Endocrine system Flashcards
1
Q
Define paracrines
A
secreted into the tissue fluid by a cell and diffuses to nearby cells
2
Q
Define hormones, and what they do in general
A
chemical messenger into the bloodstream, and stimulates a response in another tissue or organ.
3
Q
What do target cells have specifically for hormones?
A
Target cells have receptors specifically for hormones.
4
Q
What do the Endocrine glands produce?
A
Hormones
5
Q
In general what is the endocrine system ?
A
many hormone producing cells in organs such as brain, heart, and intestines,
6
Q
What two types of glands does the body have?
A
exocrine and endocrine
7
Q
How are substances secreted through exocrine glands?
A
Secreted into ducts that carry into body cavities or surfaces
8
Q
What are some examples of exocrine glands?
A
sweat glands, oily glands, mucous glands, and digestive glands.
9
Q
How are substances secreted through endocrine glands?
A
ductless glands secrete straight into the extracellular space and then diffuse into the blood vessels
10
Q
nervous system adapts ____ while endocrine system adapts_____?
A
Quickly via NT, Slowly via bloodstream(days to weeks)
11
Q
nervous system effects ____while endocrine system effects _____?
A
Local (specific target organs) , general(widespread many organs)
12
Q
What do cells undergo with the endocrine system ?
A
changes in their metabolic activities
13
Q
What does a neuroendocrine cell do?
A
secretes hormones into ECF in response to a neural stimulus.
14
Q
What are two examples of what neuroendocrines secrete?
A
Oxytocin, catecholamines
15
Q
What is an example of a chemical that can act as both a NT and a hormone?
A
Norepinephrine
16
Q
True or false the nervous system and Endocrine system can have overlapping effects on the same target organ.
A
True, both glucagon and norepinephrine causes glycogen hydrolysis
17
Q
How do the nervous system and endocrine system regulate each other?
A
Neurons trigger hormone secretion and hormones stimulate or inhibit neurons.
18
Q
What are the two general classes of hormones ?
A
Lipid soluble derivatives, and water soluble derivatives.
19
Q
What are the two main lipid soluble derivatives ?
A
steroids and fatty acids
20
Q
What are steroids derived from and where are they synthesized ? and what are they mostly for ?
A
derived from cholesterol, synthesized in the smooth ER , and are mostly for sex hormones such as estrogen, progesterone, testosterone.
21
Q
What are fatty acids (eicosanoids) derived from? and what are its two subcategories? Hint. theses are lipid soluble.
A
derived from fatty acids . They contain leukotrienes and prostaglandins.
22
Q
Leukotrienes are mostly action and are involved in what ?
A
tissue inflammation
23
Q
Prostaglandins have local action and are involved with what ?
A
inflammation, smooth muscle contraction, blood flow, intensifying pain, and promotes fever.
24
Q
What inhibits prostagladin synthesis ?
A
asprin and ibuprofen (motrin)
25
What are the three subcategories of water soluble derivatives?
Amino acid, peptide and proteins, and glycoprotiens
26
What are circulating hormones ?
hormones that pass into the blood stream and act on distant target cells.
27
How are circulating hormones inactivated and excreted ?
They are inactivated by the liver and are excreted by the kidney.
28
What are local hormones?
hormones that act locally without 1st entering the bloodstream.
29
What is the difference between paracrines an autocrines?
paracrines act on neighboring cells, autocrines act on the same cell that secretes them.
30
True or false Local hormones are usually inactivated quickly
True
31
True or false hormones can be either lipid or water soluble?
True they can be either
32
Most water soluble hormones circulate in the blood in the ____ form ( attached or not attached)
free form , not attached to a protein
33
Most lipid soluble hormones bind to what?
Transport proteins
34
What are the two transport proteins and where are they synthesized?
Albumin and globulins are synthesized in the liver.
35
What are the four functions of Albumins and globulins?
Improve transportablility, retard passage, and provide a reserve ready with hormones, protects hormones from being broke down by enzymes.
36
How does Albumins and globulins (proteins) improve transportability?
makes the lipid soluble hormone temporarily water soluble
37
How do Albumins and globulins assist in the retard passage?
slows the rate of hormone loss from the urine via the kidneys
38
How do Albumins and globulins provide a reserve for the hormones ?
The reserve is already present in the bloodstream.
39
True or false free hormones can be broken down in minutes whereas bound hormones can circulate for hours.
True
40
define bound hormones
hormones that are bound to a transport protein.
