Endocrine Flashcards
1
Q
Water soluble hormone act on…
A
Plasma membrane receptors since it cannot enter cells
2
Q
Lipid soluble hormones act on
A
Intracellular and plasma membrane receptors since it can enter the cell
3
Q
Water soluble hormones are
A
Protein and amino acid based hormones
4
Q
Lipid soluble hormones are
A
Steroid and thyroid hormones
5
Q
Main types of hormones
A
1) Protein and peptide hormones e.g. Insulin
2) Amino acid derivatives from tyrosine e.g. Epinephrine, Norepinephrine
3) Steroid hormones e.g. oestrogen, testosterone
6
Q
Hormone actions on target cells include
A
- Alters plasma membrane permeability
- Stimulates protein synthesis
- Activates (or deactivates) enzymes
- Induces secretion of other substances(Tropic hormone?)
- Stimulates cell division
7
Q
Target cells have
A
Specific receptors which the hormone binds to
8
Q
Protein/AA-based hormones
A
Freely dissolved in plamsa
9
Q
Steroid and Thyroid hormones
A
Bound to protein carriers
10
Q
Humoral stimuli
A
Changes in plasma solute concentrations of ions or
organic nutrients
11
Q
Neural stimuli
A
Regulation by the nervous system
12
Q
Hormonal stimuli
A
Regulation by other hormones
13
Q
Positive feedback
A
enhances the stimulus
14
Q
Pineal gland secretes
A
Melatonin
15
Q
Hypothalamus role is to
A
Stimulate release of hormones from the anterior pituitary gland (tropic response)
16
Q
Hypothalamus produces
A
1) Oxytocin
2) Anti-diuretic hormone (ADH)
3) Corticotropin-releasing hormone
4) Thyrotropin-releasing hormone (TRH)
5) Gonadotropin-releasing hormone (GnRH)
6) Growth hormone-releasing hormone (GHRH)
17
Q
Melatonin
A
Helps sustain sleep cycles
18
Q
Oxytocin
A
- Stimulates contraction of smooth muscle in uterus
* Secretion at birth (labour) and during breast feeding
19
Q
Anti-diuretic hormone (ADH)
A
↑ blood concentration, ↓ blood volume or ↓ blood pressure
20
Q
Corticotropin-releasing hormone
A
Stimulates adrenocorticotropic hormone release from anterior pituitary
21
Q
• Corticotropin-Releasing Hormone (CRH)
• Growth Hormone-Releasing Hormone (GHRH)
• Thyrotropin-Releasing Hormone (TRH)
initiates the
A
Long lasting response to stress
22
Q
Pituitary gland role is to
A
Secretes 9 hormones that regulate most other endocrine glands in the body
23
Q
Anterior pituitary gland releases
A
1) Oxytocin
2) ADH
1) Growth Hormone (GH)
2) Thyroid Stimulating Hormone (TSH)
3) Adrenocorticotropic Hormone (ACTH)
4) Prolactin (PRL)
5) Follicle Stimulating Hormone (FSH)
6) Luteinizing Hormone (LH)
7) Melanocyte Stimulating Hormone (MSH)
24
Q
Posterior pituitary gland releases
A
1) Oxytocin
2) ADH
25
Growth Hormone (GH)
* Promotes protein synthesis & growth of body cells
| * Influences carbohydrate & fat metabolism
26
Thyroid Stimulating Hormone (TSH)
Controls production and release of thyroid hormone by
| the thyroid gland
27
Adrenocorticotropic Hormone (ACTH)
Controls hormone production and release by the adrenal cortex
28
Prolactin (PRL)
Starts/maintains milk production
29
Follicle Stimulating Hormone (FSH)
* Women: Stimulates the development of ova & production of oestrogen
* Men: Stimulates sperm production
30
Luteinizing Hormone (LH)
* Women: Stimulates ovulation, formation of corpus luteum & secretion of progesterone
* Men: Stimulates development of interstitial cells of testes & production/secretion of testosterone
31
Melanocyte Stimulating Hormone (MSH)
Controls production & secretion of melanin
32
Negative feedback of anterior pituitary gland
1) Stimulus
2) Releasing hormone from hypothalamus
3) Trophic hormone from anterior pituitary
4) Target gland releases target hormone for necessary biological effect
33
Thyroid gland produces
1) Thyroid Hormone
| 2) Calcitonin
34
Thyroid Hormone (TH)
