TEAS 7 Endocrine System

Define: Pituitary Gland

-Ductless gland that secretes hormones directly into the bloodstream Located directly underneath the hypothalamus "Master Gland": Regulates adrenal, thyroid, and reproductive glands(ovaries and testes) Anterior and Posterior sections

What are the 5 classes of hormones made in the Adrenal Cortex?

-Glucocorticoids -Mineralocorticoids -Progestins -Androgens -Estrogens *the amount of progestin, androgens, and estrogens are minimal*

Anterior Pitutiary Gland Lobe Hormones

-TSH -LH -FSH -GH (Makes up about 40% of the AP) -Prolactin

Major functions of the Endocrine System

-Water equilbrium: Regulates solute concentration in the blood -Growth, metabolism, and tissue maturation -HR and BP management -Immune system control -Reproductive function control -Ion management: Endocrine system regulates Na+, K+, and Ca 2+ concentrations in the blood -BGL regulator

Growth Hormone:

. Anterior Pituitary. Stimulates tissue growth.

Define: Epinephrine

Catecholamine (produced in the Adrenal medulla) -Increases cardiac output: Volume of blood expelled by either ventricle of the heart in liters per minute -Raises BGL: Breaks down glycogen to glucose in the LIVER. Sympathetic Nervous System(part of the Autonomic Nervous System) -Vasoconstriction in minute blood vessels but VASODIALATION in the SKELETAL & LIVER muscles Increases heart rate, oxygen intake, and blood flow Increased contractility (how hard the heart squeezes) relaxation of smooth muscle in the airways to improve breathing

The adrenal medulla produces hormones called _________________

Catecholamines

Define: osteoclasts:

Cells that remove bone

Hormones:

Chemical messengers secreted by ductless glands to the cells or organs on which they have an affect (target sites).

Define: Inhibiting Hormones:

Chemical messengers that restrict the production of certain hormones

pituitary gland

Considered the "Master Gland" Receives signals from the hypothalamus. This gland has two lobes, the posterior and anterior lobes. The posterior lobe secretes hormones that are made by the hypothalamus. The anterior lobe produces its own hormones, several of which act on other endocrine glands.

Adrenocorticotropic (ACTH) (produced in the anterior pituitary) stimulates the production of what two hormones?

Cortisol and androgenic hormones by the adrenal cortex.

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Define: Diabetes:

Disease that results from a pancreatic hormone regulation malfunction resulting in pathologically high blood sugar levels or low blood sugar levels.

Define: Pancreas:

Exocrine function: Produces substances (enzymes) that help with digestion. Endocrine function: Sends out hormones that control the amount of sugar in your bloodstream -Glucagon: alpha cells of the pancreatic islets of Langerhans prevent blood glucose levels dropping too low. To do this, it acts on the liver in several ways: It stimulates the conversion of stored glycogen (stored in the liver) to glucose, which can be released into the bloodstream. This process is called glycogenolysis. -Insulin: beta cells in the islets of Langerhans When the blood sugar levels rise, as they do after a meal, insulin is released by the islets of Langerhans. This hormone helps sugar to be absorbed from the bloodstream into the cells of the body. Insulin also allows the liver and the muscles to store sugar, as well as keeping the liver from producing more sugar

Due to a benign tumor in the pituitary overriding the effects of growth-inhibiting hormone, --------- can result.

Gigantism.

Corticosteroids are produced by the ___________ and _____________ of the adrenal cortex and there function is:

Glomerulosa(Outer) & Fasciucalata(Middle) AC. Controls key functions in the body; acts as an anti-inflammatory; maintains blood sugar levels, blood pressure, and muscle strength; regulates salt and water balance

TSH, LH, and FSH are all classified as _____________

Glycoproteins Contain complex carbohydrates known as glycosides. Each of these hormones is composed of two glycopeptide chains (alpha which is identical and beta which differs in structure thereby explaining the difference in actions).

The production of _______ ____________ by the anterior pituitary is stimulated or suppressed by specific releasing hormones or inhibiting hormones secreted by the hypothalamus.

Growth Hormone.

Excess aldosterone can lead to _________

Hypertension and Hypokalemia (low blood potassium)

The _________ produces releasing hormones that stimulate and inhibiting hormones that restrict the production of several hormones produced by the anterior pituitary.

Hypothalamus

The ________ is located in the brain and integrates the endocrine and nervous system.

Hypothalamus.

Inhibiting hormones:

Hypothalamus. Restrict the production of certain hormones.

Releasing hormones.

Hypothalamus. Stimulate the production of certain hormones.

Prolactin (Anterior pituitary)

Initiates and maintains milk production in breasts; impacts sex hormone levels

Insulin & Glucagons role with the Liver

Insulin reduces the body's blood sugar levels and provides cells with glucose for energy by helping cells absorb glucose. When blood sugar levels are too low, the pancreas releases glucagon. Glucagon instructs the liver to release stored glucose, which causes the body's blood sugar levels to rise.

