Endocrinology: Hormones, Glands, and Regulation Mechanisms

pineal gland

located in epithalamus, produces melatonin

thyroid

establishes metabolic rate

parathyroid

calcium regulation

hypothalamus

temperature regulation and hormonal regulation, regulates the pituitary gland

pituitary gland

master gland, regulates many glands in endocrine

suprarenal glands

adrenals, produce epi and neuroepi (adrenaline). at middula inner part, and cortex has three layers

overies and testes

sex hormone

pancrease

Insulin production, glucose level regulation, and reduces blood sugar. Insulin is secreted by the pancreas, then glucose enters muscle, less glucose in blood.

glycogen

increases blood sugar

what happens if you do not produce insulin

diabetes no insulin production

how are hormones regulated

by checking blood variables, nervous system, and tropic hormones

tropic hormones

hormones that drive prodction of other hormones

hypothalamic pituitary axes

hypothalamus excretes thyroid regulating hormone stimulating the release of thyroid stimulating hormone from the anteior pituitary gland which flows in the blood to the thyroid in the follicle the thyroglobin then binds to one (MIT) or two (DIT) iodines to then add up and make t3 or t4

endocrinology

study of hormones and endocrine organs

which is faster nervours or endocrine system

nervous

main function of endocrine

control and integration of processes like reproduction, growth, electrolytes, cellular metabolism and body defense

anatamoical structure of endocrine

ductless glands, no tubes. expel into circulation or cardiovascular through apical membrane

endocrine organ list that produces hormones

pituitary gland, thyroid gland, parathyroid gland, adrenal gland, pineal gland, hypothalamus

structures that are borth exocrine or endocrine

pancreas, gonads, and placenta

other hormone-producing tissues

adipose, thymus, small intestines, stomach, kidneys and heart

what type of signalling mechanisms are used ?

localized or delocalized

autocrine

signaling effects on the same cells that secrete them. ex. t-cells

paracrines

effects cells other than those that secrete them, less localized. ex. GHIH

hormones effect radius?

Effect far beyond the site of secretion. two main classes 1. amino acid based hormones 2. steroids. both travel through blood stream and cause effects on cells that have the receptor for them.

difference between steroids and amino acids?

steroids are fatty and can penetrate plasma membrane becasue it is made of phospholipids. amino acids can not blast through.

how do aminoa acids enter the plasma membrane ?

hormone uses receptors on the plasma membrane and then second messanger by G proteins relay hormone cannot get in to enzyme ATP becomes cAMP as second messanger. if no plasma membrane receptors needed then intracellular receptors.

effects of one little hormone and ATP

makes a lot of cAMP and activates a lot of kinase

if hormone has entry without plasama membrane receptors

hormone enters and activates specific dna, mRNA transcribed and specific protein is made

what is needed for cell activation

number of receptors and blood levels affinity

cells with low hormone levels

cells make more receptors for up regulation

cells with high hormone levels

cells break down receptors, down regulation

can hormones impact receptors of another hormone

yes, like human uterus. when progesteron down it regulates estrogen receptors and when estrogen is up it regulates progesterone receptors

what controls blood levels of a hormone

negative feedback, negating out of homeostatic levels

negative feedback

if hormone levels rise it feeds back to inhibit hormone secretion

three types of hormone secretion control

humeral, neral stimulus and hormonal stimulus

humeral hormone secertion

blood, yellow bile, black bile, phlegm. hormones secretes in response to blood levels. PTH bc of calcium

neural stimulus

hormone released caused by neural input. ex. CNS spinal cord to medulla of adrenal gland releases NE or EPI to cause a response

hormonal stimulus

hormone a to hormone b. tropic hormone. TRH to TSH

pituitary

hypopysis, two major lobes. anterior and posterior.

pituitary anterior lobe

adenohyophosis, glandular tissue (gland) produces it's own hormone. produces 6 hormones; Adrenocorticotropic hormone (ACTH)

Thyroid-stimulating hormone (TSH)

Luteinising hormone (LH)

Follicle-stimulating hormone (FSH)

Prolactin (PRL)

Growth hormone (GH)

Melanocyte-stimulating hormone (MSH)

hypophyseal portal system

blood circulation of tropic hormones, blood circulates capillary to capillary instead of to heart

posterior lobe of pituirary

not glandular, neural tissue. connected to hypothalamus. hormones: ADH (antidiretic hormone) and oxytocin

oxytocine

small, uterine contraction, trigger milk injection and neurotransmiter in brain

adh (antidiretic hormone)

Small, inhibits urine formation, regulates water balance, and causes kidneys to reabsorb H2O by making holes, inhibited by alcohols and diuretics. high concentrations lead to vasoconstriction

diabetes indipidus

adh deficincy, not sugat but instead polyuria keeps peeing hypothalamus damage

anterior pituitary hormones characteristics

all proteins, larger than posterior hormones. all us cAMP but GH

what 4 anteiror pituitary gland are tropic

TSH, ACTH, FSH and LH

GH

growth hormone or somatotropin (40%) of pitutary makeing. increase fatty acids, use of fatty acids and protein synthesis. breaks down glycogen to glucose. promotes growth with insulin. regulated by hypothalamys GHRH and GHIH

imbalances of GH

hypersecretion in child, gigantism (willard 8'11" in adult, acromegaly (lumps in forehead). hyposecretion, pituitary dwarf

adrenocorticotropic hormone

ACTH, corticotropin. 20% production. stimulates release of cotricosteroids (adrenal cortex) triggered by sugar levels and corticotropin releasing hormone in hypo, fever or stresss

gonadotropins

FSH: follicular stimulating hormone (gamete production) and LH: leutonizing hormone (gonadal hormone production)

what triggers gonadotropins?

