the endocrine system Flashcards
1
Q
what is the function of the endocrine system?
A
to maintain homeostasis in the body and allow communication between various organs
2
Q
what does the endocrine system consist of and where?
A
glands (specific organs) scattered throughout the body
3
Q
functions of hormones [5]
A
regulate metabolic processes control the rate of chemical reactions aid in growth and development affect the diameter of blood vessels maintain the level of chemicals in the blood
4
Q
what can hormones be made of?
A
steroids (cholesterol)
amines
peptides
proteins (amino acids)
5
Q
what are the major glands in the body called?
A
pituitary gland thyroid parathyroid adrenal pineal reproductive (testes/ovaries) kidneys pancreas thymus
6
Q
how many hormones does the pituitary gland release?
A
9 different hormones
7
Q
where is the pituitary gland located and what size is it?
A
attached to the hypothalamus of the brain and is 1 cm in diameter
8
Q
what is the pituitary gland composed of and what are the names?
A
anterior lobe and posterior lobe
9
Q
what does the anterior lobe release and what does that do?
A
growth hormone (GH) which promotes growth and maintenance of organs
10
Q
for whom does GH secretion increase?
A
children who are growing and adults who are physically active
11
Q
what is the main target of GH
A
the liver
12
Q
how does GH work?
A
indirectly by stimulating the release of insulin-like growth factor (IGF-1) which acts on bones to promote bone density and calcium deposits and on muscles to increase amino acid uptake and protein synthesis
13
Q
what kind of hormone is GH?
A
anabolic because it induces growth/facilitates organ growth
14
Q
what does GH do on adipose tissue?
A
promotes the breakdown of triglycerides and the release of fatty acids into the circulation which are then taken tot he muscles to be used for energy and it increases the mobilization of energy molecules in the circulation –> lipolytic
15
Q
relation between insulin like growth factor and insulin
A
no association
16
Q
what regulates GH concentrations?
A
the hypothalamus
17
Q
what does the hypothalamus do if GH levels are low
A
releases GHRH which in turn stimulates the anterior pituitary gland to release GH
18
Q
where is the thyroid gland located?
A
below the larynx
19
Q
what are the two thyroid hormones and the cell’s reaction to them
A
T3 and T4; the cells respond more to T3 than T4 and T4 gets converted to T3 in the circulation before interacting with cells
20
Q
how do thyroid hormones increase metabolism?
A
increase the mobilization and uptake of energy generating molecules
21
Q
how do the thyroid hormones act on the small intestine?
A
they increase the absorption of carbohydrates
22
Q
thyroid hormones and adipose tissue
A
the hormones increase the breakdown of triglycerides and the release of fatty acids into the circulation
23
Q
what overall effect do the thyroid hormone’s interactions with the small intestine and adipose tissue have
A
increase the availability of energy molecules (glucose and fatty acids) for cells to increase ATP production and by increasing the metabolism they have an effect on producing heat and maintaining constant body temperature
24
Q
when do thyroid hormone levels increase
A
during exercise and muscle activities
25
what are the thyroid hormone's influence on the heart and blood vessels
similar to catecholamines
26
what regulates the release of thyroid hormones T3 and T4
the anterior pituitary
27
what happens when thyroid hormone levels are low?
the anterior pituitary releases thyroid stimulating hormone (TSH), which acts on the thyroid gland to activate the release of its hormones
28
where are the adrenal glands located?
on top of the kidneys
29
what is the inner layer of the adrenal gland called?
the adrenal medulla
30
what kind of cells make up the adrenal medulla and what are the hormones they excrete called?
chromaffin cells that produce and release catecholamines
31
what are the 2 major catacholamines and at what percentage?
epinephrine (80%) and norepinephrine (20%) aka adrenaline and noreadrenaline
32
what amino acid are the catacholamines derived from?
tyrosine
33
when is epinephrine released and what is it's effect (macro and chemical)
released when the sympathetic nervous system (SNS) is activated and it allows the body to adapt to the demands of exercise
it binds to adrenergic receptors around the body once in circulation
34
interaction between thyroid hormone and adrenergic receptors
thyroid hormone increases the synthesis of adrenergic receptors
35
what happens with epinephrine and the lungs
it binds to beta-adrenergic receptors on smooth muscles around the bronchioles and causes the bronchioles to relax and increases the diameter of airways
36
how does epinephrine affect the heart
increases its output by increasing the force of contraction (it beats stronger and faster)
37
how does epinephrine increase the delivery of nutrients to muscle cells
by vasodilating the the blood vessels that supply skeletal muscles
38
how does epinephrine interact with the digestive system?
