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Physiology 2 > Physiology Midterm 1 > Flashcards

Physiology Midterm 1 Flashcards

1
Q

What is physiology?

A

The science of the function of living systems

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2
Q

What is function?

A

“Why does the system exist or why does the event occur?

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3
Q

What is process?

A

How does a system work/the physiological mechanisms

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4
Q

What is homeostasis?

A

maintenance of a relatively stable internal environment (especially the ECF), oscillation around a set point

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5
Q

Who coined the term homeostasis and wisdom of the body?

A

Walter Cannon

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6
Q

Study of homeostatic mechanisms?

A

Physiology

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7
Q

Failure to compensate for change?

A

Disease

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8
Q

Study of the failure to compensate for disease?

A

Pathophysiology

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9
Q

What is local control?

A

Cells near site of change initiate response (working muscle = metabolites cause vasodilation at that site, not the whole body)

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10
Q

What is reflex control?

A

Cells at a distant site control response; uses the neural and/or endocrine systems. (blood pressure increase sensed by baroreceptors in aorta and caratid arteries = brain evaluates change and initiates response_

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11
Q

Components of response loop

A

stimulus, sensor, input signal, integrating centre, output signal, target, response

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12
Q

Negative feedback?

A

homeostatic, stabilizes variable, response coutneracts stimulus, shutting off response loop

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13
Q

Positive feedback?

A

NOT homeostatic, reinforces stimulus, sends variable further from setpoint, usually dramatic things

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14
Q

Feedforward control

A

Anticipates change, boots up system to be ready for change (seeing food = increase salivation and stomach motility in anticipation of a meal, or getting pumped before a race)

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15
Q

What are electrical signals and what cells are the restricted to?

A

changes in membrane potential and restricted to nerve and muscle cells

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16
Q

What is the most common form of cell to ell communication in the body?

A

chemical signals

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17
Q

What are target cells?

A

Cells that respond to signals

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18
Q

Endocrine signalling?

A

hormone/chemical released into bloodstream and distributed throughout body

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19
Q

Neural signalling?

A

electrical signal travels down neuron; reaches end and is translated to chemical signal (neurotransmitter) which transmits information to the next cell

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20
Q

neuro endocrine signalling?

A

electrical signal travels down neuron; reaches end and is secreted into blood

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21
Q

What cells respond to a signal

A

Only those that have RECEPTORS (presence of receptor determined by genetic expression)

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22
Q

Where are receptors located?

A

Proteins inside the cell or project to outside the membrane

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23
Q

Lopphobic.hydrophilic ligans bind where?

A

Surface receptor proteins

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24
Q

Lipophilic/hydrophobic ligans bind where?

A

intracellular receptors

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25
Q

How many transmembrane folds do GPCRs have?

A

7

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26
Q

Signal transduction steps?

A

Signal molecule binds to membrane receptor protein activating intracellular signal molecules which alter target proteins and create a response

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27
Q

Kinase?

A

Add phosphates

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28
Q

IP3?

A

Made from PI, GPCR that uses phospholipase C as an amplifier enzyme, releases calcium from intracellular stores

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29
Q

DAG?

A

made from PI, GPCR, uses phospholipase C as amplifier enzyme, activates protein Kinase C, phosphorylates proteins

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30
Q

Ca2+ in cell to cell signaling?

A

Binds to calmodulin and other proteins to alter enzyme activity, exocytosis, muscle contraction, cytoskelton movement, channel opening

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31
Q

cAMP in cell to cell signalling?

A

Amplified by adenyl cyclase and activates PKA and binds to protein ion channels, effects are phosphorylation of proteins and alters channel opening

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32
Q

How can same signal have different effects in different cell types?

A

Several different types of receptors

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33
Q

How are receptors like enzymes?

A

Exhibit saturation, specificity, competition for their ligands

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34
Q

How can cells change their response to signals?

A

By changing receptor number or sensitivty

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35
Q

How do cells increase receptor number?

A

Increase gene regulation (up regulation)

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36
Q

How do cells decrease receptor number?

A

Internalize surface receptors (down regulation)

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37
Q

How do cells change receptor sensitivity?

A

Phosphorylation

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38
Q

Agonist?

A

Similar molecule that activates receptor, giving the same response, MIMICS it

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39
Q

Antagonist?

A

molecule that is similar enough to native ligand to bind to receptor, but not activate it, BLOCKER

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40
Q

Cannon’s 4 postulates?

A
  1. Nervous system has a role in maintaining fitness of the internal environment (coordinates responses that regulate blood volume, blood pressure, osmolarity, etc) 2. some systems are under tonic control 3. some systems are under antagonistic control 4. one chemical signal can have different effects in different tissues
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41
Q

Tonic control?

A

Regulates physiological parameters in an up down fashion (blood vessel diameter)

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42
Q

Antagonistic control?

A

2 systems compete for control over parameter. Whichever has the greater tone will have the greater effect

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43
Q

Where a sensors/detectors/receptors often located?

A

in the ECF

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44
Q

Central receptors?

A

Specialized cells/structures CLOSE TO THE BRAIN that convert stimuli into electrical signals (eyes, ears, nose, tongue

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45
Q

Peripheral receptors?

A

Specialized cells/structures OUTSIDE the brain that convert stimuli into electrical signals (baroreceptors, thermoreceptors, chemoreceptors, etc)

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46
Q

Simple endocrine reflex?

A

Int/ext change, endocrine system senssor-integrating centre, output signal is a hormone, target, response

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47
Q

Simple neural reflex?

A

int/ext change, receoptor, input signal:sensory neuron, nervous system:integrating centre, efferent neuron, target, response

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48
Q

A complex neuro-endocrine reflex

A

Int/ext change, receptor, input signal: sensory neuron, nervous system integrating center, efferent neuron or neurohormone, endocrine integrating centre, output signal #2: hormone, target, response

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49
Q

Difference in specificity in neural reflex and endocrine reflex?

A

Each neuron terminates on a single target cell or on a limited number of target cells. Endocrine reflex sends hormone to most cells in the body, and only those with a recpetor respond.

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50
Q

Difference in speed between neural and endocrine reflex?

A

Very rapid versus much slower

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51
Q

Duration of action in neural vs. endocrine reflex

A

Very short. Responses of longer duration are mediated by neuromodulators. vs. Responses usually last longer than neural responses.

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52
Q

Intensity of a neural reflex is related to?

A

Each signal is identical in strength. Stimulus intensity is correlated to increased frequency of signalling.

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53
Q

Intensity of endocrine reflex is related to?

