Endocrine system consists of endocrine glands that secrete ____

Hormones

Endocrine response is broken into two responses

Endocrine
Neuro-endocrine

Neuroendocrine is typically ___ onset

Rapid

Endocrine response is typically ___ onset

Slower

Hormones are defined as

Chemical messengers

Protein hormones

>100 amino acid chains

biogenic amines

<100 amino acids

Steroid hormones

Small lipid molecules

Plasma membrane

Permeable to lipid hormones

Biogenic and protein hormone receptors are found

On the cell membrane

Thyroid hormone action is ____

At the nucleus

Feedback loops in endocrine

Self-Regulate

Something stimulates the hormone release

That hormone has self regulating effects

Hormone feedback loops are comparable to

Maintaining traveling speed while driving

When deviating from homeostasis, this causes:

Hormone release

When blood sugar increases

Insulin is released

Insulin drives sugar into cells

Causing insulin production to diminish

Positive feedback:

Pushes a system away from its set point by producing a change in the same direction

Oxytocin is ____ feedback

Positive feedback;

The more oxytocin is present, the harder uterine contractions are which causes more stretching of the cervix, which releases more oxytocin

In hypothalamus releasing factors:

Stimulate the pituitary to release hormones, which stimulate responses that ultimately give negative feedback to stop hormone release

The hypothalamus

Master endocrine controller

The pituitary gland

Middle man

Releasing hormones

Stimulate pituitary gland to release hormone

Inhibiting hormones

Stop releasing hormones

Anterior pituitary

Produces its own hormones

Adenohypophysis

Anterior pituitary

Oxytocin and ADH

Produced in hypothalamus, stored in posterior pituitary

Neurohypophysis

Posterior pituitary

Pituitary gland lives

behind optic chiasm

Pituitary tumors cause

Peripheral vision loss

Infundibulum

Contains neurons that innervates posterior pituitary

Cavernous sinus drains

behind pituitary

Cranial nerves 3,4,5,6

Pass by pituitary

Cranial nerve deficits can be caused by

Pituitary tumors

Pituitary gland

Hypophysis

(adeno anterior
Neuro posterior)

Anterior pituitary

7 hormones

Posterior pituitary

2 hormones

Tropic hormones

Hormones that target other organs

Portal systems

Vein goes to structure, then to another vein

Big portal systems

Hypothalamo-hypophyseal portal system

Hypothalamic releasing hormones

Dont have to travel far

Hypothalamic tropic hormones

Have to travel far

TRH

Thyroid releasing hormone

CTRH

Corticotropic releasing hormone produces ACTH

Somatostatin

Dopamine

Adrenocorticotropic hormone

Thyroid releasing hormone

Prolactin

Folical stimulating hormone

Growth hormone

released by Growth hormone releasing hormone

Thryotropic cells

secrete thyrotropin or TSH under the influence of TRH from the hypothalamus

TSH

Acts on the thyroid gland to stimulate the secretion of thyroid hormone

Gonadotropic cells

Produce gonadotropins

Gonadotropins

Hormones that act on the gonads

Secretion of gonadotropins is controlled by

Growth hormone releasing hormone

Interstitial cell stimulating hormone

Same thing as leutenizing hormone, but in males

GH stimulates g

growth and mitosis primarily on boens and skeletal muscles

Insulin like growth factor

IGF I and II are produced in the liver

IGF acts on epihphyseal plates to stimulate

lengthening of bones

Beta lipotropin is a precursor to other hormones

Primarily beta endorphin and MSH

MSH

Melanocyte stimulating hormone

MSH is secreted by

intermediate lobe (anterior) pituitary after exposure to UV light

MSH stimulates

melanin production and distribution of melanocytes

Prolactin is also

Dopamine

ACTH affects

Adrenal cortex

Adrenal cortex

Gives negative feedback when aldosterone, sex hormones are released

Growth hormone

Somatomedins

Thyroxine

Released by thyroid gland

FSH & LH

NEgative feedback loops by estrogen and

Prolactin

lactation

Beta LPH

Not gonna cover it much

Posterior pituitary

Stores and secretes ADH, Oxytocin, connected to hypothalamus, made up of axons as well as gland

Anterior pituitary

Not a direct connection to hypothalamus which is why releasing hormones are required

