Exam 1 - Ch.2 Structure of the nervous system

Question 1

What are the 3 functions of the nervous system? (These are also the types of neurons)

Answer 1

1. Sensory: monitors internal and external environment
2. Integration: interpretation an processing of sensory information; complex functions
3. Motor: response to information processes through stimulation of effectors

Question 2

What are the two types of neural cells?

Answer 2

1. neurons: form circuits that constitute the structural basis for brain function
2. glial cells: provide support, regulation, and protection of neurons

Question 3

What are the basic structures of the neuron? What do they do?

Answer 3

• dendrites: receive info
• cell body: metabolic center of the axon
• axon hillock
• axon: transport of substances and neural impulses (AP)
• myelin sheath: AP travels faster on these
• axon terminals/terminal buttons: NT release

Question 4

What things provide strength and aid in the transport of materials along the length of an axon?

Answer 4

• neurofilaments, actin, and microtubules

Question 5

How many glial cells are found in the CNS? PNS?

Answer 5

• 4
• 2

Question 6

Astrocytes

Answer 6

• most abundant
• development and maintenance of BBB
• remove debris and seal off damaged tissue

Question 7

Microglia

Answer 7

• least abundant
• phagocytes that engulf invading microorganisms and dead neurons

Question 8

Ependymal cells

Answer 8

• surfaces are covered in cilia that help circulate CSF

Question 9

Oligodendrocytes

Answer 9

• forming myelin sheaths in the CNS
• do not allow regeneration

Question 10

Satellite cells

Answer 10

• located in PNS
• supply nutrients and provide structural support

Question 11

Schwann cells

Answer 11

• create myelin sheaths in the PNS
• allow for regeneration

Question 12

What is the synapse?

Answer 12

space between neurons, the site at which neurons communicate

Question 13

Presynaptic neuron

Answer 13

conducts signal toward synapse - releases the NT

Question 14

Postsynaptic neuron

Answer 14

transmits signal away from synapse - receives the NT

Question 15

What are the types of synapses?

Answer 15

1. axodendritic: btwn axon terminal of one neuron and dendrites of another
2. axosomatic: btwn axons and cell bodies
3. axoaxonic: btwn axon and axon
4. dendrodendritic: btwen dendrite and dendrite
5. dendrosomatic: btwn the dendrite and the cell body of another

Question 16

What is the resting membrane potential? What contributes to this?

Answer 16

• -70 mV
• sodium, potassium, chloride, and negatively charged proteins

Question 17

What are the two ways that the resting membrane potential is maintained?

Answer 17

1. passive - passive diffusion of some ions
2. active - sodium potassium pump (3 Na are moved out, and 2 K are moved in)

Question 18

What are the stages of an action potential?

Answer 18

• local potentials depolarize to threshold (-55mV)
• sodium channels open, Na+ enters the cell, depolarizing it
• sodium channels close, gated potassium channels open, K+ leaves, hyperpolarizing the cell
• all gated channels close, cell returns to resting potential

Question 19

What is the purpose of an AP?

Answer 19

to release a NT

Question 20

Absolute refractory period

Answer 20

brief period in which it is impossible to elicit another action potential

Question 21

Relative refractory period

Answer 21

period in which a higher amount of stimulation is necessary to make a neuron fire

Question 22

Saltatory conduction

Answer 22

• one node of ranvier depolarizes the next - the AP jumps across them
• more rapid in myelinated

Question 23

Gray matter

Answer 23

cell bodies, dendrites, unmyelinated axons

Question 24

White matter

Answer 24

myelinated axons, made up mostly of fat

Question 25

What are the meninges in order of most superficial to least? What is their function?

Answer 25

- to protect the brain - dura -> arachnoid -> pia

Question 26

Ventricles

Answer 26

house CSF, which protects and adds buoyancy to the brain

Question 27

Spinal cord

Answer 27

- made up of white and gray matter - relays messages and functions in reflexes

Question 28

Brain stem, what is it made up of?

Answer 28

- attaches to the spinal cord - medulla: respiration and HR - pons: sleep cycles, visual and sensory sensations - tectum: in midbrain, visual and auditory pathways - tegmentum: in midbrain, pain pathways

Question 29

Cerebral cortex

Answer 29

- comprised of fissures and sulci and separated - important in higher intellectual functioning

Question 30

Frontal lobe

Answer 30

executive functioning (organization, planning), primary motor cortex is located here, inhibition, production of speech

Question 31

Parietal lobe

Answer 31

spatial and sensory (primary somatosensory cortex) - touch, feeling, sensation, temperature, pain

Question 32

Occipital lobe

Answer 32

vision

Question 33

Temporal lobe

Answer 33

hearing (primary auditory cortex), memory, and comprehension of speech

Question 34

The entire body is represented spatially in the ______ ______ and ________________ cortex.

Answer 34

primary motor, somatosensory

Question 35

Lateralization

Answer 35

- certain activities are exclusive to one of the 2 hemispheres - L hemi: language, math, logic R hemi: musical, artistic, and other creative endeavors

Question 36

What structure allows for information to pass btwn both hemispheres of the brain?

Answer 36

corpus callosum

Question 37

Cerebellum, what can its function be altered by?

Answer 37

- maintains balance and equilibrium, coordinates movements - drugs like alcohol

Question 38

Cerebellar ataxia

Answer 38

- damage to the cerebellum - ataxia caused by disorders of the cerebellum and its afferent and efferent connections - S/S: unsteadiness, jerky and irregular limb movements, slow speech

Question 39

Thalamus

Answer 39

- primary sensory relay station, except for smell - regulates sleep cycle

Question 40

Thalamic syndrome

Answer 40

- neurological disorder that causes hypersensitivity to pain - caused by damage to the thalamus

Question 41

Hypothalamus

Answer 41

- regulates: - autonomic response (fight or flight) - emotional response - body temp. - food intake - homones

Question 42

Basal ganglia

Answer 42

fine motor responses

Question 43

Limbic system

Answer 43

- amygdala, cingulate gyrus, hippocampus, and nucleus accumbens - integrates emotional responses, regulates motivated behavior and learning

Question 44

Amygdala

Answer 44

- regulates fear and anxiety, emotional memory

Question 45

Hippocampus

Answer 45

- long term memory (transfer of STM to LTM) - spatial navigation

Question 46

Depolarization/Excitation

Answer 46

make more positive, brings cell to threshold, causing an action potential

Question 47

Hyperpolarization/Inhibition

Answer 47

make more negative