A

Amount of hormone dumped into system

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54
Q

Evolution in animals in nervous systems?

A

Jellyfish “nerve net,” flatworm’s cerebral ganglia and nerve cords, earthworm’s primitive brain and ventral nerve cord ganglia…CEPHALIZATION…fish with a small forebrain, birds with bigger forebrain, mammals with large, folded forebrain

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55
Q

Development of vertebrate CNS?

A

Flat neural tissue converges, with the epidermis forming a covering, the neural plate border forming neural crest cells, and the nueral tube formed by the folding

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56
Q

Neural crest cells?

A

Will migrate throughout the body and contribute to many structures, including peripheral nervous system

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57
Q

Neural tube forms?

A

CNS

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58
Q

Human CNS at 4 weeks?

A

Anterior end of neural tube specialized into 3 regions

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59
Q

Human CNS at 6 weeks

A

Neural tube differentiated into major brain regions present at birth

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60
Q

At 6 weeks, hind brain differentiates into?

A

Medulla, cerebellum, and pons

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61
Q

At 6 weeks, forebrain differentiates into?

A

Diencephalon and cerebrum

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62
Q

11 weeks into human CNS development

A

Growth of cerebrum much more rapid that of other regions

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63
Q

Human CNS at birth

A

Cerebrum covers most of other brain regions; convoluted surface due to rapid growth in confined space

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64
Q

Meninges in order from superficial to deep

A

Dura mater, arachnoid mater, pia mater

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65
Q

Protection and support for CNS?

A

Surrounded by bony cage, 3 layers of connective tissue, fluid between layers –CSF

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66
Q

CSF is secreted from?

A

Choroid plexus in the 3rd and 4th ventricle

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67
Q

How is CSF made?

A

Ependymal cells pump out ions, which draw water out of plasma, making CSF

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68
Q

Oligiodendrocytes

A

form myelin sheaths within CNS

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69
Q

microglia

A

immune cell lineage–phagocytic

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70
Q

astrocytes

A

regulate local extracellular fluid by releasing chemicals

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71
Q

ependymal cells

A

create barriers between compartments

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72
Q

How often is CSF recycled/flushed and how much is made per day?

A

4x per day and 500 mL

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73
Q

Compared to blood, CSF has

A

Lower K+, Ca2+, HCO3-, glucose, nad pH, similar Na+, and VERY LOW PROTEIN AND NO BLOOD CELLS

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74
Q

How is CSF reabsobred into venous blood?

A

arachnoid villi

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75
Q

Circulation of CSF?

A

Lateral ventricles, third ventricles, fourth ventricles, through Foramen of Magendie and Luschka to arachnoid villi to superior sagittal sinus/dural sinus, venous return to heart. At the fourth ventricle, some of the CSF is exchanged with the central canal of spinal cord…some also goes back into 4th ventricle here, too

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76
Q

How are tight junctions promoted in the CNS?

A

Astrocyte foot processes secrete paracrine factors that promote tight junction formation, which prevent solute movement between endothelial cells

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77
Q

What can readily cross the blood-brain barrier?

A

Lipid soluble molecules like ethanol

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78
Q

What types of substances will only cross the blood-brain barrier if specific transports/carriers are present on endothelial cells of capillaries within CNS?

A

Hydrophilic substances like ions, amino acids, peptides, and proteins

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79
Q

How is the blood-brain barrier important for phamacological practices?

A

Allows for the design of drugs that cannot or can cross the barrier, depending on what you want. Anti-histamine doesn’t cross, so doesn’t make you drowsy, but WANT l-dops to cross using an AA transporter to become dopamine for Parkinson’s disease

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80
Q

Can neurons use anaerobic metabolism?

A

NO…obligate aerobes

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81
Q

Can oxygen readily corss the blood-brain barrier?

A

YES!!

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82
Q

How much of the body’s glucose does the body consume, and how does it access it?

A

Consumes approximately half of body’s glucose consumption, and the capillaries of CNS express high levels of glucose transporters (GLUT-1)

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83
Q

How much of the CO goes to the brain to supply oxygen and glucose?

A

15%

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84
Q

Purpose of spinal cord?

A

Major path for information flow between CNS and skin, joints, muscles and contains neural networks involved in locomotion

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85
Q

4 regions of spinal cord?

A

Cervical, thoracic, lumbar, and sacral

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86
Q

Sympathetic neuron axons leave the spinal cord at what levels?

A

Thoracic and lumbar

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87
Q

Parasympathetic neurons’ axons leave the spinal cord at what levels?

A

Brain stem and sacral regions

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88
Q

Ascending and descending tracts consist of what type of matter?

A

WHITE matter (myelinates axons)

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89
Q

Dorsal columns are part of what tracts and purpose of them

A

Part of ascending tracts an send information of touch/pressure and proprioreception from the 4 regions

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90
Q

Spinocerebellar column is part of what type of tract and its purpose?

A

Ascending tracts and is used for proprioreception/posture/coordination

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91
Q

Spinothalamic column is part of what type of tract and its purpose?

A

Ascending tract and for pain/temperature

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92
Q

Corticospinal tracts are part are part of what type of tract and purpose?

A

DESCENDING tracts for for VOLUNTARY movement

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93
Q

Spinal reflex?

A

Stimulus. sensory information to spinal cord, integrating centre is an interneron, command to muscles/glands, response…Initiates response without input from the brain (but does send some sensory information there for perception)

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94
Q

Purpose of corpus callosum>

A

Axons that allow communication between sides of the brain

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95
Q

Parts of the diencephalon>

A

Thalamus, pineal gland, hypothalamus, and pituitary gland (:interbrain, in between brain)

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96
Q

What is the oldest, most primitive part of the brain?

A

Brainstem

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97
Q

Brain stem contains structures dervied from embryonic regions____?

A

Hind and midbrain

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98
Q

How many spinal nerves originate at brain stem?

A

11 OF 12

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99
Q

Cranial nerve x?

A

VAGUS nerve

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100
Q

Reticular formation is located where?

A

Brain stem

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101
Q

Purpose of reticular formation?

A

Diffuse network of neurons that is involved in processes such as arousal/slepp, muscle tone, coordination of breathing, and blood pressure

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102
Q

Function of gray matter in medulla?

A

Involved in control of many involuntary functions–blood pressure, breathing, swallowing, vomiting

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103
Q

Function of medulla’s white matter?

A

Ascending somatosensory tracts, descending corticospinal tracts, and site of decussation (crossing over) for most neurons in corticospinal tract

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104
Q

Diencephalon is located?

A

Between brain stem and cerebrum

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105
Q

Purpose of thalamus?