Increases metabolic rate & heat production
Also
• Maintaining blood pressure
• Regulating tissue growth
• Development of skeletal & nervous system
• Reproductive capabilities
35
Calcitonin
• Stimulates Ca2+ uptake and absorption by bones
• Inhibits osteoclast activity, and thus the release of
Ca2+ from the bone matrix
36
Thyroid hormone synthesised in
Lumen of thyroid glands
37
Parathyroid releases
Parathyroid hormone
38
Parathyroid hormone
Increases plasma calcium by increasing:
• Absorption of calcium by the digestive tract
• Reabsorption of calcium by the kidneys
• Phosphate excretion by the kidneys
• Activity of osteoclasts = more calcium released into the
blood
39
Thyroid gland stimulus
Humoral stimulus
Stimulus is calcium levels too high
Releases calcitonin which increases uptake and absorption of calcium into bones
40
Parathyroid gland stimulus
Humoral stimulus
Stimulus is calcium levels too low
Releases parathyroid hormone which activates osteoclasts to breakdown bones and release calcium. Improves absorption of calcium from GI tract and decreases calcium loss in urine.
41
Pancreas (beta cells) stimulus
Humoral stimulus
Stimulus is blood glucose too high
Insulin increases uptake of glucose into tissue cell and stimulates glycogen formation in liver and muscle
Increases formation of fat
42
Pancreas (alpha cells) stimulus
Humoral stimulus
Stimulus is blood glucose too low
Glucagon stimulates breakdown of glycogen breakdown and gluconeogenesis in liver. Increase release of glucose into blood
43
Hypothalamus stimulates
Release of anterior pituitary gland which stimulates release of adrenal cortex.
Stimulus is stress
Corticotropin-releasing hormone (CRH) released from hypothalamus, stimulates anteriors piturtary to release adrenocorticotropin (ACTH), stimulates adrenal cortex to release cortisol. Cortisol is anti-inflammatory, increases blood glucose, promotes protien and fat conversion into glucose (gluconeogenesis), and more fuel to deal with stress
44
Renin-angiotensin-aldosterone system
Stimulus is low blood pressure
Causes renin to be released from kidney which converts angiotensinogen into angiotensin causing vasoconstriction. Angiotensin stimulates aldoterone release from adrenal cortex, cauing sodium reabsorption at kidney, increased water reabsorption by osmosis which increases blood volume --> negative feedback
45
Thymus secretes
Thymic Hormone which is a range of collective substances
46
Pancreas (exocrine and endocrine) duct cells produce
1) Bicarbonate neutralise
| 2) Stomach acidity
47
Pancreas (exocrine and endocrine) cells produce
Digestive enzymes
48
Alpha cells produce
Glucagon (a hyperglycaemic hormone)
49
Beta cells produce
Insulin (a hypoglycaemic hormone)
50
Acinar cells produce
Pancreatic juices for digestion
51
Glucagon
1) Elevates blood glucose
2) Major target is the Liver, where it promotes…
• Glycogenolysis
• Gluconeogenesis
• Release of glucose to the blood
52
Insulin
* Lowers blood glucose
* Enhances membrane transport of glucose into fat & muscle cells
* Inhibits glycogenolysis & gluconeogenesis
* Participates in neuronal development, learning & memory
53
Cortex produces
Cortical steroid hormones
54
Medulla produces
Epinephrine & norepinephrine
55
Adrenal cortex produces the hormones
1) Mineralocorticoids
2) Glucocorticoids
3) Gonadocorticoids
56
Mineralocorticoids
Regulate H2O and minerals in the blood (BP + volume)
• E.g. Aldosterone
• retains NaCl, bicarbonate & H2O by the kidneys
• ↑ excretion of potassium
57
Glucocorticoids
* Regulate metabolism and stress response
* E.g. Cortisol –
* promotes protein & fat breakdown, increases blood glucose
* Maintain BP by ↑ action of vasoconstrictors
