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Anatomy chapter
chapter 7 and 9
Question | Answer |
---|---|
What is the organization of the Nervous System | Structural Classification (its structures) Functional Classification (activities) |
What is the STRUCTURAL classification of the nervous system | all nervous system organs and has two subdivisions |
What are the two subdivisions of the structural classifications | 1. central nervous system (CNS) 2. peripheral nervous system (PNS) |
what does the central nervous system (CNS) consist of | brain and spinal cord which occupy the dorsal body cavity and act as the command center of the nervous |
what does the peripheral nervous system consist of | the parts of the system outside of the CNS mainly the brain and spinal cord |
What does the spinal nerve do | carries impulses to and from the spinal cord |
What does the cranial nerve do | carry impulses to and from the brain they serve as communication lines |
What is the functional classification | only involves the PNS structure, which is divided into two subdivisions |
What are the two functional divisions | SENSORY or afferent division MOTOR or efferent division |
what is the role of the SENSORY or afferent division (functional subdivision)has two parts somatic/visceral | nerve fibers that convey impulses to the CNS from sensory receptors located in different parts of the body informing the CNS of events both inside and outside of the body |
What do somatic SENSORY fibers do | deliver impulses from the skin, skeletal muscles, and joints |
What do visceral SENSORY fibers do | transmit impulses from the visceral organs |
What is the role of the MOTOR or efferent division (has 2 subdivisions) | carries impulses from the CNS to effector organs, the muscles and glands. They effect a motor response |
What are the two MOTOR (efferent) subdivisions | Somatic nervous system Autonomic nervous system |
What is the role of the Somatic nervous system (motor subdivision) | allows us to consciously or voluntarily control our skeletal muscles (voluntary nervous system) |
What is the role of the Autonomic nervous system (has two subdivisions) | regulates events that are automatic or involuntary such as cardiac muscles and glands (involuntary NS) |
What does the sympathetic part of the involuntary nervous system do | |
What does the parasympathetic part of the involuntary nervous system do? | |
the nervous system acts as a coordinated unit, both structurally and functionally. | subdivisions only for convenience |
What are neurons | respond to stimuli - have irritability transmit signals - have conductivity |
Neurons with no myelin sheaths transmit what slower than those with the myelin sheaths | messages |
Nuerons consist of what | cell body processes |
cell body contains what | almost all organelles |
What are the 2 arm like processes that reach through the body and transmit messages | dendrites - send info toward the cell body (can have many) Axan - sends info away from the cell body (can have 1) |
How many types of ganglia are there and name them | Functional classification Afferent neurons Association neurons structural classification |
Functional classifications - one of five ganglia | based on where messages are sent |
Afferent neurons - one of five ganglia | send messages TO the CNS |
Efferent neurons - one of five ganglia | send messages FROM the CNS |
Association neurons - one of five ganglia | connect afferent and efferent neurons |
Structural classification | based on # of processes leaving cell body:Multi polar neuron many processes, Bipolar 2 processes, Unipolar 1 process (axon only) |
How do they transmit messages | neurons are polarized - move positive charge outside then in stimuli will depolarize neuron which causes it to transmit a signal repolarization must occur before another message may be sent |
Neurons w/out myelin | neurons are stimulate through the cell membrane along all of the neuron stimulus causes na+ to enter the cell to set off impulses to repolarize, na+ must be pumped back out. see pg. 232 |
neurons with myelin | stimuli reach neurons only at the nodes (ends of nerves) *impulses travels down axon toward synapse *Neurotransmitters are received toward receiving neuron * Neurontransmitters bind to receptors on the next -> cause na+to enter neuron. pg. 233 |
reflexes | rapid, perceptible, involuntary responses always occur along the same neural pathway called a reflex arc |
what are the two kinds of reflexes | skeletal muscles called somatic smooth muscles called autonomic |
what are the parts of the reflex arc | sensory receptor afferent neuron ( pg 234) integration center efferent neuron effector organ |
How many regions does the brain have | 4 |
Name the 4 major regions of the brain | cerebrum, diencephaton, brain stem, cerebellum |
what is the largest part of the brain | the cerebrum (covers almost all the diencephaton, brain stem and cerebellum) |
what is divided into 2 cerebral hemispheres | the cerebrum |
what does the cerebrum have many of | gyri (ridges), sulci (shallow grooves) and fissures (deep organs) |
