Chapter 1 - Endocrine Flashcards
(164 cards)
1
Q
What is an endocrine gland?
A
A gland that is will pro-fused w/ blood where chemicals are secreted directly into the blood stream.
2
Q
What is an exocrine gland?
A
Glands that produce a secretory product from the epithelial tissue.
3
Q
Define hormone
A
Any chemical messenger released directly into the blood that travels through the blood to bind to distant target cells
4
Q
What are the three capabilities that are unique to the nervous and endocrine systems?
A
- Detecting change
- Processing change
- Responding to change
5
Q
Name the 10 organs of the traditional endocrine system
A
- Hypothalamus
- Pituitary Gland
- Pineal Gland
- Thyroid Gland
- Parathyroid Gland
- Thymus
- Adrenal Gland(s)
- Pancreas
- Ovaries
- Testes
6
Q
Define Humoral Stimulus
A
Release caused by altered levels of certain ions or nutrients
7
Q
Define Neural Stimulus
A
Released cause by neural input
8
Q
Define Hormonal Stimulus
A
Release caused by another hormone (tropic hormone)
9
Q
Define Tropic Hormone
A
A hormone that causes the release of another hormone
10
Q
What is the main difference between a water soluble hormone and lipid soluble hormone?
A
Water soluble hormones do not have a transport protein.
11
Q
What does Adenylate Cyclase do?
A
Converts ATP into cAMP
12
Q
What does cAMP activate?
A
Protein Kinase(s)
13
Q
What does activated protein kinase do?
A
Phosphorylate cellular proteins
14
Q
What kind of receptors do water soluble hormones bind to?
A
G-protein coupled receptor
15
Q
What kind of response time do water soluble hormones have?
A
Exert response within seconds - minutes
16
Q
Walk through steps of a water soluble protein.
A
- Binding of hormone to G-protein receptor activated G-protein. G protein activates adenylate cyclase.
- Activated adenylate cyclase coverts ATP to cAMP.
- CAMP serves as a second messenger to activate protein kinase.
- Protein Kinase phosphorylate cell proteins
- Millions of phosphorylated proteins cause reactions that produce physiological responses
- Phosphodiesterase inactivated cAMP
17
Q
What is amplification?
A
Multiplying/amplifying the amount of something via other proteins/substances.
18
Q
Why is protein kinase so important?
A
Protein kinase is important because they TURN ON the proteins that ultimately exert the response by pinning a phosphate group to the functional protein.
19
Q
What is meant by agonist?
A
Stimulatory drugs (activates)
20
Q
What is meant by antagonist?
A
Inhibitory Drugs
21
Q
What would happen if you developed a diabetes medication that interfered with action of glycogen phosphorylase? What turns this protein on?
A
Glycogenesis
22
Q
Water soluble hormones use proteins that _______ _______.
A
Already exist
23
Q
What are examples of a lipid soluble hormone?
A
Steroid or thyroid hormone
24
Q
Describe the pathway of a lipid soluble hormone
A
- Lipid soluble hormone diffuses into cell (via transport protein)
- Activated receptor hormone complex alters gene expression
- Newly formed MRNA directs synthesis of specific proteins to ribosomes
- New proteins alter cell activity
25
Do lipid soluble hormones work slow or fast?
Slow (hours/days/years) because they are making proteins from scratch unlike water soluble hormones that use pre—made proteins.
26
What does HP Axis stand for?
Hypothalamic Pituitary Axis
27
List the 3 endocrine pathologies
Hypersecretion - too much hormone
Hyposecretion - not enough hormone
Insensitivity - producing hormone fine but receptors that bind to it are not responsive
28
Describe how action potentials affect hormone release in the posterior pituitary gland.
Action potentials travel down axons of the hypothalamic neurons, causing hormone release from their axon terminals in the posterior pituitary.
29
What is synthesized in the paraventricular nucleus?
Antidiuretic Hormone (ADH)
30
What is synthesized in the supraoptic nucleus?
Oxytocin
31
What are oxytocin and ADH transported down to reach the posterior pituitary?
