Random Test 2 Stuff

Question 1

Name the 4 main parts of a sensory receptor

Answer 1

receptive structure, peripheral sensory axon, sensory ganglionic neuron, central sensory axon

Question 2

What two factors are required for an “adequate stimulus”

Answer 2

Correct intensity

correct stimulus for receptor present

Question 3

When adequate stimulus is applied to the correct receptor, what occurs first?

Answer 3

receptor potential is generated

Question 4

When does the receptor potential become an action potential?

Answer 4

When it reaches the first node of ranvier of the myelinated segment of peripheral process

Question 5

What determines the number of action potentials generated?

Answer 5

stimulus intensity

Question 6

What is the speed at which APs travel along an axon? 2 Determining factors?

Answer 6

Conduction velocity

1) axon diameter
2) amount of myelination

Question 7

Name 3 important receptor types as related to skin

Answer 7

1) mechanoreceptor
2) thermal receptor
3) nociceptors

Question 8

What receptor detects muscle stretch?

Answer 8

Muscle spindle

Question 9

Describe activation of a muscle stretch receptor (not response)

Answer 9

Extrafusal muscle is stretched, causing the intrafusal fiber to stretch; the annulospiral receptor wrapped about the intrafusal fiber stretches, causing its channels to open (receptor potential generated); travels to Ia afferent sensory neuorn, becomes AP and travels to CNS

Question 10

What is the purpose of the gamma motor neuron?

Answer 10

independently controlled by brain and spinal cord; innervates the ends of JUST the intrafusal fiber; stimulation causes contractions at the end, and stretches the intrafusal fiber, allowing the brain to have more precise control over contraction

Question 11

What is responsible for detecting muscle contraction? What’s its location?

Answer 11

Golgi tendon organ; in the tendon of the muscle

Question 12

What (generally) does the golgi tendon organ cause to happen?

Answer 12

stimulates inhibition of the neurons causing the muscle to contract

Question 13

Single motor neuron and the muscle fibers it innervates?

Answer 13

Motor unit

Question 14

Where can you find (in s.c.) LMNs that innervate 1) somatic muscle 2) smooth/cardiac muscle and glands?

Answer 14

1) ventral gray matter

2) intermediolateral gray column

Question 15

Which CNN lack motor function?

Answer 15

I, II, VIII

Question 16

What do UMNs use to influence LMN activity? (structure)

Answer 16

Interneurons

Question 17

What are the components of a simple reflex arc?

Answer 17

receptor–>afferent pathway–>CNS integration–>efferent pathway–>effector

Question 18

In forelimb: nerves responsible for 1) elbow flexion 2) carpal flexion 3) extension

Answer 18

1) musculocutaneous
2) median and ulnar
3) radial

Question 19

In hindlimb: nerves responsible for 1) hip flexion 2) stifle flexion 3) tarsal flexion

Answer 19

1) femoral
2) sciatic
3) common peroneal

Question 20

What nerve is tested with the perineal reflex?

Answer 20

Pudendal

Question 21

What 3 basic things can be found at NMJ?

Answer 21

1) neurotransmitter
2) receptor on muscle
3) neurotranmitter degrader

Question 22

How does denervation affect receptor distribution?

Answer 22

Less clustering of receptors near nerve terminal; become more diffuse/extrajunctional

Question 23

What test can be used to determine if something is a muscle or nerve problem?

Answer 23

electromyography

Question 24

What are two disorders that affect NT release?

Answer 24

Botulism and tick paralysis

Question 25

Immune-mediated disorder against ACh repceptor? (whats the receptor type?

Answer 25

Myasthenia gravis (nicotinic receptor)

Question 26

For which disease can you give anticholinesterase drugs?

Answer 26

Myasthenia gravis

Question 27

How do organophosphates cause disease?

Answer 27

Block ACh-ase (prevent its breakdown in NMJ)

Question 28

What will the majority of the signs be related to with organophosphates?

Answer 28

Parasympathetic signs

Question 29

If ACh is stimulatory, why can we see paralysis with organophosphates?

Answer 29

Depolarization blockade...all Na channels become inactive

Question 30

How does atropine work to resolve organophosphate symptoms?

Answer 30

Muscarinic blocker

Question 31

When is a crossed extensor reflex considered abnormal?

Answer 31

When the animal is recumbant

Question 32

The ANS uses ___ at nerve terminals to release NTs into a wide synaptic cleft?

Answer 32

Variscosities

Question 33

Neurons that release ACh? Neurons that release NE?

Answer 33

Cholinergic--ACh | Adrenergic--NE

Question 34

Which receptors are cholinergic? Adrenergic?(specific names)

Answer 34

Cholinergic--Nicotinic; muscarinic | Adrenergic--Alpha; beta

Question 35

Sweat glands in most species are ______? Exception?

Answer 35

Cholinergic... exception is horses (adrenergic)

Question 36

When other NTs are released with the primary one and alter its action?

Answer 36

Co-transmission

Question 37

ACh is made from?

Answer 37

Acetyl-CoA and choline

Question 38

What are Epi and NE synthesized from? What category of hormone are they?

