A&P 2 Exam 1

What is the body's 2nd great controlling system?

The Endocrine System

What 2 systems act to maintain homeostasis?

Nervous & Endocrine

T/F Hormones wash over all cells but only affects target cells.

True

When hormones are being classified chemically, there are two groups. What are they?

Amino Acid Based Hormones &
Steroid Based Hormones

What are the 6 major endocrine glands?

1. Pineal gland
2. Pituitary gland
3. Thyroid gland
4. Parathyroid glands
5. Thymus gland
6. Adrenal gland

What is the second great control system of the body that interacts with the nervous system to coordinate and integrate the activity of body cells?

The Endocrine System

T/F: The control and speed of the endocrine system is similar to that of the nervous system.

False

The endocrine system influences metabolic activity by means of what?

Hormones

The word "hormone" means...

to excite

What are hormones?

Chemical messengers released into the blood to be transported throughout the body

Binding of a hormone to cellular receptors initiates responses that typically occur after a lag period of seconds or even days. Although this makes the system slower than the nervous system, what is the upside to this?

Once initiated, the response tends to be much more prolonged than those induced by the nervous system

T/F: Hormonal targets ultimately include most cells of the body, and hormones have widespread and diverse effects.

True

The major processes controlled and integrated by hormones are... (5)

1. reproduction
2. growth and development
3. maintenance of electrolyte, water, and nutrient balance of the blood
4. regulation of cellular metabolism and energy balance
5. mobilization of body defenses

What is the term defined as the scientific study of hormones and the endocrine organs

Endocrinology

T/F: compared with other organs of the body, those of the endocrine system are small and unimpressive.

True

The endocrine system differs from other bodily systems in terms of arrangement. Explain.

They are not grouped together but rather widely spread throughout the body.

What is the name for the glands which produce nonhormonal substances, such as sweat and saliva, & have ducts that carry these substances to a membrane surface.

Exocrine glands

What is the name for the glands which produce hormones and lack ducts.

Endocrine glands

T/F: Endocrine glands typically have a rich vascular and lymphatic drainage that receives their hormones.

True

Most of the hormone-producing cells in the endocrine glands are arranged in _____ and _____ networks-- a situation that maximizes contact between the cells and the capillaries surrounding them.

Most of the hormone-producing cells in the endocrine glands are arranged in CORDS and BRANCHING networks-- a situation that maximizes contact between the cells and the capillaries surrounding them.

Define a neuroendocrine organ.

organs which have neural functions as well as producing and releasing hormones (ex. hypothalamus)

T/F: Very few organs contain scattered endocrine cels or small clusters of endocrine cells.

False; many organs

T/F: Hormone-producing cells are found in the walls of the small intestine, stomach, kidneys, and heart.

True

Are autocrines and paracrines part of the endocrine system? Why or why not?

No

Are hormones long or short-distanced chemical signals that travel in blood or lymph throughout the body?

Long-distanced

Chemicals that exert their effects on the same cells that secrete them are called what?

Autocrines

Chemicals that exert their effects locally but affect cell types other than those releasing the chemical are called what?

Paracrines

Certain tumor cells synthesize hormones __________ to those made in normal endocrine glands.

identical

What term can be defined as "chemical substances, secreted by cells into the extracellular fluids that regulate the metabolic function of other cells in the body"?

Hormones

Most hormones are ___________ based. (steroid or amino acid)

amino acid

Do amino based hormones vary in molecular size?

Yes.

Steroids are synthesized from ____________.

cholesterol

Of the hormones produced by major endocrine organs, only 2 hormones are steroids.. which ones are they?

Gonadal and adrenocortical hormones

T/F: All circulating hormones in the body are organic molecules.

True

Insulin, PTH, and epinephrine are the top three ________ based hormones in the human body.

amino acid based hormones

Leukotrienes and prostaglandins are considered __________.

Eicosanoids

Define eicosanoids

biologically active lipids (made from arachidonic acid) which are released by nearly all cell membranes.

These are made from arachidonic acid.

Eicosanoids

_______ are signaling chemicals that mediate inflammation and some allergic reactions.

leukotrienes

_________ are signaling chemicals that have multiple targets and effects, ranging from blood pressure and increasing the expulsive uterine contractions of birth to enhancing blood clotting, pain, and inflammation.

prostaglandins

Eicosanoids generally act as paracrines and autocrines and do not fit the definition of a true hormone. Why?

Because they are highly localized meaning they only effect nearby cells (true hormones influence distant targets)

If a hormone is a protein or peptide it is usually _______ based.

amino acid

If a hormone is derived from cholesterol, it can be assumed that the hormone is a _________.

steroid

T/F: Amino acid based hormones are pure amino acids.

False; they are modified amino acids

Most of these hormones are water soluble.

Amino acid based

Most of these hormones are lipid soluble.

Steroid base hormones

If a hormone is lipid soluble, then what does it need to do?

it needs a protein carrier to travel through plasma

Amino acid hormones are synthesized on the.... (hint: organelle)

rough ER

Steroid based hormones are synthesized on the.... (hint: organelle)

smooth ER

Most _________ based hormones work through a second messenger system (cAMP).

amino acid

Which type of hormone cannot be taken orally in most cases?

Amino acid based

Do steroid based hormones or amino acid based hormones bind to membrane receptors?

