Endocrine System

Question 1

Hormones

Answer 1

Meaning “To arouse”

A chemical substance secreted into extracellular fluid and regulates metabolic activity.

Question 2

What are the major processes controlled by hormones?

Answer 2

Reproduction 
Growth and development
Mobilizing body defenses
Electrolyte, water and nutrient balance 
Regulate cell metabolism and energy

Question 3

What are the 3 main hormone classifications?

Answer 3

Amines, steroids and peptides.

Question 4

Steroidal hormone process

Answer 4

• Hormone diffuses through the target’s cell membrane.
• Enters the nucleus and bind to receptor.
• Hormone binds to DNA and activates genes to transcribe mRNA.
• mRNA is translated resulting in synthesis of new proteins.

Question 5

Non steroidal process

Answer 5

• Unable to enter target cells.
• Bind to membrane receptor and activates an enzyme.
• Enzyme produces and second messenger.
• Second messenger oversees intracellular change

Question 6

What are the 3 controls of hormone release?

Answer 6

1. Negative feedback
2. Hormonal
3. Humoral

Question 7

What is the endocrine system?

Answer 7

Endocrine organs release chemical messengers (hormones) into the blood. Slow acting.

Question 8

Negative feedback mechanism

Answer 8

The means of regulating blood levels of nearly all hormones.

Question 9

Hormonal release

Answer 9

• Most common.
• Endocrine organs are put into action by hormones.
• Hormones produced by final target glands inhibit the release of anterior pituitary hormones.

Question 10

Humoral release

Answer 10

-Stimulated by changing blood levels.
-Chemicals in the blood stimulate endocrine glands.
Ex. Release of parathyroid hormone prompted by lack of calcium in the blood.

Question 11

What are the 2 humoral hormone types?

Answer 11

Calcitonin - Produced by pancreas, released by thyroid.

Neural - Nerve fibers stimulate hormone release

Question 12

What are the major endocrine organs?

Answer 12

• Pituitary
• Thyroid-
• Parathyroid
• Adrenal
• Pineal
• Thymus
• Pancreas
• Gonads
• Hypothalamus

Question 13

Hypothalamus

Answer 13

• Part of the nervous system.
• Produces many hormones.
• Links nervous and endocrine system.
• Controls most endocrine organs, mainly through stimulation of the pituitary.
• REGULATOR OR HOMEOSTASIS!

Question 14

Anterior Pituitary

Answer 14

• Glandular tissue - master endocrine gland.

- Hormones are proteins and act through second messenger systems.

Question 15

Posterior Pituitary

Answer 15

• Nervous tissue.
• Doesn’t make the hormone that it secretes
• Secretes Oxytocin and Antidiuretic hormone.

Question 16

Thyroid

Answer 16

• Produces Thyroxine (T3), Triiodothyronine (T4) and Calcitonin.
• Thyroid hormones are lipid soluble, needing a transport protein.

Question 17

Parathyroid

Answer 17

-Secretes PTH, regulator of calcium

Question 18

Adrenal Medulla

Answer 18

-Produces Catecholamines - Epinephrine and Norepinephrine.

Question 19

Adrenal Cortex

Answer 19

-Produces Glucocorticoids and MineralocorticoidsN

Question 20

Pineal Gland

Answer 20

• Produces Melatonin - regulated by light/dark.

Question 21

Thymus

Answer 21

-Produces Thymosin

Question 22

Pancreas

Answer 22

• Produces Insulin and Glucagon
• Has endo and exocrine tissues (exocrine being larger).
• Secreted enzymes for carb and protein digestion.
• Regulate blood glucose concentration.

Question 23

Gonads

Answer 23

• Ovaries produce Ova, Estrogen and Progesterone

- Testes produce male sex hormones - Testosterone.