Physiology Exam II review Flashcards

1
Q

Upper motor neuron uses what NT

A

Glutamate

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2
Q

Lower motor neuron uses what NT

A

Acetycholine

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3
Q

Renshaw cells -type of cell, location, receives branches from

A

Inhibitory cells in anterior horns of spinal cord

Receive branches from alpha motor neurons

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4
Q

Sensory fiber conduction rate from fastest-slowest

A

C fibers - fastest
A-d fibers
A-a or A-b

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5
Q

Nociceptors and thermoreceptors are related to what fibers

A

C or A-d

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6
Q

Muscle spindle is made up of what and innervated by

A

3-12 intrafusal fibers innervated by small gamma motor neurons

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7
Q

Central region of spindle functions as

A

Sensory receptor- no contractile fibers

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8
Q

Nuclear bag fibers

A

Detect rate of change in muscle length

Innervated by group Ia afferents and dynamic y efferents

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9
Q

Nuclear chain fibers

A

Detect static change in muscle length

Innervated by group II afferents and static y efferents

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10
Q

Stimulation of muscle spindle sensory fibers results in

A

Stimulation of a-motor neurons, contraction

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11
Q

Golgi tendon organ detects what

A

Muscle tension (contraction or stretching)

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12
Q

Golgi tendon organ circuitry

A

Type Ib afferent–> Inhibitory interneuron–> anterior motor neuron

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13
Q

Reciprocal inhibition

A

Ex. When flexing arm to move hand away from hot surface, biceps are excited and triceps inhibited

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14
Q

Premotor/supplementary motor areas

A

Create plan for movement- for more complex movements
Premotor- develops motor image
Supplementary - Programs motor sequence, mental rehearsal

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15
Q

Medial activation system of UMN innervate

A

Postural and girdle muscles

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16
Q

Lateral activation system of UMN innervates

A

Distal muscles used for fine movement

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17
Q

Nonspecific activating system of UMN

A

Facilitate local reflex arcs

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18
Q

Corticospinal/pyramidal tract origin

A

Primary motor cortex
Premotor cortex
Somatosensory area

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19
Q

Corticospinal/pyramidal tract pathway

A
Site of origin-->
Internal capsule-->
Medullary pyramids-->
(most) Cross in lower medulla-->
Lateral columns of spinal cord
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20
Q

Lateral corticospinal tract

A

Fibers that have crossed in medulla

Supplies all levels of spinal cord

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21
Q

Anterior corticospinal tract

A
Uncrossed fibers (eventually cross near LMN)
Supply neck/upper limbs
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22
Q

Corticospinal tract functions

A

Add speed and agility to conscious movements, especially hands
Provides high degree of motor control

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23
Q

Giant pyramidal (Betz) cells are located

A

In motor cortex

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24
Q

Corticospinal muscle tract lesions cause

A

Reduced muscle tone
Clumsiness
Weakness
Not complete paralysis (only if both pyramidal and extrapyramidal systems are involved)

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25
Q

Corticobulbar tract

A

UMN of cranial nerves- innervate face/head neck

-Terminate in reticular formation

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26
Q

Fibers from _____ and _____ synapse in the _______ portion of the red nucleus

A

Primary motor cortex; corticospinal tract

Magnocellular portion

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27
Q

Stimulation of red nucleus results in

A

Stimulation of flexors

Inhibition of extensors

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28
Q

Vestibulospinal tract receives info from

A

Cranial nerve VIII (vestibular nerve)

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29
Q

Vestibulospinal tract synapses with ____ which supply ___

A

LMN supplying extensors

-maintain upright posture

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30
Q

Components of vestibulospinal tract

A

Utricle w/macula on horizontal plane (upright)
Saccule w/macula on vertical plane (lying down)
Semicircular canals

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31
Q

Macula contains

A

Calcium carbonate crystals, cilia etc…

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32
Q

Cerebellum functions

A

Planning, timing, adjusting muscle movements -mainly when they have to be rapid
Not essential for locomotion

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33
Q

Cerebellar vermis zone

A

Location for control functions of muscle movements of body, neck, shoulders, hips

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34
Q

Intermediate zone of cerebellum

A

Muscle contractions in distal portions of upper/lower limbs

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35
Q

Lateral zone of cerebellum

A

Planning of sequential motor movements w/cerebral cortex

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36
Q

Dentate, emboliform, globose nuclei (intracerebellar) lesions result in

A

Extremity ataxia

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37
Q

Fastigial nuclei (intracerebellar) lesions result in

A

Trunk ataxia

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38
Q

Granular layer

A

Innermost layer of cerebellar cortex

Golgi II cells, glomeruli, mossy fibers

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39
Q

Purkinje cell layer

A

Middle layer of cerebellar cortex

Purkinje cells

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40
Q

Molecular layer

A

Outermost layer of cerebellar cortex

Stellate cells, basket cells, purkinje dendrites, granule cell axons

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41
Q

Granular cells form

A

Parallel fibers in cortex

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42
Q

Golgi cells project from and to

A

Parallel fibers to granular cell bodies

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43
Q

Basket cells project from and to

A

Parallel fibers to purkinje axon hillock (lateral inhibition)

