Chapter 18 - Endocrine System Flashcards
(96 cards)
1
Q
direct communication
A
- Exchange of ions/molecules bw adjacent cells across gap junctions
- Occurs between two cells of same type
- rare
2
Q
paracrine communication
A
Chemical signals transfer info from cell to cell within 1 tissue
3
Q
autocrine communication
A
- Messages affect the same cells that secrete them
- Chemicals involved are autocrines
- Example: prostaglandins secreted by smooth muscle cells cause the same cells to contract
4
Q
endocrine communication
A
- Endocrine cells release hormones that are transported in bloodstream
- Alters metabolic activities of many organs
5
Q
both endocrine and nervous systems
A
– Rely on release of chemicals that bind to specific
receptors on target cells
– Share many chemical messengers (e.g., norepinephrine and epinephrine)
– negative feedback
– Function to preserve homeostasis by regulating activities
6
Q
transport of hormones
A
may circulate freely or travel bound to special carrier proteins
7
Q
inactivation of hormones
A
remain functional for < hour and are inactivated when they
- Diffuse out of bloodstream and bind to receptors on target cells
- broken down by liver or kidneys
- broken down by enzymes in blood or interstitial fluids
8
Q
thyroid and steroid hormones
A
- Remain functional much longer
- > 99% become attached to special transport proteins in blood
- Equilibrium state exists bw free and bound forms
- Bloodstream contains bound hormones
9
Q
pineal gland
A
melatonin
10
Q
parathyroid glands
A
parathyroid hormone PTH
11
Q
hypothalamus
A
Production of ADH, OXT, and regulatory hormones
12
Q
thyroid gland hormones
A
thyroxine T4
triiodothyronine T3
Calcitonin CT
13
Q
adrenal glands hormones
A
Medulla -Epinephrine (E) (anabolic) -Norepinephrine (NE) Cortex -Cortisol, corticosterone, cortisone, aldosterone, androgens
14
Q
pancreas (pancreatic islets)
A
insulin, glucagon
15
Q
heart
A
atrial and brain natriuretic peptide (ANP and BNP)
16
Q
thymus
A
thymosins
17
Q
adipose tissue hormone
A
leptin
-control of appetite
18
Q
kidneys hormone
A
• Erythropoietin (EPO) • Calcitriol • renin -converts angiotensinogen to angiotensin I In the lungs, angiotensin-converting enzyme converts angiotensin I to angiotensin II
19
Q
digestive tract controls
A
glucose, metabolism, and appetite
20
Q
control of hormone secretion
A
May involve only one hormone
21
Q
humoral stimuli
A
Control hormone secretion by heart, pancreas, parathyroid gland, and digestive tract
22
Q
hormonal stimuli
A
- May involve one or more intermediary steps
- Two or more hormones involved
23
Q
neural stimuli
A
Hypothalamus provides highest level of control
24
Q
steroid hormones diffuse
A
through plasma membranes and bind to receptors. binds hormone-receptor complex to DNA. activates specific genes. transcription and mRNA production. translation and protein synthesis. target cell response.
25
production of antidiuretic hormone (ADH) and oxytocin (OXT)
release from posterior lobe of pituitary gland (hypothalamus)
26
secretion of regulatory hormones to control activity of anterior lobe of pituitary gland
controls other endocrine organs
27
hypothalamus produces a releasing hormone (RH) to
stimulate hormone production by other glands. homeostatic control occurs by negative feedback.
28
TRH -->
TSH --> thyroid gland --> thyroid hormones
29
CRH -->
ACTH --> adrenal cortex --> glucocorticoids
30
GnRH -->
FSH and LH
FSH--> testes (inhibin) and ovaries (inhibin estrogens)
LH --> testes (androgens) and ovaries (progesterone estrogens)
31
hormones
secreted into bloodstream
32
hormones of anterior lobe
- Thyroid-stimulating hormone (TSH)
– Adrenocorticotropic hormone (ACTH)
Released due to corticotropin-releasing hormone (CRH)
– Prolactin (PRL)
Release inhibited by prolactin-inhibiting hormone (PIH)
Release stimulated by prolactin-releasing hormone (PRH)
– Growth hormone (GH), or somatotropin
– Gonadotropins
33
ACTH released into blood targets
adrenal medulla and releases epinephrine and norepinephrine
34
release of epinephrine and norepinephrine? (or release of adrenaline)
hormonal release and nervous release
35
GH (growth hormone) targets
liver and releases IGF and somatomedins (has direct affect on bones and muscles)
36
PRL stimulates
(prolactin) mammary gland
37
MSH
melanocyte-stimulating hormone and releases melanocytes (uncertain significance)
38
somatomedins (GH)
- tissue growth
- increase uptake of AA
- stem cells in epithelia and connective tissues divide
- glucose sparing effect- breakdown of triglycerides in adipocytes
- diabetogenic effect- breakdown of glycogen by liver cells
39
OXT
males- smooth muscle
| females - uterine smooth muscle and mammary glands
40
T4 has
| T3 has
4 iodine atoms
| 3 iodine atoms
41
thyroglobulin
- contains tyrosine
| - secreted into colloid of thyroid follicles
42
homeostasis normal conc of GH in prof is
lower than in us. and in us is lower than in teenagers.
