Endocrine System

two classes of hormones

Amino acid based and steroid

Most conspicuous effects of GH

Child-bone, cartilage and muscle growth Adult- bone thickening and remodeling

What serves as the link between the hydrophilic hormone serving as the first messenger and the second messenger?

G-protein

Hypothyroidism

Iodine deficiency (uncommon in developed world) weight gain, cold intolerance

__________ defy rigid classification—releases hormones, releases bile into ducts, releases albumin and blood-clotting factors into blood (not hormones)

Liver cells

Chemicals that function both as hormones and nuertotransmitters

Norepinephrine, cholecystokinin, thyrotropin-releasing hormone, and antidiuretic

Primary endocrine organ

ONLY endocrine functions (ant. pituitary, thyroid, ect)

adrenal glad

Outer and inner cortex. inner is a neuroendocrine organ. produces steroid hormones and catecholamines

Hormones secreted by neuroendocrine cells (neurons that release their secretion into bloodstream)

Oxytocin and catecholamies

Harrie has recurring kidney stones. Which hormone should be checked for normal levels?

PTH

Hypothalamus

Primitive functions like water balance, thermoregulation, sex drive, and child birth. many of its functions are carried out by pituitary gland

Mechanisms of GH-IGH action

Protein synthesis increases lipid metabolism increased carb metabolism electrolyte balance

Parathyroid hormone

Stimulated from hypocalcemia. Secreted by chief cells

order of TRH

TRH, TSH, production of T3 and T4

Which of the following hormones will be elevated in a patient with primary hypothyroidism, which results in a nonfunctional thyroid gland?

TSH (because negative feedback from thyroid hormones not working)

Cells can respond to ________ hormone(s) at the same time. Cells can respond to ________ hormone(s) at the same time. an unlimited number of a few several hundred only one

a few

Hypersecretion of both aldosterone and cortisol results in

addison's disease

target tissues of cortisol

adipose tissue, muscle tissue, liver tissue

Identify the gland that produces glucocorticoids and mineralocorticoids.

adrenal cortex

neuroendocrine organ that produces and releases catecholamines.

adrenal medulla

Which hormone stimulates the synthesis of steroid hormones by the adrenal gland?

adrenocortiotropic hormone (ACTH)

Avery has high blood pressure and hypernatremia (excess blood sodium ion concentration). The hypersecretion of which hormone could lead to his condition?

aldosterone

adenohypophysis

anterior pituitary

Which hormone responds to neural control to release its product(s).

antidiuretic hormone

secondary endocrine organ

both endocrine and various other functions (heart, kidneys, small intestine)

products released from the adrenal medulla are called______ and two examples are

catecholamines epinephrine norepinephrine

insulin

causes cells to absorb these nutrients and store or metabolize them which LOWERS blood glucose levels

pathogenesis

cells cannot absorb glucose must rely on fat and proteins for energy needs, thus weight loss and weakness

hormones

chemical messengers that travel in the bloodstream to other tissues and organs

steroid hormones

cholesterol derivatives and hydrophobic

adrenal medulla consists of neuroendocrine cells called

chromaffin cells

Neuroendocrine organs

consist of nervous tissue yet secrete hormone-like chemicals (neurohormones) organs include hypothalamus, pineal gland, adrenal medulla

Which hormone acts as a potent anti-inflammatory agent?

cortisol

Which hormone promotes gluconeogenesis as a way to increase blood glucose levels?

cortisol

A patient presents with buffalo hump, weight gain, increased blood pressure, suppression of the immune response, and osteoporosis. The most likely diagnosis will be __________.

cortisol hypersecretion (Cushing disease)

Inadequate secretion of antidiuretic hormone results is a very serious condition known as __________________.

diabetes inspidus

insufficiency or inaction of insulin is cause of ________

diabetes mellitus

Posterior pituitary (does/doesn't) synthesize OT and ADH

does't

hypothyroidism will result in

elevated TSH.

Parathyroid glands

embedded in posterior surface of thyroid gland. 3-5 glands

Hormonal Stimuli

endocrine cells increase of decrease secretion in response to other hormones. ex) hypothalamus secreting releasing or inhibiting hormones that affect secretion of anterior pituitary (GHRH and Somatostatin)

humoral and neural stimuli

endocrine cells respond to concentrations of ions in the blood or extracellular fluid. some cells respond to signals from nervous system such as adrenal medulla ex) pancreas releasing insulin in response to glucose levels in the blood

Types of chemical signals

endocrine, paracrine, autocrine

When is secretions of GH highest

first 2 hours of sleep and in response to exercise.

