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Animal Physiology > Animal Physiology Exam 1 > Flashcards

Animal Physiology Exam 1 Flashcards

1
Q

Animal Physiology

A

Integrated study of how biological systems work; Integrates knowledge from all levels of biological organization; Integrates multiple disciplines like biology, chemistry, physics, and evolution

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2
Q

Levels of Biological Organization

A

atoms, molecules, organelles, cells, tissues, organs, organ systems, organisms

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3
Q

Core of Anatomical Wheel

A

Nervous and Endocrine System

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4
Q

Outside of Anatomical Wheel; Connects everything

A

Bloodstream

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5
Q

Other components of Anatomical Wheel

A

Renal, Cardiovascular, Skeletal muscle, Respiration, Digestion

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6
Q

Two Main Questions in Animal Physiology

A
  1. What is the mechanism by which a function is accomplished?
  2. What is the origin of that function?
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7
Q

Mechanism

A

Components of living organisms that enable animals to perform

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8
Q

Origin

A

The evolutionary process that conspired to produce a mechanism; The evolutionary significance of mechanisms; Natural selection is the key process of evolutionary origin

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9
Q

Natural Selection

A

Increase in frequency of genes that produce phenotypes that raise the likelihood that animals will survive and reproduce

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10
Q

Adaptation

A

Traits (or physiological mechanisms) that are products of evolution by natural selection

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11
Q

Modes of Natural Selection

A

Directional, Stabilizing, Disruptive

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12
Q

Directional Selection

A

Selection favors one of the extreme phenotypes; Mean shifts but the SD/Variance stays the same

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13
Q

Stabilizing Selection

A

Selection favors the intermediate phenotype; SD/variance changes but the mean stays the same

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14
Q

Disruptive Selection

A

Bimodal; Selection favors the two extreme phenotypes

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15
Q

What indicates modes of natural selection?

A

Changes in mean and/or SD

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16
Q

Cells in the internal environment respond to

A

the external environment to maintain suitable conditions

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17
Q

Conformer

A

Internal and external conditions are relatively equal (change with each other)

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18
Q

Conformer Benefits

A

Use less energy

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19
Q

Conformer Costs

A

Less habitats are suitable for life; lack of optimal functionality

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20
Q

Regulator

A

Maintains internal constancy regardless of external conditions

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21
Q

Regulator Benefites

A

Can survive in extreme conditions; More viable habitat options

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22
Q

Regulators Costs

A

Uses more energy

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23
Q

Salmon Migration

A

They show temperature conformity when entering a river from the sea. Their body temp changes if the river temp is different than the ocean. They show chloride regulation. The maintain a constant chloride concentrations regardless of the dilute Cl- concentration in the river and high Cl- concentration in the ocean.

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24
Q

Physiological regulation implies that

A

function occurs best over a specified range of conditions

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25
Q

Claude Bernard

A

Studied blood glucose levels; 1st to recognize that stability of conditions humans maintain in their blood

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26
Q

Walter Cannon

A

“Internal Constancy” (Homeostasis); Meaning there is internal stability AND regulatory mechanisms to make adjustments to maintain stability

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27
Q

Homeostasis

A

Coordinated physiological process which maintain most of the constant states in an organism; Homeostasis is dynamic

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28
Q

Walter Cannon 3 Postulates

A
  1. The nervous system preserves the normal conditioning of the body
  2. The tonic activity of a system can be modulated up and down
  3. There are factors that have opposing effects = antagonistic controls
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29
Q

Hormone

A

Endocrine System

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30
Q

Nerves

A

Nervous System

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31
Q

Negative Feedback Loop

A

An upstream product or signal of a pathway inhibits and earlier step in the same pathway (Ex: Blood Glucose Control)

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32
Q

Positive Feedback Loop

A

An upstream stimulus amplifies an earlier response (Ex: Oxytocin)

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33
Q

Physiological Timescales

A

Time frames in which physiology changes

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34
Q

Response to external environments

A

Physiological trait changes in response to the external environment; Acute, Chronic, Evolutionary

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35
Q

Changes in Individuals (Often reversible)

A

Acute and Chronic

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36
Q

Changes in populations (Irreversible)

A

Evolutionary

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37
Q

Acute

A

Immediate response; Ectotherm response to temp

Ex: First exposure to hot environment = lower level of energy and endurance

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38
Q

Chronic

A

Response after long term exposure; Organism experiences an environment for a long period (seasonal changes/variation); Phenotypic plasticity (acclimation (lab) and acclimatization(nature))

