The Peripheral Endocrine Glands

Human Physiology – From Cells to Systems | 9e Lauralee Sherwood The Peripheral Endocrine Glands

Thyroid gland

controls basal metabolic rate

Adrenal glands

secrete hormones important for maintaining salt balance, nutrient molecules, and adapting stress

Endocrine pancreas

secrete to metabolize nutrient molecules

Parathyroid glands

secrete a hormone important in Ca2+ metabolism

calcitonin

What do C cells secrete?

• intersperses in the interstitial spaces between follicles

Thyroid hormone

Which hormone is synthesized and stored on the thyroglobulin molecule?

colloid

Most steps of the thyroid hormone synthesis take place on the thyroglobulin molecules within the ___.

Thyroxine-binding globulin

Which plasma protein selectively binds ONLY thyroid hormone?

T4, T3

The thyroid gland transports most circulating ____ and _____.

T4

About 90% of the secretory product released from the thyroid gland is in the form of ____.

increases

Thyroid hormone ______ the basal metabolic rate and exerts other effects.

Calorigenic effect

the effect of the thyroid hormone on metabolic rate & heat production

• “heat-producing”

Sympathomimetic effect

any action similar to one produced by the sympathetic nervous system

hypothalamus-pituitary-thyroid axis

What is the most important regulator of thyroid hormone secretion?

Hypothyroidism

thyroid hormone secretion deficiency

Hyperthyroidism

thyroid hormone secretion excess

Goiter

develops when the thyroid gland is overstimulated

• enlarged thyroid gland

• highly visible

• develops whenever either TSH or TSI excessively stimulates the thyroid gland

mineralocorticoids, glucocorticoids, sex hormones

The adrenal cortex secretes what?

Adrenal cortex

Zona glomerulosa, zona fasciculata, and zona reticularis are the 3 layers of what?

Aldosterone

• promotes Na+ retention and enhances K+ elimination during the formation of urine

• Regulates Na+ and K+ to regulate our blood pressure.

circulatory shock

Without aldosterone, a person rapidly dies from __________ _______.

Mineralocorticoids

Which hormone is essential for life?

Na+; K+

The major effects of mineralocorticoids are on _____ and _____ balance and blood pressure homeostasis.

Glucocorticoids

exert metabolic effects & play a key role in adaptation to stress

Cortisol

secretion is regulated by the hypothalamus-pituitary-adrenal cortex axis

adrenal cortex

This secretes both male and female sex hormones in both sexes.

• androgens and estrogens

Aldosterone hypersecretion

causes high blood pressure and low potassium levels

Cortisol hypersecretion

high blood pressure or bone loss

Adrenal androgen hypersecretion

can cause heterosexual precocious puberty.

• associated with PCOS, congenital adrenal hyperplasia (CAH), and insulin resistance conditions

Adrenocortical insufficiency

when the adrenal glands don’t make enough of the hormones cortisol and aldosterone

Catecholamines

secreted into the blood by exocytosis of chromaffin granules

Epinephrine

reinforces the sympathetic nervous system and exerts metabolic effects

organ systems

epinephrine’s effects on _____ _______:

increases cardiac output and dilates respiratory airways

metabolic

epinephrine’s ________ effectsepinephrine’s effects on _____ ____: :

prompts mobilization of stored carbohydrate and fat so extra energy is available as needed to fuel muscular work

epinephrine

• promotes arousal

• increases alertness

• causes sweating

• etc.

sympathetic; adrenal medulla

Epinephrine is released only on ________ stimulation of the ______ ______.

Stress

state of worry or mental tension caused by a difficult situation.

• natural human response that prompts us to address challenges and threats in our lives

hypothalamus

The stress response is coordinated by which brain structure?

Anabolism

buildup of large organic macromolecules from small organic subunits

Catabolism

breakdown of large, energy-rich organic molecules within cells

True

Most small organic molecules can be converted into other types.

True or false?

Glycogenesis; Glycogenolysis

Glucose → glycogen

Which two metabolic processes?

1.) Glycogenesis

2.) Glycogenolysis

3.) Gluconeogenesis

4.) Protein Synthesis

5.) Protein degradation

Gluconeogenesis

amino acids → glucose

Which metabolic processes?

1.) Glycogenesis

2.) Glycogenolysis

3.) Gluconeogenesis

4.) Protein Synthesis

5.) Protein degradation

Protein synthesis

amino acids → protein

Which metabolic processes?

1.) Glycogenesis

2.) Glycogenolysis

3.) Gluconeogenesis

4.) Protein Synthesis

5.) Protein degradation

Energy storage forms

excess circulating glucose, circulating fatty acids, and circulating amino acids

glucose

The brain must be continuously supplied with _______.

Absorptive state

occurs after a meal

Postabsorptive state

occurs between meals

liver, adipose tissue, muscle, brain

What are the key tissues in metabolic states?

Islets of Langerhans

endocrine cells scattered throughout the pancreas

alpha cells

alpha or beta cells?

glucagon

beta cells

alpha or beta cells?

insulin

Somatostatin

inhibits the digestive system

Insulin

lowers blood glucose, fatty acid, and amino acid levels and promotes their storage

carbohydrates

Insulin actions of _______:

facilitates glucose utilization in peripheral tissues and suppresses hepatic glucose production

fat

Insulin actions of _______:

regulates adipose tissue fatty acid esterification, glycerol and TG synthesis, lipogenesis, and possibly oxidation

protein

Insulin actions of _______:

the net formation of protein is accelerated by insulin

Amylin

a centrally acting, neuroendocrine hormone synthesized with insulin in the beta cells of pancreatic islets

glucagon

Elevated blood glucose stimulates ______ secretion, but inhibits ______ secretion.

Glucagon

increased during postabsorptive state

• works with insulin to maintain blood glucose and fatty acid levels

mellitus

An excess of glucagon can aggravate the hyperglycemia of diabetes ________.

hypothalamus

Which brain structure plays a role in controlling glucose homeostasis?

bone deposition

bone remodeling:

formation

bone resorption

bone remodeling:

removal

parathyroid glands

Peptide hormone is secreted by what glands?

PTH

raises plasma Ca2+

bone deposition

Mechanical stress favors what?

1.) bone deposition

2.) bone resorption

Osteoblasts

cells that form new bones & grow and heal existing bones

kidneys

PTH acts on what structure?

Calcitonin

lowers plasma Ca2+ concentration

Vitamin D

a hormone that increases Ca2+ absorption in the intestine

• builds bones & keeps them healthy

PTH hypersecretion

excess PTH secretion

PTH hyposecretion

deficient PTH secretion

Vitamin D deficiency

major consequence is impaired intestinal absorption of Ca2+