3A: Structure and functions of the nervous and endocrine systems and ways in which these systems coordinate the organ systems Flashcards
1
Q
Neurons
A
Highly specialized cells responsible for the conduction of impulses
2
Q
How do neurons communicate?
A
Occur through electrical and chemical forms of communication
3
Q
Electrical Communication
A
Occurs via ion exchange and generation of membrane potentials down the length of the axon
4
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Electrical Communication
A
Occurs via ion exchange and generation of membrane potentials down the length of the axon
5
Q
Chemical Communication
A
Occurs via neurotransmitter release from the presynaptic cell and the binding of these neurotransmitters to the postsynaptic cell
6
Q
Chemical Communication
A
Occurs via neurotransmitter release from the presynaptic cell and the binding of these neurotransmitters to the postsynaptic cell
7
Q
Dendrites
A
Appendages that receive signals from other cells
8
Q
Dendrites
A
Appendages of the cell body that receive signals from other cells
9
Q
Cell Body/Soma
A
Location of the nucleus and organelles such as ER and Ribosomes
10
Q
Axon
A
Long appendage down which an AP travels
11
Q
Axon Hillock
A
Where the cell body transitions to the axon and where AP are initiated
12
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Axon Hillock
A
Where the cell body transitions to the axon and where AP are initiated
13
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Nerve Terminal/Synaptic Bouton
A
The end of the axon from which neurotransmitters are released
14
Q
Synapse
A
Consists of nerve terminal of the presynaptic neuron, the membrane of the postsynaptic cell and the space between the two known as the synaptic cleft
15
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Synapse
A
Consists of nerve terminal of the presynaptic neuron, the membrane of the postsynaptic cell and the space between the two known as the synaptic cleft
16
Q
Myelin
A
An insulating substance that prevents signal loss and dissipation of the impulse and crossing of neural impulses from adjacent neurons
17
Q
Oligodendrocytes
A
Creates myelin in the CNS
18
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Schwann Cells
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Creates myelin in the PNS
19
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Schwann Cells
A
Creates myelin in the PNS
20
Q
Nerves or Tracts
A
Bundles of axons
21
Q
Tracts
A
Carry only one type of information
22
Q
Ganglia
A
Cell bodies of neurons of the same type within a nerve cluster in the PNS
23
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Nuclei
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Cell bodies of individual neurons with a tract cluster in the CNS
24
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Nuclei
A
Cell bodies of individual neurons with a tract cluster in the CNS
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Neuroglia/Glial Cells
Astrocytes
Ependymal Cells
Microglial Cells
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Astrocytes
Nourish neurons and form the blood-brain barrier which controls the transmission of solutes from the bloodstream into nervous tissue
27
Ependymal Cells
Line the ventricles of the brain and produce CSF
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CSF
Physically supports the brain and serves as a shock absorber
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CSF
Physically supports the brain and serves as a shock absorber
30
Microglia
Phagocytic cells that ingest and break down waste products and pathogens in the CNS
31
Microglia
Phagocytic cells that ingest and break down waste products and pathogens in the CNS
32
Resting Membrane Potential
-70 mV
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What maintains the resting membrane potential?
Sodium-Potassium ATPase
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What maintains the resting membrane potential?
Sodium-Potassium ATPase
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Excitatory Signals [EPSPs]
Cause depolarization; Glu, ACh
36
Inhibitory Signals [IPSPs]
Cause hyperpolarization; GABA
37
Ionotropic Receptors
Ligand gated, allow K and Cl to hyperpolarize the membrane
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Metabotropic
Block Ca ions
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Metabotropic
Block Ca ions
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Threshold Potential
-55 mV
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Threshold Potential/Voltage
-55 mV
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Temporal Summation
Addition of multiple signals near each other in time
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Spatial Summation
Addition of multiple signals near each other in space
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What maintains the resting membrane potential?