ADH

Maintains BP by retaining volume

Decreased volume or pressure stimulates

ADH

If osmolality is high

ADH is released

Oxytocin

Also called the bonding hormone

Oxytocin

Stimulates ejection of milk and contraction of uterine walll

This hormone plays a role in social bonding

Oxytocin

Low oxytocin

Makes you an A-hole

Thyroid

Lives below thyroid cartilage

The thyroid has ___ lobes

two lobes on each side of trachea

Thyroid contains two distinct cell types

Follicular cells and parafollicular cells

Follicular cells

Produce thyroid hormone

Thyroid hormones produce

Thyroxine, T3, T4

Parafollicular cells

Produce calcitonin

Thyroxine

Sometimes referred to as a combination of T3 & T4

Thyroid follicles

Simple cuboidal cells filled with thyroglobulin, protein liquid

Under influence of TSH

Follicular cells will convert TG and release it into the blood

TG

Thyroglobulin

Hypothalamic-pituitary-thyroid axis

Hypothalamus detects decrease TH in blood, or very low temperature

TRH Stimulates anterior pituitary to release TSH

Increased levels of TH prevent release of TRH and TSH

Follicular cells reduce or stop production of TH

TRH stimulates

Anterior pituitary to release TSH

TSH Stimulates

Follicular cells of thyroid to convert TG into TH

Increased levels of TH

Cause negative feedback on the hypothalamus and ant pit, preventing release of TRH and TSH

When determining if thyroid is functioning properly

TSH is measured to see where body is in relation to feedback loops

TSH and TRH should be

Correlated

TSH and thyroxine should be

Inversely related

stimulating and end hormone should be

inverse

Releasing hormone and end hormone should be

correlated

Parafollicular cells are also called C cells

Because of their involvement with calcitonin

Calcitonin helps

regulate calcium levels

When calcium levels are elevated

C cells secrete calcitonin

Procalcitonin is produced

In setting of acute bacterial infection

Procalcitonin is

An acute phase reactant and can be measured to help determine sepsis

Parathyroid

Apple seed sized glands

Parathyroid is fed by

Thyroid artery

Thyroid artery

branches off of carotid artery

Parathyroid regulates calcium and is found

On the back of the thyroid gland

Parathyroid gland consists of two types of cells

Oxyphil cells
Chief cells

Parathyroid hormone

Inversely related to calcium

When calcium is low

Parathyroid is high

When calcium is high

Parathyroid is low

Parathyroid hormone works in 3 ways

Stimulate resorption of bone
Stimulates kidneys to activate vitamin D
Stimulates the reabsorption of calcium by kidneys

Calcium and phosphate have ____ relationship

Inverse

Phosphate levels increase in kidney disease, causing

low calcium,

Low calcium stimulates

Parathyroid gland

Phoslow

Medication that lowers phosphates to prevent bone resorption and weakening

Parathyroid glands are:

Calcium thermostat

Extracellular calcium sensing receptor

CaSR

CaSR is found mostly

on parathyroid cells

PTH

ParaThyroid Hormone

PTH ^

Ca v

Ca ^

PTH v

PTH does not involve

Pituitary

Calcitonin

Has calcium sensing receptor on its cells

Voshteks sign

Tap face, facial spasm

Trosseau's

Low calcium, causes arm spasm w/BP cuff increase

Hypercalcemia

More common than hypo
Cancers produce ectopic PTH related peptide, triggers receptors in bone to increase ca