Ex: High elevation for a week = increased hemotacrit –> increase in O2 binding affinity

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39
Q

Evolutionary

A

Longest time scale; Natural selection; Occurs in populations across generations; Adaptations; Irreversible changes in genotype and phenotype

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40
Q

Physics and Chemistry

A
  1. Physical properties are linked to function
  2. Chemical laws govern molecular interactions
  3. Electrical laws describe membrane function
  4. Body size influences biochemical and physical patterns
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41
Q

Body size and scaling

A

More often than not there is a (+) relation between the size and physiological trait; Many traits scale in a systematic way with body size

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42
Q

Isometric Growth

A

Proportions remain constant; Each dimension is scaled up or down by the same amount (Ex: salamander picture on slides); best seen in terms of anatomical size; 1:1 growth)

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43
Q

Allometric growth

A

Changes in body proportion with changes in body size; Different rates of growth of different parts; The proportions vary depending on rates at which SA, V, and other physical parameters changes with size (Ex: Best seen in human head size)

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44
Q

Size and SA/V impacts

A

Thermoregulation, Respiration, Water Balance, Bone and Muscle Structure, etc.

Volume helps determine the weight of an organisms; SA helps determine rate of exchange across surfaces

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45
Q

Larger size

A

Smaller SA/V Ratio –> slower exchange

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46
Q

Smaller size

A

Larger SA/V Ratio –> faster exchange

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47
Q

What constrains organisms to certain environements?

A

SA/V ratio

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48
Q

Allometric Equation

A

Y=aX^b

Y= variable being measure in relation to size
a= initial growth index (size of Y when M=1)
X= size (mass)
b= scaling exponent

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49
Q

b=1

A

isometry; no differential growth (Ex: Liver v. Body Mass)

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50
Q

b>1

A

positive allometry; Y increases at a rate faster than X (Ex: Forelimb v. Body Length)

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51
Q

b<1

A

negative allometry; Y increases at a rate slower than X (Ex: Head length v. Body Length)

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52
Q

The scaling exponent (b) is only true when

A

Comparing like dimensions (length v length)

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53
Q

Isometry of head length v. body length

A

m1/m1, b=1/1= 1

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54
Q

Isometry of head length v. body mass

A

m1/m3, b=1/3= 0.33

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55
Q

Isometry of surface area v. body mass

A

m2/m3, b=2/3= 0.67

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56
Q

Scaling

A

The structural and functional consequences of changes in size in otherwise similar organisms

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57
Q

SA is proportional to

A

Length^2 and V^2/3

As SA increase, V increases by 2/3 of SA

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58
Q

V is proportional to

A

Length^3

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59
Q

SA/V Ratio

A

Smaller objects have larger SA relative to their V than larger objects of the same shape (Smaller objects have larger SA/V ratios)

Larger SA/V ratio means quicker diffusion; Good for O2 absorption, bad for water loss

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60
Q

V increases more rapidly with size than SA

A

So as size increases the SA/V ration decreases

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61
Q

Logarithmic v. Arithmetic Plots

A

Looks like smaller differences of log plots; Looks like larger differences on arithmetic plots

Arithmetic scale: 1, 10, 100
Log scale: 0, 1, 2

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62
Q

By plotting a log scale we can asses two important aspects of the scaling relationship

A
  1. The slope of the relationship (b): Rate of change in a trait relative to body size
  2. The proportionality coefficient (a): The y-intercept
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63
Q

Secondary Signal

A

Substantial deviation from an otherwise reliable regression

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64
Q

Kleibers Law

A

Metabolic rate scales to the 3/4 power of body mass; Varies with scale of study (Individual vs across species)

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65
Q

Nervous and Endocrine Systems integrate and

A

coordinate all other functional systems

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66
Q

Basic unit (specialized cells) of the nervous system

A

Neuron

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67
Q

Neuron Anatomy

A

Dendrites (synaptic input), Cell Body (integration), Axon (conduction), Pre-Synaptic Terminals (Output)

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68
Q

Nerves

A

Bundle of neuron axons

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69
Q

Neurons and glial cells make up the

A

Nervous System

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70
Q

General Neuron Function

A

Signal –> Action potential travels along axon –> Releases neurotransmitter into Synaptic cleft/gap –> NT bind to receptors on post synaptic cell –> Response

