Unit 2 - Chpts. 23, 26, 22, 8 Flashcards
(169 cards)
1
Q
Where does synthesis of thyroid hormones occur?
A
Thyroid follicles
2
Q
In Graves’ disease, antibodies bind to TSH receptors leading to
A
increased T3/T4 and decreased TSH and TRH
3
Q
Primary hypothyroidism caused by a lack of iodine in the diet leads to
A
decreased T3/T4 and increased TSH and TRH
4
Q
Patients with hyperthyroidism experience heat intolerance. What mechanism would explain this?
A
The production of ATP is increased resulting ni more exothermic reactions taking place
5
Q
In a hypophysectomized rat, which of the following would you expect to find?
A
Decreased levels of T3 and T4
6
Q
What hormone “turns off” Growth Hormone?
A
Somatostatin
7
Q
What digestive system hormone sends a signal to the hypothalamus to produce GHRH?
A
Ghrelin
8
Q
What does GH indirectly impact?
A
The liver which produces Insulin-like growth factors, leading to cartilage growth
9
Q
What are some stimulatory factors for GH release?
A
Sleep
Stress (only a little)
Exercise
Hormones of puberty
10
Q
What are some inhibitory factors for GH release?
A
Obesity
Senescence
Somatostatin
GH (negative feedback)
Increased IGF (negative feedback)
Increased glucose
Increased fatty acids
11
Q
What are the actions of GH?
A
Increase lipolysis and gluconeogenesis, decrease glucose uptake by muscle –> increases blood glucose
12
Q
Which of the following statements about growth hormone is incorrect?
a) Cortisol released in response to stress inhibits the release of GH
b) Hypersecretion of GH in children causes gigantism
c) Hyposecretion of GH in children can be treated with bovine GH
d) Hypersecretion of GH in adults causes acromelaly
A
c) Hyposecretion of GH in children can be treated with bovine GH
GH is species specific
13
Q
True or False: Thyroid hormones play a permissive role in tissue and bone growth
A
True
14
Q
What stimulates protein synthesis and provides energy?
A
Insulin (glucose)
15
Q
Role of osteoblast
A
produce enzymes and osteoid (build bone)
16
Q
Role of osteoclast
A
secrete acid that dissolves calcified matrix (catabolize bone)
17
Q
What is the most common form of calcium phosphate?
A
Hydroxyapatite
18
Q
Role of parathyroid hormone
A
1) Mobilizes calcium from bone
2) enchances renal reabsorption of calcium
3) indirectly increases intestinal absorption of Ca2+
19
Q
Signs of hypo calcium?
A
Muscle cramps
Convulsions and seizures
Tingling and numbness
Hyperactive bowels
Brittle hair/nails
20
Q
Signs of hyper calcium
A
Muscle weakness
Constipation
Hypertension
Polydipsia
Polyuria
Lethargy, coma
21
Q
Increased levels of phosphate ions in the boddy would likely accompany ____?
A
Bone loss during osteoporosis
22
Q
Concerning calcium homeostasis, what is the correct relationship?
A
Osteoblasts build bone, osteoclasts catalyze its reabsorption
23
Q
3 sets of sex organ structures?
A
1 - internal
2 - external
3 - gonads (ovaries and testes)
24
Q
What are bipotential gonads?
A
gonad that could develop into either the ovaries or testes depending on presence of SRY gene
25
Which ducts belong to the male system?
Wolffian ducts (mullerian duct regresses)
26
Which ducts belong to the female system?
Mullerian ducts (wolffian duct regresses)
27
What hormone causes the Mullerian duct to disappear?
Anti-Mullerian hormone (produced by testes)
28
What causes the Wolffian ducts to disappear?
Absence of anti-mullerian hormone
29
What structures arise from the Mullerian duct in the female system?
Fallopian tube
Uterus
Upper part of vagina
30
What structures arise from the Wolffian duct in the male system?
