Neural

Endocrine

Neuroendocrine

Paracrine

Autocrine

pituitary gland

pineal gland

thyroid (and parathyroid) glands

Thymus

Adrenal glands

Pancreas

Reproductive

Steroid hormones are usually synthesized from _____.

Are steroid hormones stored in vesicles?

Usually synthesized from cholesterol.

Not usually stored.

How are steroids normally transported, enter cells?

Name some examples of steroid hormones.

Steroid hormones are lipid-soluble so they can diffuse across cell membrane and enter interstitial fluid and blood.

Examples: aldosterone, progesterone, cortisol

Estrogen stimulates release of LH from the anterior pituitary. Secreted LH then acts on ovaries to stimulate additional secretion of estrogen, which leads to more LH secretion.

-eventually LH reaches proper concentration and a negative feedback loop goes into effect to stop furher hormone secretion.

Name the 3 parts of the pituitary gland.

What controls the release of hormones from the pituitary?

Anterior lobe, posterior lobe, pars intermedia.

Hormoe release form the pituitary is controlled by the hypothalamus (with 'releasing' and 'inhibiting' hormones)

Thryotropin (TSH)

Growth Hormone

Corticotropin

Follicle Stimulating hormone (FSH)

Luteinizing Hormone (LH)

Prolactin

Name the two hormones secreted by the posterior pituitary .

Where are these hormones produced?

Antidiuretic hormone (ADH) aka vasopressin

Oxytocin - causes contraction of pregant uterus and helps milk letdown from mammary glands.

These hormones are synthesized by cell bodies in the hypothalmus, then transported down the axon to the posterior pituitary.

ADH causes retention of water.

Without ADH, the collecting tubules of the nephron are mostly impermeable to water, so water is lost in the urine.

With ADH, the collecting ducts/tubules develop aquaporins to allow water to reabsorption. This produces concentrated urine.

there are osmoreceptors near the hypothalamus.

When extracellular fluid is too concentrated fluid is pulled out of osmoreceptors by osmosis, decreasing its size.

These nerve signals are passed to the hypothalamus, which causes ADH secretion from the posterior pituitary, resulting in water retntion.

Since ADH causes water retntion there will be greater blood volume hence: arterial constriction and increased arterial BP.

If there is decreased blood volume the stretch receptors of the right atrium do not send signals to decrease ADH release, so more ADH is released.

thyroxin (T4)

triodothryonine (T3)

TRH (thyroid-releasing hormone) from the hypothalamus controls anterior pituitary release of TSH.

TSH from a. pituitary increases thyroid hormonal secretion.

Increased thyroid hormone in body fluids will decrease TSH secretion by a. pituitary.

Adrenal medulla:

- % composition

-nervous sytem relation

-hormone secretion

Adrenal medulla:

-central 20% of the gland

-functionally related to the sympatheic nervous system

-secretes epi and norepi in response to sympatheic stim

mineralcorticoids (Aldosterone) - affects elytes

glucocorticoids (cortisol) - affect blood glucose concentration, and protein/fat metabolism

smal amounts of androgenic hormones

Name the three layers of adrenal cortex from outside in.

Also note the function of each layer.

-Zona glomerulosa: just under capsule, secretes aldosterone

-Zona fasiculata: secretes cortisol in response to ACTH from pituitary

-Zona reticularis: deep layer of cortex, secreted dehyroepiandrosterone (DHEA)

What is affected by addisons disease?

What deficiencies does it cause?

Addisons disease: adrenal cortex affected:

deficiency of aldosterone: causes super high levels of K+ in the blood (hyperkalemia), which can lead to cardiac arrest.

Can also cause glucocorticoid deficiency- causes abnormal blood clucose levels.

What is the problem in Cushings syndrome?

What are some symptoms?

Hypersecretion of cortisol

Muscle wasting on dorsum

Poor wound healing and skin disease

Process waste and excrete it

Regulate water and elyte balance

Regulate body fluid osmolarity, elyte conc.

Regulate acid-base balance

Regulate arterial pressure

Secrete, metabolize, excrete hormones

Gluconeogenesis

Urea (from AA metabolism)

Creatine (from muscle creatine)

Uric acid (from nucleic acids)

End products of hemoglobin breakdown (ie billirubin)

Metabolites of diff hormones

Other toxins and foreign substances

Short term: kidneys are able to secrete vasoactive substances such as renin, which leads to angiotensin II.

Long term: kidneys are good at adjusting arterial pressure by excreting sodium, potassium and water.

What are the effects of Angiotensin II?

Where does it come from and what stimulates its release?

Angiotensin II is a powerful vasoconstrictor.

If there is low arterial pressure the kidney will release renin, which acts on angiotensis which signals release of angiotensin II from the lungs.

Angiotensin II comes back to act on the kidney to cause arterial pressure.

What are the two capillary beds in the kidneys that adjust glomerular filtration or tubular reabsorption?

How do eah function?

Glomerular capillaries: if the capillaries have high hydrostatic pressure, there is rapid fluid filtration.

Peritubular cappilaries: if they have low hydrostatic pressure there is rapid fluid reabsorption from th tubule system to the capilaries.