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71
Q

Endocrine Cells

A

Longer lasting effect; Endocrine cells synthesize and secret hormones into the bloodstream and travels to target cell to evoke a response

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72
Q

Response Loop

A

Stimulus, Receptor, Afferent Pathway (Sensory), Integrating Center (CNS), Efferent Pathway (Motor), Effector, Response

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73
Q

Functional Classes of Neurons

A

Sensory Neurons (afferent; PNS), Interneurons (CNS), Motor Neurons (efferent, PNS)

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74
Q

4 Functional Regions of a Neuron

A

Dendrites
Soma Cell Body
Axon Hillock
Axon Terminal

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75
Q

Neuroglia (Glial Cells; Accessory Nervous Cells)

A

Protect neurons and help them function; Insulate neurons from one another; Supportive framework for nervous tissue; Involved in impulse transmission (communication)

76
Q

Types of Neuroglia

A

Oligodendrocytes (CNS)
Ependymal Cells (CNS)
Astrocytes (CNS)
Microglia (CNS)

Schwann Cells (PNS)
Satellite Cells (PNS)

77
Q

Oligodendrocytes

A

CNS, Forms myelin sheath around axons, insulates nerve fiber from extracellular fluid, speeds signal conduction

78
Q

Astrocytes

A

Gives CNS its structure, most abundant glial cell, supportive framework for nervous tissue, regulate blood flow in the brain, regulates nerve growth

79
Q

Schwann Cells

A

Oligodendrocytes of the PNS, surrounds axons of neurons in the PNS, forms myeline sheaths, unlike oligodendrocytes the entire cell wraps around the axon, not just the arms

80
Q

Excitable Cells

A

Nerve cells and muscle cell; can change membrane potential

81
Q

Resting membrane potential

A

Unexcited state (about 70mV), difference in voltage across the membrane, membrane potentials first demonstrated in axons of the giant squid

82
Q

Current

A

Flow of electrical charge (driving force for ion movement)

83
Q

Voltage

A

Difference in charge; declines with distance from site of stimulation because leaky channels get rid of Na+

84
Q

Voltmeter

A

Measures voltage

85
Q

Reference electrode of the voltmeter is in the

A

Extracellular fluid

86
Q

What generates membrane potential?

A

Selective permeability to ions

87
Q

What is the membrane most permeable to?

A

K+

88
Q

The intracellular fluid has what in respect to ion concentration?

A

High K+ and Anions
Low Na+ and Cl-

89
Q

The extracellular fluid has what in respect to ion concentration?

A

High Na+ and Cl-
Low K+ and Anions

90
Q

Channels allow

A

ions to move around based on membrane potential

91
Q

Anions are

A

nonpermable

92
Q

Ions want to move in what direction

A

from high to low concentrations

93
Q

Ion pumps help maintain

A

concentrations of major ions via active transport by counteracting the tendency of Na+ to diffuse in and K+ to diffuse out of the cell (Counteracts leaky channels)

Ex: Na+/K+ ATPase Pump

94
Q

Membrane potential is proportional to

A

equilibrium potential of ion with greatest permeability

95
Q

How is resting membrane potential generated within a living cell?

A
  1. Sodium and Potassium gradient across membrane
  2. Differential permeability of membrane to Na+ and K+
  3. Na+/K+ ATPase pumps move ions up concentration gradients
96
Q

Changes in Membrane Potential in response to stimulus

A

Resting, Depolarization (Increase in Na+), Repolarization, Hyperpolarization(Cl- and K+ moving in), Resting

97
Q

Graded Potentials

A

“local potentials”; they can vary in strength/magnitude, produces by stimulus on dendrites or cell body, amplitude proportional to stimulus strength,

98
Q

Weak v. Strong graded potential determined by

A
  1. Number of ion channels
  2. Distance the current spreads
  3. Threshold
99
Q

Excitatory Electrical Change

A

Stimulus opens Na+ channels (depolarization); Takes it closer to threshold

100
Q

Inhibitory Change

A

Stimulus opens Cl- or K+ channels (hyperpolarization); further from threshold

101
Q

Action Potentials

A
  1. All of none
  2. Produced by graded potentials
  3. Always excitatory (depolarization)
  4. Propagates over long distance without decrease in amplitude
102
Q

What happens at threshold?

