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Human Physiology > Unit 2 > Flashcards

Unit 2 Flashcards

1
Q

General Senses

A
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2
Q

Special Senses

A
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3
Q

Accessory Structures

A
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4
Q

Lens

A
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5
Q

Middle Ear Bones

A
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6
Q

Two Types of Sensory Receptors

A
  • Primary Sensory Neurons
  • Specialized Sensory Cells
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7
Q

Primary Sensory Neurons

A

Ex: Nociceptors (Skin)

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8
Q

Specialized Sensory Cells

A

Ex: Photoreceptors (Eye)

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9
Q

Sensation vs. Perception

A
  • Consciousness: Perception is always conscious, whereas sensation may be conscious or unconscious.
  • Brain Involvement: Perception always involves the brain, wherease sensation may or may not involve the brain.
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10
Q

Sensation

A

The conscious or unconscious awareness of stimuli that may or may not involve the brain.

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11
Q

Perception

A

The conscious awareness and interpretation of stimuli that always involves the brain.

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12
Q

Where in the body do consciousness and perception occur?

A

Brain

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13
Q

Labeled Line

A
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14
Q

Which type of sensory pathways are not transmitted to the brain?

A

Reflexes

Certain reflexatory sensory pathways integrate only in the spinal cord.

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15
Q

What might cause your brain to misinterpret incoming sensory signals?

A

Labeled Lines

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16
Q

Hippocampus

A

An organ of the brain that is essential for the consolidation of information from short-term memory to long-term memory.

The hippocampus is critical for declarative memory, but not for procedural memory.

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17
Q

Broca’s Area

A

The region of the brain that relays language commands to the motor cortex.

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18
Q

Wernicke’s Area

A

The region of the brain responsible for “making sense” of language.

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19
Q

Auditory Cortex

A

The region of the brain responsible for interpretating language.

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20
Q

Motor Cortex

A

The region of the brain that sends commands to the body’s effector tissues.

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21
Q

Visual Cortex

A
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22
Q

Henry Molaison

Patient H.M.

A
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23
Q

Declarative Memory vs. Procedural Memory

A
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24
Q

Synaptic Plasticity

A

A phenomenon that describes the way that synapses change over time.

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25
Q

Two Types of Synaptic Plasticity

A
  • Synapting Pruning
  • Long-Term Potentiation
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26
Q

Synaptic Pruning

A

A reduction of synaptic connectivity within the brain.

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27
Q

Synesthesia

A
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28
Q

Long-Term Potentiation

A
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29
Q

Glutamate

A

A major excitatory neurotransmitter

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30
Q

AMPA Receptor

A

An ionotropic channel within the post-synaptic neuron cell membrane that opens in response to Glutamate binding (to allow entry of Na+ ions into the cell).

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31
Q

NMDA Receptor

A

An ionotropic channel within the post-synaptic neuron’s cell membrane that allows the entry of Na+ and Ca2+ into the cell following repeat stimulation (of the post-synaptic neuron).

  • At low membrane potentials, NMDA receptors have a Mg2+ ion bound that blocks any ions from flowing through the receptor.
  • Repeat stimulation of the post-synaptic neuron leads to an increasingly greater depolization that eventually outsts the
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32
Q

Selectivity: AMPA Receptor vs. NMDA Receptor

A
  • AMPA Receptor: More Selective (i.e. Only Allows Transport of Na+).
  • The NMDA: Less Selective (i.e. Allows Transport of Na+ and Ca2+)
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33
Q

Why is the Mg2+</sub> ion (within NMDA receptors) displaced following depolarization of the post-synaptic neuron?

A

The charge-charge repulsion between the positively charged intracellular environment and the Mg2+</sub> ion pushes Mg2+</sub> out from within the receptor.

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34
Q

Nicotinic Receptors

A

Ionotropic
Excitatory

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35
Q

Andrenergic Receptors

A

Metabotropic

Adrenergic receptors are always associated with sympathethic signaling to effector organs.

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36
Q

Examples: Oppositional Dual Innervation

A
  • Heart Rate:
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37
Q

Muscarinic Receptors

A

Metabotropic

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38
Q

Cholinergic Receptors

A
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39
Q

What type of receptors are found at all ganglionic synapses?

