Endocrine system

Question 1

Thyroid gland location, what it secretes, the hormone(s) function and target cell

Answer 1

• located in the neck below the larynx.
• secretes thyroxine, triiodothyronine calcitonin
• function of thyroxine and triiodothyronine is to increase metabolic rate thus O2 consumption and heat production
• also plays a role of regulating levels of calcium and phosphate in the blood (calcitonin)
• target cell is most body cells and the bones and kidney

Question 2

parathyroid gland location, what it secretes, the hormone(s) function and target cell

Answer 2

• located in the rear surface of the lobes of the thyroid gland
• secretes the parathyroid hormone
• function of the parathyroid hormone is to increase the levels of CA in the blood and increases rate of excretion of phosphate in the urine.
• target cell is the bones and kidneys

Question 3

thymus location, what it secretes, the hormone(s) function and target cell

Answer 3

• located in the chest just above the heart and behind the sternum.
• secretes thymosin
• function of thymosin is to stimulate the development and maturation of T-lymphocytes.
• the target cell is T-lymphocytes

Question 4

adrenal cortex location, what it secretes, the hormone(s) function and target cell

Answer 4

• located immediately above each kidney
• secretes cortisol and aldosterone
• the function of cortisol is to promote normal metabolism, helps body deal with stress and repair damaged tissues
• Aldosterone function is to increase the reabsorption of sodium and increase the excretion of potassium ions in the kidney.
• cortisol target cell is most body cells
• aldosterone target cell is the kidneys

Question 5

Adrenal medulla location, what it secretes, the hormone(s) function and target cell

Answer 5

• located directly above each kidney
• secretes the hormones adrenaline and noradrenaline
• function of adrenaline is to prep the body for the fight or flight response and reinforces the effects of the sympathetic nervous system.
• Noradrenaline function is to increase force and rate of the heart. (mostly same function as adrenaline)
• Target cell of noradrenalin and adrenaline is most tissues.

Question 6

Homeostasis

Answer 6

the maintenance of a relatively constant internal environment despite the fluctuations in the external environment. (changes in the internal or external environment = stimulus )

Question 7

Endocrine gland

Answer 7

glands which secrete hormones directly into the bloodstream.

Question 8

Exocrine gland

Answer 8

glands which secrete different fluids into ducts. e.g. sweat pore

Question 9

Hormone

Answer 9

a chemical secreted by an endocrine gland and that effects the functioning of a cell or organ.( usually carried in the blood)

Question 10

Target cell

Answer 10

A cell who is activity is effected by a particular hormone. Hormones can only influence cells with right receptors. More receptors on cell= cell is more sensitive

Question 11

Paracrine

Answer 11

smaller molecules secreted by cells to send signals a short distance.

Question 12

Pineal gland

Answer 12

• located deep in the brain
• secretes the hormone melatonin
• the function of melatonin is to regulate sleep patterns
• the target cell of melatonin is most body cells

Question 13

Pancreas location, what it secretes, the hormone(s) function and target cell

Answer 13

• located below the stomach next to the duodenum
• secretes insulin and glucagon
• The function of insulin is to promote the uptake of glucose in the blood to by the cells of the body to reduce blood glucose levels. ( does this by causing glucose to be converted to glycogen and fat)
• The function of glucagon is to stimulate the breakdown of glycogen and fat. (glycogen broken down into glucose) Resulting in a higher blood glucose level.
• Target cell of insulin is most body cells- target cell of glucagon is fat storage tissues and liver.

Question 14

Testes location, what it secretes, the hormone(s) function and target cell

Answer 14

• located in the scrotum-
• secretes androgens
• function of androgens is stimulate sperm production and growth of skeleton, muscles and male sexual characteristics.
• target cell is most body cells

Question 15

Ovaries location, what it secretes, the hormone(s) function and target cell

Answer 15

• located in the uterus
• secretes oestrogen and progesterone- function of oestrogen is that it stimulates the development of female characteristics and regulates menstrual cycle.
• Function of progesterone is that it regulates menstrual cycle and pregnancy, and prepare mammary glands for milk secretion.
• Target cell of oestrogen many tissues- Target cell of progesterone is uterus and mammary glands.

Question 16

posterior lobe of pituitary gland location, what it secretes, the hormone(s) function and target cell

Answer 16

• located in the brain below the hypothalamus connected to hypothalamus through infundibulum.
• releases oxytocin and antidiuretic hormone (neither hormone is produced in the gland, they a produced by special nerve cells in hypothalamus)
• function of antidiuretic hormone is to increase the reabsorption of water in the kidneys. ADH can also cause the constriction of small arteries.
• function of oxytocin, stimulates contractions of muscles in uterus, stimulates contracting cells in mammary glands resulting it release of milk during breastfeeding.
• target cell of ADH is the kidneys, target cell of oxytocin is uterus and mammary glands.(secretion of hormones triggered by nerve impulses)

Question 17

Anterior lobe of the pituitary gland location and hormones it secretes

Answer 17

• located in the brain below the hypothalamus, connected to the hypothalamus by the infundibulum.
• secretes growth hormone, follicle stimulating hormone, luteinising hormone, thyroid stimulating hormone, prolactin, adrenocortitropic hormone

Question 18

Functions of the hormones secreted by the pituitary gland

Answer 18

• Growth hormone stimulates the growth of the body particularly in the skeleton. this is done by increasing the rate which amino acids are taken up by cells and built into proteins. target cell is all cells.
• Follicle stimulating hormone stimulates the development of the follicle which contains eggs in the ovaries and stimulates the development and maturation of sperm in the testes. target cell is ovaries and testes.
• luteinising hormone effect is that it brings about ovulation and maintenance of the corpus lutetium. Target cell is the ovaries
• thyroid stimulating hormone stimulates the production and release of hormones from the thyroid gland.
  target cell is the thyroid.
• prolactin works with other hormones to initiate and maintain milk production in females.
  Target cell is mammary glands.
• adrenocortitropic hormone controls the production and release of hormones from the adrenal cortex.
  target cell is adrenal cortex.

Question 19

Label Pituitary gland

Question 20

describe how a steroid hormone interacts with a cell

Answer 20

• steroid hormones are lipid soluble meaning once they reach the target cell they diffuse through the bi-lipid membrane.
• the steroid hormone then binds to the receptor protein in the nucleus or membrane (forms hormone receptor complex)
• the hormone receptor complex then activates the genes which control the formation of particular proteins. it does this by binding to the promoter section of a certain gene thus inhibiting or stimulating transcription and therefore protein synthesis.
• steroids are fast acting but short lasting

Question 21

describe protein and amine hormones interact with a cell with a diagram

Answer 21

• amine hormones are water soluble but not lipid soluble

-Thus amine hormone must bind to a receptor protein on the membrane of the target cell which then sends a secondary messenger substance which diffuses through the membrane and causes changes to occur within the cell.

• slow acting but longer lasting
• diffuses in blood for transport

Question 22

Describe enzyme amplification

Answer 22

In the cell the hormone causes the the activation of thousands of molecules through a cascading effect.