it decreases the blood flow through vasoconstriction so more energy can go to the muscles
39
epinephrine and the liver
promotes glycogenlysis
40
epinephrine and the adipose tissue
lipolysis
41
how does epinephrine affect nutrient breakdown and availability in circulation
it promotes it
42
what is cortisol (type/where it's released from)
a steroid hormone released from the adrenal cortex of the adrenal gland
43
what happens to cortisol during stressful situations (exercise, emotional stress)
the amount of plasma cortisol increases
44
what stimulates the secretion of cortisol and where is this released from?
adrenocorticotropic hormone (ACTH) which is released from the anterior pituitary
45
what is one of the major reasons for cortisol release?
to mobilize fuel molecules to the necessary tissues
46
what does cortisol do?
promotes the breakdown of proteins, fats, and glycogen and during stressful situations it delegates glucose use sparingly
47
how does cortisol regulate glucose (what is happening)
minimizes the uptake of glucose by the muscles so the molecules can be saved for brain cells and promotes lipolysis in adipose tissue and proteolysis in skeletel muscles to ensure other energy molecules are available for the muscles
48
how does cortisol interact with protein synthesis and the immune system
it inhibits protein synthesis and decreases immune system activity
49
what happens when cortisol levels are high?
levels of glucose, fatty acids, and amino acids increase
50
what is proteolysis
breakdown of muscular proteins for fuel (muscle loss)
51
how does exercise affect cortisol release
the more active a person is, the more they adapt to stress and release less cortisol
52
active vs sedentary release of cortisol when exercising
active release less than sedentary who just started exercising
53
what is the outer layer of the adrenal gland called?
adrenal cortex
54
what kind of gland is the pancreas
an endocrine and exocrine gland
55
what does the exocrine function of the pancreas deal with?
release of enzymes
56
what does the endocrine function of the pancreas deal with
release of 2 hormones with roles in plasma glucose level regulation
57
what 2 hormones does the endocrine function of pancreas release?
insulin and glucagon
58
what is homeostasis
maintaining the normal (consistent) level of glucose
59
what 3 components make up the homeostatic system
a receptor, a regulator, and an effector
60
what is the receptor in a homeostatic system and what is its function?
an organ or a group of cells that measures the specific concentration of glucose in the blood - only function is to measure the level
61
what is the control center of a homeostatic system?
the decision maker which signals changes in the body and it has a "set point" which is the accepted value of the monitored parameter
62
what is the effector of a homeostatic system?
the component that makes the changes needed in the body to restore the deviation and return the value to the programmed set point
63
what is the normal level of glucose in the blood?
70 - 100 mg/dl
64
which cells are the glucose receptors?
the beta cells of the pancreas
65
how does insulin lower the amount of sugar in the blood?
it allows the sugar in circulation to enter the cells of the muscles, the liver, and adipose tissue; it increases the permeability of the cells for glucose but increasing the number of entrance channels on the membrane
66
what happens to glucose taken to the muscles
stored in the form of glycogen
67
what happens to the glucose taken to the liver?
converted to glycogen
68
what can the glucose in the muscles and liver be used for
muscles - exclusively muscle activity
| liver - any cell in the body as needed
69
what happens to the glucose taken to the adipose tissue?
energy to power the adipose tissue metabolism or converted to lipids
70
what happens during sleep to blood sugar levels and what does the body do about it?
blood sugar levels drop so the homeostatic system kicks in
71
what are the receptors for low blood sugar levels
alpha cells of the pancreas
72
what do the receptors release?
glucagon
73
where does glucagon act?
mainly the liver by promoting the breakdown of glycogen into glucose and releasing glucose back into circulation
74
how are insulin and glucagon related?
they have opposite effects so are antagonistic
75
what is an example of the homeostatic system failing?
diabetes
76
where is estrogen produced?
females: mainly ovaries and a little in the adrenal cortex
males: a testosterone conversion using the enzyme aromatase
77
what is the main role of estrogen?
to regulate the menstrual cycle
78
non reproduction functions of estrogen
increases bone density (fights osteoporosis) and decreases risk of cardiovascular diseases
79
how does estrogen decrease the risk of cardiovascular diseases
promotes vasodilation by increasing the synthesis of nitric oxide and modulates the action of epinephrine
80
how does estrogen improve the lipid profile?
lowers LDLs and increases HDLs
81
what happens to estrogen during exercise?
promotes lipid oxidation and decreases glucose oxidation
82
where is testosterone released?
males: testes
83
what is the main function of testosterone?
reproduction - affects the formation of sex cells
84
non reproductive roles of testosterone
anabolic hormone that promotes protein synthesis in muscles and calcium deposits in bones
85
how does testosterone affect the skeleton?
increases the size and strength of skeletal muscles as well as the strength of bones
86
how does testosterone affect the muscles?
induces glycogen synthesis
87
how does exercise affect testosterone levels?
increases levels
88
What is the endocrine system
A system of glands throughout the body that release hormones
88
What is the endocrine system
A system of glands throughout the body that release hormones
89
what does the hypothalamus do?
releases releasing hormones - stimulates the pituitary gland to release hormones that bind to other glands to induce them to release their hormones
89
What does the hypothalamus do?