A

Depolarization (Excitation); Voltage gates Na+ channels open up (Quick to open and close)

103
Q

What happens at the peak of the AP?

A

Repolarization; Voltage gated K+ channels open (Slow to open and close) and Na+ channels close

104
Q

Voltage gates K+ channels

A

They are slow to open (Causing repolarization) and slow to close (causing hyperpolarization)

105
Q

Action Potential Stages

A

Resting Potential, Graded Potentials, Threshold (Voltage Gated Na+ open), Depolarization (Voltage Gated K+ Channels open), Peak Depolarization (Voltage Gated Na+ channels close), Repolarization, Hyperpolarization (Voltage gated K+ channels close), Resting Potential

106
Q

Refractory Period Phases

A

Absolute and Relative

107
Q

Absolute Refractory Period

A

No AP can be produced because it is above threshold already

108
Q

Relative Refractory Period

A

AP can be produced but it is much harder due to hyperpolarization

109
Q

Conduction Veloctiy

A

Depends on axon diameter, myelination, temp

Ex: Bigger axon = Bigger conduction velocity; Unmyelinated = Decrease Conduction Velocity

110
Q

Myelinated Axons conduct

A

faster

111
Q

Warmer neurons conduct

A

faster

112
Q

Axons with bigger diameters conduct

A

faster

113
Q

Myelin sheath does what?

A

Prevents ion leakage and maintains AP more efficiently

114
Q

Synaptic transmission can be

A

electrical or chemical

115
Q

Myelinated Axons

A

Saltatory Conduction: AP jumps from 1 node to the next and has no leak channels in myelin sheath

116
Q

Pre Synaptic Cell

A

Sending Cell

117
Q

Post Synaptic Cell

A

Receiving Cell

118
Q

Electrical Synaptic Transmission

A

Rapid response; Rare in humans and mammals; Electrical coupling of cells joined by gap junction
Ex: Crayfish

119
Q

Electrical Synaptic Transmission

A

Rapid response; Rare in humans and mammals; Electrical coupling of cells joined by gap junction

Ex: Crayfish

120
Q

Chemical Synaptic Transmission

A

Takes longer; most common type; releases secondary messenger; synaptic vesicles

Ex: Common in reflex responses

121
Q

Function of Chemical Synapse

A

Pre synaptic action potential opens up VG Ca2+ channels. Ca2+ enter the pre synaptic terminal and trigger vesicles to travel and release neurotransmitters via exocytosis into the synaptic cleft. NT will bind to receptors on the post synaptic cell. Will bind to ionotropic receptors OR metabotropic receptors

122
Q

Ionotropic Receptors

A

A single molecule constitutes receptor and ion channel; the receptor directly alters permeability to ions in the post synaptic cell causing depolarization. Binding to the ligand gated channel opens it.

More receptors = greater response

123
Q

Metabotropic Receptors

A

Triggers a signaling cascade of second messengers; Have relatively slow and long lasting effects on synaptic processes

NT will bind to G protein coupled receptors that will activate a G protein to produce a second messenger

124
Q

Excitatory Post Synaptic Potential (ESPS)

A

Causes depolarization (influx of Na+) and repolarization

Neurotransmitter is acetylcholine (Skeletal muscle cell synapses (PNS)) and glutamate (CNS, Excitatory effect)

125
Q

Inhibitory Post Synaptic Potential (IPSP)

A

Causes hyperpolarization (Influx of Cl- of efflux of K+) (making AP harder to achieve)

Neurotransmitter is GABA or glycine

126
Q

Summation Types

A

Temporal, Spacial

127
Q

EPSP Temporal Summation

A

Adding up post synaptic potentials and responding to their net effect; Intense stimulation by ONE presynaptic neuron

128
Q

EPSP Spacial Summation

A

Simultaneous stimulation by SEVERAL pre synaptic neurons

129
Q

What limits the grades potentials?