1. age
2. M/F
3. physical activity (more physic activity, higher gh)
43
homeostasis disturbed by
homeostasis is restored by
decreasing T3 and T4 conc in blood
increasing T3 and T4 conc in blood
44
thyroid hormones
-affects almost every cell in body
-binds to receptors
in cytoplasm, on surfaces on mit, in nucleus
-in children, essential to normal development
45
calorigenic effect
thyroid hormones activate genes involved in glycolysis and ATP prod
- increased energy consumption and heat generation in cells
- strong, immediate, short lived increase in rate of cell. metabolism
- effects anabolic and catabolic
46
(thyroid gland) C cells produce
calcitonin (CT)
- regualtes Ca2+ conc in blood
- stimulates Ca excretion by kidneys
- prevents Ca absorption by digestive tract
47
thyroid hormones effects
- increase heart rate and force of contraction
- elevates O and energy consumption
- stimulate red blood cell formation
- increases sensitivity to sympathetic stimulation
- stimulates activity in other endocrine tissues
48
parathyroid glands
-2 pairs
| – 4 glands weigh 1.6 g
49
parathyroid hormone (PTH)
-secreted bc low Ca2+ conc in blood
– Antagonist for calcitonin
-stimulates osteoclasts
Accelerates mineral break and Ca2+ release
– Enhances reabsorption of Ca2+ by kidneys, reducing urinary losses
– Stimulates formation and secretion of calcitriol (increases Ca by taking from bones) by kidneys
50
our body temp
37 deg C
51
sympathetic stimulation: you have adrenaline everywhere. what does adrenaline do?
increases heart rate (increasing AP, faster myosin and actin) and increases sweat. for HR to come up, contractions are faster.
52
average heart rate
64
53
heart rate decreases with
age
54
antagonist
positive feedback
55
adrenal glands
-superficial adrenal cortex
-inner adrenal medulla
Lie along superior border of each kidney
– Superficial adrenal cortex
Stores lipids (cholesterol and fatty acids)
– Inner adrenal medulla
produces corticosteroids
Secretory activities controlled by sympathetic division of ANS
Produces epinephrine and norepinephrine (catecholamines)o
56
fight or fight (sympathetic hormones) controlled by
adrenal glands
57
Zona glomerulosa
| – Outer region of adrenal cortex
– Produces mineralocorticoids (ex aldosterone)
– Aldosterone
Conserves Na ions and eliminates K ions
Increases sensitivity of salt receptors in taste buds (Secreted in response to
– Drop in blood Na+, blood volume, or blood pressure
– Rise in blood K+ concentration)
58
Zona fasciculata
– Produces glucocorticoids
Ex: cortisol, corticosterone, and cortisone
-negative feedback
-inhibitory effect on CRH
-stimulated by ACTH in anterior pituitary
59
if glucocorticoids are high
your ACTH levels go down
60
effects of glucocorticoids
on body cells
– Accelerate glucose synthesis
– Have anti-inflammatory effects
Inhibit activities of white blood cells and other components of immune system
61
Zona reticularis
-Androgen secretion is stimulated by ACTH
| Some are converted to estrogens in bloodstream Stimulate development of pubic hair before puberty
62
In skeletal muscles, E and NE trigger
in adipose tissue?
in liver?
in heart?