The pituitary hormone called _______________ stimulates the male testes to produce sperm and stimulates the development of the follicle in the female on a monthly cycle.

follicle-stimulateing hormone

______ secreted by alpha cells

glucagon

Glucocorticoids effects

gluconeogenesis in the liver, relaese of amino acids from muscle tissue, release of fatty acids from adipose tissue, anti-inflammatory agent . also known as a stress hormone (running away from alligator)

What can norepinephrine and glucagon both cause

glycogen hydrolysis in the liver

When growth hormones are low, which hormone stimulates its release?

growth hormone-releasing hormone. (GHRH)

exocrine glands

have ducts that carry secretion to an epithelial surface or the mucosa (food digestion)

symptoms of hyperthyroidism

heat intolerance, increased blood pressure, rapid heart rate, weight loss

Endocrine cells that increase hormone secretion in response to other hormones are controlled by:

hormonal stimuli

What type of hormone can cross the plasma membrane to bind to a receptor in the cytosol or nucleus?

hydrophobic

What type of hormone travels in the blood plasma bound to a protein?

hydrophobic hormones

Graves's disease

hyperthyroidism abnormal production of proteins that mimic TSH. Weight loss due to elevated metabolism, heat intolerance, bulging eyes.

What might accompany an overdose of insulin

hypoglycemia

Where are releasing and inhibiting hormones made?

hypothalamus

part of the diencephalon that produces and releases releasing and inhibiting hormones

hypothalamus

Posterior pituitary hormones are produced in _________ and transported by ____________ to posterior lobe.

hypothalamus hypothalamo-hypophyseal tract

Effects of PTH

increased absorption of calcium ions by the small intestine, increased release of calcium ions from bone, increased reabsorption of calcium ions from fluid in the kidneys

ADH

increases water retention which reduces urine volume preventing dehydration. AKA vasopressin because it can cause vasoconstriction

What stimulates the release of antidiuretic hormone (ADH, or vasopressin)?

increasing solute concentration of the blood

Somatostatin

inhibits growth-hormones release from the anterior pituitary (released from hypothalamus)

_______ secreted by beta cells

insulin

type I diabetis mellitus is caused by a lack of

insulin

GH induces liver to produce

insulin-like growth factors or somatomedins

hormone secreted by adipose tissue

leptin

parafollicular cells

lie between follicles and produce calcitonin

transport maximum

limit to how fast the glucose transporters can reabsorb

target tissues of cortisol

liver, adipose, muscle

Effects of aldosterone

maintaining blood pressure, extracellular sodium and potassium ion levels

hormones produced by pineal gland

melatonin

Which of the following is NOT one of the functions of the endocrine system? maintains fluid balance regulates metabolic reactions controls memory and learning promotes growth

memory and learning

Diabetic neuropathy

nerve damage from impoverished blood flow can lead to erectile dysfunction, incontinence, poor wound healing, and loss of sensation from area

Which cells produce oxytocin?

neuroendocrine cells

How nervous and endocrine systems can regulate each other

neurons can trigger hormone secretion and hormones and stimulate or inhibit neurons

endocrine glands

no ducts, internal secretion, intracellular effects such as altering target cell metabolism

ketoacidosis

occurs as ketones decrease blood pH (deep, gasping, breathing and diabetic coma are terminal result)

Where aer the hormone receptors for protein and amine hormones?

on the cell membrane

amino acid based hormones

one-multiple amino acids long, typically hydrophillic

A tumor in the hypothalamus, which results in hypersecretion of gonadotropin-releasing hormone (GnRH) will ultimately affect the

ovaries and testies (because it stimulates release of LH and FSH from anterior pituitary)

Cushing's Syndrome

over-secretion of cortisol. symptoms include weight gain, hyperglycemia, muscle wasting

Luteinizing hormone (LH)

ovulation, progesterone and testosterone secretion,

what portion of the thyroid produces calcitonin

parafollicular cells

Identify the gland that produces and releases a hormone that raises blood calcium levels.

parathyroid

The adenohypophysis consists of two parts in the adult, the pars distalis and the

pars tuberalis

Identify the gland that produces and releases melatonin

pineal

What causes acromegaly?

pituitary gland overproducing growth hormone

Gap junctions

pores in cell membrane allow signaling molecules, nutrients, and electrolytes to move from cell to cell

gland that stores hormones produced by the hypothalamus

posterior pituitary gland

Calacitonin

produced by the thyroid's parafollicular cells. combats hypercalcemia by blocking osteoclast activity

Glucocorticoids where produced and main purpose

produced in zone fasciculata and zone reticularis. mediates blood glucose levels and stress response.