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44
Q

Stellate cells project from and to

A

Parallel fibers to purkinje dendrites (lateral inhibition)

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45
Q

Purkinje cells

A

Project to intracerebellar nuclei

-They are ONLY output from cerebellar cortex, and always inhibitory

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46
Q

Climbing fibers

A

Afferent from cerebellar cortex- cause complex spikes

Play role in motor learning, condition purkinje cells

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47
Q

Mossy fibers

A

Afferent from cerebellar cortex

Make simple spikes

48
Q

Vestibulocerebellum

A

Control of balance and eye movements

Contains flocculonodular lobes

49
Q

Loss of flocculonodular lobes results in

A

Extreme disturbance of equilibrium and postural movements

50
Q

Changes that occur when cerebellum is removed

A

Movements are slow to develop and turn off, force is weak

51
Q

Vestibulocerebellum syndrome

A

Progressive genetic disease of flocculonodular lobe
Nystagmus
Vertigo, tinnitus

52
Q

Spinocerebellum

A

Vermis/intermediate zone
Receives info from motor cortex and red nucleus
Sends corrections back to them via thalamus

53
Q

Cerebrocerebellum

A

Lateral parts of hemispheres
Receives corticopontocerebellar projections
Coordination of speech

54
Q

Corticopontocerebellar tract

A

Major link b/w cortex and cerebellum

Lesions result in weakness

55
Q

Vestibulocerebellar tract terminates

A

In flocculonodular lobes

56
Q

Reticulocerebellar tract terminates

A

In vermis

57
Q

What tracts form the mossy fibers

A

Corticopontocerebellar
Vestibulocerebellar
Reticulocerebellar
Spinocerebellar

58
Q

Axons from what form climbing fibers

A

Olivocerebellar tract

59
Q

Cerebelloreticular tract begins

A

Fastigial nuclei –> reticular

60
Q

Cerebellothalamocortical and cerebellorubral tracts begin

A

Dentate, emboliform, globose nuclei

61
Q

Basal nuclei functions

A

Plan/execute motor commands w/cerebral cortex

Modulate thalamic output to motor cortex

62
Q

Basal nuclei putamen circuit (direct pathway)

A
Cerebral cortex (+Ach)-->
Putamen (-GABA)-->
Internal Globus pallidus (IGP) (-GABA)-->
Thalamic relay nuclei (+Glutamate)-->
Primary motor cortex
63
Q

Dopamine D2 receptors vs D1 receptors

A

D2 inhibitory

D1 excitatory

64
Q

Lesions in globus pallidus

A

Inability to maintain postural support

Spontaneous movements of hand/arm etc- ethetosis

65
Q

Lesions in subthalamic nuclei

A

Sudden flailing movements of an entire limb- hemiballismus

66
Q

Lesions in striatum (putamen)

A

Flickering movements of hands/face/elsewhere- Chorea

-Occurs w/huntingtons

67
Q

Lesions in substantia niagra

A

Caused by destruction of dopaminergic neurons
Parkinsons
Tremors

68
Q

Dopamine effect on direct and indirect pathway

A

Dopamine inhibits the indirect pathway and excites the direct pathway

69
Q

Direct (putamen) pathway function

A

Excitatory

Subconscious execution of learned movements

70
Q

Indirect (caudate) pathway function

A

Inhibitory

Planning of sequential/parallel motor patterns

71
Q

Where can you find neurons that are directly sensitive to chemical/physical variables (temperature etc)

A

Hypothalamus

72
Q

Brain areas affecting body temp

A

Anterior preoptic hypothalamus

73
Q

Warm sensitive neurons

A

30% of neurons in APH

Activate neurons in paraventricular nucleus and lateral hypothalamus – Parasympathetic

74
Q

Cold sensitive neurons

A

5% of neurons in APH

Activate neurons in posterior hypothalamus –Sympathetic

75
Q

What is the brain area involved in shivering

A

Posterior hypothalamus

76
Q

Posterior hypothalamus normally inhibited by _____, when activated it sends signals to

A

Inhibited by heat center in APH

Sends signals to activate a/y-motor neurons in lateral horns

77
Q

IL-1/prostaglandins effect on fever

A

Increases it

78
Q

Aspirin effect on fever

A

Decreases by reducing prostaglandin synthesis

79
Q

Active transport of glucose occurs via ___ and where

A

Sodium glucose cotransport

GI tract, renal tubules

80
Q

End products of Citric acid cycle

A

16 hydrogens
2 ATP
4 CO2

81
Q

Increased blood glucose leads to

A

Increased osmotic pressure
Increased urine output
Damage to tissues/vessels

82
Q

When 2 electrons pass through for oxidative phosphorylation, how much ATP is produced

