Endocrine

Question 1

Compare and contrast the general control of body functions by the nervous and endocrine systems.

Answer 1

nervous system – regulates activity of muscles and glands

• • regulates via electrochemical impulses delivered by neurons and neurotransmitters
• -organs respond in milliseconds

endocrine system – influences metabolic activity by hormones
hormones are secreted by cells into the ECF, travel through blood and regulate the metabolic function of other cells in the body
–regulates processes that go on for relatively long periods of time

Question 2

Distinguish between endocrine and exocrine glands

Answer 2

Endocrine glands: ductless glands hat produce hormones and release them in to surrounding tissue fluid, typically having a lymphatic drainage that receives the hormones and leads hormones to a target cell

Exocrine glands: produce NONHORMONAL substances like sweat and has DUCTS that carry these substances to a membrane surface

Question 3

What is a hormone? What is a target cell?

Answer 3

Hormones are chemical messengers secreted by cells into the ECF, then they travel through the blood to target cells, alter target cell activity and decreases or increases rates of normal cellular processes

Target cells: cells which have a receptor specifically able to recognize and bind to a particular hormone molecule

Question 4

What enables certain cells to respond to a hormone while other cannot?

Answer 4

the receptors on the cell must be specific to the hormone

Question 5

Distinguish between classical endocrine signaling, paracrine signaling, or autocrine signaling?

Answer 5

Endocrine signaling: chemical is secreted, blood circulates through the blood and diffuses to other areas of the body, more long distance than paracrine and autocrine signaling; diffuses through the blood to get to target cell

Paracrine signaling: chemicals act locally within the same tissue but affect cell types OTHER than those releasing the paracrine chemicals; paracrine cells release a secretion that diffuses through ECF to a target cell in the local area (does not go through the blood, just ECF)

Autocrine signaling: chemicals that exert their effects on the same cells that secrete them

Question 6

In terms of their general chemistry, hormones can be broadly classified as amines, peptide or protein hormones, and steroid hormones. Explain the basic difference between each of these classes and list several examples of each class of hormone.

Answer 6

Amino acid based hormones include amines, peptide, and protein hormones. Usually WATER soluble & cannot cross the plasma membrane.
Amine hormones: simple amino acid derivatives (epinephrine, thyroxine)

Peptide hormones: hormones that are made up of short amino acid chains (prolactin, oxytocin, insulin)

Protein hormones (long polymers of amino based hormones; growth hormone)

steroid hormones synthesized from cholesterol; LIPID soluble and can cross plasma membrane; gonadal and adrenocortical