A

Nicotinic Receptors

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40
Q

Which neurotransmitter is used at all ganglionic synapses?

A

Acetylcholine

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41
Q

Parasympathetic signaling to effector tissues mostly uses which type of receptor at the synapse?

A

Muscarinic Receptors

Sweat glands express muscarinic receptors despite synapsing only with sympathetic effector neurons (i.e. Signaling to sweat glands differs from the parasympathetic-muscarinic pattern.)

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42
Q

Parasympathetic signaling to effector tissues uses which type of neurotransmitter at the synapse?

A

Acetylcholine

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43
Q

Epinephrine

Adrenaline

A
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44
Q

Norepinephrine

A
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45
Q

Sympathetic signaling to effector tissues uses which type of receptor at the synapse?

A

Adrenergic Receptor

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46
Q

Sympathetic signaling to effector tissues uses which type of neurotransmitter at the synapse?

A

Norepinephrine OR Epinephrine

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47
Q

Agonist

A

A compound that binds to and activates a particular receptor(s).

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48
Q

Antagonist

A

A compound that binds to and inhibits a particular receptor(s).

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49
Q

What effector organs/tissues receive input only from the sympathetic nervous system?

A

Blood Vessels

  • A high rate of sympathetic signaling/activation leads to vasoconstriction of blood vessels.
  • A low rate of sympathetic signaling/activation leads to vasodilation of blood vessels.
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50
Q

Humans can only sense stimuli that ____________________.

A

they have receptors to detect.

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51
Q

Why is sensation necessary for homeostasis?

A

Sensation is critical for the regulation of controlled variables; without sensation, the value/status of a controlled variable cannot be detected.

An error in a controlled variable could not be detected without sensation.

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52
Q

Sympathetic Nervous System

A

The branch of the autonomic nervous system responsible for “fight-or-flight” responses.

“Fight-or-flight” responses are those that involve the expenditure of energy.

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53
Q

Parasympathetic Nervous System

A

The branch of the autonomic nervous system responsible for “rest-and-digest” responses.

“Rest-and-digest” activities involves those that conserve and restore body energy.

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54
Q

Examples: Cooperative Dual Innervation

A
  • Sexual Arousal + Orgasm:
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55
Q

Three Types: Muscle Tissue

A
  • Skeletal Muscle
  • Smooth Muscle
  • Cardiac Muscle
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56
Q

Enteric Nervous System

A

The branch of the autonomic nervous system embedded in the walls of the gastrointestinal tract that governs gastrointestinal motility and secretion.

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57
Q

Dual Innervation

A

The notion that most organs of the body are innervated by both the sympathetic nervous system and the parasympathetic nervous system.

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58
Q

What types of tissues does the autonomic nervous system innervate?

A
  • Smooth Muscle
  • Cardiac Muscle
  • Glands

Visceral Effectors: Effector tissues that are associated with the internal organs of the body (including smooth muscle, cardiac muscle, and glands).

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59
Q

Branches of ANS

A
  • Parasympathetic Nervous System
  • Sympathetic Nervous System
  • Enteric Nervous System
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60
Q

Autonomic motor pathways consist of ____________________.

A

two autonomic motor neurons (in series) and a visceral effector.

  • The preganglionic neuron is the first neuron in the autonomic motor pathway.
  • The postganglionic neuron is the second neuron in the autonomic motor pathway.
  • The autonomic ganglion is where the preganglionic neuron synapses with the postganglionic neuron.
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61
Q

Somatic motor pathways is comprised of ____________________.

A

one somatic motor neuron that innvervations a skeletal muscle fiber.

A somatic motor neuron originates in the CNS and extends to one/multiple skeletal muscle fiber(s).

62
Q

Preganglionic Neuron

A

The first neuron in an autonomic motor pathway, which has its soma/dendrites located in the central nervous system and its axon extending to an autonomic ganglion.

  • The preganglionic neuron conveys action potential from the CNS to the autonomic ganglia.
63
Q

Autonomic Ganglion

A

A cluster of cell bodies of sympathetic/parasympathetic neurons located in the peripheral nervous system.

