Endocrine System

Question 1

Main Functions

Answer 1

• Water balance
• Uterine contractions and milk release
• Growth, metabolism, and tissue maturation
• Ion regulation
• Heart rate and blood pressure regulation
• Blood glucose control
• Immune system regulation
• Reproductive functions control

Question 2

ligands aka chemical signals

Answer 2

molecules released from one location that move to another location to produce a response

Question 3

Intracellular chemical signals

Answer 3

produced in one part of a cell, such as the cell membrane, and travel to another part of the same cell and bind to receptors, either in the cytoplasm or in the nucleus

Question 4

Intercellular chemical signals

Answer 4

released from one cell, are carried in the intercellular fluid, and bind to receptors that are found in other cells, but usually not in all cells of the body

Question 5

Autocrine chemical signals

intercellular

Answer 5

chemical signals are released by cells and have a local effect on the same cell type. Example: prostaglandin-like chemicals that are secreted in response to inflammation

Question 6

Paracrine chemical signals

intercellular

Answer 6

chemical signals are released by cells and have effects on other cell types. Example: somatostatin, secreted by the pancreas, inhibits the release of insulin by other cells in the pancreas

Question 7

Neuromodulators and neurotransmitters

intercelluar

Answer 7

chemical signals are secreted by nerve cells and aid the nervous system. Example: acetylcholine produced during stressful encounters

Question 8

Pheromones

intercellular

Answer 8

chemical signals are secreted into the environment and modify the behavior and physiology of other individuals. Example: those produced by women can influence the length of the menstrual cycle of other women

Question 9

Receptors

Answer 9

proteins or glycoproteins chemical signal binds to to produce a response

Question 10

specificity

Answer 10

only certain chemical signals can bind to a receptor sit e based on shape and chemical characteristics

Question 11

Types of receptor molecules that respond to intercellular chemical signal

Answer 11

intracellular

membrane-bound

Question 12

Intracellular receptors

Answer 12

receptors are located in either the cytoplasm or the nucleus of the cell. Signals diffuse across the cell membrane and bind to the receptor sites on intracellular receptors

Question 13

Membrane-bound receptors

Answer 13

receptors extend across the cell membrane, with their receptor sites on the outer surface of the cell membrane. They respond to intercellular chemical signals that are large, water-soluble molecules that do not diffuse across the cell membrane

Question 14

Receptors that directly alter membrane permeability

Answer 14

For example, acetylcholine (adrenaline) from nerve fiber endings binds to receptors that are part of the membrane channels for sodium ions

Question 15

Receptors and G proteins

Answer 15

G proteins (guanine nucleotide-binding proteins) are found on the inner surface of the plasma membrane and function as receptors of hormones. For example, chemical signals include cyclic adenosine monophosphate glycerol and inositol triphosphate that bind to receptor molecules in the cell and alter their activity to produce a response

Question 16

Receptors that alter the activity of enzymes

Answer 16

For example, increasing the activity of an enzyme responsible for the breakdown of glycogen into glucose makes glucose available as an energy source for muscle contractions

Question 17

term endocrine

Answer 17

implies that intercellular chemical signals are produced in and secreted from endocrine glands

Question 18

Hormones

Answer 18

produced (in minute amounts) by a collection of cells to influence the activity of those tissues in a specific way.

For example, neurohormones are hormones secreted from cells of the nervous system.

Question 19

target tissues

Answer 19

Hormones are distributed in the blood to all parts of the body, but only certain tissues

Question 20

Negative-feedback mechanisms

Answer 20

controls secretion of hormones

keep the body functioning within a narrow range of values consistent with life

Question 21

Ways to control secretion of hormones

Answer 21

Blood levels of chemicals
Hormones
Nervous System

Question 22

Blood Chemical Levels

Answer 22

secretion of some hormones is directly controlled by the blood levels of certain chemicals. For example, blood glucose levels control insulin secretion

Question 23

Hormones

Answer 23

secretion of some hormones is controlled by other hormones. For example, hormones from the pituitary gland act on the ovaries and the testes, causing those organs to secrete sex hormones

Question 24

Nervous system

Answer 24

hormones are controlled by the nervous system. For example, epinephrine is released from the adrenal medulla as a result of nervous system stimulation

Question 25

cascade effect

Answer 25

few intercellular chemical signals can bind to their membrane-bound receptors, and each activated receptor can produce many intracellular chemical signal molecules that rapidly activate many specific enzymes inside the cell