PS 3: The Endocrine System - Types of Hormones and Their Actions

hypothalamus and posterior pituitary gland

Name the two glands that function together to release hormones essential for maintaining water balance, and for giving birth and breast feeding

anterior pituitary gland

Name the gland that secretes hormones that promote growth, and control the hormonal output of several other endocrine glands, including those regulating reproduction

thyroid gland

Name the gland that secretes hormones which control the basal metabolic rate of the body

endocrine pancreas

What secretes hormones which regulate the metabolism of nutrient molecule?

parathyroid glands

What gland secretes a hormone which is important in calcium homeostasis?

adrenal glands

Name the gland that secretes hormones which are important in the metabolism of nutrient molecules, adaptation to stress, and maintaining salt balance

comprise majority of hormones, including those secreted by the hypothalamus, anterior and posterior pituitary, pancreas, and parathyroid

What are characteristics of peptide/protein hormones?

derived from the amino acid, tyrosine, and include the hormones secreted by the thyroid gland, and adrenal medulla

What are characteristics of amine hormones?

catelcholamines

Adrenomedullary hormones are also known as ____.

neutral lipids derived from cholesterol; include hormones secreted by the adrenal cortex, ovaries, and testes; lipophilic

What are characteristics of steroid hormones?

dissolved in the plasma; plasma proteins

Water-soluble hormones are transported ____, whereas lipophilic hormones are transported largely bound to ____.

target cell receptors

Hormones bind with specific ____ ____ ____ and binding starts a chain of events within the target cell which lead to the effects characteristic of that hormone

plasma membrane and intracellular

What are the two groups that hormones can be classified into based on the location of the receptors?

specificity

Hormone effects have ____, where the interaction between a hormone and its target cell receptor produce a characteristic response in the target cell, which is different for different hormones, and differs between different target cells responding to the same hormone.

contraction of vascular smooth muscle, relaxation of respiratory airway smooth muscle, breakdown of liver glycogen, increased rate and force of contraction of the heart

What different effects does the adrenal medullary catecholamine epinephrine cause?

second messenger

Most hydrophilic hormones bind to cell surface receptors and produce a ____ ____ molecule within the target cell (hormone is the “first” messenger)

cyclic AMP

Receptor occupancy activates adenylate cyclase to form ____ ____ (second messenger derived from ATP) which activates cyclic AMP dependent protein kinase causing phosphorylation of a particular protein and leads to a physiological response.

hormones binding to cell surface receptors and alter cell permeability by opening or closing particular ion channels

Another mechanism using a “second messenger” other than using cyclic AMP is ____

intracellular; genes; transcriptional regulation

Lipophilic hormones bind to ____ receptors, activate ____ through ____ ____, producing new intracellular proteins with that characteristic effect

T

(T/F) The Pancreas functions as an endocrine and an exocrine gland.

pancreatic islets (islets of Langerhans)

Clusters of cells in the pancreas are called ____ ____ (____ ____ ____).

glucagon; insulin

Within the pancreatic islets, alpha cells secrete ____, and beta cells secrete ____.

Glucagon and insulin

____ and ____ are the main regulators of blood glucose level

increase; glycogenolysis; gluconeogenesis

Glucagon ____ blood glucose levels by stimulating liver ____ (conversion of glycogen to glucose) and stimulating ____ in liver (glucose formation from amino acids, lactate, etc.)

low; high

____ blood glucose levels stimulate release of glucagon, while ____ glucose inhibits release

decreases; glycogenesis; lipogenesis; decreases

Insulin ____ blood glucose by accelerating uptake of glucose from blood into skeletal muscle, accelerates ____ (conversion of glucose to glycogen), accelerates uptake of amino acids into cells to speed protein synthesis, accelerates ____ (conversion of glucose or amino acids to fatty acids) and ____ glycogenolysis and gluconeogensis

diabetes mellitus; hyperglycemia

____ ____ is the most common endocrine disorder, characterized by elevated blood glucose ____

insulin-dependent or juvenile-onset; lack of insulin secretion; an autoimmune process leads to destruction of the pancreatic beta cells and inability to secrete insulin necessitating subcutaneous insulin injection

What is Type I Diabetes Mellatus?

non-insulin-dependent or maturity-onset); insulin secretion may be normal or increase, but insulin’s target cells are less sensitive than normal

What is Type II Diabetes Mellatus?

obesity

What is Type II Diabetes Mellatus often associated with?

glucosuria

If untreated or glycemic control is poor, elevated blood glucose levels may exceed the transport (reabsorption) capacity for glucose in the kidney, leading to excretion of glucose in the urine, a condition called ____.

polyuria

Glucose in the urine exerts an osmotic effect preventing reabsorption of water aand leading to increased urine production ____.

polydipsia

Increased urine production due to high glucose leads to excessive thirst, a condition called ____.

ketone bodies

Increased breakdown of fatty acids associated with insulin deficiency, and their use by liver results in excessive production of ____ ____.

diabetic ketoacidosis

The resulting acidosis (____ ____) from excessive production of ketone bodies as a result of increased breakdown of fatty acids when insulin is deficient leads to electrolyte imbalance, which affects the brain. This causes coma or death if untreated

a secondary complication of diabetes affecting small blood vessels in circulation causing blindness, deterioration of glomerular filtration in kidneys (kidney failure), and deterioration of blood flow to extremities (amputation)

What is diabetic neuropathy?

in a bony cavity at the base of the brain, just below the hypothalamus and connected to it by a thin stalk

Where is the pituitary gland located?

anterior and posterior

What are the 2 distinct parts of the pituitary gland?

anterior pituitary

The ____ ____ consists of glandular epithelial tissue and is connected with the hypothalamus by blood vessels.

posterior pituitary

The ____ ____ contains axon terminals whose cell bodies are located in the hypothalamus.