trigger mobilization of glycogen reserves and breaks down glucose faster
-In adipose tissue, stored fats broken down into fatty acids
– In liver, glycogen molecules are broken down
– In heart, heart beats faster and strengthens cardiac muscle contraction
63
making testosterone before
making estrogen
64
increase in glucocorticosteroids
| decrease in glucocorticosteroids
Cushings syndrome
| Addisons disease
65
increase in gonadocorticosteroids
| decrease in gonadocorticosteroids
masculinization of females (adrenogenital syndrome)
| no effects known
66
increase in catecholamines
| decrease in catecholamines
hypertension
| unimportant
67
carbohydrate/lipid/protein synthesis
mobilizes fats, important for protein synthesis
68
gastrointestinal (GI) system
increases secretion of digestive juices
69
integumentary system
secretory activity of skin and normal hydration
70
cortisol
oscillates. is ACTH oscillating? yes. catabolic.
71
growth hormone peaks
during sleep time. high levels of cortisol and no sleep will have a sig effect on a child (can cause short height). not eating enough --> stress.
72
opposite of dwarfism
gigantism
73
pancreas
gastric and endocrine organ that maintain blood sugar levels
Alpha (α) cells produce glucagon
Beta (β) cells produce insulin
74
when blood glucose levels increase
Beta cells secrete insulin
| glucose transporters into target cells, causes someone to gain weight
75
when blood glucose levels decrease
– Alpha cells secrete glucagon
| glycogen breakdown and glucose release by liver
76
insulin
- Stimulating glycogen formation
- Stimulating aa absorption and protein synthesis
- Stimulating triglyceride formation in adipocytes
77
Glucagon
- Stimulating breakdown of glycogen in skeletal muscle fibers and liver cells
- Stimulating release of glucose in liver cells (gluconeogenesis)
- Stimulating breakdown of triglycerides in adipocytes
78
hyperglycemia
Abnormally high glucose levels in the blood
79
Diabetes mellitus
high glucose concentration
– Glucose appears in urine
– Polyuria
Urine volume becomes excessive
80
Type 1 diabetes mellitus
– inadequate insulin production by pancreatic beta cells
– daily injections or infusions of insulin
– Approx 5% of cases
– Usually develops in children and young adults
81
what they tell a diabetes patient?
eat less sugars and exercise
82
Type 2 diabetes mellitus
– Most common
– Normal amounts of insulin are produced, at least initially
Tissues do not respond properly (insulin resistance)
-associated w obesity
83
Complications of untreated or poorly managed diabetes mellitus include
– Kidney degeneration --> hypertension (blood is thick)
– Retinal damage - may lead to blindness
-Heart attacks
– Peripheral nerve problems
– Peripheral tissue damage bc reduced blood flow
Tissue death, infection, and amputation
84
organs with secondary endocrine systems
```
– Intestines (digestive system)
– Kidneys (urinary system)
– Heart (cardiovascular system)
– Thymus (lymphatic system)
– Gonads (reproductive system)
```
85
When a cell receives instructions from two hormones at the same time, four outcomes are possible
-Antagonistic effect
Result depends on balance between two hormones
86
When a cell receives instructions from two hormones at the same time, four outcomes are possible
-Synergistic effect
additive effect
87
When a cell receives instructions from two hormones at the same time, four outcomes are possible
-Permissive effect
One hormone is needed for another to produce effect
88
When a cell receives instructions from two hormones at the same time, four outcomes are possible
-Integrative effect
Hormones produce different but complementary results
89
Growth hormones
in children
in adults
in children
Supports muscular and skeletal development
in adults
Maintains normal blood glucose concentrations (liver)
Mobilizes lipid reserves
90
reserve
lipocyte breakdown
91
mobilizes
move from one place to another
92
stress
Any condition that threatens homeostasis
93
General adaptation syndrome (GAS)
```
Also called stress response
Divided into three phases:
– Alarm phase
– Resistance phase
– Exhaustion phase
```
94
1. alarm phase
- Immediate response to stress
- Directed by sympathetic division of ANS
- Energy reserves (mainly glucose) are mobilized
- Body prepares “fight or flight” responses
- Epinephrine is dominant hormone
95
2. Resistance phase
- When stress lasts longer than a few hours (weeks or months)
- Lipids and aa are mobilized for energy
- glucose levels go up
- Glucocorticoids are dominant hormones
96
3. Exhaustion phase
- Begins when homeostatic regulation breaks down (hypothalamus)
- Drop in K+ levels due to aldosterone produced in resistance phase
- Failure of one or more organ systems will be fatal
ex. diarrhea, heavy breathing