  • Thepreganglionic neuron synapses with the postganglionic neuron at the autonomic ganglion.
64
Q

Postganglionic Neuron

A

The second neuron in an autonomic motor pathway, which has its soma/dendrites located in the autonomic ganglia and its axons extending to a visceral effector.

The postganglionic neuron relays action potentials from autonomic ganglia to visceral effectors.

65
Q

Parasympathic Nervous System: Craniosacral Division of ANS

A

Parasympathetic preganglionic neurons have their somas/dendrites in the brain stem (and exit through four cranial nerves) or the sacral spinal region (and exit through three sacral spinal nerves).

66
Q

Sympathetic Nervous System: Thoracolumbar Division of ANS

A

Sympathetic preganglionic neurons have their somas/dendrites in the thoracic spinal region (and exit through twelve thoracic spinal nerves) or the lumbar spinal region (and exit through five lumbar spinal nerves).

67
Q

Autonomic Ganglia: Parasympathetic Nervous System

A

Terminal Ganglia

Terminal ganglia are located near/within the walls of visceral effectors.

68
Q

Autonomic Ganglia: Sympathetic Nervous System

A
  • Sympathetic Trunk
  • Collateral Ganglia

  • The sympathetic trunk is located (close to the spine) on either side of the spinal cord.
  • Collateral Ganglia: Individual ganglia that are not associated with the sympathetic trunk.
69
Q

Parasympathetic Motor Pathway

A
  • Parasympathetic preganglionic neurons originate in the CNS (at brain stem or sacral region) and synapse at the terminal ganglia.
  • Parasympathetic postganglionic neurons originate in the terminal ganglia and extend to visceral effector/organ cells.

  • Parasympathetic preganglionc neurons are relatively long.
  • Parasympathetic post ganglionc neurons are relatively short.
70
Q

Sympathetic Motor Pathway

A
  • Sympathetic preganglionic neurons originate in the CNS (at lumbar region or thoracic region) and synapse at the sympathetic trunk or collateral ganglia.
  • Sympathetic postganglionic neurons originate in the sympathetic trunk or collateral ganglia and extend to visceral effector/organ cells.

  • Sympathetic preganglionc neurons are relatively short.
  • Sympathetic post ganglionc neurons are relatively long.
71
Q

Sympathetic Trunk

A

A chain/column of sympathetic ganglia that is located (close to the spine) on either side of the spinal cord.

72
Q

Chromaffin Cells

A

Specialized cells in the adrenal medulla that release catecholamine hormones into the blood upon stimulation by sympathetic preganglionic neurons.

  • Chromaffin cells are modified sympathetic postganglionic cells that lack dendrites and axons.
  • Chromaffin cells release a mixture of 80% epinephrine, 20% norepinephrine, and trace dopamine into the blood.
73
Q

Neuroeffector Junction (NEJ)

A

The neuron-effector synapse between an autonomic postganglionic neuron and a visceral effector.

74
Q

How does the neuroeffector junction differ from a typical neuron-neuron synapse?

A
  • Varicosities: The axon terminals of postganglionic neurons possess swollen regions (instead of synaptic end bulbs) that contain neurotransmitter-encapsulated vesicles.
  • Receptors: Receptors the visceral effector are located along the entire effector surface (intead of being confined to a particular location/region).
  • Effector Area: The autonomic postganglionic neuron’s release of neurotransmitter affects a large area of the effector tissue.
75
Q

Steps: Release of Neurotransmitter at NEJ

NEJ = Neuroeffector Junction

A
  1. An action potential arrives at a varicosity of the autonomic postganglionic axon.
  2. Depolarization caused by the action potential opens voltage-gated Ca2+ channels within the varicosity membrane. (Ca2+ ions will flow into the varicosity due to the higher extracellular Ca2+ concentration.)
  3. Increased Ca2+ concentration in the varicosity triggers release of neurotransmitters from synaptic vesicles. (The synaptic vesicles fuse with the varicosity membrane to dispense neurotransmitter into the synaptic cleft.)
  4. Neurotransmitter molecules diffuse across the synapse and bind to neurotransmitter receptors within the effector’s cell membrane.
  5. Neurotransmitter-receptor binding activates a G-protein that initiates a intracellular response within the effector cell.
76
Q

Methods: Removal of Neurotransmitter from NEJ

A
  • Diffusion away from Synapse
  • Degredation by Enzymes in Extracellular Environment
  • Uptake by Nearby Cell (via Active Transport)

These methods of neurotransmitter removal are the same as those utilized within a neuron-neuron synapse.

