The Endocrine System: Part 1 Flashcards
0
Q
Endocrine glands include…
A
Pituitary Thyroid Parathyroid Adrenal Pineal
1
Q
Hormones help regulate…
A
Extracellular fluid Metabolism Biological clock Contraction of cardiac and smooth muscle Glandular secretion Some immune functions Growth and development Reproduction
2
Q
The organs that secrete hormones as a second function are…
A
Hypothalamus Thymus Pancreas Ovaries Testes Kidneys Stomach Liver Small intestine Skin Heart Placenta
4
Q
Target cells have a specific _____ to which hormones bind
A
Protein or glycoprotein receptor
5
Q
Receptors are constantly being _____ to help regulate the cell’s response
A
synthesized and broken down
6
Q
Drugs are…
A
synthetic hormones that block the receptors for particular naturally occurring hormones
7
Q
Hormones bind to receptors _____ and may cause the cell to _____.
A
on the cell’s surface or inside the target cell
synthesize new molecules, change permeability of the membrane or alter rates of reactions
8
Q
At liver cells, insulin _____ but at adipocytes it _____.
A
stimulates glycogen synthesis
stimulates triglyceride synthesis
9
Q
Hormones that travel in the blood and act on _____ are called _____ or _____.
A
distant target cells
circulating hormones or endocrines
10
Q
Hormones that act _____ without first entering the bloodstream are called _____.
A
locally
local hormones
11
Q
Paracrines
A
Local hormones that act on neighboring cells
12
Q
Autocrines
A
Local hormones that act on the same cell that secreted them
13
Q
Lipid soluble hormones include…
A
steroids, thyroid hormones and nitric oxide
14
Q
Water soluble hormones include…
A
amines, peptides, proteins and glycoproteins, and eicosanoids
15
Q
Steroids are _____ derived from _____
A
lipids
cholesterol
16
Q
The _____ of steroids provide uniqueness.
A
different functional groups attached to the core of the structure
17
Q
Thyroid hormones are made of _____ and are _____-soluble.
A
a tyrosine ring plus attached iodines
lipid
18
Q
Nitrous oxide is _____ that _____.
A
a gas
acts as a local hormone in several tissues
19
Q
Amines, peptides and protein hormones are _____ and are _____-soluble.
Some examples include…
A
modified amino acids or amino acids put together
water
serotonin, melatonin, histamines and epinephrine as well as some glycoproteins
20
Q
Eicosanoids are _____ and include _____.
A
derived from arachidonic acid
prostaglandins and leukotrienes
21
Q
Protein hormones are _____-soluble and _____ in the blood.
A
water
circulate in free form
22
Q
Steroid (_____) and thyroid hormones must attach to _____ synthesized by _____.
A
lipid
transport proteins
the liver
23
Q
_____ and _____ hormones have a slow loss of hormones within the kidneys and create a reserve.
A
Steroid (lipid) and thyroid
24
Q
Free fraction
A
A hormone is not bound to a transport protein
25
Only _____% of _____ hormones are free fraction
0.1 - 10%
steroid (lipid) and thyroid
26
_____ hormones bind to and activate receptors within cells
Lipid-soluble
27
When a receptor is activated by a lipid-soluble hormone it _____ which results in _____. They then _____ which results in _____
alters gene expression
the formation of new proteins
alter the cell's activity
the physiological responses of those hormones
28
A lipid-soluble hormone diffuses through _____ and binds to the receptor which _____. New _____ is formed and _____ which _____.
the phospholipid bilayer into the cell
turns specific genes on/off
mRNA
directs synthesis of new proteins
alter the cell's activity
29
Water-soluble hormones alter a cell's function by _____ which _____.
activating plasma membrane receptors
sets off a cascade of events inside the cell
30
First messenger
The water-soluble hormone that binds to the cell membrane receptor
31
When the _____ of a water-soluble hormone binds to the _____ receptor, the protein/hormone complex activates _____ which activate _____. A _____ (_____) is released _____ where hormone response takes place.
first messenger
cell membrane
G-protein
adenylate cyclase
second messenger (cAMP)
inside the cell
32
Can water-soluble hormones diffuse plasma membranes?
No
33
Hormone receptors for water-soluble hormones are _____ that act as _____.
integral membrane proteins
first messengers
34
Adenylate cyclase converts _____ into _____ which _____
ATP into cyclic AMP
activates protein kinases
35
Protein kinases _____ which _____ that produce the physiological response
phosphorylate enzymes which catalyze reactions
36
A _____ binds to the membrane receptor and _____ which _____. The_____ converts _____ into _____ which _____. The _____ then _____ that produce _____.
water-soluble hormone
activates G-protein which turns on adenylate cyclase.
adenylate cyclase converts ATP into cyclic AMP which activates protein kinases
protein kinases then phosphorylate enzymes which the catalyze reactions that produce the physiological response
37
Permissive effect
A second hormone strengthens the effects of the first.
