Intro to nervous system (up to quiz 1)

Question 1

what is the central nervous system?

Answer 1

brain + spinal cord

Question 2

what is the peripheral nervous system?

Answer 2

everything else - cranial nerves, spinal nerves, ganglia, enteric plexuses, receptors

Question 3

what is neurology?

Answer 3

The branch of medical science that deals with the normal functioning and disorders of the nervous system

Question 4

what are the three basic functions of the nervous system?

Answer 4

1. Sensory Function - sensory receptors sense stimuli or changes inside and outside the body
2. Integrative Function - analyzes the sensory information and determines an appropriate response
3. Motor Function - respond to sensory information (after integration) by initiating glandular secretions or muscle contractions

Question 5

what is neuroglia?

Answer 5

-nerve glue
-support cells
- 50:1 ratio to neurons

Question 6

what are astrocytes?

Answer 6

Support and protect neurons, help to maintain a proper chemical environment for nervous impulses

Assist with the growth and migration of neurons during the development

Help form the blood-brain barrier

Question 7

what are microglia?

Answer 7

Phagocytes, can engulf microbes or injured nerve tissue

Question 8

what are oligodendrocytes (CNS) and Schwann cells (PNS)?

Answer 8

Lay down myelin around axons which act as a layer of insulation to speed up the conduction of the nerve impulse

Question 9

what are the gaps in myelin called?

Answer 9

nodes of ranvier

Question 10

what are ependymal cells?

Answer 10

Produce cerebrospinal fluid (CSF) which is found in brain ventricles, central canal of the spinal cord and the subarachnoid space within the meninges

Question 11

what are neurons?

Answer 11

-the functional cell of nervous tissue, impulse-conducting cells
-the capability of becoming electrically excitable
- produce action potentials/electrical impulses in response to stimuli

Question 12

what are dendrites?

Answer 12

short, branching, processes extending from the cell body which functions to receive impulses and conduct these impulses to the cell body

Question 13

what are axons?

Answer 13

long cylindrical process extending from the cell body that conduct impulses away from the cell body to another neuron, muscle fibre or gland cell

Question 14

what are axon side branches called?

Answer 14

axon collaterals

Question 15

what do axon collaterals turn into?

Answer 15

divide into many axon terminals

Question 16

what are at the end of axon terminals?

Answer 16

synaptic-end bulbs that possess synaptic vesicles that store neurotransmitters

Question 17

what are neurotransmitters?

Answer 17

chemical substances released from axons that will affect the cell they communicate with (neuron, muscle cell or gland)

Question 18

what is a synapse?

Answer 18

The “contact” between two neurons or between the neuron and the effector (muscle or gland)
the two cells don’t actually touch

Question 19

what does a neuromuscular junction synapse with?
what about a neuroglandular junction?

Answer 19

with a muscle cell and a gland cell

Question 20

what is an axoplasm?

Answer 20

cytoplasm of an axon

Question 21

what is an axolemma?

Answer 21

plasma membrane of an axon

Question 22

a nerve is comprised of what?

Answer 22

bundle of myelinated axons in the (PNS) covered with CT covering

Question 23

what are tracts?

Answer 23

bundles of myelinated axons in the central nervous system which lack a protective connective tissue covering

Question 24

what are multipolar neurons?

Answer 24

many dendrites, one axon

most common type in the central nervous system

somatic and autonomic motor neurons

Question 25

what are bipolar neurons?

Answer 25

one dendrite and one axon found in the retina of the eye, inner ear, and olfactory area of the brain

Question 26

what are unipolar neurons?

Answer 26

one process emerging from the cell body these are always somatic sensory neurons

Question 27

what are afferent (sensory) neurons?

Answer 27

transmit sensory nerve impulses from receptors toward the central nervous system

Question 28

what are interneurons or associated neurons?

Answer 28

transmit nerve impulses from one neuron to another neuron -most common type (90%) and located exclusively in the CNS

Question 29

what are efferent (motor) neurons?

Answer 29

transmit motor nerve impulses from the central nervous system to the effectors (muscles or glands)

Question 30

how do neurons communicate?

Answer 30

through electrical signals called action potentials or nerve impulses

Question 31

what is the resting potential of a neuron?

Answer 31

-70mv - cytoplasm inside is negatively charged -extracellular fluid outside is positively charged

Question 32

why is the inside of the cell negative?

Answer 32

due to the accumulation of large negatively charged protein molecules (-potassium) on the inside than outside and more (+sodium) on outside balanced maintained by sodium + potassium pumps

Question 33

what is the threshold for an action potential?

Answer 33

-55mv

Question 34

what makes an action potential travel more quickly?

Answer 34

if the axon insulated with myelin

Question 35

_______________ are chemicals that bind receptors on other neurons (dendrites) or on effectors such as muscles (skeletal, cardiac, and smooth) or glands

Answer 35

neurotransmitters

Question 36

what is a chemical synapse?

Answer 36

-When a neuron communicates with another neuron via neurotransmitters -Some neurons within the central nervous system communicate directly via electrical synapses where the axons connect directly to dendrites via gap junctions

Question 37

what is a sensation?

Answer 37

is the conscious or unconscious awareness of external or internal stimuli

Question 38

what are exteroceptors?

Answer 38

Found on or near the body surface where they detect stimuli from the external environment; eg. visual, smell, taste, touch, pressure, vibration, temperature, and pain examples relevant corpuscle of touch, Meisner corpuscle, hair root plexuses, Pacinian corpuscles, vibration, thermal, nociceptors- free nerve endings that detect pain

Question 39

what are interceptors?

Answer 39

are located within the body and include baroreceptors which detect stretch in smooth muscle and chemoreceptors which detect chemical changes in body fluids Detect stimuli associated with blood vessels / visceral organs Impulses produced are only occasionally felt as pain or pressure; otherwise, we are not consciously aware of these sensations

Question 40

what is the role of barorecptors?

Answer 40

detect stretch in smooth muscle

Question 41

what is the role of chemoreceptors?

Answer 41

detect chemical changes in body fluids

Question 42

what are proprioceptors?

Answer 42

located in muscles, tendons, and joints as well as the inner ear Detect body position and movement through the detection of muscle length & tension and position & movement of joints These receptors can protect muscles and joints from injury if a muscle is contracting too powerfully

Question 43

what is the role of muscle spindles?

Answer 43

detect stretch of a muscle

Question 44

what are Golgi tendons?

Answer 44

gives information to CNS regarding the force of contraction or tension in the muscle it is associated with

Question 45

what are joint kinesthetic receptors?

Answer 45

acceleration/deceleration of joint, pain

Question 46

what are mechanoreceptors?

Answer 46

stretching, touch, pressure, vibration, proprioception, hearing, equilibrium, blood pressure

Question 47

what are thermoreceptors?

Answer 47

temperature

Question 48

what are nociceptors?

Answer 48

pain receptors - physical or chemical damage to tissue acute pain and chronic pain

Question 49

what are photoreceptors?

Answer 49

light (retina of eye)

Question 50

what are chemoreceptors?

Answer 50

detect chemicals in mouth, nose, and body fluids such as blood eg. pH, oxygen and carbon dioxide levels, hormone levels, glucose levels, etc.