A&P 2 Endocrine System

Why is intercellular communication important?

It allows cells to coordinate their activities and maintain homeostasis

What is intercellular communication?

Communication between different cells

What are the two major systems involved in rapid long-distance communication?

The nervous system and endocrine system

How does the nervous system communicate?

Mainly through electrical signals and neurotransmitters

How does the endocrine system communicate?

Through hormones released into the bloodstream

What is a hormone?

A chemical messenger released by an endocrine cell that travels through the blood to affect a target cell.

What is a target cell?

A cell that has receptors for a specific hormone.

How quickly does the nervous system usually communicate?

Very rapidly

How quickly does the endocrine system usually communicate?

Generally more slowly, but effects often last longer

Which system usually has longer-lasting effects: nervous or endocrine?

Endocrine system

What is a hormone interaction?

When two or more hormones work together or influence each other's effects

What are the three common types of hormone interactions?

Permissiveness, synergism, antagonism.

What is permissiveness?

One hormone allows another hormone to have its full effect

What is synergism?

Two hormones work together to produce an effect that is greater than either hormone could produce alone

What is antagonism?

One or more hormones opposes the action of another hormone

Why are hormone interactions important?

They allow the body to produce coordinated physiological responses

What does antagonistic mean?

The hormones oppose each other's effects

What does synergistic mean?

The hormones work together

What is the endocrine system made up of?

endocrine glands, tissues, and organs that produce and release hormones into the bloodstream

What makes endocrine cells different from many other cells?

They release hormones into the interstitial fluid and bloodstream rather than through ducts

What are the two major structural classes of hormones?

Amino acid-based hormones and steroid hormones

What are steroid hormones made from?

cholesterol

Are steroid hormones lipid-soluble or water-soluble?

Lipid-soluble

Examples of steroid hormones

Cortisol, aldosterone, estrogen, progesterone, testosterone

Are amino acid-based hormones lipid-soluble or water-soluble?

water-soluble

Examples of amino acid-based hormones.

Insulin, epinephrine, and thyroid hormones

Where are receptors for water-soluble hormones usually located?

On the cell membrane

Where are receptors for lipid-soluble hormones usually located?

Inside the cell, in the cytoplasm or nucleus

Why does a hormone only affect certain cells?

Only target cells have the specific receptor for that hormone

What happens when a hormone binds to its receptor?

It triggers a response in the target cell

Where is the pituitary gland located?

base of brain below hypothalamus

What are the two major parts of the pituitary gland?

Anterior pituitary and posterior pituitary.

What hormone stimulates body growth?

growth hormone (GH)

What does GH do?

GH stimulates all cells to increase fat catabolism (breakdown), blood glucose levels, and protein synthesis

What hormone stimulates the thyroid gland?

thyroid stimulating hormone (TSH)

What hormone stimulates the adrenal cortex?

Adrenocorticotropic hormone (ACTH)

What hormones regulate the reproductive organs?

Follicle Stimulating Hormone (FSH) and Luteinizing Hormone (LH)

What does Follicle Stimulating Hormone (FSH) do?

Causes egg to mature and stimulates ovaries to produce estrogen

What does Luteinizing Hormone (LH) do?

stimulates ovulation

What does Prolactin (PRL) do?

stimulates milk production by mammary glands

What two hormones are released by the posterior pituitary?

ADH and oxytocin

What does ADH do?

controls how much water your kidneys save or release in your urine

What does oxytocin do?

uterine contractions and milk ejection

Where is the thyroid gland located?

front of the neck below the larynx

What hormones does the thyroid produce?

T3, T4, calcitonin

What do T3 and T4 do?

Increase and regulate metabolic activity

What does calcitonin do?

helps lower blood calcium levels

Where are the parathyroid glands located?

On the posterior surface of the thyroid gland

What hormone do the parathyroid glands produce?

Parathyroid hormone (PTH)

What does parathyroid hormone (PTH) do?

increases blood calcium levels

Where are the adrenal glands located?

on top of the kidneys

What are the two regions of an adrenal gland?

adrenal cortex and adrenal medulla

What are the major hormones of the adrenal cortex?

aldosterone, cortisol, and androgens.

What does aldosterone do?

helps regulate sodium, potassium, and blood pressure.

What does cortisol do?

Helps the body respond to stress and affects metabolism.

What hormones does the adrenal medulla release?

epinephrine and norepinephrine

What do epinephrine and norepinephrine do?

Help produce the fight-or-flight response

Where is the pineal gland located?

brain

What hormone does the pineal gland produce?

melatonin

What does melatonin help regulate?

sleep/wake cycle/circadian rhythms

Where is the pancreas located?

behind the stomach

What are the endocrine portions of the pancreas called?

pancreatic islets (islets of Langerhans)

What hormone lowers blood glucose?

insulin

What hormone raises blood glucose?

glucagon

What hormone does the kidney produce that stimulates red blood cell production?

Erythropoietin (EPO)

What does EPO do?

stimulates RBC production

What hormone involved in blood pressure regulation is produced by the kidneys?

renin

What hormone does the heart release?

atrial natriuretic peptide (ANP)

What does ANP help regulate?

Blood volume and blood pressure

Where is the thymus located?

behind the sternum

What hormones does the thymus produce?

thymosin

What is the thymus important for?

T-cell development and immune function

What major hormone do the testes produce?

Testosterone

What does testosterone do?

Supports male reproductive development and function and contributes to male secondary sex characteristics

What major hormones do the ovaries produce?

Estrogens and progesterone.

What does estrogen do?

Helps regulate female reproductive function and secondary sex characteristics

What does progesterone do?

Helps regulate the reproductive cycle and supports pregnancy

What hormone is produced by adipose tissue?

leptin

What does leptin help regulate?

Appetite and energy balance

What is the general adaptation syndrome (GAS)?

The body's general response to prolonged stress

Can hormones influence behavior?

Hormones can influence mood, behavior, reproduction, stress responses, and other functions.

What are the three stages of the general adaptation syndrome?

Alarm, resistance, and exhaustion

What happens during the alarm stage?

The body activates the fight-or-flight response.

Which hormones are important during the alarm stage?

Epinephrine and norepinephrine

What happens during the resistance stage?

The body attempts to adapt to continued stress

Which hormone is especially important during prolonged stress?

Cortisol

What happens during the exhaustion stage?

body functions are no longer able to maintain a response to the stressor

How can aging affect hormone production?

Production of some hormones decreases or changes with age