Releases releasing hormones which bind to the pituitary glands to release pituitary hormones which bind to those glands to induce the release of their hormones
90
how do glands know when to release hormones?
when homeostasis has been thrown off balance
90
When do glands release there hormones?
When homeostasis is out of balance
91
types of hormones [3]
peptide, steroid, amine
91
What are the 3 types of hormones
Amine; peptide; steroid
92
what is a peptide hormone made of?
made of amino acids
92
What is an amine hormone
Made of tyrosine
93
what is a steroid hormone made of?
cholesterol
93
What is a steroid hormone
Made of cholesterol
94
what is an amine hormone made of?
tyrosine
94
What is a peptide hormone
Made of amino acids
95
what type of hormone is growth hormone?
steroid
95
What type of hormone is growth hormone
Steroid hormone
96
where is growth hormone released from?
anterior pituitary
96
Where is growth hormone released from?
Anterior pituitary
97
what organ does growth hormone target and what does it do?
the liver
97
What organ does growth hormone target
The liver
98
what is the function of growth hormone
- releases IGF-1 which targets bone and muscle and induces growth in bone and muscle by increasing protein synthesis and inducing cell division in bones
98
What does the liver do once it has been stimulated with growth hormone
Releases IGF-1 which targets bones and muscles and induces growth by increasing protein synthesis in muscles and increasing cell division in bones
99
when do people release growth hormone?
during childhood/adolescence (growing) or during exercise (adults)
99
When is growth hormone released
When humans are growing or during exercise
100
what type of hormone is thyroid hormone?
amine
100
What type of hormone is thyroid hormone
An amine
101
where is thyroid hormone released from?
the thyroid gland
101
Where is thyroid hormone released
The thyroid gland
102
what does thyroid hormone target?
every cell in the body
102
What does thyroid hormone target
Every cell in the body
103
what is the function of thyroid hormone?
helps maintain temperature and increased energy molecule mobilization in blood
103
What is the function of thyroid hormone
Helps maintain temperature and increases energy molecule mobilization in blood
104
what type of hormone is epinephrine/norepinephrine?
amine (adreniline/noradrenaline)
104
What type of hormone is norepinephrine/epinephrine
Amine
105
where is epinephrine/norepinephrine released from?
adrenal gland above the kidney
105
What does norepinephrine/epinephrine do?
Fight or flight response - increases heart rate and blood pressure and diverts blood to muscles instead of gut and dilates pupils and airways (adrenaline/noradrenaline)
106
what does epinephrine/norepinephrine do?
fight or flight response: increases heart rate and blood pressure, diverts blood to the muscles and away from the gut, dilates pupils and airways
106
Where is norepinephrine/epinephrine released from?
The adrenal glands above the kidneys
107
What type of hormone is cortisol
Steroid
108
Where is cortisol released from?
Adrenal cortex (outer part of adrenal gland)
109
What does cortisol do?
Increases availability of glucose by increasing breakdown of fatty acids from adipose tissue
Increases breakdown of proteins in skeletal muscles
Can suppress immune system
110
Activity level and cortisol release relationship
Sedentary release more cortisol
| Active are adjusted to stress and release less cortisol
111
What type of hormone is insulin
Peptide
112
Where is insulin released from?
Beta cells of the pancreas
113
What does insulin do?
Decreases blood glucose
114
What organs does insulin target?
Liver, bones, adipose tissue cells
115
What type of hormone is glucagon
Peptide
116
Where is glucagon released from?
The alpha cells of the pancreas
117
What does glucagon do?
Increases blood glucose
118
What organs does glucagon target?
Only the liver
119
2 types of gonads
Testes and ovaries
120
What hormone do the testes secrete
Testosterone
121
What type of hormone is testosterone
A steroid
122
What does testosterone do?
Stimulates growth and maintenance of male reproductive system
123
What effect does testosterone have on the body?
Increases bone density and calcium deposition; increases muscle strength and size
124
How to increase testosterone secretion
Exercise
125
What do the ovaries secret
Estrogen
126
What type of hormone is estrogen
A steroid hormone
127
What does esteogen do?
Maintains and directs female reproductive system
128
What effect does estrogen have on the body?
Increases bone density and calcium deposition, increases vasodikation by increasing nitric oxide production in endothelial layer (after menopause these good effects go away)
129
Where is estrogen released from?
Ovaries (male gonads)
148
What are the 2 major catecholamines?
Epinephrine and norepinephrine (adrenaline/noradenaline)
149
Where are catacholamines released from? And what kind of cells?
Adrenal medulla (inner layer of adrenal gland) and made of chromaffin cells
