Nervous System and Senses

Question 1

Define the central nervous system

Answer 1

consists of the brain and spinal cord

Question 2

Define the peripheral nervous system

Answer 2

consists of cranial and spinal nerves; voluntary; relays information to the CNS

Question 3

Define autonomic nervous system

Answer 3

part of the peripheral nervous system; consists of the sympathetic and parasympathetic divisions; involuntary nervous system

Question 4

Describe the sympathetic division of the ANS

Answer 4

dominant in stress situations; fight or flight response; increased heart rate, vasodialation in muscles, bronchioles dilate, liver supplies body with more energy, digestion slows, vasoconstriction in the skin and viscera

Question 5

Describe the parasympathetic division of the ANS

Answer 5

dominates in non-stressful situations; normal functioning of organs; digestion will be efficient, defecation and urination may occur

Question 6

Define neuron

Answer 6

cells comprising the nervous system

Question 7

Define dendrite

Answer 7

extensions of a neuron that transmit impulses toward the cell body

Question 8

Define axon

Answer 8

single extension of a neuron that transmits impulses away from the cell body

Question 9

Describe Schwann cells

Answer 9

schwann cells wrap axons and dendrites in the PNS; layers called myelin sheath; insulates cell from other neurons; stimulate regeneration

Question 10

Define nodes of Ranvier

Answer 10

the part of the neuron cell membrane that carry the electrical impulse

Question 11

Define neurolemma

Answer 11

the nuclei and cytoplasm of the schwann cells located outside the myelin sheath

Question 12

Define neuroglia

Answer 12

provide supporting framework for neural tissue, regulate the environment around neurons, and act as phagocytes

Question 13

Define synapse

Answer 13

small gap between an axon and a dendrite

Question 14

Define neurotransmitter

Answer 14

in response to the arrival of an electrical signal, neurotransmitters are released and diffuse accross the synapse to chemical receptors

Question 15

Define acetylcholine

Answer 15

neurotransmitter found at neuromuscular joints, in the CNS and PNS

Question 16

What is a neuron not carrying an electrical impulse considered to be?

Answer 16

polarized

Question 17

Describe the charges of a polarized neuron

Answer 17

positive on the outside of the cell and negative on the inside

Question 18

What happens to a neuron once it receives stimulus from a neurotransmitter and Na+ ions rush into the cell?

Answer 18

depolarization

Question 19

What happens to a neuron once K+ rushes out of the cell?

Answer 19

repolarization

Question 20

Describe the late stage of the repolarization of a neuron

Answer 20

sodium/potassium pumps return Na+ ions outside and K+ inside

Question 21

Define sensory neurons

Answer 21

carry impulses from receptors to the CNS

Question 22

Define motor neurons

Answer 22

carry impulses from the CNS to effectors

Question 23

Define interneurons

Answer 23

only found in the CNS; carry motor or sensory impulses

Question 24

Define nerve

Answer 24

group of axons and/or dendrites of many neurons with blood vessels and connective tissue

Question 25

Define nerve tract

Answer 25

groups of neurons within the CNS; also called white matter

Question 26

State the function and cranial nerve number of the Oculomotor nerve

Answer 26

#3; movement of the eyeball, constriction of the pupil

Question 27

State the function and cranial nerve number of the Vagus nerve

Answer 27

#10; sensory for cardiac, respiratory, and blood pressure relexes; decreases heart rate; increases digestive secretions

Question 28

State the purpose of stretch reflexes

Answer 28

keep us upright without having to think about doing so; spinal cord relex, the brain is not involved

Question 29

State the purpose of flexor reflexes

Answer 29

stimuli detects danger or hazard and responds by pulling away from it; spinal cord reflex, the brain is not involved

Question 30

Describe the reflex arc

Answer 30

1. receptors detect a change and generate a response2. sensory neurons transmit impulse to the CNS3. synapse occurs between stimulated sensory neuron and a interneron4. interneuron synapses with a motor neuron5. effector receives the impulse and performs its action

Question 31

State the function of the ventricles of the brain

Answer 31

four cavities; formation of CSF

Question 32

State the function of the medulla in the brain

Answer 32

regulates heart rate, diameter of blood vessels, blood pressure, and respirations

Question 33

State the function of the pons in the brain

Answer 33

works with the medulla to produce normal breathing rhythm

Question 34

State the function of the midbrain in the brain

Answer 34

control visual and auditory reflexes; control equilibrium

Question 35

State the function of the cerebellum in the brain

Answer 35

control involuntary movement; controls equilibrium

Question 36

State the function of the cerebrum in the brain

Answer 36

largest part of the human brain; surface is called the cerebral cortex; contains lobes that control different functions

