the nervous system

Question 1

what are the three functions of the nervous system

Answer 1

(1)- Sensory input It uses its millions of sensory receptors to monitor
changes occurring both inside and outside the body. These changes are called stimuli, and the gathered information is called sensory input. (2)- Integration It processes and interprets the sensory input and decides what should be done at each moment.
(3)- Motor output It then causes a response, or effect, by activating muscles or glands (effectors) via motor output.

Question 2

is the somatic nervous system voluntary or involuntary

Answer 2

voluntary- skeletal muscles

Question 3

is the autonomic nervous system voluntary or involuntary

Answer 3

involuntary- cardiac/smooth muscle and glands

Question 4

what are the supporting cells

Answer 4

astrocytes
microglia
ependymal
oligodendrocytes

Question 5

what are the functions of astrocytes

Answer 5

abundant star-shaped cells
that account for nearly half of neural tissue
Their numerous projections that cling to neurons, bracing them and anchoring them to their nutrient supply lines, the blood capillaries. Astrocytes form a living barrier between capillaries and neurons, help determine capillary permeability
play a role in making exchanges between the two.
they help protect the neurons from harmful substances that might be in the blood.
Astrocytes also help control the chemical environment in the brain by “mopping up” leaked potassium
ions, which are involved in generating a nerve impulse, and recapturing chemicals released for communication purposes.

Question 6

what are the functions of microglia

Answer 6

spiderlike phagocytes that monitor the health of nearby neurons
and dispose of debris, such as dead brain cells
and bacteria

Question 7

what are the functions of ependymal

Answer 7

neuroglia that line the central cavities of the brain and the spinal cord (Figure 7.3c). They participate in the
production of cerebrospinal fluid (CSF) and the
beating of their cilia helps to circulate the cerebrospinal fluid that fills those cavities and forms
a protective watery cushion around the CNS.

Question 8

what are the functions of oligodendrocytes

Answer 8

neuroglia that wrap their flat extensions (processes)
tightly around CNS nerve fibers, producing fatty
insulating coverings called myelin sheaths

Question 9

what is the function of dendrites

Answer 9

convey incoming messages (electrical signals) toward the cell body

Question 10

what is the function of axons

Answer 10

those that generate nerve impulses and typically conduct them away from the cell body

Question 11

what is the function of axon terminals

Answer 11

contain hundreds of tiny vesicles or membranous sacs with neurotransmitters

Question 12

what is the function of myelin sheaths

Answer 12

myelin protects and insulates the fibers and increases the speed of nerve impulse transmission

Question 13

what are ganglia

Answer 13

small collections of cell bodies that are found outside the CNS and in the PNS

Question 14

what does white matter consist of

Answer 14

white matter consists of dense collections of myelinated fibers (tract)

Question 15

what does gray matter consist of

Answer 15

gray matter consists of unmyelinated fibers and cell bodies

Question 16

what is the function of the gray matter

Answer 16

• Localizes and interprets sensory inputs
• Controls voluntary and skilled skeletal muscle activity
• Acts in intellectual and emotional processing

Question 17

what is the function of the basal nuclei

Answer 17

Subcortical motor centers help control skeletal muscle movements

Question 18

what are the 3 main parts of the diencephalon

Answer 18

thalamus
hypothalamus
limbic system- a functional system

Question 19

what are the functions of the thalamus

Answer 19

Relays sensory impulses to cerebral cortex
* Relays impulses between cerebral motor cortex and lower motor centers
* Involved in memor

Question 20

what are the functions of the hypothalamus

Answer 20

Chief integration center of autonomic (involuntary) nervous system
* Regulates body temperature, food intake, water balance, and thirst
* Regulates hormonal output of anterior pituitary gland and acts as an endocrine organ ­(producing
ADH and oxytocin)

Question 21

what are the functions of the limbic system

Answer 21

Includes cerebral and diencephalon structures (e.g., hypothalamus and anterior thalamic ­nuclei)
* Mediates emotional response; involved in memory processing