A

Relays and integrates sensory info from lower parts of CNS, ears, eyes, motor info from cerebellum

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106
Q

Purpose of hypothalmus?

A

Tiny region, but major centre for homeostasis–contains centres that drive behaviour related to hunger, satiety, thirst, and influences autonomic responses, and endocrine responses

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107
Q

Purpose of pineal gland?

A

Secretes hormone melaatonin–involved on circadian and seasonal rhythms

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108
Q

What’s a key differnce between a local/paracrine factor regulator and a hormone?

A

Local regulators diffuse to neighbour cells; hormones travel hroughout the body to distant target cells

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109
Q

In signal transducction, ligand binding to a cell surface receptor results in information transfer in for of _____ from upstream and downstream pathways?

A

Alterations in protein confirmation (phosphates and CA2+ change protein confirmation)

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110
Q

A 2nd messenger participates in signal transduction pathway by…

A

Relaying a message from inside of membrane to cytoplasm

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111
Q

Glucagon acts via a GPCR that acts by increasing levels of cyclic AMP. What is the 1st and 2nd messengers?

A

1st = glucagon, amplifier = adenyl cyclase, 2nd messenger = cAMP

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112
Q

Four lobes of brain?

A

Frontal, parietal, occipital, and temporal

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113
Q

How many hemispheres in brain?

A

2

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114
Q

FUrrow or groove in brain?

A

Sulcus (plural = sulci)

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115
Q

Convolution?

A

Gyrus

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116
Q

Three regions of cerebral gray matter?

A

Cerebral cortex, basal ganglia/nuclei, and limbic system

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117
Q

Purpose of basal ganglia/nuclei?

A

Motor coordinatoin

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118
Q

Purpose of cerebral cortex?

A

Outermost part of cerbrum, mostly higher brain functions

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119
Q

Purpose of limbic system?

A

Emotions

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120
Q

Functional areas of cerebal cortex?

A

Sensory areas that translate sensory input into perception (awareness), motor areas that control skeletal muscles, and association areas that integrate info from sensory and motor areas

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121
Q

Frontal lobe contains what?

A

Primary motor cortex, premotor cortex/motor association area, and the prefrontal association area

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122
Q

Parietal lobe contains?

A

Primary somatic sensory cortex and sensory association area that receives info from muscoskeletal system, visceral, and taste buds

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123
Q

Occipital love contains?

A

Visual association area and visual cortex

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124
Q

Temporal lobe contains?

A

Auditory cortex and auditory association area

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125
Q

Another name for primary motor cortex in frontal lobe?

A

Precentral gyrus

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126
Q

Another name for primary somatosensory cortex in parietal lobe?

A

Postcentral gyrus

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127
Q

Neural pathways extend from sensory areas to association areas to…?

A

integrate stimuli into perception

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128
Q

Small body parts with LOTS of control have what size on the somatotopic map?

A

Bigger area of the motorcortex, like face and hands

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129
Q

Places that have lots of sensation need what size in the somatosensory somatotopic map?

A

Big regions…like the lips and hands, but NOT the toes/libs

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130
Q

Scientist credited with hte burnty toast cure to epilepsy?

A

Wildred Penfield

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131
Q

Neural pathway for voluntary movement?

A

Primary motor cortex sends signal to contract. Signal is carried in the anterior corticospinal tract, where at the caudal end of the medulla, most of the corticospinal neurons cross to opposite sides of the body. Finally, the primary motomeuron crosses over at the bottom and synapses onto the somatic motor neuron which will synapse onto the skeletal muscle

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132
Q

The blood brain barrier…

A

consists of cerebral capillaries that are more tightly sealed than other capillaries in the body and involved a relationship between glial cells called astrocytes and endothelial cells of cerebral capillaries

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133
Q

The dorsal root ganglia contain…

A

Cell bodies of somatosensory neurons

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134
Q

How can the spinal cord act as an integrating centre with cc to brain?

A

Step on a tack…withdrawal reflex is a simple neural reflex, but crossed extensor reflex requires input from the brain

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135
Q

Examples of stimulus processing that occur consciously?

A

Vision, hearing, taste, smell, equilibrium, touch, temperature, pain, itch, proprioreception

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136
Q

Stimulus processing that occurs subconsciously?

A

Somatic stimuli (muscle length and tension and proprioreception) and visceral stimuli (blood pressure, distension of GI tract, blood glucose concentrations, internal body temperature, osmolarity of body fluids, ling inflation, pH of CSF, and pH and O2 of blood

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137
Q

Example of how a sensory pathway works

A

Stimulus (some form of physical energy) acts on a receptor. Receptor trasduces stimulus into intracellular signal (typically a change in membrane potential). If change in MP reaches threshhold, APs travel along afferent neuron for either subconscious processing or conscious processing in correct region in cortex

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138
Q

Sensory receptors for pain, touch, temp?

A

Free nerve endings…NO MYELIN

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139
Q

Sesory receptors for cutaneous touch?

A

Pacinian corpuscle…nerve endings enclosed in connective tissue capsules

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140
Q

Receptors for special senses?

A

Usually cells that release neurotrasnmitter onto sensory neurons…like hair cells

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141
Q

Chemoreceptors respond to? Examples?

A

Respond to chemicals…examples area O2, pH, carious organic molecules such as glucose

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142
Q

Mechanoreceptors?

A

Respond to pressure (baroreceptors), cell stretch (osmoreceptors), vibration, acceleration, sound

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143
Q

Photoreceptors respond to?

A

Pohtons of light

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144
Q

Thermoreceptors respnd to?

A

Varying degrees of heat and cold

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145
Q

Stimulus to a sensrry neuron usulally does what?

A

Opens or closes ion channels in receptor cell membrane directly or via a 2nd messenger…mostly open cation channels for hyperpolarization but sometimes open K+ channels for hyperpolrization

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146
Q

What are receptive fields?

A

Stimuli that fall within a certain area that activate cutaneous receptors (patch of skin) or photoreceptors (light falling on an area of the retina)

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147
Q

How many afferent neurons are needed in pathway to CNS?

A

2…first order/primary that is directly associated with stimuli and second order/secondary that relays information from first neuron

148
Q

Convergence of sensory info?

A

Several primary sensory neurons converge onto a secondary neuron, convergence allow for summation of multiple stimuli at hte secondary sensory neuron, making it more likely to reach AP. Perceived as one signl because the 2 separate points cannot be discriminated

149
Q

Smaller receptive fields results in?

A

The stimuli will activate separate pahteays to teh brain and the two points are perceived as distinct stimuli

150
Q

Visceral sensory info mostly travels via what?