How many lobes does the cerebrum have | 4 |
Name the 4 lobes of the cerebrum | frontal, parietal, occipital, temporal |
What is the role of the frontal lobe | controls your personality, problem solving, spontaneity, memory, language, intuition, judgement, social behavior |
What is the role of the parietal lobe | responsible for information processing, pain, and touch, perception, spatial orientation, speech, visual perception |
What is the role of the occipital lobe | responsible for visual processing centers of the brain (movement, color, depth) |
Where is the temporal lobe located | anterior to the occipital lobe and lateral to the mid-line |
What is the role of the temporal lobe | involved in hearing, memory, speech, language and emotional responses. |
Where is the occipital located | located most posterior of the brain |
Where is the parietal lobe located | superior to the occipital lobe and posterior to the frontal lobe. |
where is the frontal lobe located | most anterior and superior lobe of the brain. |
what is the role of the diencephalon | thalamus-relays sensory impulses (gives a crude recognition of pleasant or unpleasant sensations |
Where is the diencephalon located | atop the brain stem and enclosed by the cerebral hemispheres |
What is the role of the hypothalamus | autonomic nervous center (body temp, water balance, metabolism)also the center for many drives and emotions |
where is the hypothalamus located | makes up the floor of the diencephalon. |
What is the role of the epithalamus (brain stem) | mid-brain helps convey messages up and down, pons help control breathing, medulla oblongata help control heart rate, blood pressure, swallowing, vomiting |
What is the role of the reticular formation | helps with consciousness |
Where is the reticular formation located | extended along all of the brain stem |
what is the cerebellum made up of | 2 hemispheres |
What is the role of the cerebellum | controls skeletal muscle activity balance and equilibrium-allows you to operate on auto pilot |
what protects the nervous system | bone meninges watery cushion blood |
what is the bones role in protecting the nervous system | skull and vertebrae encase brain and spinal cord |
what is the meninges role in protecting the nervous system | 3 connective tissues membrane that line the skull |
what is the water cushions role in protecting the nervous system | cerebrospinal fluid 1. fluid is made from blood plasma 2. is constantly being circulated |
what is the bloods role in protecting the nervous system | brain barrier-capillaries supplying nutrients to the brain are the least permeable in the body |
what passes through the brain barrier easily | water, glucose, and amino acids |
what is blocked from passing through the brain barrier | wastes, toxins, proteins, and most drugs are blocked. |
Brain stem | **continuation of the brain stem part of the CNS, collection of neurons bundled together to form a cylindrical cord about 17 inches long (ends just below the ribs), composed of gray matter surrounded by white matter (page 247-248) |
Structures of the spinal cord | |
nervous tissue | made up of 2 principal types of cells |
what are the two types of nervous tissue cells | supporting cells and neurons |
what is another name for supporting cells | neuroglia (nerve glue) |
what does neuroglia (glia/glial)do | support, insulate, and protect the delicate neurons |
what are the CNS glial (nerve glue) | astrocytes, microglia, ependymal cells, oligodendrocytes |
what is the role of the the astrocytes glial (CNS glial) | Form a living barrier between capillaries and neurons. Help protect the neurons from harmful substances that might be in the blood. Capture excess ions & recapturing released neurotransmitters, help control chemical environment in the brain |
what do astrocytes look like (CNS glial) | star shaped cells that make up 1/2 of the neural tissue. Numerous projections have swollen ends that cling to neurons, bracing them and anchoring them to their nutrient supply lines, the blood capillaries |
what is the role of microglia (CNS glial) | dispose of debris, including dead brain cells and bacteria |
what do microglia look like (CNS glial) | spider like phagocytes |
What is the role of Ependymal cells (CNS glial) | Line the cavities of the brain and the spinal cord. Cilia helps to circulate the cerebropsinal fluid that fills the cavities and forms a protective cushion around the CNS |
What is the role of the Oligodendrocytes (CNS glial) | wrap their flat extensions around the nerve fibers, producing fatty insulating coverings called myelin sheaths. |
What don't Glial do that neurons do (CNS glial) | they are not able to transmit nerve impulses |
Glial never lose their ability to divide however most neurons do (CNS glial) | since the never lost their ability to divide most brain tumors are glimoas (formed by glial cells, neuroglia) |
PNS supporting cells (glial ?) | Schwann cells Satellite cells |
What do Schwann cells do (PNS) | form the myelin sheaths around nerve fibers that are found in the PNS |
What do Satellite cells do | act as protective cushioning cells |