Seminal vesical
Vas deferens
Epididymis
31
What do the genital tubercle, uretheral folds and grooves, and labioscrotal swellings form in the female system?
Genital - Clitoris
Uretheral - Labia minora, opening of vagina and urethra
Labioscrotal - labia majora
32
What do the genital tubercle, uretheral folds and grooves, and labioscrotal swellings form in the male system?
Genital - Glans penis
Uretheral - Shaft of penis
Labioscrotal - Shaft of penis and scrotum
33
What do interstitial cells secrete?
Testosterone
34
What do sertoli cells secrete?
anti-mullerian hormone
35
Pathway for GnRH in males
1) GnRH --> LH --> interstital cells of leydig --> testosterone
2) GnRH --> FSH --> sertoli cells (sastenacula) --> anti-mullerian hormone, sperm
36
Stem cell for sperm
Spermatogonia
37
Stem cell for eggs
Oogonium
38
Sex determination during development depends on the presence of
SRY gene
39
Testosterone is required for testicular development
False
40
Which is true for an individual with Turner's Syndrome (X0)?
Embryo develops in a female, female reproduction function is impaired
41
How does the amount of DNA in the first polar body compare to that in the second polar body?
2x as much
42
What organ stores sperm?
Epididymis
43
What accessory glands contribute to secretions to semen?
Prostate gland and Bulbourethral gland
44
What is the role of the sertoli cell in spermiogenesis
secrete proteins to support
45
What type of junctions are present in the lumen of the seminiferous tubule and what role do they play?
Gap junctions between sertoli cells to provide developing sperm with nutrients
46
Role of blood testis barrier?
Keeps immune cells out
47
What is a spermatid?
a haploid cell that is not yet a sperm, develop into spermatozoa
48
What is the acrosome?
Allows sperm to get to egg by erroding part part of cell wall
49
Role of mitochondrial spiral in sperm?
help provide energy for flagella to move
50
Why does semen need buffers?
to neutralize acidic environment of vagina
51
What is unique about the production of GnRH?
It is pulsitile
52
What is Androgen-binding protein and what role does it have?
Produced by sertoli cells, keeps testosterone cells at a steady state, can bind to excess testosterone to keep it in the seminiferous tubules
53
Pathway of erection
Testosterone --> sexual arousal --> increase in parasympathetic signaling to penis --> increased nitric oxide release --> arterial and trabecular smooth muscle relaxation --> arterial dilation --> increased arterial blood flow and pressure & decreased blood flow out --> increased intracevernosal pressure --> increased penile rigidity --> erection
54
What are the 3 erection tissues?
Corpora cavernosa
Cavernosal artery
Corpus spongiosum
55
Developing spermatozoa are nourished by
sertoli cells (aka nurse cells)
56
In the erection reflex, stimulation of parasympathetic neurons causes vasodilation so erectile tissues in the penis shaft receive increased blood flow
True
57
After leaving the seminiferous tubule, spermatozoa enter the ___
epididymis
58
Pathway of spermatozoa
Seminiferous tubule --> epididymis --> vas deferens --> urethra
59
Why do anabolic steroids cause testes to shrink, making males temporarily infertile?
FSH secretion decreases
60
In males, what is the main target for FSH?
Sertoli cells
61
What does LH stimulate in males?
testosterone production
62
What are the 2 layers of the endometrium?
Basal layer (stem)
Functional layer (thicken)
63
What type of tissue is the myometrium made of?
smooth muscle
64
Where do cramps come from?
Cramps are the result of the myometrium contracting and pinching off the spiral ateries (the functional layer of the endometrium)
65
What are Granuloso cells?
make the enzyme aromatase, converts androgens to estrogen and inhibin (estrogen inhibits FSH and GnRH, inhibin inhibits FSH)
66
Pathway of an egg
Primordial follicles --> primary follicle --> secondary follicle --> early tertiary follicle --> dominant follicle w/oocyte --> ovulated oocyte --> Corpus luteum --> regressing corpus luteum
67
What pathway does LH use to make estrogen?