Hypothalamic Hypophyseal Tract
32
Once down the hypothalamic Hypophyseal tract, where are oxytocin and ADH stored?
Axon terminals of the posterior pituitary.
33
How are oxytocin and ADH released?
When associated hypothalamic neurons fire, action potentials arriving at the axon terminals cause oxytocin or ADH to be released into the blood.
34
What kind of regulation is the posterior pituitary under?
Neural regulation
35
Where are oxytocin and ADH released into?
The blood
36
What is the stimulus for release of hormones from the posterior pituitary?
Action potentials traveling down the axons of the hypothalamic neurons
37
How is the anterior pituitary gland regulated?
Hormonally
38
How does the hypothalamus regulate the anterior pituitary gland?
Hypothalamus receives signals from sensors in body that cause the reuse of hormones that stimulate the pituitary glands to secrete hormones to act on other endocrine glands.
39
What is a tropic hormone?
A tropic hormone is any hormone that causes the release of another hormone.
40
What will be in the name of all hypothalamic hormones?
“Releasing”
41
When you’re dehydrated, what happens to the Na+ (sodium) in your blood?
Na+ in blood INCREASES
42
What are the two primary roles of the hypothalamus?
1. Regulates activity of the autonomic nervous system (sympathetic and parasympathetic)
2. Regulates activity of the pituitary gland
43
Why is the hypothalamus capable of regulating these functions?
It can come into contact w/ blood.
44
When a person becomes dehydrated, the concentration of their blood will -
Increase
45
When a person becomes dehydrated, stretch gated Na+ channels in the dendrites -
Open. (They absorb water)
46
When neurons originating in the paraventricular nucleus are firing action potentials, ADH (anti-diuretic hormone) secretion will -
Increase.
47
What will happen to the cells in the collecting duct of the kidney in the presence of ADH?
They will being to re-absorb more water.
48
Describe the pathway for the release of ADH (anti-diuretic hormone) -
What kind of feedback pathway is this?
Stimulus - increase in concentration of salt
Receptor - Osmo-receptor
Control center - Hypothalamus
Effector - ADH (Anti-diuretic hormone)
Target - Nephron
Response - Increased blood volume (hydration)
Negative feedback loop
49
Explain the pathway for the release of oxytocin during childbirth starting w/ stimulus -
What kind of feedback loop?
```
Stimulus - breast feeding/childbirth
Receptor - hypothalamus/stretch receptor
Control Center - Hypothalamus
Effector - Oxytocin
Target - Smooth muscle in uterus
Response - Bonding/Cervical Dilation
```
Positive feedback loop
50
What are some other functions of oxytocin?
Mood regulation and pair bonding
51
If you had a RAGE agonist, what would it do to oxytocin levels in the brain?
The levels of oxytocin would decrease as RAGE allows the crossing of oxytocin.
52
What kind of hormone is HGH (Human growth hormone) and where does it come from?
1. Releasing hormone
| 2. Hypothalamic Hormone
53
What is the hormone produced by the hypothalamus that triggers the release of growth hormone?
Growth Hormone Releasing Hormone (GHRH)
54
Explain the release of growth hormone starting with stimulus -
Stimulus - drop in circulating concentration of growth hormone / when in deep sleep
Receptor - Growth Hormone Receptors
Control Center - Hypothalamus
Effect - Growth Hormone Releasing Hormone (GHRH)
Target - Liver, muscle, bone, cartilage, and other tissues.
Response - GH increases/activate growth in bone and muscle
55
When do you get the biggest spikes of growth hormone throughout the day?
When you’re sleeping
56
True or false - Prolactin is only produced and used by women
False
57
Explain the release of prolactin starting with the stimulus -
```
Stimulus - Breast Feeding
Receptor - Suckling receptors
Control Center - Hypothalamus (Prolactin Releasing Hormone (PRH))
Effector - Release of Prolactin
Target - Mammary glands
Response - Production of milk
```
58
Prolactin release is inhibited by which neurotransmitter
Dopamine, Bromocriptine, and Cabergoline
59
What does HPT stand for? (Think thyroid)
Hypothalamic Pituitary Thyroid Axis
60
What are the 2 hormones we need to know?