A

Vagus nerve fibres

151
Q

Visceral sensory info is integrated where?

A

Brainstem…usually subconscious, although fullness and pain can reach consciousness

152
Q

Olfactory info is sent?

A

Directly to the olfactory cortex/bulb

153
Q

Equilibrium sensory info is usually sent?

A

To the cerebellum

154
Q

Somatic senses, hearing and vision sent to?

A

Appopriate cortex after processing in thalamus

155
Q

How can brain distinguish different sensations if all APs are identical?

A

CNS must be able to decode the type of stimulus/modality, location, intensity, and duration

156
Q

How is sensory modality determined in brain?

A

Determined by the type of neuron activated and where the pathway terminates in brain

157
Q

How is location of stimulus decoded in brain?

A

Coded according to which receptive fields are activated. Example, touch receptors from a particular part of body project to a specific location in somatosensory cortex.

158
Q

What is lateral inhibition, and how does it work?

A

Primary neuron response is proportional to stimulus strength. Pathway closest to the stimulus uses branches from its secondary neuron to inhibit its neighbours. Inhibition of lateral neurons enhances pereption of stimulus onto tertiary neuron, making the sensation more easily localized.

159
Q

How is stimulus intensity coded for?

A
  1. number of receptors activated (populartion coding) 2. Frequency of APs coming from individual receptor cells
160
Q

How does the number of receptors activated code for stimulus intensity?

A

Different thresholds for stimulation among group of receptors. With low intensity stimulus, most sensitive (lowest threshold) receptors recruited first. As stimulus intensifies, more receptors activated.

161
Q

How do the frequency of APs code for stimulus intensity?

A

Frequency of APs increases with stimulus intensity, up to maximum that the axon can transmit. More intense = higher frequency AP

162
Q

How is a long, strong stimulus coded for?

A

Lots of receptors potentials for a long duration of time are integrated at trigger zone. Then, the frequency of APs is proportional to stimulus intensity. Duration of a series of APs is proportional to stimulus duration. NT release varies with pattern of APs arriving at axon terminal

163
Q

Tonic receptors?

A

Slowly adapt, and respond throughout stimulus. Fire rapidly when first activated, and then slow and maintain their firing as long as the stimulus is present. In general, the stimuli that activate tonic receptors must be monitored continuously by the body, like blood pressure.

164
Q

Phasic receptors?

A

Rapidly respond to a stimulus and then turn off if stimulus remains constant. Like smelling cologne at first, but then the smell goes away.

165
Q

Pain, temp., and coarse touch cross where in the spinal cord and ascend in what tracts?

A

Cross midline in spinal cord and ascend via dorsal columns

166
Q

Fine touch, vibration, and proprioreception cross midline where, and ascend in what tracts?

A

Corss in medulla and ascend in spinothalamic tracts

167
Q

Cutaneous sensory receptors that are just free nerve endings serve what purpose?

A

Pain, temperature, and hair movement

168
Q

Where are free nerve endings for cutaneous sensation located?

A

Various places, including wrapped around hair root and as nocireceptors

169
Q

Merkel disk receptive field, location, adaptation, and function?

A

Small, superficial, slow, and for sustained touch/pressure, texture

170
Q

Meissner’s corpuscle receptive field, location, adaptation, and function?

A

Small, superficial, fast, for beginning and end of fine touch/pressure

171
Q

Ruffini corpuscle receptive field, location, adaptation, and function?

A

Large, deep, slow, and for sustained gross touch/vibration

172
Q

Pacinian corpuscle receptive field, location, adaptation, and function?

A

Large, deep, fast, for beginning and end of gross touch/vibration

173
Q

Where are nocireceptors found?

A

In many tissues (not just skin)

174
Q

What is pain?

A

A sensation rather than a stimulus

175
Q

Nocireception is mediated by?

A

Free nerve endings that express ion channels that respond to a variety of strong stimuli (chemical/mechanical/thermal)

176
Q

Pain is mediated by a release of what local chemicals, and what do they do?

A

K+, histamine, prostaglandins, serotonin, and substance P. Wither directly activate nocireceptors or sensitize them by lowering their thresholds (inflammatory pain)

177
Q

Pain is mediated by what type of channels?

A

Transient Receptor Potential Channels

178
Q

What are Transient Receptor Potential Channels?

A

Expressed on the membranes of many different cells and mediate a cariety of sensations including pain, heat/warmth, cold, some tastes, pressure, vision, osmotic pressure, stretch…

179
Q

What type of channels are TRP channels?

A

Relatively non-selective cation channels (Na, Ca, Mg)

180
Q

TRP V (vanilloid) receptors respond to?

A

Temperature (receptor subtypes have different ranges), pepper, allicin/garlin, clove oil, thyme, oregano, wasabi, menthol, and peppermint

181
Q

Pathways for somatic pain?

A

Spinal reflexes and ascending pathways to cerebral cortex (info also sent to limbic system and hypothalamus, leading to emotional reactions and autonomic responses like nausea, vomiting, and sweating)

182
Q

Fibre type for fast pain?

A

Delta fibres…small, myelinated

183
Q

Fibre type for slow pain?

A

C fibres…small unmyelinated

184
Q

How does visceral/referred pain work?

A

Pain from viscera synapses onto sane 2nd order neuron as a part of skin, so brain cannot distinguish between the skin and viscera, so you feel pain in the area of skin, not the viscera where the pain is originating from

185
Q

Most primitive sense?

A

Olfaction

186
Q

Olfactory pathway?

A

Olfactory receptor cell (primary neuron) in olfactory epithelium, to Cranial Nerve 1, to secondary neuron on olfactory bulb, to the olfactory tract, to olfactory cortex in temporal lobe

187
Q

Non-motile cilia on olfactory receptor neuron acts as?

A

Dendrites for odorant receptors

188
Q

Olfactory Receptor Neurons are what tpe of neurons?

A

Bipolar neurons

189
Q

Axons of olfactor receptor neurons go through?

A

Gaps in cribiform plate

190
Q

How many types of odorant receptors does an olfactory receptor neuron expresss?

A

1

191
Q

Odarant receptors are?

A

GPCRs and form one of the largest gene families in vertebrates (3-5% genome)

192
Q

How is a particular odor interpreted?

A

Input from 100s of olfactory neurons in combinations

193
Q

5 BASIC TASTES?

A

Sweet (carbs…energy?), sour (H+), salty (Na+), bitter (many compounds…warning of possible toxicity), and umami (glutamate, some nucleotides…protein?)