Secondary messengers (cAMP)
68
3 phases of ovarian cycle
Follicular cycle, ovulation, luteal phase
69
3 phases of uterine cycle
Menses, proliferative phase, secretory phase
70
What happens when ovulation occurs?
Estrogen, which had hit a peak, starts to decline and progesterone and inhibin start to increase.
71
How long is the secretory phase?
always 14 days
72
What hormone is high right before ovulation?
LH
FSH does peak but nowhere near the amount LH hits
73
Which hormone stimulates uterine contraction?
Oxytocin
74
A 42-year-old female has a total hysterectomy and bilateral oophorectomy (removal of both ovaries). What effect would this have on her hormone levels?
increase FSH and LH, decreased estrogen and progesterone
75
Which hormones control the ovairan and uterine cycles?
Inhibin, estrogen, progesterone, GnRH, FSH, and LH
76
What occurs during menstration?
The endometrium sloughs its surface layer (aka functional layer)
77
What occurs during the proliferative phase of the menstrual cycle?
A new uterine lining forms
78
Which of the following affects female reproductive function?
a) nutritional status
b) stress
c) changes in day-night cycle
d) all
d) all
In general, anything and everything can affect the female reproductive cycle
79
During which phase of ovarian cycle is estrogen lowest?
a) early follicular phase
80
As it moves down the fallopian tube, an egg ____
is moved by Fallopian tube cilia and muscular contractions
81
On average, a menstrual cycle is ___ days
28
82
What is the definition of contraception?
no fertilization occurrs (sperm and egg do not meet for whatever reason)
83
Oral contraceptives act by
decreasing FSH and LH release from the pituitary and decreasing GnRH release from the hypothalamus
84
What are some examples of contraceptive methods?
Oral pill
Vaginal ring
IUD
Condom
85
What is NOT considered a method of contraceptive
Mifepristone (abortive pill, means fertilization has already occurred)
86
What hormones does the pancreas secrete?
insulin and glucagon
87
what do beta cells secrete?
insulin
88
What do alpha cells secrete?
Glucagon
89
What do delta cells secrete?
somatostatin
90
In what state does insulin dominate?
the fed state, or post absorptive
91
In what state does glucagon dominate?
the fasting state
92
In what order does blood flow through the Islet of Langerhans?
delta --> alpha --> beta
delta: can inhibit beta and alpha cells if range is good
alpha: if glucose is low, will release glucagon and inhibit beta cells
beta: if glucose is high, will release insulin and inhibit alpha cells
93
What relationship do insulin and glucagon have?
Antagonistic
94
How is glucose stored?
Short term = glycogen
Long term = fat
95
What factors stmiulate insulin secretion?
Increased plasma glucose
Increased plasma amino acids
Feed forward effects of GI hormones
Parasympathetic activity
96
What roles does adipose tissue have when exposed to insulin?
Increase glucose uptake
Increase rate of lipogenesis
Decrease rate of lipolysis
97
What roles does the liber have when exposed to insulin?
Decrease rate of gluconeogenesis
Increase rate of glycogen synthesis
Increase rate of lipogenesis
98
What roles do striated muscles have when exposed to insulin?
Increase rate of glucose uptake, glycogen synthesis, and protein synthesis
99
What does Hexokinase II do?
Attaches a phosphate group to glucose, trapping glucose in the cell
100
Primary target of glucagon?
the liver
101
What factors stimualte the release of glucagon?
low blood glucose
increased plasma amino acids
102
How is glucose transport different in the liver compared to all other cells?
Glucagon does not activate hexokinase II, so glucose can leave liver if needed
103
Type 1 diabetes
insulin deficiency from autoimmune destruction of beta cells
104
Type 2 diabetes
insulin resistant diabetes
105
During the absorptive state in a person at rest, ___
the liver forms glycogen
106
What is TRUE about fasted-state metabolism?
