Chapter 17 STUDY: THE ENDOCRINE SYSTEM

Posterior pituitary

neurohypophysis

(PRL)

Prolactin

1.Binding of hormone to receptor 2.Release of HSP90 proteins 3.Entry of hormone into the nucleus what order is this?

The order of glucocorticoid hormone action

How do most steroids differ from one another?

They differ in the functional groups attached to their backbone structure.

(TH)

Thyroid Hormone

(TSH)

Thyroid-stimulating hormone

True or False: Hypothalamic neurons secrete hormones that are stored in neurohypophysis until released into blood

True

Anterior pituitary

adenohypophysis

(GnRH)

gonadotropin releasing hormone

Linked to hypothalamus by hypophysial portal system •Primary capillaries in hypothalamus connected to secondary capillaries in adenohypophysis by portal venules •Hypothalamic hormones regulate adenohypophysis cells

(adenohypophysis) Anterior pituitary

•Adaptation to long-term stimuli -Nervous: -Endocrine:

-Nervous: response declines (adapts quickly) -Endocrine: response persists (adapts slowly)

•Area of effect -Nervous: -Endocrine:

-Nervous: targeted and specific (one organ) -Endocrine: general, widespread effects (many organs)

What is a hormone receptor?

A specific protein or glycoprotein embedded in the plasma membrane

(ACTH)

Adrenocorticotropic hormone

Which adrenal cortical hormone helps maintain blood pressure and blood volume?

Aldosterone

Inadequate hormone release is called hyposecretion. It can result from __________. tumors or lesions that destroy an endocrine gland tumors or lesions that interfere with its ability to receive signals from another gland inadequate stimulation of the gland or All of the choices are correct

All of the choices are correct.

(ADH)

Antidiuretic hormone

Which pituitary hormone reduces urine volume and increases blood volume? Nephron stimulating hormone Oxytocin Antidiuretic hormoneCorrect Urine hormone

Antidiuretic hormone

Which pancreatic cells secrete insulin? Alpha cells Chromaffin cells Beta cells Acinar cells

Beta cells

To get from an endocrine gland to its target cell, a hormone must travel through what?

Blood

The stress response is mediated by what system(s)?

Both the endocrine system and the sympathetic nervous system

What is the effect of long term exposure to cortisol on the immune system?

Cortisol depresses the immune system.

Target cells can become less sensitive to a hormone by decreasing the number of receptors via which process?

Down- regulation

Which of the following defines hormone specificity? Each hormone is made only from one tissue. Each receptor binds to only one hormone. Each hormone has only one specific effect.

Each receptor binds to only one hormone.

define hormone specificity?

Each receptor binds to only one hormone.

-No ducts -Contain dense, fenestrated capillary networks which allow easy uptake of hormones into bloodstream -"Internal secretions" -Intracellular effects such as altering target cell metabolism

Endocrine glands:

Which glands secrete their product by way of a duct directly onto an epithelial surface? Endocrine Exocrine Paracrine

Exocrine

-Have ducts; carry secretion to an epithelial surface or the mucosa of the digestive tract: "external secretions" -Extracellular effects (food digestion)

Exocrine Glands

Name the four principal mechanisms of communication between cells?

Gap Junctions Neurotransmitters Paracrines Hormones

(GH)

Growth Hormone

Hormones of the hypothalamus stimulate the anterior pituitary to release a hormone. This is what type of stimulus for hormone secretion?

Hormonal

Rising blood glucose levels stimulate the release of insulin. This is what type of stimulus for hormone secretion?

Humoral

Many of its functions carried out by pituitary gland

Hypothalamus

Regulates primitive functions from water balance and thermoregulation to sex drive and childbirth

Hypothalamus

•Speed and persistence of response Nervous: Endocrine

Nervous: reacts quickly (ms timescale), stops quickly -Endocrine: reacts slowly (seconds or days), effect may continue for days or longer

•The two systems can regulate each other, how?

Neurotransmitters can affect glands, and hormones can affect neurons

The initial response to stress is an alarm reaction mediated mainly by which two hormones?

Norepinephrine and Epinephrine

In the nervous and endocrine system, Several chemicals function as both hormones and neurotransmitters:- what are they? (3)

Norepinephrine, dopamine, and antidiuretic hormone

Both stored and released by posterior pituitary •Hypothalamus produces ______ and ________ .•Posterior pituitary does not synthesize them

OT and ADH

Which secrete steroid hormones? Ovary Adrenal Medulla Testes Adrenal Cortex Liver

Ovary, Testes, Adrenal Cortex

Which endocrine gland also acts as an exocrine gland?

