Endocrine System

Question 1

Thyroid Stimulating Hormone (TSH)

Answer 1

• targets thyroid gland
• stimulates the release of Thyroxin
• thyroid won’t stop producing FSH until thyroxin is released
• when hypothalamus reduces its level of TSH, causes a decrease in thyroxine production/release (negative feedback loop)

Question 2

Prolactin

Answer 2

• targets mammary glands
• stimulates milk production (lacrosse geneis)
• stimulates development of mammary tissue
• increased prolactin levels during pregnancy suppress the production of LH which stops ovulation
• no disorders associated with

Question 3

Posterior Pituitary

Answer 3

-backside of pituitary gland
Stores : oxytocin and antidouretic hormone (ADH)

They’re created by the hypothalamus and stored in the posterior pituitary

Question 4

Non- steroid Hormones

Answer 4

Adrenaline, thyroxin, calcitonin, thymosin, prolactin, oxytocin, melatonin, insulin, glucagon, ACTH, LH, FHS, ADH, TSH, PTH, HGH

Question 5

Steroid hormones

Answer 5

• fat soluble, able to pass through cell membranes

- cortisol, progesterone, testosterone, aldosterone, estrogen

Question 6

Target organs

Answer 6

Organ that contains receptors for a particular hormone

Question 7

Hormones

Answer 7

Chemicals that circulate throughout the blood and exert some measure of control over almost every organ and tissue in the body

Question 8

Exocrine (gland)

Answer 8

Produce chemicals which travel directly to target organ through channels or ducts

Example: sweat glands, tear glands, salivary glands, mammary glands and they secrete substances such as sweat, saliva, tears, milk or digestive enzymes

Question 9

Endocrine (gland)

Answer 9

Glands that don’t have ducts, hormones travel through the bloodstream for transport to target cells (organs)

Question 10

Hypothalamus

Answer 10

Controls the endocrine hormone system (also the autonomic nervous system)

Question 11

Non-steroid hormones (how they work)

Answer 11

• water based, unable to enter cells because they are not soluble in the membrane
• first messagers (hormone) binds to a receptor on the surface of the target cell, causing ATP to be changed into Cyclic AMP (cAMP)
• Cyclic AMP causes chemical reactions to occur within the cell

Question 12

Tropic hormones

Answer 12

Hormones that regulate the hormone production of many other glands

Example: Thyroid Stimulating hormone (TSH) and ACTH

Question 13

Antagonist hormones

Answer 13

Hormones that work against each other or have opposite effects on the body

Example: insulin and glucagon, parathyroid hormone and calcitonin

Question 14

Hypersecretion

Answer 14

TOO MUCH

Over secretion of a hormone within the body

Question 15

Adrenocorticotropic hormone (ACTH)

Answer 15

• targets adrenal cortex

- causes the adrenal cortex to produce cortisol and aldosterone

Question 16

Negative feedback loop

Answer 16

Works to reverse or decrease changes in the body

Example: hypothalamus- pituitary feedback mechanism

*know and understand diagrams in notes

Question 17

Hyposecretion

Answer 17

TOO LITTLE

Under secretion of a hormone within the body

Question 18

Follicle Stimulating hormone (FSH)

Answer 18

Targets ovaries & testes
- causes maturation of a follicle within an ovary (females produce FSH in short burst)

-starts developmental of sperm (makes are always producing FSH)

Question 19

Lutenizing hormone (LH)

Answer 19

Targets ovaries & testes

Females

• causes follicle to release an egg
• forms a corpus luteum (one day)

Males
-stimulates production of testosterone in males (without LH testosterone can’t be produced)

Question 20

Positive feedback mechanism

Answer 20

Serves to increase the effect of an action

Example: oxytocin feedback loop

*know & understand diagrams in notes

Question 21

Pituitary gland

Answer 21

Master gland

• located at the base of the Brain
• connected to hypothalamus

Signals from nervous system to hypothalamus to control over pituitary

• posterior pituitary
• anterior pituitary

Question 22

Anterior pituitary

Answer 22

Located towards front of head, largest portion of pituitary gland

Produces 6 hormones

• human growth hormone (HGH)
• adrenocorticotropic hormone (ACTH)
• prolactin (PRL)
• thyroid Stimulating hormone (TSH)
• follicle Stimulating hormone (FSH)
• lutenizing hormone (LH)

Question 23

Human growth hormone (HGH)

Answer 23

Targets long bones/tissues

• regulates growth/development of body tissues
• increases intestinal absorption of Ca, increasing cell division and growth in bones and cartilage
• stimulates protein synthesis and lipid (fat) metabolism (converts fats to sugars so they can be used)

Question 24

Pituitary dwarfism

Answer 24

TOO LITTLE HGH

• insufficient production of HGH during childhood
• abnormally short bones
• can be treated with injections of HGH, but there are side effects
• normal torso and head
• small limps

Question 25

Oxytocin during childbirth

Answer 25

• stimulates contractions of smooth muscles in the uterus
• when the baby’s hear pushes on the pressure receptors in the uterus, impulses are sent to the hypothalamus (positive feedback loop)
• causes oxytocin to be released from the posterior pituitary
• oxytocin stimulates uterine muscles to contract, contractions cause pressure receptors to release more oxytocin

Question 26

Oxytocin

Answer 26

Targets : uterine muscles & mammary glands

• causes muscles to contract to help expel baby
• causes mammary glands to contract to release milk

Question 27

Antidiurtic hormone (ADH)

Answer 27

Targets blood, arteries and collecting ducts of kidneys

• regulates sodium levels in blood
• causes damaged blood vessels to constrict to reduce blood loss
• causes kidneys to retain water