It is catabolic
Maintains plasma glucose for the brain
Leads to formation of ketone bodies
Promotes gluconeogenesis
107
The amount of insulin secreted in response to intravenous glucose is ___ insulin secretion in response to oral glucose
less than
108
Generally, insulin and glucagon are released by opposing stimuli and have opposing effects. However, both hormones are released by the stimulus of increased blood amino acids because ___?
glucagon prevents hypoglycemia following a pure protein meal
109
Which is NOT a main target for insulin action?
reneal glucose reabsorption
110
Which is NOT true about type 2 diabetes mellitus?
caused by beta cell destruction
111
Patients with diabetes inject insulin rather than taking it as a pill because
oral insulin is broken down in the digestive tract
112
What two organs make up the CNS?
Brain and spinal cord
113
What is a pseudounipolar neuron?
have a single process called the axon. Dendrite fused with the axon. Type of sensory neuron
114
What is a bipolar neuron?
2 relatively equal fibers extending odd the central cell body. Type of sensory neuron
115
What is an anaxonic neuron?
Have no apparent axon, type of interneuron
116
What are the two types of multipolar neurons?
a) Multipolar neurons of interneuron type are highly branched but lack long extensions
b) Multipolar neurons of efferect type have 5-7 dendrites, each branching 4-6 times. Single long axon, may branch several times and end at enlarged axon terminals
117
What is a synapse?
region where an axon terminal communicates with its postsynaptic target cell
118
What are the two types of axonal transport?
1) Anterograde - soma to synaptic knob
2) Retrograde - synaptic knob to soma
119
What type of neural cells are found in the CNS?
Ependymal cells
Astrocytes
Microglia cells
Oligodendrocytes
120
What type of neural cells are found in the PNS?
Schwann cells
Satellite cells
121
Role of ependymal cells?
Line ventricals
Cerebrial spinal fluid
Create barriers between compartments
Source of neural stem cells
122
Role of astrocytes?
Source of neural stem cells
Support cell
Completely surround capillaries, protecting against toxins and pathogens
123
Role of microglia cells?
Modified immune cells
Act as macrophages
124
Role of Oligodendrocytes?
creates myelin sheath
in CNS, it has many projefctions taking care of axons (repair)
125
Role of Schwann cells?
create myelin sheath
Secrete neurotrophic factors
126
Role of satellite cells?
Support cell bodies
Stimulant for growth, repair, and recycle
127
True or False: if the cell body dies, the neuron dies
True
128
True or False: if the axon is severed, the neuron dies
False
129
Steps of neuronal repair?
- Axoplasm leaks and seals damaged end, attached segment of axon swells
- Schwann cells release chemical signals alerting of tissue damage
- degeneration of distal axon segment, myelin sheath unravels, cellular debris removed
- Schwann cells secrete neurotrophic factors to keep cell body alive and encourage axon regeneration
130
Steps of membrane potential
1 Open leaky K+ channel
2 K+ exits cell (efflux)
3 Anions left behind, inside of cell becomes negative
4 Some K+ goes back in, flow now in and out
5 New equilibrium reached, outward drive = inward drive, resting membrane potential reached
131
What is the Nerst equation used for?
Predicts the membrane potential that a single ion would produce if the membrane were permeable to only that ion
132
What is the Goldman-Hodgkin-Katz equation used for?
Calculates membrane potential that results from contribution of all ions that can cross the membrane
133
What is the resting membrane potential primarily determined by?
K+ conc. gradient
Cells permability to K+, Na+, and Cl-
134
What is depolarization?
When the cell's RMP becomes more positive/less negative
135
What is hyperpolarization?
When the cell's RMP becomes more neagtive
136
Between the activation gate and the inactivation gate, which one is faster?
activation gate is faster
137
If the ECF K+ concentration increases from 3 mM to 5 mM, what happens to the resting membrane potential of cells?
It becomes less negative
138
Would a cell with a resting membane potential of -70mV depolarize or hyperpolarize if the cell became more permeable to Ca2+?