Example: thyroid hormone increases receptors for epinephrine.
38
Synergistic effect
Two hormones acting together for greater effect
Example: estrogen and LH are both needed for oocyte production
39
Antagonistic effect
Two hormones act with opposite effects
Example: insulin promotes glycogen formation and glucagon stimulates glycogen breakdown
40
Hormone secretion is regulated by _____.
signals from the nervous system, chemical changes in the blood or by other hormones
41
Negative feedback control
decrease.increase in blood level is reversed
42
Positive feedback control
the change produced by the hormone causes more hormone to be released
43
Disorders involve either _____ or _____ of a hormone.
hyposecretion or hypersecretion
Example: human growth hormone (HGH) and dwarfism vs. gigantism
44
The hypothalamus is the _____ between _____.
major integrating link between the nervous and endocrine systems
45
The hypothalamus receives input from _____.
the cortex, thalamus, limbic system and internal organs
46
The hypothalamus controls the _____ with _____.
pituitary gland with different releasing factors and inhibiting factors
47
The _____ and _____ regulate virtually all aspects of _____
hypothalamus and the pituitary gland
growth, development, metabolism, and homeostasis
48
The pituitary gland is also known as...
the master gland
49
The pituitary gland is located _____ and is differentiated into the _____ (_____) and _____ (_____).
in the sella turcica of the sphenoid bone
anterior pituitary (adenohypophysis) and the posterior pituitary (neurohypophysis)
50
The pituitary gland is a _____ gland found _____ and attaches _____ via the _____.
pea-shaped, 1/2 inch
in the sella turcica of the sphenoid
to the brain via the infundibulum (stalk)
51
The pituitary gland is split into the _____ (_____) which makes up _____% of it and the _____ (_____) which makes up the remaining _____%
anterior lobe (adenohypophysis); 75%
posterior lobe (neurohypophysis); 25%
52
Neurohypophysis
The ends of axons of 10,000 neurons found in the hypothalamus
53
_____ enter the blood and travel through _____ before entering the anterior pituitary at _____.
Hypothalamic controlling hormones; portal veins; capillaries
54
The anterior pituitary hormones are...
```
Human growth hormone (HGH)
Thyroid-stimulating hormone (TSH)
Follicle-stimulating hormone (FSH)
Luteinizing hormone (LH)
Prolactin (PRL)
Adrenocorticotrophic hormone (ACTH)
Melanocyte-stimulating hormone (MSH)
```
55
Human growth hormone (HGH) is secreted by...
somatotrophs
56
Thyroid-stimulating hormone (TSH) is secreted by...
thyrotrophs
57
Follicle-stimulating hormone (FSH) is secreted by...
gonadotrophs
58
Luteinizing hormone (LH) is secreted by...
gonadotrophs
59
Prolactin (PRL) is secreted by...
lactrotrophs
60
Adrenocorticotrophic hormone (ACTH) is secreted by...
corticotrophs
61
Melanocyte-stimulating hormone (MSH) is secreted by...
corticotrophs
62
_____ is the most plentiful anterior pituitary hormone.
Human growth hormone (HGH)
63
HGH acts _____ on tissues by _____ from _____.
indirectly; promoting secretion of insulin-like growth factors (IGFs) from the liver, skeletal muscle, cartilage and bone
64
HGH increases _____ by _____ and it also _____ blood sugar.
cell growth and division by increasing their uptake of amino acids and synthesis of proteins; raises
65
Diabetogenic effect
Excess HGH can lead to diabetes because it raises blood sugar
66
Thyroid-stimulating hormone stimulates _____ as well as _____ the metabolic rate.
the synthesis and secretion of T3 and T4; increases
67
In females, follicle-stimulating hormone (FSH) _____.
initiates the formation of follicles within the ovary and stimulates follicle cells to secrete estrogen
68
In males, follicle-stimulating hormone (FSH) _____.
stimulates sperm production in the testes
69
In females, luteinizing hormone (LH) stimulates _____.
ovulation of the oocyte (egg) from the ovary, formation of corpus luteum, secretion of progesterone and secretion of estrogen.