T3 and T4
61
When the hypothalamus identifies low levels of thyroid hormone, it releases -
Thyrotropin Releasing Hormone (TRH)
62
Low levels of circulating thyroid hormone ________ the pathway.
Activate
63
Describe the pathway of T3 and T4 release beginning with hypothalamus and ending with target cells
Hypothalamus - releasing TRH w/ the Hypothalamic Hypophyseal Portal System. TRH tells the Anterior Pituitary to release another hormone called thyroid stimulating hormone. (Stimulates Anterior Pituitary)
Anterior Pituitary - Releases TSH (Stimulates Thyroid Gland)
Thyroid Gland - Release thyroid hormones to target cells (stimulates target cells)
64
What inhibits the hypothalamus and anterior pituitary?
Thyroid Hormones
65
If TRH (Thyrotropin releasing hormone) isn’t being released, they ___ won’t be released.
TSH
66
If TSH isn’t released, _______ _______ won’t be released.
Thyroid hormone
67
In the pathway for the release of thyroid hormones (T3 and T4), what is the stimulus?
TRH (Thyrotropin Releasing Hormone)
68
In the pathway for releasing thyroid hormone (T3 and T4), what type of feedback is taking place?
Uptake
69
In general terms, what effect does thyroid hormone have on target cells?
It cranks up metabolism
70
What is the middle of a Follicular Cell called?
Colloid
71
What kind of cells make up a follicle?
Follicular Cells
72
What hormone is produced by thyroid follicles?
Thyroid Hormone
73
What hormone is produced by parafollicular cells?
Calcitonin
74
What are the symptoms you’d expect from a patient w/ Hypothyroidism?
Fatigued, cold, sleepy, weight gain, brittle hair and brain fog.
75
What are symptoms you would expect from a patient w/ hyperthyroidism?
Hot, can’t sleep, losing weight, irritable, bulging eyes and fast beating heart.
76
What 2 things are considered the building blocks for thyroid hormone?
Thyroglobulin and Iodine
77
Describe the pathway for the release of thyroid hormone into the blood.
1. Cell synthesizes thyroid globulin and ships it off to the colloid
2. Uses transporters to move iodine into the colloid
3. Combines iodine with thyroglobulin to for DIT and MIT
4. DIT and MIT combine to form T3 and T4
5. T3 and T4 are shipped back to the cells. Enzymes chop them into certain active compounds.
6. T3 and T4 get released into the blood.
78
We need a protein to move iodide through blood because they are -
Lipid soluble
79
Name the active and inactive thyroid hormone
T3 = active
T4 = inactive
80
What is a PRIMARY endocrine disorder?
A disorder stemming DIRECTLY from an endocrine gland
81
What are the 3 main functions of the thyroid gland?
- Metabolic Rate and Temp regulation
- Carb/Lipid/Protein Metabolism
- Controls integumentary system
82
What is a secondary endocrine disorder?
A disorder stemming from dysregulation that is not a direct problem with the gland itself.
83
What is Hashimotis Thyroiditis?
Increase in antibodies. Initially there is hyperthyroidism from the Thyroid glad being attacked by the immune system. Overtime, the thyroid gland takes a punch and in turn there will be hypothyroidism.
84
If thyroid hormones are HIGH, will TRH and TSH be high or low?
TRH and TSH would be low. This would be hyposecretion.
85
If TRH is high, then TSH will be -
What would T3 and T4 be?
High.
Super low
86
Is Graves Disease from hyper or hypothyroidism?
Hyperthyroidism
87
What is secreted in the zone Glomerulosa?
Aldosterone
88
What is secreted in the Zona Fasiculata?
Cortisol and Androgens
89
What is secreted in the Zona Reticularis?
Cortisol and Androgens
90
What is secreted in the adrenal medulla?
Epinephrine and nor-epinephrine
91
If Cortisol levels are high, what should they do to the hypothalamus and pituitary gland?
The high levels should turn both of them off.
92
If cortisol is LOW and Adrenocorticotropic Hormone is HIGH, what structure is NOT working?
Anterior Pituitary
93
Explain the pathway for cortisol release.