* ↓ inflammation & depresses the immune system
58
Gonadocorticoids
Sex Hormones
| • E.g. Androgens, Estrogens, Progesterone
59
Adrenal medulla produces the hormone
1) Catecholamines
• Epinephrine & Norepinephrine
• Also known as Adrenaline/Noradrenaline
60
Catecholamines
Released in response to stress, they cause:
• ↑ blood glucose & fatty acid levels
• ↑ blood vessel constriction
• ↑ heart rate
• Blood to be diverted to the brain, heart and skeletal muscle
61
Gonads produce
1) Oestrogen
2) Progesterone
3) Testosterone (& Inhibin)
62
Gonads
Develop gametes (ova & sperm)
• Maturation of the reproductive tract at puberty
• Development of secondary sexual
characteristics
Female gonads are ovaries and male gonads are
testes
63
Testosterone
```
• Maturation of reproductive organs
• Appearance of secondary sex
characteristics & sex drive
• Necessary for normal sperm
production
• Maintains organs in functional state
```
64
Oestrogen and progesterone
```
• Maturation of reproductive organs
• Appearance of secondary sex
characteristics
• Breast development & cyclic changes
in lining of uterus
• Increased flexibility of tissues
involved in labour (Relaxin)
```
65
The heart produces
Atrial Natriuretic Peptide
66
Atrial natriuretic peptide
Reduces BP, blood volume and blood Na+ concentration
67
The kidneys produce
1) Erythropoietin
| 2) Renin
68
Erythropoietin
Signals production of red blood cells
69
Renin
Starts the Renin-Angiotensin mechanism
70
The liver produces
Angiotensin
71
Angiotensin
Stimulates secretion of aldosterone, to increase Na+ and water retention by kidneys
72
The gastrointestinal tract cells produce
1) Gastrin
| 2) Secretin
73
Gastrin
Stimulates release of HCl
74
Secretin
Stimulates liver & pancreas to produce bicarbonate
75
Adipose Tissue produces
Leptin
76
Leptin
Is involved in appetite control, and stimulates increased energy expenditure
77
The skin produces
Cholecalciferol
78
Cholecalciferol
Is the precursor of vitamin D
79
A stressor
Any stimulus that produces a stress response
80
Stress benefits
* Increased oxygen and glucose
* Increased activity of respiratory and cardiovascular systems
* Glucagon from pancreas increases metabolism
* Functions not useful for ‘Fight or Flight’ are inhibited
* Enhanced attention, motivation and memory
81
Stress disadvantages
Stressors can cause illness when they:
1) Severely disrupt a person’s life
2) Are uncontrollable
• Prolonged stress (at least 6 months) can deplete the body’s resources
• Chronic stress can also lead to development of diseases & illness
82
Stress response
1) Perception of stressor
2) Activation of the Hypothalamic-PituitaryAdrenal Axis (HPA axis) results in the secretion of:
• Epinephrine & Norepinephrine
• Adrenal Steroids – glucocorticoids & mineralocorticoids
3) Suppression of non-vital functions
83
Short-term stress response
* Increased heart rate
* Increased blood pressure
* Liver converts glycogen into glucose and release glucose into the blood
* Dilation of bronchioles
* Changes in blood flow patterns leading to decreased digestive system activity and reduced urine output
* Increased metabolic rate
84
Long-term stress response
* Retention of sodium and water by kidneys
* Increased blood volume and blood pressure
* Proteins and fats converted to glucose or broken down for energy
* Suppression of immune system
85
General adaptation syndrome
• Controlled by hypothalamus
• Systemic, response to challenge on homeostasis
and returns balance, physical manifestation
coordinated
86
General adaptation syndrome steps
1) Initial flight or fight response (ALARM) Epinephrine & Norepinephrine (catecholamines)
2) Resistance (stress longer than few hours) Cortisol
3) Exhaustion resources depleted, systemic damage
