BIOG 1440 L18 — Core Coverage (Prelim Cram)

Animal hormones: objectives and live-key content with no logged miss, including Ms. Doe fault patterns and the blood-sugar tests.

Spell out CRH and ACTH.

Corticotropin-releasing hormone; adrenocorticotropic hormone.

Spell out TRH and TSH.

Thyrotropin-releasing hormone; thyroid-stimulating hormone.

Spell out GHRH, GHIH, and IGF-1.

Growth hormone-releasing hormone; growth hormone-inhibiting hormone (somatostatin); insulin-like growth factor 1.

What is the posterior pituitary, and how does it connect to the hypothalamus?

The neurohypophysis: a collection of axonal projections from hypothalamic neurons.

What is the anterior pituitary, and how does the hypothalamus control it?

The adenohypophysis: glandular tissue controlled by releasing and inhibiting hormones carried in portal blood vessels.

What does ADH do?

Promotes water reabsorption in the kidney.

What are oxytocin's two lecture effects?

Uterine contraction and milk ejection.

Why do GH's breakdown of reserves and tissue growth work together?

Reserve tissue mobilizes resources (catabolic); growing tissue uses them (anabolic).

What do excess and deficient GH during growth cause?

Gigantism; dwarfism.

Name the effects of thyroid hormone.

Increases basal metabolic rate, fat mobilization, body temperature, protein synthesis, and growth.

Give the symptoms of hypothyroidism and the reason for them.

Weight gain, lethargy, cold intolerance, from decreased basal metabolism.

Give the symptoms of hyperthyroidism and the autoimmune example.

High temperature, sweating, weight loss, high blood pressure. Graves' disease.

Define primary versus secondary hormonal dysregulation.

Primary: the hormonal gland itself. Secondary: upstream, in the pituitary or hypothalamus.

Hypothyroidism with the fault in the thyroid: TRH, TSH, T3/T4?

TRH high, TSH high, T3/T4 low.

Hypothyroidism with the fault in the anterior pituitary: TRH, TSH, T3/T4?

TRH high, TSH low, T3/T4 low.

Hypothyroidism with the fault in the hypothalamus: TRH, TSH, T3/T4?

TRH low, TSH low, T3/T4 low.

Low cortisol from an anterior pituitary fault: CRH and ACTH?

CRH high, ACTH low.

What is the most informative blood-sugar test, and how is it done?

Oral glucose tolerance test: fast overnight, drink a sugary drink, measure sugar every hour.

Why is a random blood-sugar test not very informative?

A high value could just come from eating something sugary.

After a glucose drink, how does a diabetic curve differ from a non-diabetic one?

It peaks higher and stays high. A non-diabetic curve falls back to about basal level.

Which hormone would you test for developing type 2, and what result suggests it?

Insulin: elevated levels suggest insulin resistance.

What happens to insulin as type 2 progresses?

The pancreas can no longer compensate, insulin crashes, and full diabetes develops.

Which hormonal systems regulate blood sugar?

HPT and GH axes, insulin and glucagon, and the stress hormones. One variable, many hormones.

Thyroid hormone raises liver glucose synthesis. Why isn't it simply like glucagon?

It also increases cellular uptake, so faster flux need not mean higher blood glucose.

List the four adrenal regions from inside to outside, with what each makes.

Medulla: epinephrine. Zona reticularis: androgen precursors. Zona fasciculata: glucocorticoids. Zona glomerulosa: mineralocorticoids.

How is each stress arm controlled?

Rapid: sympathetic nerves → adrenal medulla. Sustained: HPA hormone chain → adrenal cortex.

Name the short-term effects of epinephrine and norepinephrine.

Glycogen breakdown and higher blood sugar; higher blood pressure, breathing, and metabolic rate; less digestion, excretion, and reproduction.

Sympathetic effects on heart, airways, and gut?

Accelerates heartbeat, relaxes airways, decreases gut motility.

Parasympathetic effects on heart, airways, and gut?

Slows heartbeat, constricts airways, stimulates gut motility.

How do epinephrine and cortisol each travel in blood?

Epinephrine dissolved; cortisol mainly bound to carrier proteins.

Where are the receptors for epinephrine and cortisol?

Epinephrine: in the plasma membrane, binding outside. Cortisol: inside the cell, in cytoplasm or nucleus.

In dehydration, what do ADH and aldosterone each promote?

ADH: water reabsorption. Aldosterone: water and salt reabsorption.

What does the thymus secrete, and what is it for?

Thymosins, which stimulate T cell development.

What does PTH do, and where is it from?

From the parathyroid glands. Raises blood calcium through release from bone and reabsorption in the kidneys.

What does the pineal gland secrete, and when?

Melatonin, at night; linked to sleep.