Neurophys 5-6

Question 1

Somatic motor pathways

Answer 1

Control skeletal muscle

Question 2

Visceral motor pathways

Answer 2

Control GIT, glands etc

Question 3

Telencephalon

Answer 3

Cerebrum

Question 4

Diencephalon

Answer 4

Thalamus, hypothalamus

Question 5

Mesencephalon

Answer 5

Midbrain

Question 6

Metencephalon

Answer 6

Cerebellum & pons

Question 7

Myelencephalon

Answer 7

Medulla oblongata

Question 8

Motor areas

Answer 8

Prefrontal cortex - planning
Premotor cortex - coordination
Frontal eye field - control of eye movement
Motor cortex - sit of upper motor neuron cell bodies

Question 9

Motor cortex

Answer 9

Post cruciate gyrus - pelvic, thoracic limb
Rostrum suprasylvian gyrus - eyelid, ear, masseter, temporalis muscles, lateral cervical muscles

Question 10

pyramidal decussation

Answer 10

Site where axon in lateral corticospinal tract crossing midline
Located in caudal medulla

Question 11

Corticospinal tracts

Answer 11

Composed of upper motor neurons
Cell bodies in motor cortex
Axons descending through white matter of brain
Synapse Lower motor neuron in ventral grey matter of spinal cord
Neurotransmitter = glutamate
All axons cross to other side - cross over pyramid region of medulla (lateral corticospinal tract)

Question 12

Lateral corticospinal tracts function

Answer 12

Voluntary control of skeletal muscle in distal limbs
Upper motor neuron - cell body in primary motor cortex
Axon crosses midline in the ventral medulla
Axon descends in the lateral corticospinal tract
Synapses on lower motor neuron in ventral horn

Question 13

Extrapyramidal system functions

Answer 13

Other pathways synapse on upper and lower motor neurons
Functions:
Control postural reflex
Control of head and eye movement
Regulation of muscle tone
Alternative motor pathway

Question 14

Basal nuclei function

Answer 14

Initiation movement selection of motor response eye movement motivation

Question 15

Reticular formation function

Answer 15

Web group of interconnected nuclei in brain stem
Regulating alertness and consciousness
Norepinephrine, acetylcholine, serotonin

Question 16

Vestibular nuclei

Answer 16

Input from inner ear
Info abt position & acceleration
Transmitter = glutamate
Vestibular ataxia

Question 17

Cerebellum function & organization

Answer 17

Motor coordination
Hemispheres and vermis
Grey matter & white matter
- granular - purkinje - molecular
Connected to brain stem by white matter tracts

Question 18

Input sensors of cerebellum

Answer 18

Vestibular nerve & nuclei - detect movement
Spinocerebellar tracts - detect body position
Motor cortex - movement info

Question 19

UMN LMN synapse

Answer 19

Neurotransmitter = glutamate
Ionotropic receptors
Results = EPSP

Question 20

Lower motor neuron function & location cranial nerves

Answer 20

Transmits signals to CNS to effector organ
Somatic = skeletal, directly Innervation
Ventral horn of spinal cord
- cell bodies in brain nuclei (cranial nerves)

Question 21

Alpha motor neurons

Answer 21

Located in ventral grey matter of spinal cord
Inputs excitatory from upper MN (glutamate)
Inhibitory from Interneurons (GABA)
Modulators from extrapyramidal system
Output - axon synapses on skeletal muscle cells
Releases acetylcholine, causes contraction

Question 22

Upper motor neuron disease

Answer 22

Results in paralysis or paresis
Spasticity

Question 23

Lower motor neuron disease

Answer 23

Paralysis
Flaccidity

Question 24

Pyramidal tract section

Answer 24

Paresis
Flaccidity

Question 25

Motor unit

Answer 25

One alpha motor neuron + all innervated muscle fibers Fine motor control, strength, each muscle fiber is innervated by just 1 motor neuron

Question 26

Motor pool

Answer 26

Groups of motor neurons that innervate all the fibers in a single muscle MN extends over several spinal cord segments

Question 27

Motor spinal nerves

Answer 27

Cell bodies in ventral horn Spinal nerve branches combine to innervate specific muscles

Question 28

Structure of peripheral nerves

Answer 28

Axon - myelinated or unmyelinated Connective tissue - endometrium, around individual axons Perineurium - around bundles of axons Epineurium - around nerves Schwann cells - myelinates axons

Question 29

NMJ

Answer 29

Synapse between a motor neuron and a muscle cell

Question 30

Somatic NS

Answer 30

Neurotransmitter = acetylcholine Receptors - nicotinic cholinergic = channel opens & Na+ flows into cell = depolarization Ca released in to Endo ret = muscle contraction

Question 31

Cranial nerves vs spinal nerves

Answer 31

Cranial - have either Motor or sensory Spinal - always have both sensory & motor

Question 32

Nerves w sensory nerves

Answer 32

Olfactory, optic, trigeminal, facial, vestibulocochlear, glossopharyngeal, vagus

Question 33

Nerves with motor function

Answer 33

Occulomotor, trochlear, trigeminal, abducent, facial, glossopharyngeal, vagus, spinal accessory, hypoglossal

Question 34

Nerves with both motor and sensory

Answer 34

Trigeminal, facial, glossopharyngeal, vagus

Question 35

Origin of cranial nerve III, IV, VI

Answer 35

Occulomotor, trochlear, abducent Mesencephalon, myelencephalon

Question 36

Origin of cranial nerve V

Answer 36

Trigeminal Metencephalon (3 branches)

Question 37

Origin of cranial nerve VII

Answer 37

Facial Myelencephalon

Question 38

Origin of cranial nerve IX

Answer 38

Glossopharyngeal Myelencephalon

Question 39

Origin of cranial nerve X

Answer 39

Vagus Myelencephalon

Question 40

Origin of cranial nerve XI

Answer 40

Spinal accessory Myelencephalon

Question 41

Origin of cranial nerve XII

Answer 41

Hypoglossal Myelencephalon

Question 42

Out put of cerebellum

Answer 42

Motor cortex via thalamus - limb & body movement Cranial nerve motor nuclei - head & eye movement

Question 43

Neurotransmitters of cerebellum

Answer 43

Trans : purkinje cells - GABA Neurons in cerebellar nuclei release glutamine

Question 44

Location and function of lower motor neurons - spinal nerves

Answer 44

Ventral grey matter of spinal cord (spinal nerves) Axons - in spinal or cranial nerves Axon terminal - synapses w muscle or gland cell

Question 45

Alpha motor neurons - input & output

Answer 45

Inputs excitatory from upper MN (glutamate) Output - axon synapses on skeletal muscle cells

Question 46

Alpha motor neurons - inhibition and modulation

Answer 46

Inhibitory from Interneurons (GABA) Modulators from extrapyramidal system

Question 47

Neurotransmitters released by alpha motor neurons

Answer 47

Releases acetylcholine, causes contraction

Question 48

location of corticospinal neurons

Answer 48

Composed of upper motor neurons Cell bodies in motor cortex Axons descending through white matter of brain

Question 49

Reactions of corticospinal neurons

Answer 49

Synapse Lower motor neuron in ventral grey matter of spinal cord Neurotransmitter = glutamate All axons cross to other side - cross over pyramid region of medulla (lateral corticospinal tract)

Question 50

lateral corticospinal tracts axon

Answer 50

Axon crosses midline in the ventral medulla Axon descends in the lateral corticospinal tract

Question 51

Lateral corticospinal tracts neurons

Answer 51

Upper motor neuron - cell body in primary motor cortex Synapses on lower motor neuron in ventral horn