41
define unbound (free) hormone
Not attached to a transport protein.
42
True or false Only the free hormone can leave a blood capillary and get to a target cell.
True
43
What are the 10% of lipid bound proteins that aren't bound to a transport hormone called?
Free fraction
44
What do free fractions do ?
diffuses out to capillaries, binds to receptors, and triggers responses
45
True or false Transport proteins release new ones to replenish the free fraction
True
46
What protein does the thyroid hormone bound mostly to?
thyroxine binding globulin(TBG)
47
True or false T3 and T4 99.8% of the time bound to a protein.
true
48
hormone response depends on what two general things.
The hormone and the target cell.
49
True or false hormones elicit different responses in different target cells .
True , EX, insulin stimulates glycogen synthesis in the liver and triglyceride synthesis in fat cells
50
water soluble hormones have their receptors ____ the cell membrane whereas lipid soluble hormones have their receptors ____ of the cell membrane.
water soluble have their receptors on the membrane , lipid soluble have their receptors within the cytosol or nucleus of the cell.
51
What are the 5 hormone responses ?
synthesis of new molecules, changing permeability of plasma membrane, stimulating the transport of substances into or out of the cell ,altering the rate of specific metabolic reactions, causing contractions of smooth cardiac muscle.
52
How do activated receptors alter gene expression?(lipid soluble)
They can turn off or on specific genes in the DNA .
53
When genes are turned off or on because of an activated hormone receptor how is the cells activity and physiological traits changed because of that hormone ? (lipid soluble)
new messenger RNA is transcribed from which new proteins are synthesized at the ribosomes
54
Describe the steps to activating the second messenger for a water soluble hormone.
1st hormone binds to receptor on plasma membrane
2nd The binding hormone activates the G protein
3rd The G protein activates molecules that activate the enzyme ( adenylate cyclase)
4th The enzyme converts ATP into cAMP (the second messenger)
55
How are G proteins deactivated?
They slowly deactivate on their own unless stimulated by more hormones.
56
Why does Cholera kill ppl
Gives them watery diarrhea and therefore dehydrating them till death
57
The toxin in cholera does what to the G protein that results in large intracellular concentration of cAMP. What results because of this?
modifies the G protein in the IG tract to where it gets locked in the activated state resulting in stimulation of active transport pump that ejects chloride ions followed by sodium ions and water.
58
what does the responsiveness of a target cell to a hormone depends on?
The hormone concentration,The abundance of the target cell’s hormone receptors and Influences exerted by other hormones
59
Explain the permissive effect of a hormone
when the actions of a hormone require recent exposure to another hormone.
60
Explain the synergistic effect of a hormone?
When the effect of two hormones is greater than one acting alone.
61
Explain antagonistic effect of a hormone ?
when one hormone opposes the activation of another hormones
62
Define enzyme amplification
Hormones are amplified because one hormone can trigger thousands of enzymes at a time !
63
Define metabolic clearance rate (MCR)
The rate of hormone removal.
64
Most hormones are taken up and degraded by what two organs?
liver and kidneys
65
True or False, some cells are degraded by the target cells
True
66
Define Half-life
length of time required to clear 50% of the hormone from the blood
67
The faster the MCR the ____ the half life
Shorter
68
Explain down regulation
Cell can decrease responsiveness to hormones by reducing the amount of receptors when hormone is in excess.
69
Explain up regulation
Cell can increase cell sensitivity by increasing the amount of receptors when hormone is deficient
70
What hormone does the abortion pill block ?
Progesterone
71
Hormone secretion is regulated by what 3 ways?
```
Signals from the nervous system (nerve impulses to the adrenal medulla regulate the release of epinephrine)
Chemical changes in the blood (blood calcium regulated the release of parathyroid hormone)
Other hormones (Adrenocorticotropic hormone from the pituitary gland stimulates the release of cortisol by the adrenal cortex)
```
72
Hypo secretion is ______ release of hormone while Hyper secretion is _____ release of hormone.
Hypo secretion: Inadequate
| Hyper secretion : Excessive release
73
True or False most hormonal regulatory systems work via negative feed back
True, except in child birth
74
What structure in the brain sends information to the pituitary and is in charge of water balance and sex drive?
Hypothalamus (forms the walls of the third ventricle)
75
Where is the pituitary gland housed?
housed in the sella turcica and hangs by the infundibulum stalk.
76
What is the major integrating link between the nervous system and endocrine system ?
The hypothalamus
77
The hypothalamus receives input from what 7 structures?
