Nervous system part 2

Question 1

CNS

Answer 1

-brain and spinal cord
-responsible for integration of nervous inputs and response

Question 2

Gray matter

Answer 2

-unmyelinated nerve cells bodies
-cluster of cell bodies in the CNS are nuclei
-dendrites
-axon terminals

Question 3

white matter

Answer 3

-myelinated axons
-axon bundles connecting CNS regions are tracts
-contains very few cell bodies

Question 4

cerebrospinal fluid

Answer 4

-filtered from blood
-astrocytes help control what moves (blood brain barrier)

Question 5

Cerebrum

Answer 5

from a functional viewpoint, it can be divided into three specialization.
-sensory areas
-motor areas
-association areas

Question 6

cerebrum sensory areas

Answer 6

sensory input translated into perception (awareness)

Question 7

cerebrum motor areas

Answer 7

direct skeletal muscle movement

Question 8

cerebrum association areas

Answer 8

-integrate information from sensory and motor ares
-can direct voluntary behaviors

Question 9

cerebellum

Answer 9

-“little brain”
-helps coordinate somatic motor actions throughout the body
-balance, coordination, motor pattens
-intercepts signals from frontal lobe as they pass the pons
- compares activity of the body to frona

Question 10

cerebellum

Answer 10

-“little brain”
-helps coordinate somatic motor actions throughout the body
-balance, coordination, motor pattens
-intercepts signals from frontal lobe as they pass the pons
- compares activity of the body to frontal lobe signal and adjusts as necessary

Question 11

Brainstem

Answer 11

-11 of 12 cranial nerves originate.
cranial nerves can include sensory fibers, efferent fibers, or both (mixed nerves)
-many nuclei are associated with reticular formation
-medulla, pons, midbrains

Question 12

spinal cord

Answer 12

-31 segments, each with pair of spinal nerves

Question 13

nerve

Answer 13

bundle of axons, blood vessels, connective tissue

Question 14

three main divisions

Answer 14

-spinal cord ( proper)
-conus medullaris -narrowing right after L2
-conus equina - horses tail

Question 15

Intergration by the CNS

Answer 15

spinal cord only spinal reflexes
-signals carried up to brain ( brainstem, cerebellum, cerebrum, or combinations

Question 16

spinal reflexes

Answer 16

-stretch
-autogenic
-flexor

Question 17

stretch

Answer 17

a muscle is rapidly stretched, causes muscle to contract
ex. patellar

Question 18

autogenic

Answer 18

strong pull on a tendon, immediate relaxation of associated muscles
ex. clasped knife reflex

Question 19

flexor

Answer 19

rapid flexion to avoid painful stimulus.
ex. touching something hot

Question 20

spinal reflexes

Answer 20

integration of motor response happens in spinal cord
-brain bypassed
-patellar reflex

Question 21

PNS - afferent division

Answer 21

• inputs to the CNS

Question 22

somatic senses

Answer 22

touch, temperature, pain, itch, proprioception, stretch

Question 23

special senses

Answer 23

vision, hearing, taste, smell, equilibrium

Question 24

sensory receptor

Answer 24

initial stimulus is received by a specialized neuron.
-convert physical stimuli into electrical ( A.P) and chemical signals

Question 25

receptor potential

Answer 25

stimulus causes a change in the receptor's membrane potential - can be depolarization or hyperpolarization -transduced into neurotransmitters release

Question 26

Sensory neuron

Answer 26

carries information to the CNS. -synapses onto

Question 27

Common types

Answer 27

- mechanoreceptors -photoreceptors -chemoreceptors

Question 28

mechanoreceptors

Answer 28

receive movement or pressure

Question 29

photoreceptors

Answer 29

receive light.

Question 30

chemoreceptors

Answer 30

receive chemical signals

Question 31

modified into other special types

Answer 31

-baroreceptors/ osmoreceptors -thermoreceptors -electroreceptors -magnetoreceptors

Question 32

Baroreceptors/ osmoreceptors

Answer 32

Pressure

Question 33

thermoreceptors

Answer 33

heat

Question 34

electroreptors

Answer 34

electric fields

Question 35

magnetoreceptors

Answer 35

magnetic fields -record touch, vibration, pain, heat, etc

Question 36

Depolarization in mechanoreceptors

Answer 36

-changes in the shape and tension of the membrane -lysis of the membrane -temperature mediated changes in channel shape

Question 37

Human dermal mechanoreceptors

Answer 37

various types record different types of touch stimuli -depth -adaptation speed

Question 38

Superficial mechanoreceptors

Answer 38

-relatively weak stimuli -ephemeral stroking, flutters (needs fast adaptation) -steady pressure (needs slow adaptation) -Merkel receptors

Question 39

Deep ( strong stimuli)

Answer 39

-vibration - pacinian -stretching - Ruffini

Question 40

Frequency

Answer 40

translated into pitch

Question 41

Perception of energy

Answer 41

carried by sound waves

Question 42

loudness

Answer 42

an interpretation of intensity, a function of wave amplitude

Question 43

Basilar membrane

Answer 43

hair sits on and moves as it vibrates

Question 44

stereocillia

Answer 44

hair cell tips -embedded in the tectorial membrane , push against it

Question 45

auditory sensors

Answer 45

-at the tip of each stereocilium in a K+ channel - K+ is concetrated outside the cell -absence of sound- some are open periodic A.Ps and NT release -sound wave pushes hair, opening more channels- more frequents A.Ps and NT release -reflection wave shuts all channels- stops AP and NT release

Question 46

photoreceptors

Answer 46

transduce light energy into electrical signal

Question 47

neural pathways

Answer 47

process electrical signals into visual images