Sodium-Potassium ATPase
| K Leak Channels
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Spatial Summation
Addition of multiple signals near each other in space
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Action Potential Outline
Resting -> Depolarization -> Repolarization -> Hyperpolarization -> Refractory Period
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Resting Stage
-70 mV maintained by ATPase and Leak Channels
Lots of sodium outside and lots of potassium inside
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Depolarization
Voltage gated sodium channels open, sodium rushes in and membrane potential increases to +30 mV
Lots of sodium inside and lots of potassium inside
49
Depolarization
Voltage gated sodium channels open, sodium rushes in and membrane potential increases to +30 mV
Lots of sodium inside and lots of potassium inside
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Repolarization
Potassium channels open and sodium channels inactivate, potassium rushes outside and membrane potential drops
Lots of sodium inside and lots of potassium outside
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Repolarization
Potassium channels open and sodium channels inactivate, potassium rushes outside and membrane potential drops
Lots of sodium inside and lots of potassium outside
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Hyperpolarization
Potassium channels close but due to the timing the membrane potential briefly drops below the resting potential to around -90 mV
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Hyperpolarization
Potassium channels close but due to the timing the membrane potential briefly drops below the resting potential to around -90 mV
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Refractory Period
Na/K ATPase works to reestablish the original resting state (more K inside and Na outside); neuron cannot general another action potential during this time
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Absolute Refractory Period
Depolarization to original resting state
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Relative Refractory Peroid
After hyperpolarization til the resting state; AP can fire if the stimuli is strong enough
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Relative Refractory Peroid
After hyperpolarization til the resting state; AP can fire if the stimuli is strong enough
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All-or-None Principle
The neuron will either respond completely or not at all to the stimuli
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All-or-None Principle
The neuron will either respond completely or not at all to the stimuli
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Neurotransmitter Breakdown
Done enzymatically or absorbed via reuptake channel or diffused out of the synaptic cleft
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Types of Neurons
Motor (Efferent)
Interneurons
Sensory (Afferent)
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CNS
Brain & Spinal Cord
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White Matter
Consists of myelinated axons
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Grey Matter
Consists of unmyelinated cell bodies and dendrites
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Location of Matter in the Brain
White matter is deeper than grey matter
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Location of Matter in the Spinal Cord
Grey matter is deeper than white matter
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Location of Matter in the Spinal Cord
Grey matter is deeper than white matter
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PNS Divisions
Somatic [Voluntary]
| Autonomic [Involuntary]
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Autonomic Nervous System
Parasympathetic [Rest & Digest]
| Sympathetic [Fight-or-Flight]
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Autonomic Nervous System
Parasympathetic [Rest & Digest]
| Sympathetic [Fight-or-Flight]
71
Reflex Arcs
Use the ability of interneurons in the spinal cord to relay information to the source of stimuli while simultaneously routing it to the brain
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Reflex Arcs
Use the ability of interneurons in the spinal cord to relay information to the source of stimuli while simultaneously routing it to the brain
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Monosynaptic Reflex Arc
Presynaptic Sensory Neuron fires directly onto the Postsynaptic Motor Neuron
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Polysynaptic Reflex Arc
Sensory neuron fires onto a motor neuron as well as interneurons that fire onto other motor neurons
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Major Functions of Nervous System
High level control, integration of body systems, adaptive capability to external influences, integrative and cognitive abilities
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Major Functions of Nervous System
High level control, integration of body systems, adaptive capability to external influences, integrative and cognitive abilities
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CNS, Forebrain Structures
Telencephalon, Diencephalon
78
Telencephalon Structures
Cerebral Cortex, Basal Ganglia, Hippocampus, Amygdala
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Diencephalon Structures
Thalamus, Hypothalamus
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CNS, Midbrain Structures