1. Limbic system
2. Cerebral cortex
3. Thalamus
4. Reticular activating system
5. Sensory input from internal organs
6. Retina
7. Painful, stressful, and emotional experiences cause changes in hypothalamus activity
78
what does the hypothalamus control ?
Autonomic nervous system, Regulates body temperature, Thirst, Hunger, Sexual behavior, Defense reaction such as fear and rage
79
What is the crucial endocrine gland?
hypothalamus (synthesizes 9 different hormones)
80
What is another name for the posterior pituitary and anterior pituitary gland?
```
Anterior = Adenohypophysis
Posterior = Neurohypophysis
```
81
True or false Anterior pituitary synthesizes and secretes 6 hormones
True
82
True or false posterior pituitary stores and releases 2 hormones
True, produced in the hypothalamus
83
Which part of the pituitary gland contains axons whose cell bodies are located in the hypothalamus ?
Posterior pituitary
84
What are the three parts to the anterior pituitary gland?
1. pars distalis (most distal to pituitary stalk)
2. pars tuberalis (small mass of cells on anterior side)
3. pars intermedia (only in fetus and other animals)
85
Define hypophyseal portal system?
Complex blood vessels that carries blood between two capillary beds without going through the heart and connect the hypothalamus to the anterior pituitary
86
What connects the primary capillary plexus to the secondary capillary plexus? (hint: hypothalamus to anterior pituitary)
Portal veins
87
what three parts make up the neurohypophysis?
1. Median Eminence (extension of hypothalamus)
2. infundibular stalk
3. posterior lobe (Pars nervosa) [largest part]
88
True or False the neurohypophysis is not a true gland but a mass of neuroglia and nerve fibers
True
89
What is the name of the tract that has cell bodies in the hypothalamus and end in the posterior lobe of the pituitary gland?
hypothalamo-hypophyseal tract
90
Where are the hormones that hypothalamic neurons synthesized stored in the pituitary gland
Posterior pituitary
91
What do tropic hormones target ?
Other endocrine glands
92
What are the 4 tropic hormones of the anterior pituitary lobe?
FSH (follicle stimulating hormone), LH (luteinizing hormone), TSH (thyroid stimulating hormone), ACTH (adrenocorticotropic hormone)
93
what are the 2 direct acting hormones in the anterior pituitary lobe?
PRL (prolactin)
| GH (growth hormone)
94
How many hormones does the hypothalamus produce? How many are for each lobe of the Pit.?
Hypothalamus produces 9 hormones. 7 are for the ant. pit. while the other 2 are for the post. pit.
95
What are the 5 releasing hormones that stimulate the ant. pit. to secret its hormones?
gonadotropin, thyrotropin, corticotropin, prolactin, and growth hormone
96
What are the 2 inhibiting hormones that suppress ant. Pit. secretion ?
prolactin and somatostatin
97
What are the 2 hypothalmic hormones that are secreted to the post. pit.?
Oxytocin and Antidiuretic hormone
98
Which one of the hypothalmic hormone triggers the release of two Ant. Pit. hormones ? (hint: FSH and LH)
Gonadotropin
99
Thyrothrophs secrete TSH that controls what?
| Hint: Tropic
Thyroid gland
100
Gonadotrophs secrete LH and FSH that controls what?(Hint: Tropic)
Ovary and testes
101
Corticotrophs secrete ACTH that controls the what? (Hint: Tropic)
Adrenal gland function
102
Lactotrophs ecretes prolactin (PRL) that controls what?(hint: non-tropic)
controls milk production in the breast
103
Somatotrophs secretes growth hormone (GH) that stimulates what? (hint: non-tropic)
stimulates several tissues to secrete insulin-like growth factors, hormones that stimulate general body growth
104
what is the FSH hormone stimulate in male and females?
stimulates development of eggs, follicles, and estrogen production in females.
stimulates the production of sperm in males
105
What is the LH hormone stimulate in male and females?
stimulates ovulation and formation of corpus, secretes progesterone in females
stimulates testes to secrete testosterone in males
106
What are Leydig cells and what do they produce?
cells that produce testosterone
107
What are sortoli cells and what do they do?
Nurture the developing sperm cells and secrete inhibin
108
what is the PRL hormone stimulate in male and females?
```
female= milk synthesis
male= raises testosterone secretion
```
109
what is the role of the ACTH hormone?
regulates responses to stress, adrenal cortex secretion of glucocorticoids