194
Q

Taste receptors cells are?

A

Non-neural epithelial cells that frequently come into contact with nocious chemicals, and they are replaced approximately every 10 days

195
Q

What tastes release ATP onto primary afferent neurons?

A

Sweet, Umami, and Bitter

196
Q

How do bitter taste buds transmit information to primary afferent neurons?

A

Release NT

197
Q

Taste transduction for sweet, umami, or bitter

A

Ligands activate TRC, various intracellular pathways activated, Ca2+ signals triggers ATP formation, ATP released, Primary sensory neuron fires and APs sent to brain

198
Q

Taste transduction of Sour?

A

Ligand activates TRC, various intracellular pathways activated, Ca2+ signal triggers exocytosis of NT, NT is released, primary sensor neuron fires, and AP sent to brain

199
Q

Sweet, umami, and bitter ligands are believed to bind to?

A

GPCRs

200
Q

Taste sensory pathway?

A

Presynaptic taste cell, primary sensory neuron through cranial nerves, medulla (synapse with secondary neuron), thalamux, gustatory cortex in parietal lobe.

201
Q

Low=frequency waves translate to?

A

Low-pitched sounds

202
Q

High-frequency waves translate to?

A

High-pitched sound

203
Q

Amplitude of sound wave determines?

A

Loudness

204
Q

Sound transduction?

A

Sound swaves striking outer ear are directed down the ear canal until they hit the tympanic membrane and cause it to vibrate (1st transduction) Tympanic vibrations are transferred to the malleus, incus, and the stapes. Stapes’ vibration pulls and pushes on the oval window to create waves in the fluid-filled cochlea (2nd transduction). As waves move through the cochlea, they push on flexible membranes of the cochlear duct and bend sensory hair cells inside the duct. Movement of cochlear duct open or closes ion channels on hair cell membranes, creating electrical signals (3rd transduction) Electrical signals alter NT release (4th transduction) NT binding to primary sensory neurons initiates AP (5th transduction) that send coded information about sound through cranial nerve and brain

205
Q

3 fluid-filled channels of cochlea?

A

Vesitbular, cochlear, and tympanic duct

206
Q

What 2 ducts on the cochlea are continuous?

A

Vestibular and tympanic. Cochlear duct is a dead-end tube that connects with the vestibular apparatus

207
Q

Perilymph?

A

Fluid in vestibular and tympanic ducts. Similar to plasma (high Na+, low K+)

208
Q

Endolymph?

A

Fluid in cochlear duct. Similar to intracellular fluid (low Na+ and high K+)

209
Q

Organ of Corti?

A

Found in the cochlear ductm composed of hair cell receptors and support cells. Sits on the basilar membrane and is partially covered by the tectorial membrane

210
Q

Signal transduction in hair cells for hearing?

A

In neutral position, tonic rate of APs are sent, MP about -30mV. Waves deflect cilia towards tallest members of bundle, more channels open nd cation ion entry depolarizes the cell. When the tectorial membrane pushesthe cilia away from the tallest members, channels close, and less cation entry hypoerpolarizes cell.

211
Q

Sensory coding for pitch in cochlea?

A

Higher frequencies near oval window, and lower frequencies further from oval window.

212
Q

How is loudness coded for?

A

How much the hair cells bend = increase the rate of APs = more frequent AP = louder noise

213
Q

Auditory pathway?

A

Cochlear nerve, cochlear nuclei in medulla, secondary neurons on pons, nuclei in midbrain and thalamuc before projecting to auditory cortex in temporal lobes. Collateral pathways take info to the reticular formation and the cerebellum

214
Q

Conductive hearing loss?

A

No transmission through either external or middle ear, issues with earwax or fluid, can usually be repaired

215
Q

Central hearing loss?

A

Damage to neural pathway between ear and cerebral cortex or damage to cortex itself (stroke)…uncommon

216
Q

Sensorineural hearing loss?

A

Damage to structures of inner ear/death of hair cells due to loud noises, common in young and old. Hair cells cannot be replaced in mammals

217
Q

Dynamic component of equilibrium?

A

Movement of body through space

218
Q

Static component of equilibrium?

A

Position of head

219
Q

Otolith orgrans?

A

Utricle and saccule, for linear acceleration and head position

220
Q

Semicircular canals?

A

Rotational acceleration

221
Q

Hair cells of semicircular canals are grouped in?

A

Cristae, within ampulla of canals

222
Q

Cupula?

A

Like the tectonic membrane in hearing, a gelatinous mass that embeds hair cells.

223
Q

Utricle for?

A

Forward/backward acceleration. Head tilt. Riding in a car

224
Q

Saccule for?

A

Vertical displacement…elevator

225
Q

How do otolith organs sense linear acceleration and head positioN?

A

Hair cells grouped in maculae, within utricles nad saccules. Otoliths move, the gelatinous otolith membrane slides with them, bending the hair cell cilia and setting off a signal

226
Q

Afferent fibres that transmit info about a dull ache in your arm are most likely…

A

Small diamter, unmyelinated (C fibres)

227
Q

Afferent neurons for fast pain?

A

Small, myelinated…delta fibres

228
Q

Heat afferent fibres?

A

Small diamter, unmyelinated

229
Q

You’ve stepped on a tack with your bare left foot. What type of receptor would detect this?

A

Free nerve endings

230
Q

Pathway for stepping on a tack?

A

Spinal nerve, dorsal horn gray matter, spinothalamic tract, thalamus, somatosensory cortex

231
Q

Temperature, pain, and course touch sent via what tract?

A

Spinothalamic

232
Q

Fine touch, proprioreception, and vibration sent via what tract?

A

Dorsal columns

233
Q

You’re snow blowing. The ____ cutaneous receptors that are stimulated by vibration?

A

Pacinian (beginning and end) and Ruffini (sustained)

234
Q

The cutaneous receptors that’d be used for Braille would have _______ receptive fields and ascend to the brain via the _________

A

small, dorsal columns

235
Q

Neural pathway for equilibrium?

A

Vestibular hair cells release NT onto primary sensory neurons of the vestibular nerve. Those sensory neurons either synapse in the vestibular nuclei of the medulla or run without synapsing to the cerebellum, which is the primary site for equilibrium processing. Collateral pathways run from the medulla to the cerebellum or upward through the reticular formation and the thalamus.

236
Q

Purpose of canal of Schlemm?

A

Collects aqueous humour and recycles it to the bloodstream. If blocked, there is an increase in intraeye pressure, which can lead to glaucoma

237
Q

What is the optic disk?