77
Q

What type of proteins are neurotransmitter receptors?

A

Integral Membrane Proteins

Neurotransmitter receptors are located within the plasma membrane of the postsynaptic neuron/cell.

78
Q

Two Main Classifications of Neurotransmitters

A
  • Cholinergic Neurotransmitter
  • Adrenergic Neurotransmitter
79
Q

Cholinergic Neuron

A

A type of autonomic neuron that releases the acetylcholine neurotransmitter.

Cholinergic neurons include all parasympathetic/sympathetic preganglionic neurons, most parasympathetic postganglionic neurons, and sympathetic postganglionic neurons innervating sweat glands.

80
Q

Cholinergic Receptor vs. Adrenergic Receptor

A
  • Cholinergic Receptor: Activation occurs via binding of acetylcholine and results in either excitation or inhibition of the postsynaptic cell.
  • Adrenergic Receptor: Activation occurs via binding of norepinephrine/epinephrine and results in either excitation or inhibition of the postsynaptic cell.
81
Q

Which ANS cells release norepinephrine as a neurotransmitter?

A

Sympathetic Postganglionic Neurons

82
Q

Which neurons in the ANS are cholinergic neurons?

A
  • All Parasympathetic/Sympathetic Preganglionic Neurons
  • Most Parasympathetic Postganglionic Neurons
  • Sympathetic Postganglionic Neurons Innervating Sweat Glands
83
Q

Which neurons in the ANS are adrenergic neurons?

A

Most Sympathetic Postganglionic Neurons

84
Q

Adrenergic Neuron

A

A type of autonomic neuron that releases the norepinephrine and epinephrine neurotransmitters.

85
Q

Acetylcholine

ACh

A

A widespread neurotransmitter (i.e. released by both PNS neurons and CNS neurons) that is liberated by cholinergic neurons of the ANS.

  • Acetylcholine is excitatory at a neuromuscular junction (NMJ).
  • Acetylcholine is excitatory or inhibitory at a non-NMJ synapse.
86
Q

Types of Cholinergic Receptors

A
  • Nicotinic Acetylcholine Receptors
  • Muscarinic Acetylcholine Receptors
87
Q

Adrenergic Receptor

A

A type of metabotropic receptor found in visceral effectors tissues innvervated by sympathetic postganglionic neurons that is activated by norepinephrine/epinephrine binding.

88
Q

Nicotinic Receptor

A

A type of ACh-binding cholinergic receptor that is located within the plasma membranes of parasympathetic/sympathetic postganglionic neurons, skeletal muscle motor end plates, and adrenal medulla chromaffin cells.

  • Nicotine can mimic the actions of ACh by binding to nicotinic receptors.
  • All nicotinic receptors are ionotropic receptors.
89
Q

Muscarinic Receptor

A

A type of ACh-binding cholinergic receptor located on all visceral effectors innervated by parasympathetic postganglionic axons and on sweat glands innervated by cholinergic sympathetic postganglionic axons.

  • Muscarine can mimic the actions of ACh by binding to muscarinic receptors.
  • All muscarinic receptors are metabotropic receptors.
90
Q

Nicotinic Receptors vs. Muscarinic Receptors

A
  • Structure: Nicotonic receptors are ionotropic receptors (i.e. ligand-gated channels), whereas Muscarinic receptors are metabotropic receptors (i.e. G protein-coupled channels).
  • Location: Nicotonic receptors are located on ANS postganglionic neurons, skeletal muscles, and chromaffin cells; Muscarinic receptors are located on parasympathetic-innervated visceral effector cells and sympathetic innervated sweat gland cells.
  • Postsynaptic Response: Nicotinic receptors excite the postsynaptic cell, whereas Muscarinic receptors excite or inhibit the postsynaptic cell.
91
Q

Postsynaptic Response: Muscarinic Receptors

A

Excitation or Inhibition

  • M1/M3/M5: An increase in intracellular [Ca2+] results in excitation of the effector cell.
  • M2/M4: Opening of K+ ion channels results in inhbition of the effector cell.
92
Q

Postsynaptic Response: Adrenergic Receptors

A

Excitation or Inhibition

  • α1/β1 = Excitation
  • α2/β2: Inhibition
93
Q

What terminates the activity of Acetylcholine?