A

Number of receptors and amount of NT released

130
Q

Neurotransmitters

A

Chemical messengers released by a nerve signal into the synaptic cleft that bind to the receptor on another cell and alters that cells physiology

131
Q

3 Categories of NT

A
  1. Amines
  2. Amino Acides
  3. Neuropeptides
132
Q

Amines

A

Acetylcholine (Found in neuromuscular junctions and most synapses of the autonomic nervous systems; Excites skeletal muscle (ESPS ionotropic) and inhibits cardiac muscle (ISPS metabotropic)

More Ex: Epinephrine, norepinephrine, dopamine, histamine

133
Q

Amino Acids

A

GABA (IPSP ionotropic)
Glutamate (EPSP ionotropic)
Glycine (IPSP ionotropic)

134
Q

Neuropeptides

A

Small chains of amino acids (2-40 aa) (metabotropic)

135
Q

Model System for Understanding Chemical Synapses

A

Vertebrate Neuromuscular Junction (Between a motor neuron and skeletal muscle neuron)

136
Q

Purpose of Junctional Folds

A

Increase SA to increase the response

137
Q

What works together (antagonistically) to control overall level of brain excitation?

A

GABA (IPSP) and Glutamate (EPSP)

138
Q

An imbalance of GABA and Glutamate can be found in those with

A

Autism and anxiety disorders (Elevated gluametergic neurotransmission)

139
Q

Alcohol potentiates sedentary effects of

A

GABA; Increases GABA/Glu ratio; Sensations of relaxation and at later stages loss of control (slurred speech, unsteady gait, loss of social anxiety)

140
Q

High levels of GABAergic

A

Relaxation and sedation

141
Q

Synaptic Plasticity

A

Synaptic properties change with time and activity

Thought to be mechanism for how the nervous system function changes over time (memory and learning)

142
Q

Presynaptically

A

Changing rate of NT synthesis, storage, and release

143
Q

Postsynaptically

A

Sensitivity to NT can be increased or decreased under different circumstances

144
Q

Synaptic potentials are

A

short lived (millisecond to second)

145
Q

Synaptic Strenght

A

Amplitude of postsynaptic potential in response to presynaptic AP

146
Q

Facilitation

A

More sensitive with stimulation; Successive post synaptic potentials increase in amplitude in response to repeated pre synaptic action potentials

147
Q

Antifacilitation

A

Dampened with stimulation; Successive post synaptic potential in a series decrease with amplitude

148
Q

Posttetanic potentiation

A

extended enhancement of synaptic response

149
Q

Tetanic stimulation

A

Very rapid firing of action potentials

150
Q

Facilitation is pronounced after

A

tetanic stimulation of pre synaptic neurons

151
Q

What regions of the brain are associated with learning and memory function?

A

Hippocampus and Cerebral Cortex

152
Q

Habituation

A

Decrease in intensity of reflex response to stimulus

Ex: Getting used to loud noises near house over time

153
Q

Sensitization

A

Prolonged enhancement of reflex response to stimulus

Ex: Smell of grandmas house

154
Q

How does habituation and sensitization occur?

A

Repeated stimulation causes less NT to be released (Pattern in pre synaptic plasticity)

Resensitivity via 2nd messenger system and serotonin (additional Ca2+ channels)

155
Q

Long Term Potentiation in Hippocampus

A

LTP is post synaptic
Tetonic stimulation depolarized the post synaptic cell and casued Mg2+ to be released allowing Ca2+ to enter.
More channels = greater response

156
Q

Chemical signals act over

A

short and long distances in the body

157
Q

Types of signals that travel short and long distances

A

Neurons, Non neural endocrine cells (Outside of the NS, contained within endocrine glands), Neurosecretory cells (Neural cells that secrete into the bloodstream; Soma cell body stays in the CNS), Local paracrine and autocrine signals

158
Q

3 Chemical classes of hormones

A
  1. Steroid hormones (sex and stress)
  2. Peptide (protein) hormones
  3. Amine hormones
159
Q

Steroid Hormones

A

Synthesized from cholesterol, sex and stress hormones, lipid soluble (can permeate through lipid bilayer; carrier protein required to travel in bloodstream), receptors located inside target cells (cytoplasm or nucleus; intracellular receptors)

in vertebrate secreted by gonads, adrenal cortex, skin, and placenta

in antropods molting hormone (Ex: ecdysone): regulates exoskeleton shedding

160
Q

Peptide Hormone

A

Water soluble (cant easily pass through lipid bilayer, interact through membrane bound receptors), vary in molecular size

in vertebrates: include antidiuretic hormones, insulin, and GH

in invertebrates: gamete shedding hormones (sesastars) and diuretic hormones (insects)

161
Q

Amine Hormones (modified aa)