A

Region where optic nerve and blood vessels leave the eye

238
Q

Neural pathways for vision?

A

Optic nerve, optic chiasm, optic tract, thalamic relay, visual cortex (occipital lobe)

239
Q

What is the pupillary light reflex?

A

Control of pupil diameter according to intensity of light

240
Q

Autonomic pupillary light reflex pathway?

A

Detector: photoreceptors in retina. Afferent: afferent neurons travelling in optic nerve Integrating Centre: Thalamus/brainstem (midbrain). Efferent: motor neurons travelling in oculomotor nerve. Effectors: Smooth muscles regulating pupil diameter–circular/sphincter = constriction (parasympathetic) and radial = dilation/sympathetic

241
Q

Reflex that dilates the pupil is?

A

Sympathetic…radial muscles

242
Q

Reflex that constricts the pupil?

A

Parasympathetic…sphincter/circular muscles

243
Q

If light is shined in the left eye, what happens to the left and right pupils? Why?

A

Both will constrict…consensual reflex because of the crossing over of info in the midbrain

244
Q

What is phototransduction?

A

Conversion of light into changes in membrane potential by photoreceptor cells in retina

245
Q

3 types of photoreceptors?

A

Rods–monochromatic vision/low light
Cones–colours (red, green, blue)
Modified ganglion cells–mediate pupillary light reflex and circadian/seasonal rhythms (non-visual responses to light)

246
Q

Purpose of pigment epithelium?

A

Absorbs excess light

247
Q

Cellular organization of the retina?

A

Cone/rod to bipolar cell to ganglion cell, whose axons form the optic nerve

248
Q

What makes the fovea’s cellular organization different than the rest of the retina’s?

A

Cones receive light directly because the intervening neurons (ganglion and bipolar) are pushed aside. The fovea is also free of blood vessels.

249
Q

Convergence in the retina onto rods serves what purpose?

A

The high degree of convergence of rods onto ganglion cells increases the visual field of the rods, allowing for increased sensitivity to low light. Rods aren’t for fine reading or colour (can’t see colour in low light).

250
Q

Purpose of cones?

A

Colour and fine light/reading

251
Q

What is rhodopsin is composed of what 2 molecules?

A

Opsin, a protein embedded in the membrane of the rod disks and retinal, the light absorbing of the pigment

252
Q

When retinal absorbs light, what happens?

A

The orientation of the double bond flips, allowing retinal to leave opsin (opsin bleaching)

253
Q

Signal transduction in photoreceptor cells in the dark?

A

Rhodopsin is inactive cGMP is high, CNG and K+ channels open (Na+ and Ca2+ entering cell), membrane potential is around -40 mV, and there is a tonic release of glutamate onto bipolar neurons

254
Q

Signal transduction in photoreceptor cells in light conditions?

A

Activated opsin (retinal leaves, opsin bleaching), active transducin, decreased levels of cGMP, closes CNG channels, cell hyperpolarized, and glutamate release decreases in proportion to amount of light onto bipolar neurons.

255
Q

Recovery phase in photoreceptor cells?

A

Retinal converted to inactive form in pigment epithelium cell, and then recombines with opsin to form rhodopsin

256
Q

Sweet tastes are detected when…

A

Sugars bind to GPCR expressed by taste receptor cells and intiate a signal transduction cascade leading to Ca2+ influx and release of signal molecule (ATP) that binds to a primary afferent neuron

257
Q

The olfactory bulb is…

A

the structure in which secondary neurons that have recieved a neural input from olfactory receptor neurons continue on to the olfactory cortex as the olfactory tract (CN1) NO THALAMIC RELAY!!

258
Q

The most direct initiator of the pressure wave with in the perilymph of vestibular duct is…

A

vibration of oval window

259
Q

How does the pressure wave in the vestibular duct fluid get transduced into stimulation of cochlear hair cells?

A

Fluid wave pushes on tectorial mebrane, bending cilia embedded in it. Bending of cilia as a result of the fluid waves causes opening or closing of ion channels, a change in NT release and a change in AP frequency to primary afferent neuron

260
Q

Perceived pitch determined by…

A

location of activated hair cells on basilar membrane

261
Q

Perceived volume determined by…

A

frequency of AP to brain

262
Q

What is a hormone?

A

Chemical messenger secreted into the blood by specialized cells

263
Q

What tpyoe of long-term/ on going things do hormones regulate?

A

Growth/development, metabolism, regulation of internal environment (temp, water balance, ions), reproduction

264
Q

Hormones act on target cells by regulating…

A

Enzyme activity, ion transport across a membrane, and gene expression to protein synthesis

265
Q

Endogenous means?

A

Generated from within the body (insulin from beta cells in pancreas)

266
Q

Exogenous means?

A

Generated from outside the body (recombinant insulin)

267
Q

What were the first endocrinology experiments, and who performed them?

A

Arnold Berthold did experiments on removing chickens’ gonads.

268
Q

Classical approaches in experimental endocrinology?

A

Ablate (remove the suspected gland), replace (gland or extract of gland), create a situation of excess, and run biological assats on intact animals and cell/tissue cultures, and introduce putative hormone

269
Q

Features of Typical Classical Hormones?

A
  1. Secreted by a group of cells derived from epithelial tissue that form discrete glands 2. Secreted into blood 3. Travel to distance targets 4. Act at very low concentrations
270
Q

Exception to the typical hormones?

A

Non-classic hotmones are not secreted by identifiable glands (endocrine cells of gut, neurons, and immune cells), some molecules clearly identified as hormones are also secreted in CNS, and act as NT, and sometimes hormones act locally (testosterone doing maintenance work in testes)

271
Q

Exocrine gland?

A

Secrete out via ducts…still in contact with epithelium

272
Q

Endocrine gland?

A

Dump into capillaries…no contact with surface

273
Q

Ways that equilibrium between free and bound hormone?

A
  1. Hormones are inactivated on their way through liver/kidney (major determinant of hormone’s half life) 2. Nonspecific proteases in ECF break them down (peptidases) 3. Hormone-receptor complex can be internalized (endocytosis)
274
Q

3 ways to classify hormones?

A

Source, mechanism of action, and chemistry

275
Q

Mechanisms of hormones?

A

GPCR, receptor tyrosine-kinases, and intracellular receptors

276
Q

3 types of hormones?

A

Peptide/protein, steroids (derived from cholesterol), and amine/amino acid (derived from either tyrosine or tryphtophan)

277
Q

Largest group of hormones?

A

Peptide/protein hormones

278
Q

Half-life of peptide/protein hormones?

