attached to? | 1. Corium 2. attached to peristeum of 3rd phalanx 3. rich with blood vessels provide cells with nutrients |
Skeletal food of horse includes: | 1. distal part of 2nd phalanx 2. distal sesamoid bone (navicular bone) 3. entire third phalanx (coffin bone) |
Lamunae | hoof and corium formed in elaborate array of interdigitation |
Coffin bone | 1. has layer of corium which is covered by the cornified hoof |
The hoof and corium form interdigitations called what? | Laminae |
The equine hoof is generally divided into 3 parts: | wall, sole, frog |
Wall of equine hoof | 1. External portion of hoof 2. Divided into toe, quarters, heels |
Sole of equine hoof | 1. Plantar or palmar surface of hoof 2. lacks innervation 3. avascular 3. white line -> junction of sale & hoof wall |
The frog of the hoof | 1. insensitive, triangular, horny structure betw heels on underside of hoof 2. divided by central depression aka central sulcus 3. Lateral cartilages extend proximally from distal phalanx |
Digital cushion | thick pad of fat & fibrous tissue lying beneath sensitive frog |
Horns | 1. epidermal in origin 2. made keratin 3. emerge from frontal bones 4. horny 5. corium lies at root of horn bound to horn by periosteum 6. wall thinner at base than apex 7. body is made of tightly packed tubules |
Adult horn | hollow & communicates directly with frontal sinus |
Anatomy | Form and structure of the body |
Sagittal | left/right now necessarily equal |
Median plane | qual left & right halves |
Transverse | divides into cranial & caudal (not always =) |
Dorsal | 1. right angles to sagittal & transverse plans 2. divides into dorsal & ventral |
Cranial | toward head |
Caudal | toward tail (humans use superior & inferior) |
Rostral | towards nose |
Dorsal | Back |
Ventral | toward belly (humans use anterior and posterior) |
Medial | median line |
Lateral | away from median plane |
Deep | toward center of body |
Superficial | surface |
Proximal | toward body |
Distal | away |
Carpus | proximal distal dividing line for front leg |
Tarsus | dividing line for rear leg |
Palmar | back surface of front leg distal to carpus |
Plantar | back of hind leg distal to tarsus |
Dorsal: CNS Body Cavity | Cranial cavity: cranium Spinal cord: spinal cavity |
Ventral cavity: viscera | 1. Diaphragm divides into thoracic & abdominal cavity 2. Organs in thoracic covered by then membrane pleura 3. layer covers organs -> viscera 4. layer lines thoracic cavity parietal layer of pleura |
Cells | basic functional unit |
Tissue | group of specialized cells |
Organs | group of tissue work for common purpose |
Organ system | group of organs involved in common set of activities |
Types of tissue | 1. epithelial 2. CT 3. Muscle 4. Nervous |
Homeostasis | 1. Maintain dynamic equilibrium of body |