A

Enzymatic Degradation via AChE

94
Q

Which types of cells possess nicotinic receptors within their plasma membrane?

A
  • All Parasympathetic/Sympathetic Postganglionic Neurons
  • Chromaffin Cells of the Adrenal Medulla
  • Skeletal Muscle Cells of a Neuromuscular Junction
95
Q

Which types of cells possess muscarinic receptors within their plasma membrane?

A
  • Visceral Effector Cells innverated by Parasympathetic Postganglionic Neurons
  • Sweat Gland Cells innervated by Sympathetic Postganglionic Neurons
96
Q

Which types of cells possess adrenergic receptors within their plasma membrane?

A

Visceral Effector Cells innervated by Sympathetic Postganglionic Neurons

97
Q

Postsynaptic Response: Nicotinic Receptors

A

Excitation

Activation of nicotinic receptors results in depolarization of the postsynaptic cell (due to the net inflow/influx of positive ions), which brings the postsynaptic cell closer to threshold.

98
Q

Postsynaptic Response: Muscarinic Receptors

A

Excitation or Inhibition

  • M1/M3/M5: An increase in intracellular [Ca2+] results in excitation of the effector cell.
  • M2/M4: Opening of K+ ion channels results in inhbition of the effector cell.
99
Q

Acetylcholinesterase

AChE

A

An enzyme located in the postsynapic cell’s membrane that degrades acetylcholine within the synaptic cleft.

The effects triggered by cholinergic neurons are brief due to the rapid breakdown of AChE by acetylcholinesterase.

100
Q

What terminates the activity of Norepinephrine?

A
  • Enzymatic Degradation via COMT or MAO
  • Uptake by Releasing Adrenergic Neuron

  • COMT = Catechol-O-Methyltransferase
  • MAO = Monoamine Oxidase
101
Q

Norepinephrine/Noradenaline

NE

A

A widespread neurotransmitter-hormone that is secreted by sympathetic postganglionic neurons (as a neurotransmitter) and the adrenal medulla (as a hormone).

102
Q

Which ANS cells release norepinephrine as a hormone?

A

Chromaffin Cells (Adrenal Medulla)

103
Q

Types of Adrenergic Receptors

A
  • Alpha (α) Adrenergic Receptors
  • Beta (β) Adrenergic Receptors
104
Q

Length of Triggered Effect: Adrenergic Neurons vs. Cholinergic Neurons

A
  • Cholinergic Neurons: Triggered effects are shorter-lasting due to rapid degredation of ACh by AChE.
  • Adrenergic Neurons: Triggered effects are longer-lasting due to NE lingering in the synaptic cleft for longer.
105
Q

Nonadrenergic Noncholinergic Neuron

A

A type of autonomic neuron that releases neither norepinephrine nor acetylcholine.

106
Q

Agonist

A

A substance that binds to and activates a receptor to produce an effect mimicking that caused by the natural neurotransmitter/hormone.

107
Q

Antagonist

A

A substance that binds to and blocks a receptor to prevent the natural neurotransmitter/hormone from producing its typical effect.

108
Q

Autonomic Tone

A

The balance between parasympathetic activity and sympathetic activity that is regulated by the hypothalamus.

109
Q

Why do the parasympathetic nervous system and sympathetic nervous system produce different effects on body tissues?

A
  • Each possesses postganglionic neurons that release different neurotransmitters.
  • Each possesses different types of receptors within the innervated effector cells.
110
Q

Which body tissues receive only sympathetic innervation?