A

A few minutes…sustained responses require continuous release of hormone

279
Q

Typical responses to peptide hormones?

A

Bind to membrane receptors, responses usually rapid (modifying existing enzymes or transport proteins and opening/closing membrane channels), can also have slower effects via changes in gene expression

280
Q

Peptide hormone synthesis and secretion?

A
  1. Product of ribosome is preprohormone (large inactive precursor) 2. Signal sequence directs it to rough ER’s lumen 3. Cleaved into prohormone as it moves through ER/golgi 4. Packaged into vesicles in Golgi, along with enzymes that will carry out cleavage to final active form
281
Q

3 signal transducction pathways for peptide hormones?

A

Receptor/second messengers, Receptor/Tyrosine kinase, or G-protein coupled ion channel opening

282
Q

The perceived volume of a sound is determined by…

A

the frequency of AP sent by primary afferent neuron and the amount of NT released by sensory hair cell

283
Q

The vertebrate retina is said to be “inverted” because…

A

Photoreceptors cells are at back of retina, furthest from light entering the eye, with their light sensing end facing away from entering light

284
Q

Aps are generated in what cells during vision?

A

Ganglion cells (local potentials in rods/cones and bipolar cells)

285
Q

The visual fields of the fovea are…

A

very small

286
Q

Would a person with occipital lobe trauma have a normal pupillary light reflex in both eye?

A

YES! Because of crossing over in midbrain.

287
Q

Steroid hormones are made in what cells?

A

Cells that express cholesterol side chain cleavage enzyme…the adrenal cortex, gonads and placenta

288
Q

Half life of steroid hormones is usually?

A

1/2 hour to hours to days because they are chemically stable, simple molecules

289
Q

Steroid synthesis and release?

A

Cholesterol imported into cell or synthesized in cell. Steroidogenic enzymes in inner mitochondrial membrane or smooth ER determines which steroid the cell makes

290
Q

Are steroids stored?

A

No, made on demand by increasing activity of enzymes. Released from cell by simple diffusion.

291
Q

How do steroid hormones circulate in the body?

A

Ciruclate bound to proteins, either pecific carriers or albumin

292
Q

Equilibrium equation for steroid hormones?

A

Bound to carrier protein free bound to receptor

293
Q

Steroid hormones in testes?

A

Testosterone (DHT)

294
Q

Steroid hormones in ovaries?

A

Estradiol and progesterone

295
Q

Steroid hormones in adrenal cortex?

A

Cortisol (glucocorticoid), aldosterone (mineralocorticoid)

296
Q

Steroid hormone action?

A
  1. Most steroids circulate bound to protein carriers. Only unbound hormones can diffuse into cell. 2. Classic steroid receptors are in cytoplasm or nucleus. 3. Receptor-hormone complex binds to DNA and activates or represses expression of particular genes. 4. Genes transcribed to mRNA that moves out to cytoplasm 5. Translation produces new proteins
297
Q

Steroid receptor proteins are?

A

Ligand activated transcription factors

298
Q

Transcription factors activated by steroids bind to?

A

Steroid response elements (regulatory sequences upstream of particular genes) New proteins are typically other transcription factors…

299
Q

Amine hormones are derived from what AAs?

A

Tryptophan and tyrosine

300
Q

What are the tyrosine-derived hormones?

A

Catecholamines and thryroid hormones

301
Q

What are the catecholamines?

A

Dopamine, norepinephrine, and epinephrine

302
Q

What are the thyroid hormones?

A

Thyoxine and triiodothyonine (need iodine)

303
Q

What is the purpose of the adrenal medulla?

A

It is a specialized group of neurons that secrete epinephrine (neurohormone) from the chromaffin cells in adrenal medulla (analogous to postganlionic sympathetic neurons)

304
Q

In the endocrine system, what does hte hypothalamus do?

A

Produces neurohormones that are stored in, and secrete by posterior pituitary gland, and produces neurohormones that control release of hormones from anterior pituitary gland

305
Q

Posterior pituitary gland made from?

A

Neural tissue (pars nervosa/neurohypophysis) NOT A TRUE GLAND

306
Q

Anterior pituitary gland made from?

A

Rathke’s puch…adenohypophysis/pars distalis…TRUE gland

307
Q

Pathway in posterior pituitary gland??

A
  1. Neurohormone is made and packaged in neuron cell body in hypothalamus 2. Vesicles are transported down axon 3. Vesicles containing neurohormone are stored in posterior pituitary 4. Posterior pituitary releases neurohormone into blood
308
Q

Hormones of posterior pituitary gland?

A

Oxytocin and vasopressin

309
Q

Anterior pituitary gland pathway?

A
  1. Neurons synthesizing neurohormones in hypothalamus release them into first capillary bed of portal system 2. Portal veins carry neurohormones directly to second capillary bed into anterior pituitary gland 3. Endocrine cells in anterior pituitary releae peptide hormones into second set of capillaries, and peptides exit via venous drainage.
310
Q

Hypothalaminc hormones?

A

Dopamine, thyro-tropin releasing hormone, corticotropin releasing hormone, somatostatin (negative), Growth-hormone releasing hormone, gonadotropin releasing hormone

311
Q

Anterior pituitary hormones?

A

Prolactin, thyroid-stimulating hormone, adrenocorticotropic hormone, growth hormone, follicle-stimulating hormone, luteinzing hormone

312
Q

Feedback loop of hypothalamus-pituitary axis involve what 3 integrating centres?

A

Hypothalamus, anterior pituitary, and endocrine target of pituitary hormone

313
Q

In a feedback loop of the hypothalamus-pituitary axis, what are the feedback signals?

A

The hormones themselves

314
Q

Long loop feedback in hypothalamic pituitary axis?

A

Hormone acting on the anterior pituitary and/or hypothalamus

315
Q

Short loop feeback of hypothalamic-pituitary axis?

A

Trophic hormones acts on hypothalamus

316
Q

What is a trophic hormone?

A

A hormone that controls the secretion of another hormone and nourishes the target cell

317
Q

Synergism in hormones?

A

Combined effect is greater than the sum of individual effects

318
Q

Example of synergism in the endocrine system?

A

Glucagon + epipnephrine + cortisol = huge effect on blood glucose

319
Q

Permissiveness in endocrine system?

A

Hormone is required but is not enough for full effect.

320
Q

Example of permissiveness in endocrine system?

A

Puberty cannot occur unless thyroid and reproductive hormone are available

321
Q

Antagonism in endocrine system?

A

One hormone opposes the action of another

322
Q

Types of endocrine pathologies?

