ch2

Question 1

exocrine glands

Answer 1

secrete into a duct that carries the secretion to the body surface or to one of the body cavities

Question 2

endocrine glands

Answer 2

ductless glands of the endocrine system that secrete their products, hormones, directly into the blood.

Question 3

Hormones

Answer 3

Three types steroid, protein and Amine

Chemical secreted by the endocrine glands that are transported throughout the body in the blood

Question 4

what can hormones do

Answer 4

Activate certain genes in the nucleus so that the particular enzyme or structural protein is produced

Change the shape of the structure of the enzyme so is turned on and off

Change the rate of production of the enzyme or structural proteins by changing the rate of transcription and translation during protein production

Question 5

Steroid hormones

Answer 5

lipid-soluble, slow, long lasting

They bind to transport proteins in the blood enabling them to travel in the bloodstream

When reach the target sell they separate from the transport protein and defuse across the cell membrane

Combined with the receptor in the cell the complex activates the gene is controlling the formation of a particular protein

Does this by binding to the promoter section of a certain gym stimulating transcription and therefore protein synthesis

Question 6

Protein and Aminé hormones

Answer 6

Water soluble, quick, short lasting

Work by attaching the receptor protein in the membrane of the target cell

The combination causes a secondary Messenger substance to diffuse through the cell and activate particular enzymes.

An example is when insulin binds to a receptor protein and this leads to an increase in glucose absorption by the cell

Question 7

saturation

Answer 7

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

Question 8

Amplification

Answer 8

Enzyme amplification is the process whereby thousands of enzyme molecules are activated by one hormone molecule. The hormone triggers a cascading effect so that the number of reacting molecules involved is increased hundreds or thousands of times for each step in the metabolic pathway.

Question 9

how are secretions regulated

Answer 9

negative feedback

Question 10

Hypothalamus

Answer 10

Regulates temperature, water balance and heart rate

Also increases or decreases secretions when necessary

Question 11

Hypothalamus functions

Answer 11

Secrete releasing factors or inhibiting factors
Other hormones are produced here and passed along the nerve fibers to the posterior leg for the picture to pituitary then released

The hypothalamus produces the hormones oxytocin and ADH, which travel by way of nerve fibres to the posterior lobe of the pituitary. Secretion of these hormones from the posterior lobe is stimulated by nerve impulses from the hypothalamus.

Question 12

infundibulum

Answer 12

connects hypo to the pituitary

anterior lobe

Question 13

pituitary gland both lobes

Answer 13

Anterior
- no nerves (blood vssels)

Posterior
- nerve fibres
doesn’t secrete
anterior lobe

Question 14

Follicle stimulating hormone

Answer 14

target organs:
ovaries and testes

effects:
growth of follicles
Production of sperm
anterior lobe

Question 15

Luteinising hormone

Answer 15

target organs:
ovaries and testes
effects:
Ovulation and maintenance of corpus luteum, secretion of testosterone
anterior lobe

Question 16

Growth hormone

Answer 16

target organs: all cells
effects: growth and protein synthesis
anterior lobe

Question 17

Thyroid stimulating hormone

Answer 17

target organs: thyroid gland
effects: secretion of hormones from thyroid
anterior lobe

Question 18

Adrenocorticotropic hormone

Answer 18

target organs: adrenal cortex
effects: secretion of hormones from the adrenal cortex

anterior lobe

Question 19

Prolactin

Answer 19

Mammary gland
milk production

anterior lobe

Question 20

antidiuretic hormone

Answer 20

kidneys
reabsorption of water
Posterior

Question 21

Oxytocin

Answer 21

uterus mammary glands
contractions of the uterus during childbirth
release of milk

Posterior

Question 22

pineal gland

Answer 22

Down deep inside brain

Secrete hormones melatonin which regulate sleep patterns

Question 23

Thyroid gland

Answer 23

Secretes to hormones thyroxine (T-4) and triiodothyronine (t3)

t4- for I don’t iodine atoms, less active, last longer
t3- more active

Once released enzymes convert T-4 into T-3. T-3 controls metabolism by regulating reactions in which complex molecules are broken down to release energy

Diet also regulates the levels of calcium and phosphate in the blood and by releasing calcitonin

Question 24

Calcitonin

Answer 24

is Released when levels o calcuim in blood to high reducing reabsorption in kidney. If phosphate levels too high it moves phosphate into the bone