A

3 ATP

83
Q

ATP formed per glucose molecule per cycle

efficiency is %

A
Glycolysis-2
CAC-2
OP-34
38 total per glucose
66% efficiency
84
Q

Pentose phosphate pathway

A

Synthesis of triglycerides from glucose

Uses NADPH

85
Q

Uptake of triglycerides

A

They are first digested into monoglycerides/fatty acid
Intestinal cells resynthesize them into triglycerides that enter lymph as chylomicrons
-Bile salts form micelles w/lipids for absorption

86
Q

Lipoprotein lipase

A

Adipose/heart/skeletal muscle

Hydrolyzes triglyceride/chylomicron to fatty acids and glycerol

87
Q

VLDL

A

High concentration of triglycerides, moderate amount of phospholipids and cholesterol
Transports lipids from liver to adipose

88
Q

LDL

A

High concentration cholesterol, moderate amount of phospholipids

89
Q

HDL

A

High concentration protein, low cholesterol/fatty acid

90
Q

What happens to ketones

A

Converted to acetyl CoA

91
Q

Conditions favoring ketosis

A

Starvation
Diabetes
Fatty diet

92
Q

Ornithine cycle mitochondrial steps

A

Ammonia + CO2–> Carbamoyl phosphate

Carbamoyl phosphate + Ornithine–> Citrulline

93
Q

Ornithine cycle cytoplasmic steps

A

Citrulline + aspartate–> arginosuccinate
Arginosuccinate –> arginine + fumarate
Arginine–> urea + ornithine
Fumarate can enter CAC

94
Q

What is the best known stimuli for increasing rate of thyroid stimulating hormone

A

Cold

95
Q

Thyroxine and metabolic rate

A

Increases metabolic rate

96
Q

Testosterone and metabolic rate

A

Can increase 10-15% due to anabolic effect of increasing muscle mass

97
Q

Malnutrition and metabolic rate

A

Reduces it significantly

98
Q

Propulsive movements

A

Contractile ring occurs at point of stimulation in gut and can move orally or rectally (usually dies out orally)
Myenteric plexus is needed

99
Q

Mixing movements

A

Can be caused by peristaltic contractions themselves

100
Q

What cells generate slow waves and what are they

A

Cells of Cajal

  • slow waves are not action potentials;they spread through gap junctions and occur spontaneously
  • set maximum frequency of contraction
101
Q

Spike potentials

A

Action potentials when GI membrane > +40mV

Opens calcium-sodium channels in GI smooth muscle

102
Q

Reflexes integrated entirely within gut wall- function

A

Much of GI secretion
Peristalsis
Mixing contractions
Local inhibitory

103
Q

Reflexes from gut to prevertebral sympathetic and back to gut

A

Long distance signals
Evacuation of colon
Inhibit stomach motility/secretion
Empty ileal contents

104
Q

Gastrin activation/actions

A

Eating/Phe/Trp
Stimulates gastric acid secretion by parietal cells
Stimulates mucosal growth
Inhibited by acid (negative feedback)

105
Q

Zollinger-Ellison syndrome

A

Gastrin secreting non-b cell tumors of pancreas

106
Q

What secretes cholecystokinin and what is its action

A

I-cells of small intestine
Controls feedback of duodenum
Pancreas functions
Inhibit appetite

107
Q

What secretes secretin and what are functions

A

S cells of small intestine

Stimulates pepsin, inhibits gastric acid secretion

108
Q

GIP secreted by, action

A

Only GI hormone secreted in response to fat/carb/protein
K cells of duodenum/jejunum
Stimulates insulin release, inhibits gastric acid secretion

109
Q

Motilin secreted by/actions

A

M-cells of duodenum/jejunum
Stimulates gastric motility
Secreted during fasting

110
Q

Saliva secretion regulated by

A

Mostly parasympathetic, but also sympathetic- both result in increased saliva
Cranial nerves VII and IX

111
Q

Parasympathetic saliva receptor/ second messengers

A

Cholinergic

IP3 and Calcium

112
Q

Sympathetic saliva receptor/ second messengers

A

B-adrenergic

cAMP

113
Q

Direct parasympathetic stimulation of H+

A

CN X innervates parietal cells to release H+

Ach is NT

114
Q

Indirect parasympathetic stimulation of H+

A

CN X innervates G cells
G cells secrete gastrin which stimulates H+ secretion
GRP is NT

115
Q

Histamine secretion action

A

Stimulates H+ secretion by activating parietal cells

116
Q

Somatostatin secreted by/functions

A

Delta cells of pancreas
Inhibits secretion of insulin, glucagon, gastrin
Decreases motility/secretion/absorption of GI tract

117
Q

Crypts of Lieberkuhn

A

Goblet cells
Enterocytes-absorptive
Paneth cells-antimicrobial
Enteroendocrine cells-peptide hormones