A

Excess/hypersecretion, deficiencieshyposecretion, or abnormal responsiveness of target tissues

323
Q

Oxytocin, a peptide, is released by neuron terminals in the posterior pituitary gland enters the blood stream and acts on uterine smooth muscle. This substane would be classified as…

A

A hormone and neurohormone

324
Q

Acinar cells of the pancreas secrete proteins into the lumen of the small intestine in response to PNS stimulation. These proteins would be considered…

A

Exocrine secretions

325
Q

Endocrine cells producing large amounts of peptide hormone would have?

A

Lots of rough ER and vesicles containing hormone product near plasma membrane

326
Q

Endocrine cells producing steroid hormone would have?

A

LOTS of SMOOTH ER

327
Q

Steroid hormones are made in what cells?

A

Cells that express cholesterol side chain cleavage enzyme…the adrenal cortex, gonads and placenta

328
Q

Half life of steroid hormones is usually?

A

1/2 hour to hours to days because they are chemically stable, simple molecules

329
Q

Steroid synthesis and release?

A

Cholesterol imported into cell or synthesized in cell. Steroidogenic enzymes in inner mitochondrial membrane or smooth ER determines which steroid the cell makes

330
Q

Are steroids stored?

A

No, made on demand by increasing activity of enzymes. Released from cell by simple diffusion.

331
Q

How do steroid hormones circulate in the body?

A

Ciruclate bound to proteins, either pecific carriers or albumin

332
Q

Equilibrium equation for steroid hormones?

A

Bound to carrier protein free bound to receptor

333
Q

Steroid hormones in testes?

A

Testosterone (DHT)

334
Q

Steroid hormones in ovaries?

A

Estradiol and progesterone

335
Q

Steroid hormones in adrenal cortex?

A

Cortisol (glucocorticoid), aldosterone (mineralocorticoid)

336
Q

Steroid hormone action?

A
  1. Most steroids circulate bound to protein carriers. Only unbound hormones can diffuse into cell. 2. Classic steroid receptors are in cytoplasm or nucleus. 3. Receptor-hormone complex binds to DNA and activates or represses expression of particular genes. 4. Genes transcribed to mRNA that moves out to cytoplasm 5. Translation produces new proteins
337
Q

Steroid receptor proteins are?

A

Ligand activated transcription factors

338
Q

Transcription factors activated by steroids bind to?

A

Steroid response elements (regulatory sequences upstream of particular genes) New proteins are typically other transcription factors…

339
Q

Amine hormones are derived from what AAs?

A

Tryptophan and tyrosine

340
Q

What are the tyrosine-derived hormones?

A

Catecholamines and thryroid hormones

341
Q

What are the catecholamines?

A

Dopamine, norepinephrine, and epinephrine

342
Q

What are the thyroid hormones?

A

Thyoxine and triiodothyonine (need iodine)

343
Q

What is the purpose of the adrenal medulla?

A

It is a specialized group of neurons that secrete epinephrine (neurohormone) from the chromaffin cells in adrenal medulla (analogous to postganlionic sympathetic neurons)

344
Q

In the endocrine system, what does hte hypothalamus do?

A

Produces neurohormones that are stored in, and secrete by posterior pituitary gland, and produces neurohormones that control release of hormones from anterior pituitary gland

345
Q

Posterior pituitary gland made from?

A

Neural tissue (pars nervosa/neurohypophysis) NOT A TRUE GLAND

346
Q

Anterior pituitary gland made from?

A

Rathke’s puch…adenohypophysis/pars distalis…TRUE gland

347
Q

Pathway in posterior pituitary gland??

A
  1. Neurohormone is made and packaged in neuron cell body in hypothalamus 2. Vesicles are transported down axon 3. Vesicles containing neurohormone are stored in posterior pituitary 4. Posterior pituitary releases neurohormone into blood
348
Q

Hormones of posterior pituitary gland?

A

Oxytocin and vasopressin

349
Q

Anterior pituitary gland pathway?

A
  1. Neurons synthesizing neurohormones in hypothalamus release them into first capillary bed of portal system 2. Portal veins carry neurohormones directly to second capillary bed into anterior pituitary gland 3. Endocrine cells in anterior pituitary releae peptide hormones into second set of capillaries, and peptides exit via venous drainage.
350
Q

Hypothalaminc hormones?

A

Dopamine, thyro-tropin releasing hormone, corticotropin releasing hormone, somatostatin (negative), Growth-hormone releasing hormone, gonadotropin releasing hormone

351
Q

Anterior pituitary hormones?

A

Prolactin, thyroid-stimulating hormone, adrenocorticotropic hormone, growth hormone, follicle-stimulating hormone, luteinzing hormone

352
Q

Feedback loop of hypothalamus-pituitary axis involve what 3 integrating centres?

A

Hypothalamus, anterior pituitary, and endocrine target of pituitary hormone

353
Q

In a feedback loop of the hypothalamus-pituitary axis, what are the feedback signals?

A

The hormones themselves

354
Q

Long loop feedback in hypothalamic pituitary axis?

A

Hormone acting on the anterior pituitary and/or hypothalamus

355
Q

Short loop feeback of hypothalamic-pituitary axis?

A

Trophic hormones acts on hypothalamus

356
Q

What is a trophic hormone?

A

A hormone that controls the secretion of another hormone and nourishes the target cell

357
Q

Synergism in hormones?

A

Combined effect is greater than the sum of individual effects

358
Q

Example of synergism in the endocrine system?

A

Glucagon + epipnephrine + cortisol = huge effect on blood glucose

359
Q

Permissiveness in endocrine system?

A

Hormone is required but is not enough for full effect.

360
Q

Example of permissiveness in endocrine system?

A

Puberty cannot occur unless thyroid and reproductive hormone are available

361
Q

Antagonism in endocrine system?

A

One hormone opposes the action of another

362
Q

Types of endocrine pathologies?

A

Excess/hypersecretion, deficiencieshyposecretion, or abnormal responsiveness of target tissues

363
Q

Oxytocin, a peptide, is released by neuron terminals in the posterior pituitary gland enters the blood stream and acts on uterine smooth muscle. This substane would be classified as…

A

A hormone and neurohormone

364
Q

Acinar cells of the pancreas secrete proteins into the lumen of the small intestine in response to PNS stimulation. These proteins would be considered…

A

Exocrine secretions

365
Q

Endocrine cells producing large amounts of peptide hormone would have?

A

Lots of rough ER and vesicles containing hormone product near plasma membrane

366
Q

Endocrine cells producing steroid hormone would have?

A

LOTS of SMOOTH ER

Physiology 2 (16 decks)

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