Mesencephalon
81
Mesencephalon Structures
Tectum, Cerebellum
82
CNS, Hindbrain Structures
Metencephalon, Myelencephalon
83
Metencephalon Structures
Pons, Cerebellum
84
Myelencephalon Structures
Medulla
85
Myelencephalon Structures
Medulla
86
Sensory Neurons
Transmit sensory information, carries sensory input from the outside to the CNS
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Effector Neurons
Cause an effect, transmit motor signals from CNS to an effector organic to respond to physiologically to external stimuli
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Effector Neurons
Cause an effect, transmit motor signals from CNS to an effector organic to respond to physiologically to external stimuli
89
Antagonistic Control of SNS and PSNS
They have opposing effects on the internal organs they innervate
90
Sympathetic Function
```
Increases HR, BP
Increase Blood Flow to Muscle
Pupillary Dilation
Decrease Blood Flow to Digestive System
Increases Glycolysis and Glycogenolysis
```
91
Parasympathetic Function
```
Decreases HR, BP
Decreases Blood Flow to Muscle
Pupillary Constriction
Increase Blood Flow to Digestive System
Increases Glycogenesis
```
92
Supraspinal Circuits
Involves input from the brain or brainstem to process a stimuli, unlike most reflex arcs
93
Supraspinal Circuits
Involves input from the brain or brainstem to process a stimuli, unlike most reflex arcs
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Voltage-Gated Channels
Group of transmembrane ion channel that open or close based on changes in the cells membrane potential; include sodium, calcium and potassium channels
95
Ligand-Gated Channels
Group of transmembrane ion channel proteins that open when a specific ligand molecule binds to the receptor protein; the binding causes a confirmational change
96
Receptor Enzymes
| [Enzyme-Linked Receptors/Catalytic Receptors]
Extracellular ligand binds and activates intracellular enzymatic activity
97
Types of Receptor Enzymes
Receptor Serine-Threonine Kinases
Receptor Tyrosine Kinases
Tyrosine-Kinase Associated Receptors
98
Receptor Tyrosine Kinases
Kinase enzymes that specifically phosphorylate tyrosine amino acids; growth factor binds to the extracellular domain which eventually leads to the production of a second messenger cascade
99
G-Protein Coupled Receptors
Large integral membrane proteins; its ligand is usually cAMP, peptides or large proteins
100
G-Protein Coupled Receptors
Large integral membrane proteins; its ligand is usually cAMP, peptides or large proteins
101
GPCR Outline
Ligand binds to an active receptor causing conformational change that activates the protein, transmits the extracellular signal to inside of the cell
102
GPCR Outline
Ligand binds to an active receptor causing conformational change that activates the protein, transmits the extracellular signal to inside of the cell
103
G Protein On vs. Off State
```
GTP = active
GDP = inactive
```
104
G Protein On vs. Off State
```
GTP = active
GDP = inactive
```
105
GPCR Activity
GDP binds to the alpha subunit and the GP Complex binds to nearby GPCR,
GTP replaces GDP and activates the receptors and the subunits dissociate causing activity
GTP is hydrolyzed back to GDP when it's no longer needed
106
GPCR Activity
GDP binds to the alpha subunit and the GP Complex binds to nearby GPCR,
GTP replaces GDP and activates the receptors and the subunits dissociate causing activity
GTP is hydrolyzed back to GDP when it's no longer needed
107
Endocrine Signaling
Involves the secretion of hormones directly into the bloodstream; travel to distant target tissues where they bind to receptors and induce a change
108
Peptide Hormones
Composed of amino acids and are derived from large precursors that are cleaved during posttranslational modificaiton
109
Peptide Hormones
Composed of amino acids and are derived from large precursors that are cleaved during posttranslational modificaiton
110
Peptide Hormone Characteristics
Polar and cannot pass through the plasma membrane; bind to extracellular receptors where they trigger the transmission of a second messenger
111
Peptide Hormones
Composed of amino acids and are derived from large precursors that are cleaved during posttranslational modification; travel freely through the bloodstream
112
Peptide Hormone Characteristics
Polar and cannot pass through the plasma membrane; bind to extracellular receptors where they trigger the transmission of a second messenger; rapid onset but short-lived
113
Steroid Hormones
Derived from cholesterol, they are minimally polar and can pass through the plasma membrane; cannot dissolve in the blood stream and must be carried by specific proteins
114
Steroid Hormone Characteristics
Bind to intracellular or intranuclear receptors where they promote conformational change and bind to DNA, affecting the transcription of a particular gene; slow onset and are long-lived
115
Steroid Hormone Characteristics
Bind to intracellular or intranuclear receptors where they promote conformational change and bind to DNA, affecting the transcription of a particular gene; slow onset and are long-lived
116
Amino Acid-Derivative Hormones
Modified Amino Acids; share some features with peptide and steroid hormones; common examples are epinephrine, norepinephrine, T3 and T4
117
Amino Acid-Derivative Hormones
Modified Amino Acids; share some features with peptide and steroid hormones; common examples are epinephrine, norepinephrine, T3 and T4
118
Direct Hormones
Have effects on non-endocrine tissues
119
Tropic Hormones
Have effects on other endocrine tissues