Define: Parathyroid Hormone: (PTH):

It is produced in the parathyroid, small grouping of usually four bean shaped endocrine glands on the dorsal aspect of the thyroid gland.

Renin and Angiotensin

Kidneys Angiotensin: protein hormone that causes blood vessels to become narrower. It helps to maintain blood pressure and fluid balance in the body. Renin: an enzyme secreted by and stored in the kidneys which promotes the production of the protein angiotensin . Controls blood pressure, both directly and also by regulating aldosterone production from the adrenal glands

Oxytocin:

Made in Hypothalamus. Stored in Posterior Pituitary. Stimulates uterine contractions during childbirth and milk ejection.

Adrenal Androgens:

Male sex hormones, mainly dehydroepiandrosterone (DHEA) and testosterone, are present in both men and women. All have weak effects, but play a role in early development of the male sex organs in childhood, and are important for the normal onset of female body hair following puberty.

_________ is produced by the pineal gland in the center of the brain.

Melatonin

Oxytocin is produced in the ___________ and secreted into the bloodstream by the ______________. It is responsible for _____________

Produced in the Hypothalamus Secreted into the bloodstream by the Posterior Pituitary Gland Stimulates contraction of uterus and milk ducts in the breast

Erythropoietin (EPO)

Produced predominantly by specialized cells called interstitial cells in the kidney. Acts on red blood cells to protect them against destruction. At the same time it stimulates stem cells of the bone marrow to increase the production of red blood cells.

Thymosin and the other hormones secreted by the __________ have immune functions.

Thymus

Thyrotropin(produced in the hypothalamus) stimulates the production of _______ hormone

Thyroid

The ______ hormone plays a role in regulating growth, development, and metabolic rate, homeostatic levels of _______ blood levels are neccesary.

Thyroid Hormone, Thyroid hormone

Thyroid hormone:

Thyroid. Regulates growth, development, and metabolic rate.

What are a few symptoms of hyperthyroidism?

Weight loss, anxiety, and a rapid heartbeat.

Define: Glucocorticoids

Zona Fasciucalata (Middle Layer) (CORTEX) Hypothalamus to CRH to AP gland to ACTH to Glucocorticoids Mainly CORTISOL, which is also known as the body's 'natural steroid'. -Involved in the response to illness and also helps to regulate body metabolism. - Released during the 'stress response' to illness. -Stimulates glucose production to help maintain blood glucose levels. -Has anti-inflammatory effects especially at higher amounts.

What are the three layers of the Adrenal Cortex?

Zona Glomerulosa(Outermost layer) -Produces Mineralcorticoids Zona Fasciucalata (Middle Layer): - Glucocorticoids Zona Reticularis (Innermost layer) -Produces Androgen precursors (mostly DHEA and some androstenedione)

The presence of TH in the blood stream causes a ____________ ________ inhibition on the release of both (TSH) from the pituitary and TRH from the hypothalamus. negative feedback

negative feedback

Parathyroid hormone indirectly activates ___________, causing reabsoprtion of calcium from bones.

osteoclasts

The ___________ secretes PTH when plasma calcium levels are low (hypocalcemia). Parathyorid plays a role in the regulation of plasma calcium levels

parathyroid

Adrenal Glands

2 glands: Cortex and Medulla Produce hormones in response to stress and regulate blood pressure, glucose metabolism, and salt/water balance.

Define: Estrogen:

A female sex hormone released by the ovaries

Define: Adrenal:

A gland above the kidney that produces hormones to regulate heart rate, blood pressure, and other functions

Define: Thyroid Gland:

A gland in the neck that secretes hormones that regulate growth, development, and metabolic rate.

Define: Thymus: (NOT ENDOCRINE)

A gland located behind the manubrium(broad upper part of the sternum) in adults, and is considerably larger in children until about age 6. Thymus gland lymphoid organ and it is the place where the immune systems T cells are produced.

Define: Oxytocin:

A hormone made by the hypothalamus and stored in the posterior pituitary. One of its functions is to stimulate uterine contractions during childbirth.

Define: FSH

A hormone secreted by the APG that stimulates development of eggs in ovaries and sperm in testes

Define: Insulin:

A hormone that triggers the influx of glucose into cells, thus lowering blood glucose levels.

Define: Hypothalamus:

A location in the brain that is an integration center between the endocrine and nervous system.

Define: Hyperthyroidism:

A malfunction of regulatory feedback loops leading to the overproduction of thyroid hormone.

Define: Positive feedback:

A mechanism that stimulates glandular secretions to continue to increase temporarily pushing levels further out of homeostasis, until a particular biological effect is reached (ex. expulsion of the fetus during childbirth)

Define: Epinephrine:

A polar, water-soluble hormone released by the adrenals in response to stress. Also known as adrenaline.

Define: Growth Hormone:

A secretion of the anterior pituitary that stimulates tissue growth. Also known as somatotropin.