Adrenal gland AKA

Suprarenal gland

Adrenal gland size and shape of

fortune cookie

Outer cortex of adrenal gland

Cortex

Inner adrenal

Medulla

Adrenal cortex produces more than 25 different corticosteroid in response to

stimulation from ACTH

Corticosteroid hormones are

Stress hormones

Adrenal cortex has 3 regions

Outer Zona Glomerulosa
Middle Zona Fasciculata
Inner Zone Retiuclaris

Glomerulosa

Thinnest layer of adrenal cortex

GLomerulosa produces

Aldosterone

Aldosterone stimulates

Retention of Na, secretion of K by kidneys

RAAS system

main method of regulating BP

Zona Fasciulata produces glucocorticoids

Min

Mineralcorticoid

Aldosterone

Glucocorticoid

Cortisol

Cortisol affects

Blood Sugar

Aldosterone has no effect on

Blood sugar

Gonadocorticoids

Androgen precursors

Inner layer

sex hormone layer

Salt, stress, sex

Outer glomerulosa
Corticosteroid
Gonadocorticoid

Androgens are responsible for

Secondary sex characteristics

Adrenal medulla

innermost part of adrenal gland

Adrenal medulla

innervated directly by sympathetic nervous system

Sympathetic nervous system

Can fire big levels quickly, but not maintain

Hormones prolong the

sympathetic response

Sympathetic nervous system stimulates chromaffin cells directly

Chromaffin cells directly secrete epi/norepi

Make card labeling adrena gland layers

Capsule
Glomerulose
Fasciulata
Reticularis
medulla

Pancreas

Adrenal gland

Controlled by hypothalamus through release of

LH

From pituitary gonadotropin mostly reticularis

FSH

From pituitary gonadotropin mostly reticularis

Zona Glomerulosa

Controlled by kidney, to regulate BP

Middle fasciculata

Under control of sympathetic nervous system

CRH triggers ACTH which

triggers fasciulata,

Pancreas

GI organ, main job to digest sugar and fat

Pancreas secretes

Amylase and Lipase

Secretion of Amylase and Lipase

Exocrine enzymes

Islands in the pancreas

A
B

Pancreas 6" long, LUQ,

curvy tail

99% of pancrease made of

acinar cells

Pancreatic islet ceclls

Main ducts of pancreas

Main duct dumps enzymes into gallbladder

Accessory ducts

Pancreatitis

Pancreas digests itself if enzymes leak out of ducts

Blood from pancreatic islets

Drains by hepatic portal vein

Hormones from pancreatic islets

Drain straight into the liver

Alpha cells

20% of islet cells, produces glucagon, raises blood sugar

Beta cells

70% of cells, produces insulin, lowers blood sugar

Delta cells

10% of cells, secretes somatostatin, plays an important role in GI motility, counter hormone of growth hormone

Synthetic glucagon

dumps glycogen stores in liver to increase blood sugar

70-110mg/dL

Normal glucose

Eat snickers, drink coke

Sugar goes up, osmolality increases, islet cells dump insulin, sugar is pushed into cells,

High glycemic index food,

Drops sugar due to big insulin dump forcing sugar into cells, paradoxical lowering

This paradoxical low blood sugar is counteracted by

Glycogen stores releasing to increase blood sugar

Somatostatin

Growth hormone inhibiting hormone,
Inhibits GH, TSH, PRL,Gastrin, insulin, glucagon, helps digestion

Gastrin

Helps make stomach acid

Pineal gland is in the

Epithalamus

Pineal gland

Produces melatonin

Melatonin

Stimulated by darkness and inhibited by light

Increased melatonin

makes you sleepy

Thymus located

Deep in sternum, just anterior to aortic arch

Thymus most active in

children

At puberty

Thymus begins to involute and is replacced by adipose tissue

Thymopoetin

Produced by thymus

Thymosin

produced by thymus

Kidneys produce two hormones

Calcitriol
Erythropoetin
Renin

calcitriol

Stimulated by PTH when calcium levels are low, increase absorption of caclium

Erythropoetin

Stimulated during times of hypoxemia, increases production of RBS in marrow

Renin

Stimulated by lower BP, activates angiotensin, which stimulates aldosterone production by adrenal cortex which results in sodium and water retention

Heart produces hormone calledd

Atrial Natriuretic Peptide (ANP)

ANP

Released in response to increased blood volume or pressure in right atrium

ANP stimulates

the kidneys to increase excretion of water and sodium

When the right atrium gets stretched this peptide is released

ANP

ANP does the opposite of

Aldosterone

BNP

Released in atria and brain

ANP vs BNP

ANP released in atria only
BNP released in atria and brain

When heart muscle is stretched

BNP is released

RAAS System

makes you retain sodium and water

Counter hormone to RAAS system

ANP/BNP

Renin causes release

of angiotensin II

Angiotensinogen causes release of

Angiotensin I

ACE

Converts angiotensin I to II

Major activity of GI hormones

Promote digestion

Gastrin

Stimulates stomach acid

Motilin

Causes chruning

Gastric inhibition polypeptide

cholecystokinin

stimulates release of exocrine pancreatic enzymes and release of gall bladder contents

Fatty acids and amino acids in small intestine releases

cholecystokinin

Food in stomach releases

gastrin

Acid pH in small intestin releases

secretin

Secretion peaks prior to feeding and diminishes with gastric filling

Ghrelin

Increases with fasting

Motillin

Secretion peaks prior to feeding and diminishes with gastric filling

Gastric inhibitory peptide

Gastric inhibitory peptide

Weight loss meds

Ghrelin

Makes you feel hungry

GIP

Gastric inhibitory peptide

GIP effects

feels satiated

Gonades produce

Gametes

Ovaries produce two hormones

Estrogen
Progesterone

Testes produce

Testosterone

Obaries and testes both produce

Inhibin

Inhibin inhibits

FSH