Hormones - Chapter 2

Question 1

Exocrine glands

Answer 1

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

Question 2

Endocrine glands

Answer 2

a gland that secretes hormones directly into adjacent tissue; also called a ductless gland

Question 3

Hormones

Answer 3

a chemical that is secreted by an endocrine gland and that affects the functioning of a cell or organ; often carries into bloodstream.

Question 4

Steroid hormones

Answer 4

(oestrogen, progesterone, cortisol + aldosterone) - lipid soluble

hormones bind to transport proteins, enabling them to travel in blood

once target cell is reached, it separates from transport protein and diffuses across cell membrane

combines with receptor protein inside cytoplasm/nucleus

hormone-receptor complex activates the genes controlling the formation of particular proteins - by binding to promoter section of gene, stimulating/inhibiting transcription

Question 5

Protein/Amine hormones

Answer 5

• water soluble

unable to diffuse across cell membrane

attaches to receptor proteins in membrane of target cell

combination of hormone and receptor causes secondary messenger substance to diffuse through cell and activate particular enzymes

Question 6

Enzyme amplification

Answer 6

a series of chemical reactions in which the product of one step is an enzyme that produces an even greater number of product molecules at the next step (one hormone molecule activates thousands).

Question 7

Hormone clearance

Answer 7

• hormones being turned off - done by breaking down the hormone molecules
• some broken down in target cells - most broken down in liver/kidneys
• degraded hormones excreted in bile/urine

Question 8

Hypothalamus

Answer 8

part of the brain lying just below the thalamus and above the pituitary gland; controls many homeostatic mechanisms, such as body temperature, water balance and heart rate.

Question 9

Releasing factors

Answer 9

stimulate the secretion of a hormone

Question 10

Inhibiting factors

Answer 10

slow down the secretion of a hormone

Question 11

Pituitary gland

Answer 11

and endocrine gland located below the brain; joined to the hypothalamus by a stalk called the infundibulum.

Question 12

Anterior lobe of pituitary gland

Answer 12

(front) connected to the hypothalamus by a complex network of blood vessels lying in the infundibulum.

Question 13

Posterior lobe of pituitary gland

Answer 13

(rear) joined to the hypothalamus by nerve fibres that come from the hypothalamus and pass through the infundibulum to the posterior lobe.

Question 14

Secretions of Anterior lobe

Answer 14

• gonadotropins
• growth hormone
• thyroid stimulating hormone
• adrenocorticotropic hormone
• prolactin

Question 15

Secretions of Posterior lobe

Answer 15

• oxytocin
• antidiuretic hormone