Depolarize
139
Would a cell with a resting membrane potential of -70mV depolarize of hyperpolarize if the cell became less permeable to K+?
Depolarize
140
What are some characteristics of graded potential?
Has variable strength
Used for short distance communication
141
What are some characteristics of action potentials?
Very brief, large deploarizations
Rapid signaling over long distances
All or nothing stimulus
142
What is the local current flow?
a wave of deploarization that moves through the cell
143
Subthreshold graded potential?
Graded potential starts above threshold, but decreases in strength as it travels until it is below the threshold at the trigger point
144
Suprathreshold graded potential?
Stronger stimulus at same point on cell bod creates a graded potential still above threshold when is reaches the trigger point
145
If a cell was to increase its Na+ entry, would it depolarize or hyperpolarize?
depolarize
146
If a cell was to increase its Cl- entry, would it depolarize or hyperpolarize?
hyperpolarize
147
If a cell was to increase its K+ exit, would it depolarize or hyperpolarize?
hyperpolarize
148
If a cell was to increase its Ca2+ entry, would it depolarize or hyperpolarize?
depolarize
149
Absolute refractory period
due to voltage-gated Na+ channels resetting, cannot generate an action potential no matter the stimulus strength
150
Relative refractory period
occurrs after absolute refractory period, stimulus must be greater to cause new action potential
151
Ouabain, a specific inhibitor of the Na+K+ ATPase pump, is applied to a neuron. What effect will this have on the next action potential fired by that neuron?
There will be no effect
152
What causes the repolarization phase of the action potential?
K+ exiting the cell through voltage-gated ion channels
153
Which is TRUE about one of the two gates in Na+ channels in axons?
The closing of the inactivation gate stops the depolarization during an action potential
154
What are two factors that increase speed of action potential?
Larger diameter and more myelin sheath
(myelin sheath higher priority than diameter)
155
Which of the following would have the fastest conduction?
a) Myelinated axon, diameter 20 mm
b) Unmyelinated axon, diameter, 20 mm
c) Unmyelinated axon, diameter 200 mm
a) Myelinated axon, diamter 20 mm
156
Which of the following would have the slowest conduction?
a) Myelinated axon, diameter 20 mm
b) Unmyelinated axon, diameter, 20 mm
c) Unmyelinated axon, diameter 200 mm
b) unmyelinated axon, diameter 20 mm
157
What do electrical synapses have?
gap junctions, create bi-directional flow of electrochemical gradient
158
What type of receptors does norepinephrine and epinephrine have?
Adrenergic (alpha and beta), located in smooth and cardiac muscles and glands
159
Pathway for synthesis and recycling of Acetylcholine
1 - ACh made from choline and acetyl CoA
2 - In synaptic cleft, ACh rapidly broken down by the enzyme acetylchoinesterase
3 - Choline is transported back into axon terminal by cotransport with Na+
4 - Recycled choline is used to make more ACh
160
Hormones derived fro trytophan
Serotonin
161
Hormones derived from histidine
Histmine
162
Hormones derived from tyrosine
Dopamine, Norepinephrine, Epinephrine
163
How does a single stimulus create a long lasting effect?
Amplitude cannot change to make response more severe, so frequency changes to release a constant amount of neurotransmitter
164
Release of a transmitter requires
an action potential and Ca2+ entry into the cell
165
An excitatory postsynaptic potential is
depolarizing the next cell
166
An inhibitory postsynaptic potential is
hyperpolarizing the next cell
167
Spatial summation
2 or more neurons fire simultaneously, have an additive effect (like 50 people screaming fire at once)
168
Temporal summation
One neuron repeatedly firing graded potentials that overlap, having an additive efffect (like one person screaming fire over and over)
169
Assume the postsynaptic neuron ha a resting membrane potential of -70mV and a threshold of -55mV. If the inhibitory presynaptic neuron creates an ISPS of 5mV and the 2 excitatory presynaptic neurons have EPSPs of 10mV and 12mV, will the postsynaptic neuron fire an action potential?
yes