1. Stress from prefrontal cortex makes it’s way to the Amygdala
2. Amygdala identifies stress. Amygdala notifies hypothalamus.
3. Hypothalamus activates sympathetic nervous system (Short-term) & Hypothalamus activates chronic stress systems (Long-term)
4. Hypothalamus produces corticotropin releasing hormone (CRH)
5. CRH then tells anterior pituitary to release (ACTH)
5. ACTH travels to Zona Fasciculata where it tells the cells to release cortisol
94
What are the two primary functions of cortisol?
1. Suppresses immune system
| 2. Elevates blood sugar
95
If cortisol is LOW, is this hypo or hypersecretion?
Hyposecretion
96
Is cortisol is HIGH, is this hypo or hypersecretion?
Hypersecretion
97
If Cortisol is HIGH, ACTH and CRH should be ______.
What type of disorder would this be?
Low.
If ACTH and CRH are low, this would be a secondary disorder since the Hypothalamus and Anterior Pituitary would be doing their job.
98
Describe what would happen to the chemistry in your body if you were about to engage in a physical confrontation with another person:
1. Prefrontal Cortex tells amygdala about stress
2. Amygdala tells hypothalamus
3. Hypothalamus releases CRH and notifies neurons in spinal cord.
4. Preganaglionic sympathetic fibers extend to adrenal medulla
5. Adrenal medulla releases epinephrine (increases length of response)
6. Pupils dilate. HR rises. BP rises.
99
Describe the HPA Axis -
What kind of feedback loop is this?
Hypothalamus releases CRH (Corticotropin releasing hormone) which then activates the -
Anterior Pitutary to release ACTH which then activates the adrenal cortex to release cortisol
Negative feedback loop
100
What are the cells called that make up the parathyroid gland?
Chief Cells
101
Walk through the secretion of parathyroid hormone, starting with Stimulus -
What kind of feedback pathway is this?
```
Stimulus - Hypercalcemia
Receptor - Chief cells in parathyroid
Control Center - Parathyroid Gland
Effector - Parathyroid hormone
Targets - Osteoclasts, kidneys and small intestine
Response - Increase in calcium levels
```
Negative feedback Pathway
102
What is the metabolic disturbance for 2nd degree hypoparathyroidism?
Hypocalcemia
103
If there is a metabolic disturbance caused by changes in the circulating parathyroid hormone, what will this cause?
Changes in blood calcium levels
104
What is primary hyperparathyroidism?
The unregulated overproduction of parathyroid hormone (PTH) resulting in abnormal calcium homeostasis
105
What is secondary hyperparathyroidism?
The overproduction of parathyroid hormone secondary to hypocalcemia
106
What is another name for the pineal gland?
Consortium or Epiphysis Cerebri
107
What is the stimulus for melatonin?
What is the primary functional role of melatonin?
STIMULUS: Darkness
PRIMARY FUNCTION: Regulate sleep and wake cycles
108
What are some second functional roles of melatonin?
Reproduction, body and bone mass regulation, antioxidant action, psychiatric disorders, stimulates immune system, placenta development, etc.
109
What hormones does Adipose Tissue secrete?
Leptin, Resistin and Adiponectin
110
What does Leptin do?
BRAIN: Suppresses appetite and increases metabolism
111
What do Resistin and adiponectin do?
FAT, MUSCLE, LIVER: Resisting antagonizes insulins action and adiponectin enhances the resistance
112
What hormone is released by heart tissue?
Atrial Natriuretic Peptide
113
What does Atrial Natriuretic Peptide do?
KIDNEYS: Inhibits sodium ion reabsorption and renin release
ADRENAL CORTEX: Inhibits secretion of aldosterone; decreases blood pressure
114
What hormone is secreted by the thymus?
Thymulin, thymopoietins and thymosins
115
What do Thymulin, thymopoietins and thymosins do?
Mostly act locally as paracrines; involved in T lymphocyte development and in immune response
116
Are the Islet’s of Langerhans in the exocrine or endocrine pancreas?
Endocrine Pancreas
117
Are Acinar cells in the Endocrine or Exocrine pancreas?