Answer 38

Tyrosine... monoamines (catecholamines)

Question 39

What two things determine NT action?

Answer 39

Type of receptor | Receptor location

Question 40

What does NANC stand for? What's one NT they release?

Answer 40

Nonadrenergic, noncholinergic; NO

Question 41

What CNS region is concerned with emotional behavior and motivational drives? What area is the primary output?

Answer 41

Limbic system; hypothalamus

Question 42

In addition to classical signs, what else do we see in horses with horner's syndrome? On what side?

Answer 42

Sweating; on the affected side

Question 43

Why do we see sweating in horses with horner's? (2 words)

Answer 43

Denervation hypersensitivity (receptors become more sensitive to Epi/NE in circulation)

Question 44

When a decrease in flexor tone allows extensor tone to predominate?

Answer 44

Spasticity

Question 45

If lesion is rostral to midbrain, signs will be on ______side of body? Caudal to midbrain?

Answer 45

Cranial: contralateral Caudal: ipsilateral

Question 46

What do we call UMN axons?

Answer 46

Long descending tracts

Question 47

What are he 3 locations of UMNs? Which is most important for flexor muscles?

Answer 47

Medullary reticular formation Pontine reticular formation Midbrain red nucleus (most important for flexor muscles)

Question 48

What is the tract name for the UMNs originating at the reticular formation and projecting to the spinal cord?

Answer 48

Reticulospinal tracts

Question 49

What muscle makes up the bladder wall? What receptors does it have?

Answer 49

Detrusor muscle; muscarinic and beta

Question 50

Which sphincter is under involuntary control? Which receptors are found in each sphincter?

Answer 50

``` Internal sphincter is involuntary (smooth muscle)---alpha receptors External sphincter (voluntary)--nicotinic receptors ```

Question 51

What 3 nerves innervate the bladder? Which area? Fibers composition?

Answer 51

Hypogastric--detrusor muscle and internal sphincter (sympathetic) Pelvic nerve-- detrusor muscle (parasymp) Pudendal Nerve--external sphincter (somatic)

Question 52

Used to evaluate micturition?

Answer 52

cystometrogram

Question 53

UMN bladder vs. LMN bladder?

Answer 53

UMN: lost voluntary control; difficult to express (increased sphincter tone) LMN: loss of voluntary control; easy to express

Question 54

Breakdown of tight junctions due to prolonged bladder distension?

Answer 54

Detrusor atony

Question 55

What CONTROLS gait?

Answer 55

Long descending tracts

Question 56

Region of the brain that controls UMNs controlling gait?

Answer 56

Mesencephalic locomotor region

Question 57

Most important area for controlling gait? (i.e. abnormalities will be most obvious)

Answer 57

Spinal cord/peripheral nerves (C6-T2, L4-S1)

Question 58

The closer a lesion is to _____ the more obvious its effects on gait.

Answer 58

Spinal cord

Question 59

Which PNS connective tissue layer contains tight junctions?

Answer 59

Perineurium

Question 60

When you handle a nerve grossly, what layer are you contacting?

Answer 60

Epineurium

Question 61

Which germ layer do ganglia develop from?

Answer 61

Neural crest ectoderm

Question 62

Are gaglia inside or outside the CNS?

Answer 62

Outside

Question 63

Regeneration possible? (CNS and PNS)

Answer 63

CNS: no PNS: Yes

Question 64

Function of Cajal-retzius cells?

Answer 64

direct migration of radial glia cells

Question 65

Where can the "youngest" neurons be found in the developing cerebrum?

Answer 65

closest to the pia

Question 66

From which layer do the migrating cells arise?

Answer 66

Germinal zone

Question 67

What cell types are present in Layers 2 and 4? Information direction?

Answer 67

Granular cells; information incoming

Question 68

What cell types are present in layers 3 and 5? Information direction?

Answer 68

Pyramidal cells; information outgoing

Question 69

Which cells are responsible for pruning the dendritic trees to strengthen synapses?

Answer 69

Microglia

Question 70

Which layer contains commissural neurons?

Answer 70

Layer 6

Question 71

Cerebral buldges? Spaces between?

Answer 71

Gyri, sulci

Question 72

Functional unit of the cerebrum?

Answer 72

Cerebral column

Question 73

Main function of cerebellum?

Answer 73

produce smooth motor control

Question 74

What are the 3 main cerebellar inputs? Fiber types?

Answer 74

1) Cerebral--climbing fibers 2) spinal cord--mossy fibers 3) vestibular nucleus--mossy fibers

Question 75

Which layer do climbing fibers innervate? Mossy fibers? Excitatory or inhibitory?

Answer 75

Climbing fibers--purkinje dendrites (EX) | Mossy fibers--granular cell layer (EX)

Question 76

Purkinje fiber output to DCN is EX or INHIB?

Answer 76

INHIB

Question 77

Where does DCN send post-information?

Answer 77

Back to the areas of original input

Question 78

What are the 3 cerebellar interneurons? General function?

Answer 78

Stellate, golgi, and basket | Fine tune excitatory input (they are inhibitory interneurons)