Autonomic Nervous system Flashcards Preview

Neuroscience Deja Review USMLE 1 > Autonomic Nervous system > Flashcards

Flashcards in Autonomic Nervous system Deck (67):
1

Sympathetic effect on Eyes

Pupillary dilation (α1)

2

Sympathetic effect on Salivary glands

Increased thick, viscous secretions

3

Sympathetic effect on Bronchioles

Bronchodilation (β2), ↑ secretions

4

Sympathetic effect on Heart

Tachycardia (β1), ↑ contractility (β1), ↑ AV nodal conduction (β1)

5

Sympathetic effect on Vascular smooth muscle

Vasoconstriction of cutaneous mucous membrane and splanchnic vessels (α1); vasodilation in skeletal muscle (β2)

6

Sympathetic effect on Gastrointestinal (GI) tract

↓ Muscle motility and tone (β2), contraction of sphincters (α1)

7

Sympathetic effect on Male sex organs

Ejaculation (α2)

8

Sympathetic effect on Uterus

Relaxation (β2), contraction (α1)

9

Sympathetic effect on Bladder and ureters

Relaxation of detrusor (β2) contraction of trigone and sphincter (α1)

10

Sympathetic effect on Sweat glands

↑ Secretions (muscarinic)

11

Sympathetic effect on Kidneys

↑ Renin secretion

12

Sympathetic effect on Adipocytes

↑ Lipolysis (β1)

13

Sympathetic effect on Pancreas

↓ Insulin secretion (α2), ↑ insulin secretion (β2)

14

Parasympathetic effect on Eyes

Pupillary constriction

15

Parasympathetic effect on Bronchioles

Bronchoconstriction

16

Parasympathetic effect on Heart

Bradycardia, ↓ contractility, ↓ AV nodal conduction

17

Parasympathetic effect on GI tract

↑ Motility, relaxation of sphincters

18

Parasympathetic effect on Male sex organs

Erection

19

Parasympathetic effect on Bladder and ureters

Contraction of detrusor, relaxation of sphincters and trigone

20

What type of cholinergic receptor mediates all of the effects of the parasympathetic nervous system?

Muscarinic

21

What type of motor fiber innervates extrafusal muscle fibers?

A-alpha (A-α)

22

What type of motor fiber innervates intrafusal muscle fibers?

A-gamma (A-γ)

23

What is the function of Ia (A-α) fibers

Proprioception, muscle spindles

24

What is the function of Ib fibers

Proprioception, Golgi tendon organs

25

What is the function of II (A-β) fibers

Touch, pressure, and vibration; secondary afferents of muscle spindles

26

What is the function of III (A-δ) fibers

Touch, pressure, fast pain, and temperature

27

What is the function of IV (c) fibers

Slow pain and temperature (unmyelinated)

28

What types of sensory fibers have the largest diameter and consequently the fastest conduction velocity?

Ia and Ib

29

What type of motor fibers have the largest diameter and consequently the fastest conduction velocity?

A-α

30

What type of sensory fibers have the smallest diameter and consequently the slowest conduction velocity?

C

31

What is the electrochemical effect of an inward Na+ current on a sensory fiber?

Depolarization

32

What is the function of the Sensory receptor

Translates environmental stimulus into an electrical impulse

33

What is the function of the First-order neuron

Carries impulse from sensory receptor into central nervous system (CNS)

34

What is the function of the Second-order neuron

Carries impulse from primary neuron to the thalamus

35

What is the function of the Third-order neuron

Carries impulse from second-order neuron to the cerebral cortex

36

What is the function of the Fourth-order neuron

Carries impulses from third-order neurons to appropriate somatosensory area of cerebral cortex

37

Onion-like subcutaneous receptors that respond to vibration and tapping

Pacinian corpuscle

38

Primary receptors of the dermal papillae that mediate two-point tactile discrimination

Meissner corpuscle

39

Encapsulated receptor that responds to pressure

Ruffini corpuscle

40

Disc-shaped touch receptor of the deep dermis

Merkel tactile disc

41

Rods or cones?
Sensitive to low-intensity light
 

Rods 

42

Rods or cones?
Sensitive to high-intensity light
 

Cones 

43

Rods or cones?
Receptor used primarily for night vision
 

Rods 

44

Rods or cones?
Receptor used primarily for day vision
 

Cones 

45

Rods or cones?
Present in fovea
 

Cones 

46

Rods or cones?
High visual acuity
 

Cones 

47

Rods or cones?
Receptor which adjusts to low light conditions most rapidly
 

Cones 

48

Rods or cones?
Receptor capable of color vision
 

Cones 

49

Muscle sensor that detects static and dynamic changes in muscle length

Muscle spindles

50

Muscle sensor that detects muscle tension

Golgi tendon organs

51

Muscle sensor that detects vibration

Pacinian corpuscles

52

Muscle sensor that detects pain

Free nerve endings

53

What type of motoneuron is responsible for ensuring that a muscle will respond appropriately throughout contraction, despite changes in tension?

γ-Motoneurons

54

What type of muscle reflex, mediated by type Ia afferent fibers, causes muscle contraction in response to muscle stretch?

Stretch or myotatic reflex

55

What type of muscle reflex, mediated by type Ib afferent fibers, causes muscle relaxation in response to muscle contraction?

Golgi tendon reflex

56

What type of muscle reflex, mediated by types II, III, and IV afferent fibers, causes ipsilateral flexion and contralateral extension?

Flexor withdrawal reflex

57

What are the components of the afferent limb of a myotatic reflex arc?

Muscle spindle receptor → Ia fiber → dorsal root ganglion

58

What comprises the efferent limb of a myotatic reflex arc?

Ventral motor neuron

59

Muscle group and spinal level of Ankle jerk

Gastrocnemius (S1)

60

Muscle group and spinal level of Knee jerk

Quadriceps (L2-L4)

61

Muscle group and spinal level of Biceps jerk Biceps

(C5-C6)

62

Muscle group and spinal level of Forearm jerk

Brachioradialis (C5-C6)

63

Muscle group and spinal level of Triceps jerk

Triceps (C7-C8)

64

What type of posturing is caused by a transecting lesion above the level of the medulla but below the midbrain?

Decerebrate rigidity

65

What type of posturing is caused by a transecting lesion above the level of the red nucleus (midbrain)?

Decorticate rigidity

66

What are the three layers of the cerebellar cortex? 

1. Granular layer (innermost)
2. Purkinje layer (middle)
3. Molecular layer (outermost)
 

67

Which is the major NT of cerebellar Purkinje cells? 

γ-Aminobutyric acid (GABA).
Note: The output of Purkinje cells is always inhibitory.