androgenic sterioids

produced largely as a bi-product of cortisol synthesis

Ketonuria

promotes osmotic diuresis, loss and K+, irregular heartbeat, and neurological issues

colloid

protein rich gel that fills inside of follicle, stores precursor of thyroid hormone

What is the target tissue of erythropoietin (EPO)?

red bone marrow

effects of thyroid hormone

regulation of metabolic rate and thermoregulation, promotion of growth and development, synergism with the sympathetic nervous system

Oxytocin

released during sexual arousal and orgasm. feelings of sexual satisfaction. stimulates labor contractions. stimulates flow of milk

neurotransmitters

released from neurons to travel across synaptic cleft to second cell

What is delivered over the hypothalamic-hypophyseal portal system?

releasing and inhibiting hormones

Anterior lobe control

releasing hormones and inhibiting hormones in hypothalamus in cold weather, pituitary stimulated by hypothalamus to release TSH, leads to generation of body heat.

paracrine (local) hormones

secreted into tissue fluids to affect nearby cells

Thyroid- stimulating Hormone (TSH)

secretion of thyroid hormone. triggered by hypothalmic releasing hormone thryotropin releasing hormone (TRH)

Follicle-stimulating hormone (FSH)

secretions of ovarian sex hormones, ovarian development, and sperm production

follicular cells

simple cuboidal epithelial cells, produce thyroid hormones

Adrenocorticotropic hormone (ACTH)

stimulates adrenal cortex to secrete glucocorticoids. secretion stimulated by corticotropin releasing hormone

Growth hormone (GH)

stimulates mitosis and cellular differentiation. stimulated by GHRH and inhibited by somatostatin

Prolactin (PRL)

synthesize milk, enhances secretion of testosterone by testes

hormone important for T lymphocyte maturation

thymosin

gland that is the target organ of thyroid-stimulating hormone.

thyroid

Thermoregulation is the responsibility of

thyroid hormones

What hormone(s) determines the basal metabolic rate at rest when fasting?

thyroid hormones

thermoregulation is the responsibility of

thyroid hormones

Types of Thyroid gland hormones

thyroid hormones (growth and metabolism) calcitonin (calcium ion homeostasis)

What hormone is imbalanced in both hypothyroidism and hyperthyroidism?

thyroxine

Endocrine cell

transports through blood to a different cell type

paracrine

transports through extracellular fluid to a different cell type

autocrine

transports through extracellular fluid to same cell or cell type

insulin is used to treat type (1 or 2) diabetes

type 1

symptoms of hypothyroidism

weight gain, cold intolerance, low blood presure

Symptoms of Hashimoto's thyroiditis

weight gain, muscle ache, fatigue, depression

what decides a hormones mechanism of action

whether its hydrophobic or -philic

The mineralocorticoids produced by the adrenal glands are produced within the ___________________.

zona glomerulosa

hydrophobic hormone mechanism

1. -phobic hormone diffuses into the target cell 2. hormone binds to an intracellular receptor and enters the nucleus of the cell 3. hormone receptor complex interacts with the DNA to initiate a cellular change

Relationship between hypothalamus and posterior pituitary (4)

1. Hypothalamic neurons make either ADH or OT 2. hormones travel through hypothalamic axons in the infundibulum 3. ADH and OT are stored in axon terminals in posterior pituitary 4. hormones secreted to blood when hypothalamic neurons fire

Hydrophillic hormone and secondary system

1. hydrophilic hormone (first messenger) binds to its receptor in the plasma membrane 2. receptor activates peripheral protein 3. peripheral protein activates enzyme 4.enzyme catalyzes formation of second messenger. 5. second messenger initiates series of events in the cell that changes in its activity

Negative feedback loop

1. stimulus 2. receptor (receptors on endocrine cells detect deviation of the variable) 3. control center (stimulated control center, often endocrine cell, increases or decreases in secretion of particular hormone. 4. hormone triggers a response in target cells that moves conditions towards the normal range

IGF-I half life

20 hours

anterior lobe of pituitary synthesizes and secrets ___ hormones

6 FSH, LH, TSH, ACTH, PRL, GH

GH half life

6-20 mins

How many hormones produced in the hypothalamus?

8. 6 releasing and inhibiting hormones stimulate or inhibit anterior pituitary. 2 others are oxytocin and anitdiuretic hormones. BOTH STORED AND RELEASED BY POSTERIOR PITUITARY.

Type 2 DM

90-95% of diabetics problem is insulin resistance. treatment includes weight loss and exercise

Which hormones work synergistically to retain water?

ADH and aldosterone