A

Catecholamines (Tyrosine derivative): Dopamine, Norepinephrine, Epinephrine –> H2O soluble

Iodothyronines (Tyrosine derivative): Thyroxine and Triiodothyronine (Thyroid hormones) –> lipid soluble

Melatonin (Tryptophan derivative) –> H2O soluble

162
Q

Hormones Produce

A

biochemical changes in target cells

Ex: alter gene expression by altering rates of transcription and translation

163
Q

3 Receptor types mediate hormone action

A
  1. intracellular receptors
  2. G-Protein cascade membrane receptors
  3. Enzyme linked membrane receptors
164
Q

Lipid soluble hormones (steroids and iodothyronines) bind to

A

intracellular receptors and form hormone receptors complexes

165
Q

Hormone Receptor Complex

A

act as transcription factor and interact directly with the cells DNA to alter gene expression –> directly influences protein synthesis of target cell

Process requires time (delay between hormone binding and cellular response)

166
Q

Water soluble hormones (peptides and catecholamines) bind to

A

membrane receptors to mediate action by changing membrane permeability or activating second messengers vis G proteins

167
Q

Control of Endocrine Secretion

A

Vertebrate Pituitary Gland

168
Q

2 Major Controls of Hormone Secretion

A
  1. Neural control of secretion by neurosecretory cells
  2. Neurosecretory control of secretion by endocrine cells
169
Q

Anterior Pituitary

A

Endocrine Tissue and Non Neural Tissue and endocrine cells provide control of secretion

170
Q

Posterior Pituitary

A

Neural Tissue and Neurosecretory Cells provide neural control of secretion

171
Q

Hypothalamus

A

Endocrine system control center; CNS is the initial site for control

172
Q

In most mammals two peptide hormones are released by the Posterior Pituitary

A

Oxytocin and Vasopressin

173
Q

Oxytocin

A

Causes contraction of uterus during birth and ejection of milk from mammary glands

174
Q

Vasopressin

A

Anti diuretic hormone; limits the production of urine and constricts arterioles

Water stressed = Increased ADH = Increased H2O retention = Increased Blood Volume
Wounded = Decreased Blood Volume = Increased ADH = Increased Blood Volume via Increased H2O Retention

175
Q

Hormones of the Anterior Pituitary are synthesized and secreted by

A

cells in its tissues; all hormones from this site are peptides

176
Q

Hormones are categorized into 2 groups according to target tissue

A
  1. influence non-endocrine tissues
  2. influence endocrine tissues (topins)

All are secreted by the anterior pituitary in response to signals from the hypothalamus

177
Q

Hormones influencing non endocrine tissues

A

TSH (Thyroid), ACTH (Adrenal Cortex), LH (Gonads), FSH (Gonads)

178
Q

Hormones influencing endocrine tissues (tropins)

A

MSH (Skin), Prolactin (Mammary Glands), GH (Liver, Muscle, Fat)

179
Q

Endocrine Control Axis

A

HPT Axis (Hypothalamus Anterior Pituitary Thyroid Axis)

Ex: TRH –> TSH –> Thyroid Hormones

Secretions of one endocrine gland act on another

180
Q

HPA Axis

A

Hypothalamus Pituitary Adrenal Cortex Axis

Illustrates hormone modulation

181
Q

Modulation of Endocrine Control Pathways

A

Adrenal Cortex secretes several hormones (Ex: Glucocorticoids)

182
Q

Glucocorticoids

A

Steroid hormone secreted by adrenal cortex
They increase glucose concentrations in the blood and are critical for homeostasis

Cortisone, Cortisol, Corticosterone

183
Q

What activated the release of glucocorticoids

A

Stress or challenging conditions

184
Q

Main Glucocorticoid in Primate and Fish

A

Cortisol

185
Q

Main Glucocorticoid in Others (Birds, Reptiles, Rodents, Amphibians)

A

Corticosterone

186
Q

Modulation of Endocrine Control Pathway

A

HPA Axis; Pathway modulated by negative feedback

Stress is the stimulus/neural input. Stress increases CRH secretion from the hypothalamus. The anterior pituitary secretes ACTH then the adrenal cortex secretes glucocorticoids. Glucocorticoids exert a negative feedback loop on the anterior pituitary and the hypothalamus to stop secreting ACTH and CRH.

Animal Physiology (2 decks)

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