A
  • Sweat Glands
  • Arrector Pili Muscles (of Hair Follicles)
  • Blood Vessels
  • Kidneys
  • Spleen
  • Adrenal Medullae

Anincrease in sympathetic tone and/or a decrease in sympathetic tone produce opposing effects in tissues receiving only sympathetic innervation.

111
Q

SLUDD: Parasympathetic Responses

A
  • Salivation
  • Lacrimation
  • Urination
  • Digestion
  • Defecation
112
Q

“Three Decreases”: Parasympathetic Responses

A
  • Bradycardia
  • Bronchoconstriction
  • Pupillary Constriction
113
Q

“Four E Situations”: Sympathetic Reponses

A
  • Exercise
  • Emergency
  • Excitment
  • Embarrassment
114
Q

Why are the effects of sympathetic stimulation longer-lasting (and more widespread) than the effects of parasympathetic stimulation?

A
  • Divergence: Sympathetic postganglionic neurons diverge more extensively than parasympathetic postganglionic neurons, so more cells/tissues are activated simultaneously.
  • Enzymatic Degredation: Norepinephrine (released by sympathetic postganglionic neurons) persists in the synaptic cleft for longer than Acetylcholine, so its effects linger for longer.
  • Hormonal Effects: The body-wide circulation of hormonal Neurorepinephrine/Epinephrine (secreted by the adrenal medulla) activates all tissues containing adrenergic receptors; there is no hormonal form/equivalent of Acetylcholine that is secreted into the bloodstream.
115
Q

Comparison Chart: Sympathetic Nervous System vs. Parasympathetic Nervous Systm

A
116
Q

Neurotransmitters: Parasympathetic Nervous System

A
  • Preganglionic Release: ACh
  • Postganglionic Release: ACh
117
Q

Neurotransmitters: Sympathetic Nervous System

A
  • Preganglionic Release: ACh
  • Postganglionic Release: Mostly NE

Sympathetic postganglionic neurons innervating sweat glands and skeletal muscle blood vessels release ACh.

118
Q

Autonomic Reflexes

A

Rapid and involuntary responses that occur when action potentials pass through an autonomic reflex arc.

Autonomic reflexes play a critcial role in maintaining homeostasis by regulating cardiovascular activities, digesion, defaction, and urination.

119
Q

Components: Autonomic Reflex Arc

A
  • Sensory Receptor
  • Sensory Neuron
  • Integrating Center
  • Motor Neuron(s)
  • Effector(s)
120
Q

What part of the brain is the major control/integration center of the ANS?

A

Hypothalamus

121
Q

What does the somatic nervous system innervate?

A

Skeletal Muscles

122
Q

Control of Somatic Nervous System

A

Voluntary/Conscious Control

Exception: Somatic motor neurons innervating skeletal muscles involved in posture, balance, breathing, and somatic responses are involuntarily/unconsciously controlled.

123
Q

Where are the cell bodies of somatic motor neurons located?

A
  • Brain Stem
  • Ventral Horn of Spinal Cord
124
Q

Which type of somatic motor neurons innervate facial/cranial skeletal muscles?

A

Cranial Nerves

125
Q

Which type of somatic motor neurons innervate skeletal muscles of the limbs and trunk?

A

Spinal Nerves

126
Q

Neuromuscular Junction

NMJ

A

The synapse formed between a somatic motor neuron and a skeletal muscle fiber.

The NMJ consists of (1) the somatic motor neuron’s synaptic end bulbs, (2) the synaptic cleft, and (3) the muscle fiber’s motor end plate.

127
Q

What neurotransmitter is released at the NMJ?

A

ACh

128
Q

Effect at NMJ: Acetylcholine

A

Excitatory

Binding of ACh to the motor end plate causes the muscle fiber to contract.

129
Q

Motor End Plate

A

The region of the muscle fiber sarcolemma opposite of the neuronal synaptic end bulbs that contains nicotinic ACh receptors.

130
Q

Junctional Folds

A

Deep folds within a muscle fiber’s motor end plate that contain numerous ACh receptors.

131
Q

How many motor end plates does a skeletal muscle fiber possess?

A

One

The single NMJ of a skeletal muscle fiber is usually located near the midpoint of the fiber.