70
In males, luteinizing hormone (LH) stimulates _____.
the testes to secrete testosterone
71
Prolactin (PRL), together with other hormones, _____. It stimulates _____.
initiates and maintains milk secretion by the mammary glands
breast growth, mammary gland development and milk production
72
Adrenocorticotrophic hormone (ACTH) controls _____ called _____ by stimulating _____.
the production of hormones called glucocorticoids by stimulating the cells of the adrenal cortex that produce them
73
Melanocyte-stimulating hormone (MSH) _____ although _____. It is stimulated by the same _____ that stimulates _____.
increases skin pigmentation although its exact role in humans is unknown.
pituitary hormone; MSH production
74
The posterior pituitary gland (_____) does not _____ but it does _____
neurohypophysis; synthesize hormones; store and release oxytocin (OT) and antidiuretic hormone (ADH)
75
Oxytocin (OT) is made by _____ and is stored in _____ which secretes it.
the hypothalamus; the posterior pituitary (neurohypophysis)
76
Antidiuretic hormone (AH) is made by _____ and is stored in _____ which secretes it.
the hypothalamus; the posterior pituitary (neurohypophysis)
77
The posterior pituitary gland (_____) consists of _____ that release _____ into _____
neurohypophysis consists of axon terminal of hypothalamic neurons that release the neurotransmitters AH and OT into capillaries
78
Oxytocin (OT) has _____ involved in _____.
two target tissues; neuroendocrine reflexes
79
After childbirth, _____ is released by _____ to stimulate _____. _____ can further stimulate that release to help _____ as well as _____.
oxytocin (OT); the posterior pituitary gland; uterine contraction and ejection (let-down) of breast milk.
Nursing a baby; promote uterine contractions as well as the expulsion of the placenta;
80
During childbirth _____ is released to cause uterine contractions. The more baby pushes, the more _____ gets released until the baby is born.
oxytocin (OT)
81
Antidiuretic hormone (AH) stimulates _____ by _____.
water reabsorption by the kidneys and arteriolar constriction
82
The effect of Antidiuretic hormone (AH) is to _____.
decrease urine volume and conserve body water
83
Antidiuretic hormone (AH) is controlled primarily by...
osmotic pressure of the blood
84
Antidiuretic hormone (AH) is also known as...
vasopressin
85
Antidiuretic hormone (AH) functions to _____ by _____.
increase blood pressure by decreasing urine production, decreasing sweating and constricting arterioles.
86
The thyroid gland is located _____ and has _____.
just below the larynx and has right and left lateral lobes
87
Histologically, the thyroid gland consists of _____ composed of _____.
the thyroid follicles composed of follicular cells and parafollicular cells.
88
Follicular cells
Cells found in the thyroid gland that secrete thyroxine (T4) and triiodothyronine (T3)
89
Parafollicular cells
Cells found in the thyroid that secrete calcitonin (CT)
90
Each _____ of the thyroid, which weighs _____, is located _____ and has _____.
lobe; 1oz; on either side of the trachea; a rich blood supply
91
A follicle is _____ (examples: _____) and is located in between _____ which _____
a sac of stored hormones surrounded by the follicle cells that produced it (examples: triiodothyronine (T3) and thyroxine (T4)/; parafollicular cells which produce calcitonin
92
The thyroid hormones _____ and _____ are responsible for _____.
triiodothyronine (T3) and thyroxine (T4); our metabolic rate, synthesis of protein, breakdown of fats, and use of glucose for ATP production
93
Calcitonin (CT) is responsible for _____ and stops _____ by _____.
the building of bone and stops reabsorption of bone by lowering the levels of calcium in the blood
94
Negative Feedback For The Release of T3 & T4:
1) Low blood levels of T3 and T4, or low _____, stimulates the release of _____.
2) _____ is carried by _____ to _____ which stimulates the release of _____ by _____.
3) _____ is released into the blood and stimulates _____.
4) _____ are released into the blood by _____.
5) Elevated _____ inhibits _____
1) metabolic rates; TRH
2) TRH; hypophyseal portal veins to the anterior pituitary gland; TSH by thyrotrophs
3) TSH; thyroid follicular cells
4) T3 and T4; follicular cells
5) T3 inhibits the release of TRH and TSH
95
Parathyroid glands are found _____ and are the _____ that produce _____.
embedded on the posterior surfaces of the lateral lobes of the thyroid; principal cells; parathyroid hormone (PTH)
96
Parathyroid hormone (PTH) regulates _____.
the homeostasis of calcium
97
Parathyroid hormone (PTH) _____ the level of _____ in the blood by either _____, _____, or _____.
increases; calcium; increasing the number and activity of osteoclasts, increasing the rate of calcium reabsorption from urine, or promoting formation of calcitriol
98
Calcitriol, which is secreted by _____, is activated by _____ and works to _____.
parathyroid glands; vitamin D; increase the absorption of calcium from the GI tract
99
There are _____ glands found _____ called parathyroid glands.
4 pea-sized; on the back of the thyroid gland
100
Blood calcium levels directly control _____ via _____ that do not involve _____.
the secretion of calcitonin and PTH via negative feedback loops; the pituitary gland
101
High calcium levels cause the release of _____ from _____.
calcitonin from the parathyroid glands
102
Low calcium levels cause the release of _____ from _____.
PTH from the thyroid glands