Question 37

Describe the function of the frontal lobes of the cerebral cortex

Answer 37

motor areas that generate impulses for voluntary movement; Broca's motor speech area

Question 38

Describe the function of the parietal lobes of the cerebral cortex

Answer 38

interpret the cutaneous sensations; receives impulses from stretch receptors for conscious muscle sense; taste buds

Question 39

Describe the function of the temporal lobes of the cerebral cortex

Answer 39

auditory areas; olfactory areas; speech areas concerned with the thought that precedes speech

Question 40

Describe the function of the occipital lobes of the cerebral cortex

Answer 40

visual areas; judging distance; seeing in 3D

Question 41

Name the outermost meninge made of fibrous connective tissue that lines the skull and vertebral canal

Answer 41

dura mater

Question 42

Name the middle meninge made of web like strands of connective tissue

Answer 42

arachnoid membrane

Question 43

Name the innermost meninge that covers the surface of the spinal cord and brain

Answer 43

pia mater

Question 44

Where is cerebrospinal fluid found?

Answer 44

between the arachnoid and the pia mater, the subarachnoid space

Question 45

Describe the functions of cerebrospinal fluid

Answer 45

brings nutrients to the CNS and removes waste products; acts as a cushion for the CNS

Question 46

Define sensations

Answer 46

enables the body to respond appropriately to ever changing situations to help maintain homeostasis

Question 47

Define receptors

Answer 47

detect stimuli and generate a response

Question 48

Define projection

Answer 48

sensation that seems to come from the area where the receptors were stimulated

Question 49

Define intensity

Answer 49

sensation felt more distinctly and to a greater degree

Question 50

Define contrast

Answer 50

effect of a previous sensation on a current sensation

Question 51

Define adaptation

Answer 51

becoming unaware of a continuing stimulus

Question 52

Define after-image

Answer 52

sensation remains in the consciousness even after the stimulus has stopped

Question 53

Name the cutaneous senses and their purpose

Answer 53

touch, pressure, heat, cold, and pain; provide us with information about the external environment

Question 54

Define referred pain

Answer 54

pain felt in a cutaneous area that originates in an internal organ

Question 55

Define proprioception

Answer 55

muscle sense; ability of the brain to know where the muscles are and how they are positioned

Question 56

Define chemoreceptors

Answer 56

receptors that detect chemicals in solutions as taste and vaporized chemicals that have been sniffed as smell

Question 57

Define conjunctiva

Answer 57

thin membrane lining the inside of the eyelids and covering the whites of the eye

Question 58

Where are tears produced?

Answer 58

lacrimal glands

Question 59

Define sclera

Answer 59

thickest layer of the eyeball; visible as the whites of the eye

Question 60

Define cornea

Answer 60

transparent and has no capillaries; the first part of the eye that refracts light

Question 61

Define choroid layer

Answer 61

contains blood vessels; dark blue pigment that absorbs light to prevent glare

Question 62

Define lens

Answer 62

made of transparent, elastic protein; has no capillaries; shape changed by ciliary muscle to allow focus

Question 63

Define iris

Answer 63

colored part of the eye

Question 64

Define retina

Answer 64

contains rods and cones; lines the posterior two thirds of the eyeball

Question 65

Define rods

Answer 65

detect the presence of light

Question 66

Define cones

Answer 66

detect colors

Question 67

Define fovea

Answer 67

small depression directly behind the center of the lens that contain cones

Question 68

Neurons carrying impulses from the cones and rods travel down what path?

Answer 68

converge at the optic disc and pass through the wall of the eyeball as the optic nerve

Question 69

Define the function of vitreous humor

Answer 69

semi solid fluid that keeps the retina in place

Question 70

Define aqueous humor

Answer 70

tissue fluid between the lens and the cornea that nourish each

Question 71

What is another name for the ear drum?

Answer 71

tympanic membrane

Question 72

Name the three bone in the middle ear

Answer 72

malleus, incus, and stapes

Question 73

Define eustachian tube

Answer 73

extends from the middle ear to the nasopharynx and permits air to enter or leave

Question 74

Define cochlea

Answer 74

in the inner ear; comprised of three fluid canals

Question 75

Explain the function of the utricle and saccule in the inner ear

Answer 75

membranous sacs with hair cells that are moved by gravity as the position of the head changes that is interpreted by the brain to maintain equilibrium subconsciously