Question 22

what are the main parts of the brain stem

Answer 22

pons
midbrain
medulla oblongata

Question 23

what are the functions of the midbrain

Answer 23

Contains visual and auditory reflex centers
* Contains subcortical motor centers
* Contains nuclei for cranial nerves III and IV; contains projection fibers (e.g., fibers of the
pyramidal tracts)

Question 24

what are the functions of the pons

Answer 24

Relays information from the cerebrum to the cerebellum
* Cooperates with the medullary centers to control respiratory rate and depth
* Contains nuclei of cranial nerves V–VII; contains projection fibers

Question 25

what are the functions of the medulla oblongata

Answer 25

Relays ascending sensory pathway impulses from skin and proprioceptors * Contains nuclei controlling heart rate, blood vessel diameter, respiratory rate, vomiting, etc. * Relays sensory information to the cerebellum * Contains nuclei of cranial nerves VIII–XII; contains projection fibers

Question 26

what are the functions of the reticular formation

Answer 26

Maintains cerebral cortical alertness; filters out repetitive stimuli * Helps regulate skeletal and visceral muscle activity

Question 27

what are the functions of the cerebellum

Answer 27

Processes information from cerebral motor cortex, proprioceptors, and visual and equilibrium pathways * Provides “instructions” to cerebral motor cortex and subcortical motor centers, resulting in smooth, coordinated skeletal muscle movements * Responsible for proper balance and posture

Question 28

what are reflexes

Answer 28

reflexes are rapid, predictable and involuntary responses to stimuli

Question 29

give the function of the olfactory cranial nerve (say whether it is sensory/motor/both)

Answer 29

Purely sensory; carries impulses for the sense of smell

Question 30

give the function of the optic cranial nerve

Answer 30

Purely sensory; carries impulses for vision

Question 31

give the function of the oculomotor cranial nerve

Answer 31

Purely motor; supplies motor fibers to four of the six muscles (superior, inferior, and medial rectus, and inferior oblique) that direct the eyeball; to the eyelid; and to the internal eye muscles controlling lens shape and pupil size

Question 32

give the function of the trochlear cranial nerve

Answer 32

Purely motor; supplies motor fibers for one external eye muscle (superior oblique)

Question 33

give the function of the Trigeminal cranial nerve

Answer 33

Mixed nerve; conducts sensory impulses from the skin of the face and mucosa of the nose, mouth, and corneas; also contains motor fibers that activate the chewing muscles

Question 34

give the function of the Abducens cranial nerve

Answer 34

Purely motor; supplies motor fibers to the lateral rectus muscle, which rolls the eye laterally

Question 35

give the function of the facial cranial nerve

Answer 35

Mixed nerve; activates the muscles of facial expression and the lacrimal and salivary glands; carries sensory impulses from the taste buds of anterior tongue

Question 36

give the function of the vestibularcoclear cranial nerve

Answer 36

Mixed nerve; vestibular branch transmits impulses for the sense of balance, and cochlear branch transmits impulses for the sense of hearing; small motor component adjusts sensitivity of sensory receptors

Question 37

give the function of the Glossopharyngeal cranial nerve

Answer 37

Mixed nerve; supplies motor fibers to the pharynx (throat) that promote swallowing and saliva production; carries sensory impulses from taste buds of the posterior tongue and from chemical and pressure receptors of the carotid artery

Question 38

give the function of the vagus cranial nerve

Answer 38

Mixed nerve; fibers carry sensory impulses from and motor impulses to the pharynx, larynx, and the abdominal and thoracic viscera; most motor fibers are parasympathetic fibers that promote digestive activity and help regulate heart activity

Question 39

give the function of the accessory cranial nerve

Answer 39

Purely motor fibers activate the sternocleidomastoid and trapezius muscles

Question 40

give the function of the hypoglossal cranial nerve

Answer 40

Purely motor fibers control tongue movements