Endocrine Glands and hormones

Question 1

Homeostasis

Answer 1

the maintenance of a relatively constant internal environment despite fluctuations in the external environment.

Question 2

List of endocrine glands (12)

Answer 2

pineal gland
Hypothalamus
pituitary gland
thyroid gland
Parathyroid gland
thymus
Adrenal gland
kidneys
pancreas
ovaries
uterus
Testes

Question 3

exocrine gland

Answer 3

Gland that secretes into a duct that carries the secretion to the surface of the body cavities

Question 4

endocrine gland

Answer 4

Secrete hormones into the extracellular fluid that surrounds the cells that make up the gland
secretion then usually passes into the capillaries to be transported by the blood
Sometimes called ductless gland

Question 5

hormones

Answer 5

Chemicals secreted by endocrine system and transported in bloodstream.
changes the function of cells by activating certain genes in nucleus so a particular enzyme or protein is produced.

Question 6

Hormone receptor

Answer 6

each type of receptor will bind wt only one specific molecule

Question 7

Saturation

Answer 7

once all receptor molecules are occupied by hormone molecules, the addition of more hormones does not produce any greater effect.

Question 8

Negative feedback loop

Answer 8

feedback that reduces the effect of, or eliminates, the original stimulus.
Body responds to a change (stimulus) -> new hormone made -> circulates -> back to original endocrine gland -> stops sending out anymore.

Question 9

pancreas

Answer 9

Both endo and exo
exo - amylase, protease, lipase (pancreatic enzymes)
Endo - insulin and glucagon

Question 10

lock and key model

Answer 10

Hormone will only work on a part of the body if it ‘fits’
if hormone binds to receptor on cell membrane, hormone can have effect.
Cells with no specific receptors can’t be affected by certain hormones.

Question 11

3 types of hormones

Answer 11

Protein
Steroid
Amine

Question 12

Protein

Answer 12

Those secreted by the pituitary gland and pancreas

Question 13

steroid

Answer 13

Made from cholesterol, an important lipid.
secreted by gonads and adrenal cortex

Question 14

Amine

Answer 14

made of small amino acid molecules

Question 15

Hormone pathway into cell - protein and amine hormones

Answer 15

are water soluble.
Attach to receptor proteins on cell membrane of target cell. This triggers a secondary messenger called cyclic AMP (cAMP) in cytoplasm to activate enzymes to alter cell metabolism.
cAMP may move through cell, activating genes and causing a change in the cells function.
Quick to cause a response, but effect short lasting.

Question 16

enzymes

Answer 16

Are proteins that increase speed of reactions ‘organic catalyst’
enzymes adjust chemical activity of cells, the speed of reactions will either increase or decrease

Question 17

Hormone pathway into cell - steroid hormones

Answer 17

lipid/fat soluble, can diffuse through cell membrane through lipid bilayer.

Question 18

Water soluble hormones (Protein/amine)

Answer 18

Hormones made from pituitary and pancreas

Question 19

lipid soluble hormones (Steroids)

Answer 19

Hormones made by gonads and adrenal cortex

Question 20

hypothalamus

Answer 20

Controls the pituitary gland and is attached to it by the infundibulum
secretes factors: releasing factors (rf) - stimulates secretions, inhibiting factors (if) - slows down secretion
Factors flow through blood vessels to reach anterior lobe of pituitary gland, whereas for posterior lobe of pituitary gland, hormones pass through nerve fibres in the infundibulum from the hypothalamus.

Question 21

pituitary gland

Answer 21

“The master” gland because it regulates the functions of the other endocrine glands and many body functions.
Factors travel down through blood vessels to the anterior lobe.
other hormones are made by the hypothalamus and pass along nerve fibres to the posterior lobe where they are released.

Question 22

Anterior pituitary hormones (6)

Answer 22

Growth hormone (GH)
Thyroid stimulating hormone (TSH)
Adenocorticotropic hormone (ACTH)
Prolactin (PRL)
Follicle stimulating hormone (FSH)
Luteinising hormone (LH)

Question 23

Posterior pituitary hormones (2)

Answer 23

Antidoretic Hormone (AH)
Oxytocin (OT)

Question 24

Growth hormone (GH)

Answer 24

Target - all cells
effect - promotes body growth, bone and muscle, protein synthesis. Maintains size of body organs through life.

Question 25

Thyroid stimulating hormone (TSH)

Answer 25

Target - thyroid gland
effect - stimulates the production and release of thyroid hormones (TSH)

Question 26

Adenocorticotropic Hormone (ACTH)

Answer 26

Target - adrenal gland
effect - controls production and release of aldosterone and cortisol (corticosteroids)

Question 27

Prolactin (PRL)

Answer 27

target - mammary glands
Effect - breast development and stimulates milk production

Question 28

Follicle stimulating hormone (FSH)

Answer 28

Target - ovary/testes
effect - stimulates the growth of the Graafian follicle and maturation of the ova or the development of seminiferous tubules and maintenance of spermatogenesis.

Question 29

Luteinising hormone (LH)

Answer 29

target - ovary/testes
Effect - induces ovulation and stimulates the formation of the corpus luteum. In males stimulates interstitial cells in testes to produce testosterone.

Question 30

antidiuretic hormone (AH)

Answer 30

Target - kidney tubules
effect - reabsorption of water from urine at the tubule, return water to blood and hence decreasing urine

Question 31

Oxytocin (OT)

Answer 31

target - uterus wall
Effect - stimulates the contraction of the smooth muscles of the uterus wall during the birth process (labour). It also causes the ejection of milk from the mammary glands.

Question 32

pineal gland

Answer 32

Size of pea, decreases in size after puberty
secretes melatonin which is stimulated by darkness and inhibited by light.

Question 33

Cortisol

Answer 33

promotes normal metabolism
During stress, glucogenesis and increased blood glucose
helps body fight the effects of short term stress.