Exocrine Pancreas
118
What type types of cells are found in pancreas Islets?
What hormone is produced by each?
Alpha Cells = Glucagon
Beta Cella = Insulin
119
List the 3 fates of glucose once it enters the cell:
1. Absorbed along GI tract to distribute through blood to cell tissue
2. Glycogenesis = Glucose —> Glycogen (storage form of glucose)
3. Lipid Synthesis
120
What is the difference between Fed & Fasted?
FED: If you’ve had food w/ glucose in it within an 8 hour period of time
FASTED: If you haven’t had food w/ glucose in it over an 8 hour period of time
121
Does Insulin or Glucagon dominate during a “fed” period?
Insulin Dominates.
High glucose oxidation
High glycogen synthesis
High Fat Synthesis
High Protein Synthesis
122
Does insulin or glucose dominate during a “fasting period”?
Glucose Dominates.
High Glycogenolysis
High Gluconeogenesis
High Ketogenesis
123
Walk through the pathway for a normal system with high blood sugar starting with stimulus -
```
STIMULUS - High Blood Sugar
RECEPTOR - Beta Center
CONTROL CENTER - Pancreas
EFFECTOR - Insulin
TARGET - Fat, skeletal muscle and liver
RESPONSE - Blood sugar is lowered to normal
```
124
What does insulin tell fat and skeletal muscle to insert?
A fat transporter that allows glucose to move from blood into the cell.
125
Walk through the pathway for a normal system with LOW BLOOD GLUCOSE starting with stimulus -
```
Stimulus - Low Blood Glucose
Receptor - Alpha Cells
Control Center - Pancreas
Effector - Glucagon
Target - Liver
Response - Increase in Blood Glucose Levels to normal
```
126
What does insulin come from?
DNA
127
What do GLUT transporters do?
Transport glucose into cell
128
Would oral or IV glucose caught a high BS spike?
ORAL would cause the higher spike.
Oral Glucose = 3 insulin stimuli
IV glucose = 1 insulin stimuli
129
What are the 3 stimuli for the release of insulin?
Neural
Hormonal
Humoral (circulating levels of blood glucose) *MOST IMPORTANT*
130
How may sulfonylureas help treat diabetes?
Blocking potassium channels increases the release of insulin
131
What do doctors measure when they want to know insulin concentration in the blood and why do they use this rather than insulin?
C-Peptide because this test can tell the difference between the insulin that the body is producing vs. insulin that has been injected.
132
What are insulin independent GLUT transporters?
Proteins that specifically move glucose from outside into the cell
133
Are GLUT 2 transporters insulin dependent or independent?
Insulin independent
134
What are GLUT 2 transporters found?
1. Beta Pancreatic Cells
| 2. Liver Cells
135
Walk through the pathway of how GLUT 2 transporters work -
1. The moment glucose enters the cell, ATP is being made.
2. When ATP levels are high, they bind to potassium channels.
3. Potassium channels then close and can no longer diffuse out
4. Potassium builds up w/ a positive charge
5. Cell depolarizes
6. Voltage gated calcium channel activates
7. When channels are activated, calcium rushes in and causes the release of insulin
8. Blood sugar decreases because of insulin release
136
Walk through the mechanism of Beta Cell Sensing -
1. High Glucose Levels in Blood
2. Metabolism Increases
3. ATP increases
4. Potassium ATP Channel closes
5. Cell depolarizes and calcium channels open
6. Calcium’s entry acts as an intracellular signal
7. Calcium signal triggers exocytosis and insulin is secreted
137
In response to something that activates a voltage gated calcium channel, do you think blood glucose levels would increase, decrease or stay the same?
Decrease
138
Are GLUT 4 transporters independent or dependent?
Insulin Dependent.
139
What has to be present for a GLUT 4 transporter to be found in a membrane?
Insulin
140
What happens when Insulin binds to an insulin receptor? What does this allow?
This allows a GLUT 4 Transporter to then enter the member of a cell.