1. Human growth hormone hGH

2. Thyroid-stimulating hormone TSH; Thyrotropin

3. Adrenocorticotropic hormone ACTH

4. Follicle-stimulating hormone FSH

5. Luteinizing hormone LH

6. Prolactin PRL

7. Melanocyte-stimulating hormone MSH

Name the 7 peptide hormones that the anterior pituitary produces and secretes

human growth hormone hGH

What hormone causes cells to grow and multiply by facilitating entry of amino acids into cells and conversion into proteins?

thyroid-stimulating hormone TSH; thyrotropin

What hormone stimulates secretion of thyroid hormone and growth of the thyroid gland?

adrenocorticotropic hormone ACTH

What hormone stimulates cortisol secretion by the adrenal cortex?

follicle-stimulating hormone FSH

What hormone in females stimulates the maturation of eggs within the ovarian follicles, and stimulates secretion fo estrogen by the ovaries and, in males, is required for sperm production?

luteinizing hormone LH

What hormone stimulates ovulation and other sexual and reproductive activities?

prolactin PRL

What hormone acts together with other hormones to initiate and maintain milk production in mammary glands?

melanocyte-stimulating hormone MSH

What hormone increases skin pigmentation

tropic hormones

____ ____ control the secretion of hormones by other endocrine glands

TSH, ACTH, LH, FSH

What are the four tropic hormones that the anterior pituitary secretes?

neurohormones; hypothalamus

The anterior pituitary is controlled by ____ produced by cells in the ____.

releasing; release-inhibiting hormones

The ____ and ____ ____ are transported through portal blood vessels to the anterior pituitary.

thyrotropin-releasing hormone

____ ____ stimulates thyrotropin release

posterior pituitary

The ____ ____ gland stores and releases hormones, but does not make them.

oxytocin and antidiuretic hormone

What two hormones are produced within cell bodies of neurosecretory cells in the hypothalamus and are released from the axon terminals in the posterior pituitary?

oxytocin

____ is released in large amounts prior to birth and stimulates contraction of the smooth muscle cells in the uterus, and affects contractile cells of the mammary glands causing milk ejection

antidiuretic hormone

____ decreases urine production by effects on the kidney

tropic hormone; hypothalamus

A short-loop negative feedback consists of the ____ ____ inhibiting the ____.

hormone; anterior pituitary; hypothalamus

A long-loop negative feedback consists of the ____ inhibiting the ____ ____ or the ____.

thyroid

The ____ is located below the larynx in front of the trachea.

thyroid gland

Thyroxine and calcitonin are produced by the ____ ____.

thyrotropin

____ stimulates secretion of thyroxine (T4)

increases body’s basal metabolic rate and stimulates amino acid uptake and protein synthesis

What does thyroxine (T4) do to the body?

cold

____ exposure stimulates T4 release.

an enlarged thyroid gland

What is a goiter?

hyperthyroidism or lack of iodine or Graves disease, involving antibody to TSH receptor

What is a goiter associated with?

calcitonin and parathyroid hormone PTH

What two hormones regulate calcium levels?

calcitonin

What hormone is produced by the the thyroid and lowers blood calcium?

PTH

What hormone is produced by the parathyroid glands and raises blood calcium?

osteoblasts; osteoclasts

What cells convert blood Ca2+ to bone? Bone to blood Ca2+?

collagen fibers with Ca(PO4)3

What is the structure of bone?

gives bone hard/dense structure

What does Ca(PO4)3 do in bone?

Increases bone turnover by activating osteoblasts and osteoclasts with a net effect shifting calcium from bone to blood

How does PTH raise blood calcium?

Vitamin D is converted to calcitriol following secretion of PTH, increasing calcium absorption in kidneys and gut

How is vitamin D relevant in increasing blood calcium?

adrenal

____ glands are located above each kidney

mineralocorticoids, glucocorticoids, sex steroids

What 3 groups of steroid hormones does the adrenal gland’s outer cortex secrete?

inner medulla

The ____ ____ of the adrenal glands secretes catecholamines (epinephrine and norepinephrine), which stimulate the liver to supply glucose to the blood, as well as other fight-or-flight reactions.

aldosterone

Mineralocorticoids - ____ stimulates the kidney to conserve sodium and to excrete potassium, increasing blood volume

cortisol

Glucocorticoids - ____ decreases glucose utilization by most cells increasing blood glucose - important role in adaptation to stress

stress

____ refers to the response of the body to any factor that overwhelms, or threatens to overwhelm, the ability of the body to maintain homeostasis

stressors

Stimuli which may induce a stress response (____) may be physical, chemical, physiological, psychological, or social.

sympathetic NS; endocrine system

The hypothalamus integrates the responses of both the ____ ____ ____ and the ____ ____ during stress