120
Function of the Endocrine System
Regulate mood, growth, development, metabolism, sexual function and tissue function
121
Function of the Endocrine System
Regulate mood, growth, development, metabolism, sexual function and tissue function
122
Endocrine Glands
Hypothalamus, Pituitary Gland, Pineal Gland, Thyroid Gland, Parathyroid Gland, Adrenal Gland, Pancreas, Ovary, Testis
123
Hypothalamus
Releases hormones that stimulate the anterior pituitary gland through paracrine release of hormones through the hypophyseal portal system
124
Hypothalamic Hormones
GnRH, GHRH, TRH, CRF, PIF/Dopamine
125
GnRH
Promotes release of FSH and LH
126
GHRH
Promotes release of GH
127
TRH
Promotes release of TSH
128
CRF
Promotes release of ACTH
129
PIF/Dopamine
Inhibits release of Prolactin
130
PIF/Dopamine
Inhibits release of Prolactin
131
Anterior Pituitary Hormones
FSH, LH, ACTH, TSH [Tropic] & Prolactin, Endorphins and GH [Direct]
132
FSH
Promotes development of ovarian follicles in females and spermatogenesis in males
133
LH
Promotes ovulation in females and testosterone production in males
134
ACTH
Promotes synthesis and release of glucocorticoids (cortisol) from the adrenal cortex
135
TSH
Promotes synthesis and release of T3 and T4
136
Prolactin
Promotes milk production (letdown)
137
Prolactin
Promotes milk production (letdown)
138
Endorphins
Decrease perception of pain and cause euphoria
139
Endorphins
Decrease perception of pain and cause euphoria
140
GH
Promotes growth of bone and muscle and shunts glucose to these tissues; raises blood glucose concentrations
141
GH
Promotes growth of bone and muscle and shunts glucose to these tissues; raises blood glucose concentrations
142
Posterior Pituitary Hormones
ADH/Vasopressin, Oxytocin
143
ADH/Vasopressin
Secreted in response to low blood volume or increased blood osmolarity and increases reabsorption of water in the collecting duct of the nephron, increase blood volume and decreasing blood osmolarity
144
ADH/Vasopressin
Secreted in response to low blood volume or increased blood osmolarity and increases reabsorption of water in the collecting duct of the nephron, increase blood volume and decreasing blood osmolarity
145
Oxytocin
Secreted during childbirth and promotes uterine contractions as well as milk letdown; regulated through positive feedback loop
146
Thyroid Hormones
T3 and T4, Calcitonin
147
T3 & T4
Produced by follicular cells and contain iodine; increase basal metabolic rate and alter the utilization of glucose and fatty acids
148
Calcitonin
Produced by parafollicular cells, decreases plasma calcium concentration by promoting calcium excretion in the kidneys, decreasing calcium absorption in the gut and promoting calcium storage in bone
149
Calcitonin
Produced by parafollicular cells, decreases plasma calcium concentration by promoting calcium excretion in the kidneys, decreasing calcium absorption in the gut and promoting calcium storage in bone
150
Parathyroid Gland Hormones
PTH
151
PTH
Increases blood calcium concentrations;
Decreases calcium by the kidneys;
Increase bone resorption directly to increase blood calcium concentrations
Activates vitamin D
Promotes resorption of phosphate from bone and reduces reabsorption
152
PTH
Increases blood calcium concentrations;
Decreases calcium by the kidneys;
Increase bone resorption directly to increase blood calcium concentrations
Activates vitamin D
Promotes resorption of phosphate from bone and reduces reabsorption
153
Adrenal Cortex Hormones
Glucocorticoids [Cortisol, Cortisone]
Mineralocorticoids [Aldosterone]
Cortical Sex Hormones [Androgens, Estrogens]
154
Adrenal Cortex Hormones
Glucocorticoids [Cortisol, Cortisone]
Mineralocorticoids [Aldosterone]
Cortical Sex Hormones [Androgens, Estrogens]
155
Cortisol/Cortisone
Increase blood glucose concentration, reduce protein synthesis, inhibit immune system, participate in the stress response; stimulated by ACTH
156
Aldosterone
Promote sodium reabsorption in the distal convoluted tubule and collecting duct thus increasing water reabsorption; increases potassium and hydrogen ion excretion; regulated by RAAS
157
Aldosterone
Promote sodium reabsorption in the distal convoluted tubule and collecting duct thus increasing water reabsorption; increases potassium and hydrogen ion excretion; regulated by RAAS
158
Adrenal Medulla Hormones
Catecholamines [Epinephrine, Norepinephrine]
159
Catecholamines
Promote glycogenolysis, increasing basal metabolic rate, heart rate, dilate bronchi and alter blood flow
160
Catecholamines
| [Epi, Norepi]
Promote glycogenolysis, increasing basal metabolic rate, heart rate, dilate bronchi and alter blood flow
161
Catecholamines
| [Epi, Norepi]
Promote glycogenolysis, increasing basal metabolic rate, heart rate, dilate bronchi and alter blood flow
162
Pancreatic Hormones
Glucagon
Insulin
Somatostatin
163
Pancreatic Hormones
Glucagon
Insulin
Somatostatin
164
Glucagon
| [Alpha Cells]
Raises blood glucose levels by stimulating protein and fat degradation, glycogenolysis and gluconeogenesis
165
Insulin
| [Beta Cells]
Lowers blood glucose levels by stimulating uptake by cells and anabolic processes like glycogenesis, fat and protein synthesis
166
Insulin
| [Beta Cells]
Lowers blood glucose levels by stimulating uptake by cells and anabolic processes like glycogenesis, fat and protein synthesis
167
Somatostatin
| [Delta Cells]
Inhibits insulin and glucagon secretion
168
Somatostatin
| [Delta Cells]
Inhibits insulin and glucagon secretion
169
Pineal Gland Hormones
Melatonin
170
Melatonin
Regulates circadian rhythms