141
Explain Insulin’s cellular mechanism of action -
1. Insulin binds to tyrosine kinase receptor
2. Receptor phosphorylates insulin-receptor substrates (IRS)
3. Second messenger pathways alter protein synthesis and existing proteins
4. Membrane transport is modified
5. Cell metabolism is changed
142
Explain the neural stimulus for insulin release -
1. Eat a meal (stimulus)
2. Distention of GI tract wall (STIMULUS)
3. Stretch Receptors (Sensor)
4. Sensory neuron input (Sensor)
5. CNS (Integrating center)
6. Parasympathetic Output (Output Signal)
7. Beta Cells of Pancreas (Integrating Center)
143
Explain the hormonal stimulus for insulin release -
1. Eat a meal (Stimulus)
2. Presence of Carbs in GI lumen (stimulus)
3. Endocrine cells of small intestines (integrating center)
4. GLP-1 and GIP (Output signal)
5. Beta Cells of Pancreas (Integrating center)
144
Explain the humoral stimulus for insulin release -
1. Nutrient Digestion and Absorption (systemic response)
2. High Plasma Glucose (stimulus)
3. Beta Cells of pancreas (integrating center)
145
Explain Type 1 Diabetes
- Autoimmune disease that destroys beta pancreatic cells
- Hyposecretion
- Primary Disorder
146
Describe Type 2 Diabetes
- Insulin receptors become insensitive
- Inadequate secretory response by beta pancreatic cells
- Hormone is fine. Receptors are the problem.
147
Describe Metabolic Syndrome -
- precursor to diabetes
- centralized obesity
- high BP
- high triglycerides
- low HDL-cholesterol
- insulin resistance
148
How is C-Peptide release? (Ratio)
1:1 ratio with insulin
149
In Type 1 Diabetes, what happens to you C-Peptide levels?
They are decreased because your beta pancreatic cells (where it comes from) are destroyed.
150
What does it mean to say a GLUT is insulin dependent?
Insulin dependent have to have insulin attached to a receptor to enter cell membrane
151
What does it mean to say a GLUT is insulin independent?
Means the GLUT is always present in the cell membrane where produced. Insulin is NOT needed.
152
Which GLUT transporters are insulin dependent?
Where are they found?
GLUT 4 = dependent.
Found: resting skeletal muscle and adipose tissue
153
Which GLUT transporters are insulin independent?
Where are they found?
GLUT 2 = Independent.
NEVER NOT THERE.
Found in beta pancreatic cells and liver cells.
154
Why is exercise so beneficial to diabetics?
When exercising, need for insulin decreases and GLUT4 transporters are inserted into the cell. Exercise acts as glucose and GLUT4 transporters suck the glucose out of the cells and send it to the muscle. Act as insulin.
155
What is hyperglycemia?
What blood sugar levels constitute hyperglycemia?
High blood sugar.
125 mg/dL and above.
156
What is hypoglycemia?
What blood sugar levels constitute hypoglycemia?
Low blood sugar.
Below 70 mg/dL.
157
What is normoglycemia?
What blood sugar levels constitute normoglycemia?
Normal levels.
Between 70 mg/dL and 100 mg/dL
158
If someone is fasting and their blood sugar is 130 mg/dL or above, what will be diagnosed?
Diabetes
159
In _______ _______, GLUT 4 transporters will be moved into the cell. GLUT 4 transporters wont be inserted into the cell membrane until _______ is present.
1. Resting Muscle
| 2. Insulin
160
When _________, the need for insulin is over-ridden by internal mechanisms within the cell.
What are inserted into the cell membrane and act as insulin?
1. Exercising
| 2. GLUT4 Transporters
161
List four ways below that diabetes can be fetal?
1. Diabetic Ketoacidosis
2. Tissue loss
3. Blood volume drops from dehydration and will then have circulatory failure
4. Toxins in blood
162
True or false: Diabetes is just an endocrine disorder
FALSE
163
Describe the functions of glucagon -
1. Triggers breakdown of glycogen
2. Triggers gluconeogenesis
3. Triggers let down (increases glucogynylysis and gluconeogenesis as well as improved insulin receptor improvement)
164
What are 3 signs of diabetes?
Excessive peeing, drinking and eating
