ENDOCRINE I. Sp25

Question 1

What are the major organs of the endocrine system?

Answer 1

Pituitary, Thyroid, Parathyroid, Adrenal, Pineal

Other organs/tissues include Hypothalamus, Thymus, Pancreas, Ovaries/Testes, Kidneys, Liver, Stomach, SI, Heart, Skin, Adipose Tissue.

Question 2

How are endocrine functions distributed through the body?

Answer 2

Hormones are released in one part of the body and regulate activity in other parts.

Question 3

What is the primary difference between the endocrine and nervous systems?

Answer 3

Endocrine system uses hormones; nervous system uses action potentials and neurotransmitters.

Question 4

What is the role of negative feedback regulation in homeostasis?

Answer 4

It counteracts changes in monitored parameters to maintain stability.

Question 5

Define homeostasis.

Answer 5

The ability to maintain a relatively stable internal state despite external changes.

Question 6

What are the two types of feedback circuits?

Answer 6

Negative feedback loops and Positive feedback loops.

Question 7

What is a negative feedback loop?

Answer 7

A control mechanism that counteracts changes in a monitored parameter.

Question 8

What is a positive feedback loop?

Answer 8

A control mechanism that amplifies changes in a monitored parameter.

Question 9

What are the three basic components of homeostatic control systems?

Answer 9

• Receptors
• Control center
• Effector

Question 10

What distinguishes exocrine glands from endocrine glands?

Answer 10

Exocrine glands secrete products into ducts; endocrine glands secrete hormones into interstitial fluid or blood.

Question 11

What is the difference between local hormones and circulating hormones?

Answer 11

Local hormones act on neighboring cells or the same cell; circulating hormones enter the bloodstream.

Question 12

What are lipid-soluble hormones derived from?

Answer 12

Cholesterol.

Question 13

Name two examples of lipid-soluble hormones.

Answer 13

• Cortisol
• Testosterone

Question 14

What are water-soluble hormones typically composed of?

Answer 14

Chains of amino acids (peptides and proteins).

Question 15

What is a function of hormones?

Answer 15

• Maintain homeostasis
• Regulate organ system functions
• Affect growth and development
• Influence reproduction

Question 16

What is the general mechanism for circulating hormones?

Answer 16

Hormones bind to specific receptors on target cells.

Question 17

Describe the action of steroid hormones.

Answer 17

They diffuse into target cells and alter gene expression.

Question 18

How do peptide hormones exert their effects?

Answer 18

They bind to cell surface receptors and use second messengers.

Question 19

What is a second messenger?

Answer 19

Intracellular molecules that mediate the effects of hormones.

Question 20

Name an example of a second messenger.

Answer 20

cAMP.

Question 21

What initiates the activation of second messengers?

Answer 21

Binding of the hormone (first messenger) to its receptor.

Question 22

True or False: Different cells can respond differently to the same hormone.

Answer 22

True.

Question 23

What is the role of protein kinases in hormone action?

Answer 23

They phosphorylate proteins, altering their activity.

Question 24

What determines if a cell is a target cell for a hormone?

Answer 24

The presence of a specific receptor for that hormone.

Question 25

What generates different second messengers?

Answer 25

Different types of receptors generate different second messengers! ## Footnote This concept highlights the specificity of cellular responses to hormones based on receptor types.

Question 26

How can a hormone cause different responses in different target cells?

Answer 26

Different types of receptors generate different second messengers! ## Footnote The variation in receptor types leads to distinct cellular responses even to the same hormone.