Organ systems 5) The endocrine system Flashcards
Hormones move around the body in the blood so they need to be __________.
Soluble in blood
How are hormones that are water insoluble carried in the blood?
Special proteins
What is the half life of a hormone dependent on?
Activicty of enzymes in the blood?
Hormones that are water soluble typically find their receptor in the _________
Cell membrane
What kind of hormones can pass through the cell membrane?
Lipid soluble
What hormones regulate metabolism?
Thyroid hormones
What hormones regulate water and electrolyte balances?
antiduoretic hormone
What controlls the patuitry gland?
The hypothalmus
Nerves from the ________extend down into the posterior pituitary and produce ___________
hypophysis
NEUROHORMONES
How do neurohormones get to the anterior patuitry?
Nerves in the hypoathalumus release neurohormones into their capillary bed and capillaries carry them to the anterior patuitry
Where is Antiduoretic hormone (Vasopressin) produced?
When is it released?
What does it do?
Posterior patuitry
blood pressure falls or blood becomes concentrated
causes kidneys to retain water
Where is oxytosin produced?
When?
Posterior pituitary
Stretch of the uterus, mechanical stimulation of the cervix as well as stimulation of the nipples when a baby is nursing cause release of oxytocin.
What does oxytosin cause? (physically)
- assist in expulsion of the foetus.
- in non-pregnant women to remove menses and assist movement of sperm after sexual intercourse.
- Milk ejection in lactating females
What are hormones produced by the anterior pituitry known as?
What is their special function?
TROPHIC
these control the activity of other glands
Control of secretion of GH is by _____________ and Growth ___________ produced by the _________typically in response to _______________.
GH releasing hormone
GH inhibiting hormone
hypothalamus
low blood glucose etc
What is the effect of GH?
Stimulate growth in most tissues.
Regulate metabolism.
Regulate blood nutrient levels
What does prolactin do?
Milk production
Enhanced progesterone secretion by the ovaries following ovulation.
What hormone brings about the following ?
CORTISOL from the Adrenal Cortex
release of ___________stimulating hormone that binds to ___________in the skin causing an increase in skin pigmentation.
Adrenocorticotropic Hormone (ACTH) Melanocyte
What are the effects of Leutinising Hormone (LH) and Follicle Stimulating Hormone (FSH)?
aka
GONADOTROPINS
Their effect is to :-
Promote the growth of the gonads - testes and ovaries and the production of sperm and oocytes.
In combination with prolactin, LH and FSH regulate reproduction.
Control the production of reproductive hormones – oestrogens and progesterone in the ovaries and testosterone in the testes.
What hormones are produced by the thyroid gland?
TRIIODOTHYRONINE
TETRAIODOTHYRANINE (T4, sometimes called thyroxine)
CALCITONIN
TRH from the hypothalamus and TSH from the anterior pituitary lead to __and __release from the thyroid into the blood stream
T3 and T4
TRH -Thyroid Releasing hormone
TSH thyroid stimulation hormone
Are thyroid hormones water soluble?
No,
What do T3 and T4 do?
- Control metabolism
- regulate natural growth
What cells secrete calcitocin?
Parafollicular cells
What is the effect of calcitocin?
reduce plasma CA++
There are 4 small islands of cells embedded in the posterior thyroid tissue. These are the _______. These glands produce______________
PARATHYROID GLANDS PARATHYROID HORMONE (PTH,
The role of PTH is to help regulate [Ca++] by ___________. It essentially does the opposite to calcitonin. It also increases the rate of formation of ________
Increasing plasma levels of Ca++
Vitamin D
What glands are located near the kidneys?
Adrenal glands
What are the 2 parts of the adrenal gland?
inner medulla and outer cortex
What 2 hormones does the inner medula of the adrenal gland secrete?
Adrenaline (epinephrine) 80%
Noradrenaline (norepinephrine) 20%
What so adrenalline and noradrenaline do?
- ______blood glucose levels
- _________lipid breakdown
- ______heart rate and force of contraction
- Cause _________in skin, kidney and GI tract
- Cause _________in heart and skeletal muscle.
When released into the blood they have a widespread effect across the body. They:-
- Increase blood glucose levels
- Increase lipid breakdown
- Increase heart rate and force of contraction
- Cause vasoconstriction in skin, kidney and GI tract
- Cause vasodilation in heart and skeletal muscle.
Adrenal Cortex
Secretes 3 hormone types?
What are they
Mineralocorticoids
Glucocorticoids
Androgens
Steroids so not water soluble
Mineralocorticoids
The main one is __________. Secreted in response to low blood pressure. Action is to cause the _____to retain Na+ and water thereby increased blood volume.
ALDOSTERONE. kidney
Glucocorticoids
The main one is ______. Produced in response to _____, the effects are mainly metabolic and anti-inflammatory.
CORTISOL. stress
PANCREAS
Located between ________and ______. It is EXOCRINE and ENDOCRINE.
Sromach and duodenum
The endocrine part of the pancreas , the ______________, secrete hormones into the blood stream.
ISLETS OF LANGERHANS,
What are the islets of langerhans made up of?
ALPHA (α) cells that secrete ________that increases the breakdown of______ releasing it into the circulation.
BETA (β) cells that secret ______that causes cells to increase their uptake of ______and amino acids.
Delta (δ) cells that secrete ________that _____insulin and glucagon secretions.
ALPHA (α) cells that secrete GLUCAGON that increases the breakdown of GLUCOSE releasing it into the circulation.
BETA (β) cells that secret INSULIN that causes cells to increase their uptake of GLUCOSE and amino acids.
Delta (δ) cells that secrete SOMATOSTATIN that inhibits insulin and glucagon secretions.
What are the male reproductive hormones produced in the testes?
Testosterone and inhibin
What are the female reproductive hormones produced in
Oestrogen and progesterone