Pancreas

With respect to hormones, what does saturation mean?

Saturation means that all of the receptor molecules have bound hormone molecules.

What is a situation that upsets homeostasis and threatens one's physical and emotional well-being?

Stress

What are the three types of interactive effects hormones can have?

Synergistic Permissive Antagonistic

Among their many functions, norepinephrine and epinephrine also play an important role in ________________ ?

The alarm reaction of the stress response

Target cells can become more sensitive to a hormone by increasing the number of receptors via which process?

Up-regulation

When cells cannot absorb glucose, they must get their energy someplace else, and in turn they metabolize fat and protein. In time, this leads to __________.

a condition called ketoacidosis, causing deep, gasping breathing

What do Gap Junctions do?

allow signaling molecules, nutrients, and electrolytes to move from cell to cell

Eight hormones produced in hypothalamus •Six regulate the _____________ pituitary •Two are released into capillaries in the ___________ pituitary

anterior posterior

•Hypothalamic -releasing and -inhibiting hormones travel in hypophysial portal system from hypothalamus to the ______________

anterior pituitary

•TRH, CRH, GnRH, and GHRH

are releasing hormones that promote anterior pituitary secretion of TSH, PRL, ACTH, FSH, LH, and GH

(CRH)

corticotropin releasing hormone

What is the fate of most hormones?

degraded by liver and kidneys

(FSH)

follicle-stimulating hormone

(GHRH)

growth hormone releasing hormone

The steroid hormone-receptor complex binds to __________.

hormone response elements in DNA

The pituitary gland is suspended from hypothalamus by a stalk— called?

infundibulum

PIH inhibits or promotes secretion of prolactin?

inhibits

What effect does thyroid hormone have on the body's metabolic rate?

it increases it

Most hormones are taken up and degraded by the __________ and __________.

liver; kidney

(LH)

luteinizing hormone

The rate of hormone removal is called the __________, and the length of time required to clear 50% of the hormone from the blood is the __________.

metabolic clearance rate; half life

Target organs regulate the pituitary through feedback loops. Most often, this is in the form of __________. positive feedback direct nervous stimulation negative feedback inhibition All of the choices are correct

negative feedback inhibition

Target organs regulate the pituitary through feedback loops. Most often, this is in the form of __________. positive feedback direct nervous stimulation negative feedback inhibition All of the choices are correct

negative feedback inhibition

The hypothalamus controls the posterior pituitary by way of __________. neuroendocrine reflexes the hypophyseal portal system secreting hormones that enter capillaries, travel down the portal venules, and diffuse out into the pituitary tissues timulating its tissue to synthesize hormones

neuroendocrine reflexes

(OT)

oxytocin

Which gland is thought to play a role in establishing 24-hour circadian rhythms?

pineal gland

Nerve cell bodies in hypothalamus pass down the stalk as hypothalamo-hypophysial tract and end in ______________ lobe in pituitary gland

posterior

Steroid hormones bind to ____________ of the target cell.

protein receptors in the cytoplasm or nucleus

Similar to neurotransmitters, hormones exert their action only on cells that have specific __________ that the hormones bind to.

receptor

One hormone molecule can stimulate the synthesis of hundreds of enzyme molecules. What is this known as?

signal amplification (or the cascade effect)

Aldosterone stimulates the kidneys to retain ______.

sodium

Glucocorticoids are __________ hormones secreted by __________ glands. peptide; endocrine peptide; exocrine steroid; endocrine steroid; exocrine None of the choices are correct.

steroid; endocrine

The mode of action of steroid hormones involves __________.

stimulation of mRNA transcription

What do hormones do?

they're chemical messengers that travel in the bloodstream to other tissues and organs

What do neurotransmitters do?

they're released from neurons to travel across synaptic cleft to second cell

what do Paracrines do?

they're secreted into tissue fluids to affect nearby cells

(TRH)

thyroid releasing hormone

Housed in sella turcica of sphenoid bone• Size and shape of kidney bean

Pituitary Gland

somatostatin inhibits or promotes secretion of growth hormone and thyroid-stimulating hormone by the anterior pituitary?

Inhibits

releases hormones, releases bile into ducts, releases albumin and blood-clotting factors into blood

Liver cells

Which of the following is not a process that is stimulated by glucocorticoid hormones? Synthesis of glucose Mobilization of fats Breakdown of proteins Maturation of ovarian follicles

Maturation of ovarian follicles