132
Q

Steps: Initiation + Propogation of Muscle Action Potential

A
  1. A nerve action potential arrives at the synaptic end bulb of a somatic motor neuron.
  2. Voltage-gated Ca2+ channels (within the synaptic end bulb membrane) open to allow the inflow/influx of Ca2+ from the extracellular fluid.
  3. Increased intracellular [Ca2+] in the synaptic end bulb triggers the exocytosis of synaptic vesicles to release ACh into the synaptic cleft.
  4. ACh diffuses across the synaptic cleft and binds to nicotinic ACh receptors of the skeletal muscle fiber motor end plate (to allow for transmembrane passage of cations).
  5. The net influx of Na+ ions into the skeletal muscle fiber (through ACh receptors) creates an end plate potential (EPP).
  6. The EPP spreads to and depolarizes adjacent regions of the sarcolemma (via localized current flow).
  7. Threshold-level depolarization of adjacent sarcolemmic regions opens voltage-gated Na+ channels (in these regions) to produce a net inflow of Na+ (that initiates a muscle action potential).
  8. The muscle action potential propogates throughout the muscle fiber sarcolemma (in both directions) away from the NMJ to eventually cause contraction of the muscle fiber.
133
Q

End Plate Potential

EPP

A

A change in a skeletal muscle fiber’s membrane potential (i.e. a graded potential) that results from ACh-binding to the motor end plate.

134
Q

EPP vs. EPSP

A
135
Q

What terminates the effects of ACh-binding at the motor end plate?

A
136
Q

Endocrine Gland

A

A ductless gland that secretes hormones into the interstitial fluid (to then be diffused into the bloodstream).

137
Q

Hormone

A

A chemical messenger molecule that is carried by the bloodstream to distant target cells.

138
Q

Endocrine System

A

The network of all glands, organs, and tissues that contain hormone-secreting cells.

Exclusively Endocrine Glands: Pituitary, Thyroid, Parathyroid, Adrenal, Pineal

139
Q

Down-Regulation

A

A decrease in the number of target-cell receptors (for a hormone) that occurs in response to an excess of the hormone.

Down-regulation causes the target cell to become less sensitive to a hormone.

140
Q

Up-Regulation

A

An increase in the number of target-cell receptors (for a hormone) that occurs in response to a deficiency of the hormone.

Up-regulation causes the target cell to become more sensitive to a hormone.

141
Q

Types of Hormones

A
  • Steroid Hormones
  • Amine Hormones
  • Peptide/Protein Hormones
142
Q

Types of Hydrophobic Hormones

Hydrophobic = Lipophilic

A
  • Steroid Hormones
  • Thyroid Hormones
143
Q

Types of Hydrophilic Hormones

Hydrophilic = Lipophobic

A
  • Amine Hormones
  • Peptide/Protein Hormones
144
Q

Steroid Hormones

A

Lipid-soluble hormones derived from cholesterol that possess four interconnected hydrocarbon rings.

Ex: Cortisol, Testosterone, Aldosterone, Estrogen, Progesterone

145
Q

Thyroid Hormones

A

Lipid-soluble hormones synthesized via Iodine-Tyrosine attachment that contain two hydrocarbon rings.

Ex: T3, T4

146
Q

Amine Hormones

A

Water-soluble hormones that are synthesized from the modification of an amino acid(s).

Ex: Epinephrine, Norepinephrine, Dopamine, Melatonin

147
Q

Peptide/Protein Hormones

A

Water-soluble hormones composed of many amino acids.

Ex: Oxytocin, Insulin, Growth Hormone, Thyroid-Stimulating Hormone

148
Q

Catecholamine

A

An amine hormone derived from the Tyrosine amino acid.

Ex: Epinephrine, Norepinephrine, Dopamine

149
Q

What type of hormone is the most common type?

A

Peptide/Protein Hormones

150
Q

Hormone Circulation: Free Fraction

A

The proportion of a lipid-soluble hormone that is not bound to a transport protein while in the bloodstream.

The lipid-soluble hormone’s free fraction diffsuses, we will ssfds

Human Physiology (5 decks)

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