Units 1-3: Homeostasis and the Endocrine System

Question 1

Hormones

Answer 1

Chemical messenger sent to many parts of the body to produce a specific effect on a target cell or organ.

Question 2

Endocrine System

Answer 2

In vertebrates, system that works in parallel with the nervous system to maintain homeostasis by releasing chemical hormones from various glands: composed of the hormone producing glands and tissues of the body.

Question 3

Early Experiments Proving The Existence Of Chemical Messengers

Answer 3

stole rooster’s balls. Berthold. 1849.

Question 4

Receptor Proteins

Answer 4

Bind to hormones in order to carry out chemical messages within the cell.

Question 5

Lipid Soluble (Steroid) Hormones

Answer 5

Lipid-based; can permeate the lipid bilayer of the cell membrane, change cell genes from within.

Question 6

Water Soluble (Non-Steroid) Hormones

Answer 6

Binds to a receptor protein on the surface of the cell membrane. Phone fan-out causes an amplified impact on the hormone.

Question 7

Negative Feedback Loops

Answer 7

When the output of a system inhibits the activity of a system.

Question 8

Tropic Hormone

Answer 8

A hormone that targets endocrine glands and stimulates them to release other hormones.

Question 9

Homeostasis

Answer 9

The tendency of the body to maintain a relatively constant internal environment.

Question 10

Endocrine Gland

Answer 10

Secretes hormones directly into the bloodstream.

Question 11

Exocrine Gland

Answer 11

Secretes hormones directly into target areas of the body.

Question 12

Hypothalamus

Answer 12

Sends signals to the pituitary glands to release or inhibit the release of hormones.

Anterior pituitary glands receive tropic hormones.

Posterior pituitary glands receive nerve impulses.

Question 13

Anterior Pituitary

Answer 13

Releases FSH, LH, ACTH, TSH, Prolactin, ICSH, hGH.

Question 14

FSH

Answer 14

Aids gamete production.

Question 15

LH

Answer 15

Causes the release of sex hormones.

Question 16

ACTH

Answer 16

Tropic stimulating hormone.

Stimulates adrenal cortex to release cortisol and aldosterone.

Question 17

TSH

Answer 17

Tropic stimulating hormone.

Stimulates thyroid gland to release thyroxin.

Question 18

Prolactin

Answer 18

Stimulates milk production in mammary glands.

Question 19

ICSH

Answer 19

Causes the release of sex hormones.

Question 20

hGH

Answer 20

Human growth hormone. Has direct impacts as well as stimulating the liver to cause the growth of skeletal muscles and bones. Also increases protein synthesis and fat metabolism.

Insufficent amounts of hGH in childhood result in dwarfism, excess hGH results in gigantism.

Excess amounts of gigantism in adulthood results in acromegaly.

Question 21

Posterior Pituitary Gland

Answer 21

Releases ADH and oxytocin. Hormones are produced in the hypothalamus and then transferred, stored, and released in the posterior pituitary by neuronal axons.

Question 22

ADH

Answer 22

Causes kidney tubules to become permeable to water, thereby reducing urine output.

Secreted from the posterior pituitary gland.

Diabetes Insipidus

Question 23

Oxytocin

Answer 23

Stimulates contraction of smooth muscles in the uterus and mammary glands.

Question 24

Thyroid Gland

Answer 24

Releases thyroxin and calcitonin.

Question 25

Thyroxin

Answer 25

Increases the body’s metabolism.

Question 26

Cretinism

Answer 26

Underdeveloped thyroid glands result in a lack of thyroxin.
Short stocky stupid children.
Results in hypothyroidism.

Question 27

Goitre

Answer 27

Caused by a lack of iodine, leading to an insufficient amount of thyroxine to be produced. This increases the demand for thyroxine and therefore a build-up of TSH in the thyroid.

Question 28

Grave’s disease

Answer 28

The immune system attacks the thyroid gland, causing hyperthyroidism.
Symptoms of hyperthyroidism are related to the promoted metabolism, i.e. anxiety, weight loss, insomnia, and heat intolerance.
Symptoms of grave’s disease cause swelling around the eyes that decrease vision.

Question 29

Calcitonin

Answer 29

Lowers the blood calcium by increasing the deposit into the bones and urine.

Question 30

Parathyroid Gland

Answer 30

Releases parathyroid hormone

Question 31

Parathyroid Hormone

Answer 31

Increases blood calcium by removing it from the bones, increasing absorption from the intestines and kidney tubules.

Question 32

Pancreas (Islets of Langerhans)

Answer 32

Beta cells release insulin and alpha cells release glucagon.

Question 33

Insulin

Answer 33

Reduces blood glucose concentration by making target cells more permeable to glucose.

Question 34

Glucagon

Answer 34

Increase blood glucose by converting glycogen into glucose.

Question 35

Adrenal Medulla

Answer 35

Releases epinephrine (adrenaline) and norepinephrine (noradrenaline).

Question 36

Epinephrine and Norepinephrine

Answer 36

Control the fight or flight response.

Question 37

Adrenal Cortex

Answer 37

Releases cortisol (glucocorticoids) and aldosterone (mineralcortoid).

Question 38

Cortisol

Answer 38

Glucorticoids responsible for longterm stress response. Raises blood glucose levels by breaking down muscle proteins and fat cells.

Question 39

Aldosterone

Answer 39

Mineralocorticoids that increase blood pressure. Causes reabsorption of sodium in kidney tubules and increases water reabsorption.

Question 40

Addison’s Disease

Answer 40

Caused by the body’s inability to produce adequate amounts of mineralocorticoids and glucocorticoids. Sodium is present in urine and lowers blood glucose concentrations.

Question 41

Pineal Gland

Answer 41

Releases melatonin.

Question 42

Melatonin

Answer 42

Responsible for the circadian rhythms - sleep/wake cycle.

Question 43

Testes

Answer 43

Release testosterone

Question 44

Testosterone

Answer 44

Male sex hormone.

Question 45

Ovary

Answer 45

Estrogen (female sex hormone) and progesterone (female sex hormone).