Neurophys block 4

Question 1

Describe the subdivisons of the CNS

Answer 1

Brain
- receives and processes info from PNS
-initiates responses
- stores memories, thoughts, emotions

Spinal cord
- conducts signals to and from CNS
- controls reflex

Question 2

List all 7 parts that make up a neuron

Answer 2

1. Dendrites
2. Cell Body/ Soma/ Pericaryon
3. Axon Hillock
4. Axon Hillock/ Trigger zone
5. Presynaptic Terminal
6. Myelin Sheath
7. Nodes of Ranvier

Question 3

What is the function of dendrites?

Answer 3

Receives info

Question 4

What is the function of the cell body/ stoma/ pericaryon?

Answer 4

Contains organelles

Question 5

What is the function of the axon?

Answer 5

Carries info, passes messages

Question 6

What is the function of the Axon Hillock/ Trigger zone?

Answer 6

The origin of the axon, it makes the action potential (AP)

Question 7

What is the function of the presynaptic terminal?

Answer 7

It is the end of the axon, transmits info

Question 8

What is the function of the myelin sheath?

Answer 8

-enhances speed of info transfer

-Produced by Schwann cells in the PNS and Oligodendrocytes in the CNS

-saltatory conduction

• Faster depol is unmyelinated cells

Small axons < 1um are unmyelinated

Question 9

Nodes of Ranvier

Answer 9

• gaps in between myelin sheaths

-Generates AP, jumps from node to node

Question 10

Glial cells in the CNS?

Answer 10

1. Microglial
2. Astrocytes
3. Oligodendrocytes
4. Ependymal cells

Question 11

Glial cells in the PNS?

Answer 11

Schwann cells (makes myelin in the periphery)

Question 12

Functions of glial cells

Answer 12

• helps make myelin
• modulates growth in damaged neurons
• buffers conc. of K+ and neurotransmitters
• helps form synapses INDIRECTLY

-Helps with immune responses

Question 13

Microglial cells

Answer 13

(Glial cells in the CNS)

• brain immune cells
• act as macrophage to clear debris (phagocytosis)
• releases NO to prevent viral replication
• protects and helps develop the brain

-destroys unnecessary synapses

Question 14

Astrocytes

Answer 14

(Glial cells in the CNS) - 50%

• structural and metabolic support for neurons
• forms inner/outer glial membrane

-releases neurotrophic factors

• helps elongate axons/dendrites
• helps w repair (regeneration)

-helps maintain BBB

CONTROLS:
- levels of neurotransmitters
- conc. of ions (has ion channels)

Question 15

Oligodendrocytes

Answer 15

(Glial cells in the CNS)

-supports axons

• can touch multiple axons @ the same time

-makes myelin in CNS, speeds up conduction

Question 16

Ependymal cells

Answer 16

(glial cells in CNS)

• creates cerebrospinal fluid (CSF)

-covers ventricles in brain, central canal of CNS, choroid plexus in medulla oblongata

Question 17

Schwann cells

Answer 17

(glial cell in PNS)- also called neurolemmocytes

• makes myelin in periphery

-side by side axon, provides support

Question 18

Structural classification of neurons

Answer 18

1. Multipolar- most common. 1 axon, many dendrites
2. Bipolar- 2 processes. 1 axon, 1 dendrite
3. Pseudo-unipolar- single stem process that forms 2 processes. 1 goes to PNS, other goes to CNS. Sensory afferent- info from PNS to CNS

Question 19

Functional classifications of neurons

Answer 19

1. Sensory/ Afferent
2. Interneurons/ Association
3. Motor neurons/Efferent

Question 20

Sensory/Afferent neurons

Answer 20

info from PNS to CNS

mostly PSEUDO-UNIPOLAR

Question 21

Interneurons/Association

Answer 21

in the CNS

Connects motor and sensory neurons

mostly MULTI-POLAR or BIPOLAR

Question 22

Motor/ Efferent neurons

Answer 22

info from CNS to PNS (muscle/glands)

mostly MULTIPOLAR

Question 23

Ganglia

Answer 23

bunch of cell bodies in the periphery

Question 24

What makes up the brainstem?

Answer 24

1. Medulla Oblongata
2. Pons
3. Midbrain/Mesencephalon

Question 25

Basal Nuclei

Answer 25

bunch of cell bodies in the CNS

Question 26

Functional areas of the cerebral cortex

Answer 26

1. Primary sensory cortex 2. Primary motor cortex 3. Association cortex

Question 27

Olfactory lobe

Answer 27

perception of smell, part of the primary sensory cortex

Question 28

Frontal lobe

Answer 28

motor areas of the brain sends commands to control movement (skeletal musc)

Question 29

Parietal lobe

Answer 29

Somatosensory area, part of the primary sensory cortex Ex: touch, pain, temp, pressure, taste

Question 30

Temporal Lobe

Answer 30

auditory and vestibular, conscious perception of sound and balance part of primary sensory cortex

Question 31

Occipital lobe

Answer 31

visual cortex, interprets vision part of primary sensory cortex

Question 32

Primary motor cortex

Question 33

Who carries commands from the CNS to the peripheral tissues and systems?

Answer 33

Motor system/ motor neurons

Question 34

What controls reflex activities?

Answer 34

Spinal cord

Question 35

What controls skeletal muscle contractions?

Answer 35

somatic motor neuron

Question 36

myelin production in the CNS

Answer 36

Oligodendrocytes

Question 37

originates action potentials in the neuron

Answer 37

axon hillock

Question 38

saltatory conduction in the neuron

Answer 38

myelin sheet

Question 39

controls levels of neurotransmitters around synapses

Answer 39

astrocytes

Question 40

detailed sensory perception, conscious perception of pain

Answer 40

primary cortical sensory areas

Question 41

initiation of voluntary movement

Answer 41

cerebral cortex

Question 42

learning and intelligent behavior

Answer 42

association cortex

Question 43

connects regions of cerebral cortex from right to left

Answer 43

commissural fibers

Question 44

coordination of voluntary movement

Answer 44

cerebellum

Question 45

preprocesses info reaching the cerebral cortex

Answer 45

thalamus

Question 46

fighting, fleeing, fighting, sex

Answer 46

hypothalamus

Question 47

cervical neck region of spinal cord

Answer 47

C1-C5

Question 48

Cervical intumescence: thoracic limb

Answer 48

C6-T2

Question 49

Thoracolumbar: Thorax + ABD

Answer 49

T3-L3

Question 50

Lumbar intumescence: pelvic cavity, pelvic limb, perineum

Answer 50

L4-S3

Question 51

Caudal tail

Answer 51

Cd1- Cd5

Question 52

Dorsal root

Answer 52

where SENSORY (afferent) NERVES enter spinal cord

Question 53

Ventral root

Answer 53

Where MOTOR (efferent) NERVES leave spinal cord (from CNS)

Question 54

Components of spinal cord

Answer 54

1. Main trunk 2. Peripheral branches 3. Root (dorsal + ventral)

Question 55

Commissural fibers

Answer 55

Connects right and left hemispheres

Question 56

Fibers that compose all spinal nerves

Answer 56

1. Somatic Sensory- enters thru dorsal root 2. Visceral Sensory- enters thru dorsal root 3. Somatic motor- leaves through ventral root 4. Visceral motor- leaves thru ventral horn

Question 57

Visceral motor system

Answer 57

ANS- sympathetic (fight or flight) and parasympathetic (rest and digest)