triggered by puberty

What suppressed gonadotropin

Leutinising causes a lot of testosterone, causing negative feedback

prolactin

production of milk (20% production), regulated by dopamine and increased by suckling

thyrotopin

thyroid stimulating hormone (5% production) stimulates thyroid activity, triggered by thyrotropin-releasing hormone, inhibited by increased blood levels of t3 in thyroid negative feedback

colloid-filled follicles

high in protein, storing thyroid hormone

parafollicular cells

larger than colloid filled follicles and produce caalcitonin which decreases calcium when too high

isthmus

connects thyroid tissue, filled with colloid follicles

thyroid hormone effects

increases metabolic rate, produces heat by proteins, promotes skeletal development and nervous system, reproduction

two hormones of thyroid

t3 and t4

how do we get iodine

from diet

what does iodine bind to

thyroglobin in colloid

which is more common t3 or t4

t3 and if low on t3, it can be converted to t4. increased th levels inhibit tsh bt trh can override during pregnancy

what causes a goiter

lack of iodine and nonfunctional, no negative feedback because colloid keeps building and not being released in blood

adrenal cortec

pyramid glands superior to kidneys, deepest layer is medulla and produces NE

three layers of adrenal cortex

zona glomerulosa (outer), zona fasciculata (middle), zona reticularis (deepest)

what does zone glomerulosa produce

mineralocorticoids

what does zona fasciculata make

gucocorticoids

what does zona reticularis make

glonadocorticoids

mineralcorticoids

regulate sodium and potassium, patissup important for repolarization for AP. NA important for blood fluid

aldesterone

mineralcorticoid, most important, stimulates sodium reabsorption and water retention by kidneys and eliminates potassium

what regulates aldosterone

renin angiotensin axis

low bp renin angiotensin

kidney releases renin, goes to lungs and angiotensin 1 becomes two by ACE which activates aldosterone so sodium is reabsorbed and water follows then BP is increased

high bp renin angiotensin

load of blood to heart, aorta then produces atrial natriuretic peptide, atrial sodium output in urine then blocks aldosterone and not absorbing as much salt

functions of blood

circulates circular vasculat system to transport nutrients from SI to liver. regulates pH and ions , restriction of fluid loss, defense, stabalized blood temp

blood composition

flid connective tissue, plasma (matrix), eythrocytes (RBCs), leukocytes (WBC), platelets. (not cells)

centrifuge blood

55% plasmsa, buffy coat (leukocytes WBC and platelets), 45% erythrocytes RBC heavier

physical characteristics of blood

5-6L for males and 4-5L of females. high o2 scarlet, low o2 dark red. 7.35-7.45. below acidosis and above alkalosis.

blood plasma

90 % water, if dehydrates lose a lot of water and bp drops, more than 100 dissolved solutes

solutes in blood plasma

albumins, globulins - antiboides, fibrinogen - coagulation

albumin

60 % of plasma protein. major function is to generate plasma osmotic pressure, reabsorbs fluid into capilarry system and avoids edema

cells in blood

erythrocytes, platelets and wbcs

erythrocytes

rbc, bioconcave, size of capillary but flexibly pass through, can stack, no nucleus reduced to organelles inside, FUNCTION: carry CO2 and O2

why is it important for RBC to not have mitochondria to transport oxygen

to maximize available space for hemoglobin and to ensure they do not consume the oxygen they are designed to deliver to the rest of the body

how do erythrocytes transport gases

hemeglobin, made up of 4 proteins with beta and alpha globin chains, each eith a heme group and uses iron

oxyhemoglobin

oxygen loading in lungs

deoxyhemoglobin

oxygen unloading in tissues

carbainohemoglobin

carbon dioxide loading in tissues, carbon dioxide must be released so we aren't acidic but only 20% by hemoglobin 80% turned into bicarbonate from carbonic acid for liver

erthropoliesis

process of making RBC

hemocytoblast

all formed elements in blood start here, sem cell in marrow

reticulocyte

immature erythrocyte when it loses it's nucleus day 4/5

how do we make more RBCs

RBC's take up space but not too many otherwide blood is too thick and hard to pump, controlled hormonally

what organ checks oxygen

kidney capillary system around nephron, blood comes into capsule and is filtered back out and peritubular capillary checks o2 levels

what does liver do if low oxygen

peritubular capillary secrete erythropoletin make reticular sites to mature faster, make repid maturation 1-2 days

if erythropoietin is abused ?

blood doping lance armstrong more access to RBCs

hypoxia

low levels of oxygen from hemorrhage, insufficient hemoglobin per RBCs, maybe from a weird shape like sickle cell anemia

needs for RBC production

hemeglobin, 4 heme, iron, vitamin b12 and folic acid

hemosiderin

bound iron in kidney 35%

lifespan of rbcs

100-120 days

after 120 days what happens

rbcs break down, 10% eliminated in urine other is recaptured to save nutrient