Question 25

Parathyroid 4 glands

Answer 25

Secrete parathyroid hormone which increases calcium levels in the blood and phosphate excretion in euro

Question 26

Thymus

Answer 26

Secretes a group of hormones called thymosins these influence the maturation of disease fighting cells called T- lymphocytes

Question 27

Adrenal glands

Answer 27

medulla and cortex

Question 28

medulla

Answer 28

Produces adrenaline and noradrenaline Adrenaline/ epinephrine – helps prepare body for reaction to a threatening situation Noradrenaline – increases rate and force of heart beat

Question 29

cortex

Answer 29

20 different hormones called corticosteroids Aldosterone- axon kidneys to reduce amount of sodium and increase potassium in urine Cortisol – promotes normal metabolism – without stress and repair damage tissues

Question 30

Pancreas

Answer 30

exocrine by digestive enzymes into small intestine's Endo crime by special cells called a slut or lethargic and secreting insulin and glycogen

Question 31

Insulin

Answer 31

Secreted by beta cells, negative feedback system Reduces amount of glucose in blood sugar level Does this by promoting the uptake of glucose from the blood by cells of body

Question 32

Glucagon

Answer 32

Secured by alpha cells, opposite to insulin | Increase blood glucose levels by promoting the breakdown of glycogen to glucose in liver

Question 33

Define ‘hormone’.

Answer 33

: Hormones are substances that affect the functioning of cells. They are secreted by endocrine glands. Hormones may be proteins, steroids or amines. Most are transported throughout the body in the blood. A hormone may affect particular groups of cells, or one or more organs, or it may affect all the cells of the body.

Question 34

Describe enzyme amplification and state why it is important

Answer 34

Enzyme amplification is the process whereby thousands of enzyme molecules are activated by one hormone molecule. The hormone triggers a cascading effect so that the number of reacting molecules involved is increased hundreds or thousands of times for each step in the metabolic pathway. It is possible for one hormone molecule to trigger the production of more than a billion enzyme molecules. This is important because a very small stimulus can produce a very large response.

Question 35

. Describe the pituitary hormones that are involved in the control of other endocrine glands.

Answer 35

Gonadotropins: Follicle stimulating hormone (FSH) stimulates development of the follicles in the ovary, thus stimulating the production of oestrogen. Luteinising hormone (LH) works with FSH in the female to bring about ovulation and to form the corpus luteum after ovulation. The corpus luteum then produces oestrogen and progesterone. In males, LH stimulates interstitial cells in the testes to secrete male sex hormones. * Thyroid stimulating hormone (TSH) stimulates production and release of hormones from the thyroid gland. * Adrenocorticotropic hormone (ACTH) controls production and release of some of the hormones from the cortex of the adrenal glands.

Question 36

Examples of endocrine glands include

Answer 36

the pituitary gland, the thyroid gland, the ovaries, the testes, the adrenal glands, the thymus, the pineal gland, the parathyroid glands and the pancreatic islets.

Question 37

Examples of exocrine glands include

Answer 37

the sweat glands, the mucous glands, the salivary glands, the part of the pancreas that secretes pancreatic juice, the gastric glands, the sebaceous glands, the tear glands, the milk glands, the bulbourethral glands, the seminal vesicles and the prostate gland.

Question 38

Hormones act by changing the functioning of a cell. Explain how they are able to do this.

Answer 38

Hormones change the functioning of cells by attaching to receptor molecules on the cell membrane or by entering a cell and attaching to a receptor molecule inside the cell. Hormones change the type, activities or quantities of proteins the cell produces. Often hormones exert their influence by changing the activity of enzymes or by changing the concentration of enzymes. This may be done by: * activating certain genes in the nucleus so that a particular enzyme or structural protein is produced * changing the shape or structure of an enzyme so that it is turned ‘on’ or ‘off’ * changing the rate of production of an enzyme or structural protein by changing the rate of transcription or translation during protein production.

Question 39

14 Hormones affect the activity of their target cells. Explain why the addition of more and more hormone does not continue to increase the intensity or rate of the response.

Answer 39

Once all the receptor molecules of a cell are combined with hormone molecules, the addition of more hormone cannot produce any greater effect. This is called saturation.

Question 40

athletes take the illegally hormone erythropoietin for what reason

Answer 40

Erythropoietin - stimulates blood cells in bone marrow more red blood cells circulate means more oxygen uptake and circulation of oxygen more aerobic respiration to take place for energy