Amino acid based hormones

Do steroid based hormones or amino acid based hormones bind to intracellular receptors?

Steroid based hormones

_______ based hormones stimulate gene activation and protein synthesis.

Steroid

These hormones can be taken orally.

Steroid based hormones

Thyroid hormones act like ________ hormones but are not.

Thyroid hormones act like STEROID BASED hormones but are not.

Being _____ soluble, these hormones can diffuse directly into the cell and direct gene activation.

lipid soluble (steroid based hormones)

Cells that have receptors for specific hormones are called what?

Target Cells

Hormones bring about their characteristic effects on target cells by _______ cell activity.

altering

T/F: Hormones increase or decrease the rates of normal cellular processes.

True

T/F: Thyroid hormone is water soluble.

False; although it is an amino acid based hormone, it acts like a steroid in many ways. One being that it is not water soluble

Water soluble hormones act on receptors in the...

plasma membrane.

With the exception of thyroid hormone, all amino acid-based hormones exert their signaling effects through intracellular ________ generated when a hormone binds to a receptor on the plasma membrane.

With the exception of thyroid hormone, all amino acid-based hormones exert their signaling effects through intracellular SECOND MESSENGER generated when a hormone binds to a receptor on the plasma membrane.

On of the second messengers, _______, is used by neurotransmitters and olfactory receptors.

cyclic AMP (aka cAMP)

5 Steps to the cAMP signaling mechanism.

1. Hormone acts as first messenger by binding to plasma membrane receptor protein forming a R-H complex
2. R-H complex stimulates formation of cAMP (2nd messenger)
3. cAMP activates specific protein kinases in the cell
4. protein kinases phosphorylate enzymes and other proteins already in the cell
5. step 4 then activates or inactivates specific enzymes to open or close membrane channels

4 actions made by steroid hormones...

1. lipid soluble hormones diffuse though the lipid bilayer and bind to intracellular receptors
2. R-H complex binds to and activates a specific gene (direct gene expression occurs)
3. protein synthesis is stimulated
4. the new protein may be an enzyme, secretion, a membrane protein, etc.

T/F: cAMP is slow.

False; cAMP is very FAST

All major endocrine glands are linked ONLY by the __________.

blood

Melatonin is produced by what gland?

Pineal gland

What gland regulates amounts of calcium?

Parathyroid gland

What is the hypophysis?

referring to the hypothalamus and pituitary gland as one structure

GH, TSH, FSH, LH, ACTH, prolactin are produced where?

anterior pituitary

Posterior lobe of the pituitary is made up of....

nervous tissue.

also known as "The Master Gland"

Hypothalamus

T/F: Hypothalamus releases & inhibits hormones

True

When referring to the hypophyseal portal system of the pituitary, are we dealing with the anterior or posterior pituitary?

Anterior pituitary

The anterior pituitary produces ___(#) hormones, ___(#) of which are tropic hormones.

The anterior pituitary produces 6 hormones, 4 of which are tropic hormones.

75% of glandular weight is found in the anterior or posterior pituitary?

anterior pituitary

When referring to the hypothalamic-hypophyseal tract of the pituitary, are we dealing with the anterior or posterior pituitary?

Posterior

In terms of hormones, the posterior pituitary does what?

STORES 2 hormones that are produced by hypothalamus (ADH & oxytocin)

What two hormones are stored in the posterior pituitary?

ADH & oxytocin

2 main actions of hGH

-release of insulin-like growth factors from liver
-increase blood glucose levels (anti-insulin effects)

Are proteins able to be taken orally?

No

The term "tropic" means what?

to stimulate another gland

What's the term used to describe the situation when one hormone cannot exert its full effects without another hormone being present.

Permissiveness

________ of hormones occurs in situations where more than one hormone produces the same effects at the target cell and their combined effects are amplified.

Synergism

When one hormone opposes the action of another hormone, the interaction is called _________.

antagonism

T/F: The synthesis and release of most hormones are regulated by some type of positive feedback.

False; negative feedback

T/F: Thyroid Stimulating Hormone acts like a steroid based hormone although it is not one.

False; do not confused thyroid hormone with thyroid STIMULATING hormone

________ stimulates iodide uptake and production of T3 and T4

TSH (thyroid stimulating hormone)

T3 & T4 refers to the __________ hormones.

Thyroid hormones (which do act like steroids)

_____ stimulates release of ACTH.

CRH (corticotropin releasing hormone)

ACTH (adrenocorticotropic hormone) stimulates release of _______ from the adrenal cortex to help fight _________.

ACTH (adrenocorticotropic hormone) stimulates release of CORTISOL from the adrenal cortex to help fight EVERYDAY STRESSORS.

What hormone is released when you fall under stress (all stress-both physical & emotional)?

ACTH (adrenocorticotropic hormone)

What are the 2 main gonadotropins?

FSH & LH

Gonadotropins are under the control of _____ from the _________.

Gonadotropins are under the control of GnRH from the HYPOTHALAMUS.

____ & ____ are both hormones whom regulate the functions of ovaries and testes.

FSH & LH

T/F: Prolactin is tropic.

No!

Why is prolactin not considered tropic?

Because mammary glands are exocrine glands through milk production

In females, _________ stimulates development of mammary glands and milk production.

Prolactin (PRL)