Define: Pineal Gland:

A small gland near the center of the brain that secretes melatonin

Mineralcorticoids (aldosterone)

ALDOSTERONE (Zona Glomerulosa/Outer layer) (CORTEX) Helps to maintain the body's salt and water balance, vital to maintain blood pressure. Helps the KIDNEY conserve salt when it is needed. Acts in the kidney to cause sodium and water to be retained, and potassium to be lost. Important if the body has low salt and water levels, that could risk a low blood pressure

PTH also increases plasma _________ levels by inhibiting (preventing) the kidneys ability to transfer calcium ions to urine.

Calcium

All steroid hormones have________ composition that allows them to pass easily through cell membranes and nuclear membranes.

lipid

Epinephrine:

Adrenal. Regulates heart rate, blood pressure

Growth Hormone (GH) (produced in the anterior pituitary)

Affects growth and development; stimulates protein production; affects fat distribution

Addisons Disease

Aka primary adrenal insufficiency. -Due to underactive AG associated with a lack of hormones typically produced in the Adrenal Cortex (Cortisol, Aldosterone and androgens) -Low BP, fatigue, weight loss, -Craving salt -Medical emergency -Hydrocortisone IV or IM

Without _____________ the kidney loses excessive amounts of salt (sodium) and, consequently, water, leading to severe dehydration and low blood pressure

Aldosterone

Overproduction of __________ can occur sometimes due to a benign tumor of the adrenal gland.

Aldosterone (primary hyperaldosteronism)

__________ cells of the pancreas are also able to detect blood glucose levels. When blood glucose levels are too LOW, _____ cells secrete a hormone called glucagon (which is produced in the pancreas)

Alpha cells, Alpha cells

What is the difference between an endocrine gland and an exocrine gland?

An endocrine gland does not have an associated duct, whereas an exocrine gland is one that delivers its secretions by a tube to an epithelial surface or mucosa.

Define: Gland:

An organ that secretes a substance.

ACTH (adrenocorticotropic hormone)

Anterior Pituitary Controls production of sex hormones (estrogen in women and testosterone in men) and the production of eggs in women and sperm in men.

TSH (thyroid stimulating hormone)

Anterior Pituitary Stimulates the production and secretion of thyroid hormones

Luteinizing Hormone.

Anterior Pitutitary. Triggers ovulation ovaries and the production of testosterone by testes.

Follicle-stimulating hormone:

Anterior pituitary. Stimulates development of eggs in ovaries and sperm in testes.

What is the difference in tissue between the AP and the PP

Anterior: Hormone secreting epithelial cells -Posterior lobe: Unmyelinated secretory neurons

_____ cells are able to adjust the amount of insulin they secrete in proportion to the amount of blood glucose they detect.

Beta

Some _______________ ______________ hormones have an immune function.

Non steroid hormones

Norepinephrine

Norepinephrine can also make your blood vessels become narrower, increasing blood pressure.

Cushing's syndrome

Overactive adrenal glands due excess production of cortisol or excess ACTH from a tumor in the PG. -Easy bruising, truncal obesity, high BP

The ___________ is one of a few organs in the body that secrete both enzymes and hormones.

Pancreas

Insulin:

Pancreas. A hormone that triggers the influx of glucose into cells, thus lowering blood glucose levels.

Glucagon:

Pancreas. Triggers liver to convert hepatic glycogen stores into glucose and release glucose into the blood.

PTH:

Parathyroid. Elevates plasma calcium level.

Melatonin:

Pineal. Plays a role in maintainng circardian rhythms.

Major organs in the Endocrine system:

Pituitary (AP, PP) Adrenal (Cortex and Medulla) Pancreas Thyroid Gonads (Ovaries, Testes)

Antidiuretic hormone (vasopressin)

Posterior Pituitary Affects water retention in kidneys; controls blood pressure

Define: transcription:

Process by which the information in a strand of DNA is copied into a new molecule of messenger RNA (mRNA)

Define: Estrogens

Produced (minimal amount) in the Adrenal Cortex (Zona Reticularis/Innermost) a steroid hormone associated with the female reproductive organs and is responsible for developing female sexual characteristics

Define: Progestins

Produced in the Adrenal Cortex (minimal amounts) Steroid hormone, such as progesterone, that maintains pregnancy and prevents further ovulation during pregnancy.

Define: Catecholamines

Produced in the Adrenal Medulla -Epinephrine -Norepinephrine -Small amounts of Dopamine Fight or Flight response increased heart rate, blood pressure, breathing rate, dilated pupils in the eye, and looking flushed or pale.

Adrenocorticotropic hormone (ACTH)

Secreted by the APG Primarily affects the release of glucocorticoids and adrenal androgens by the adrenal gland and, to a much lesser extent, also stimulates aldosterone release.

Define: Endocrine system:

Set of organs that release hormones directly into the circulatory system.

LH (luteinizing hormone) (produced in the anterior pituitary)

Stimulates testosterone release by the Leydig cells of the testes. Stimulates steroid release from the ovaries Ovulation(time when an egg is released from the dominant follicle (winner of the race) within an ovary) Release of progesterone after ovulation by the corpus luteum

The release of _________ is triggered by the presence of thyroid releasing hormone (TRH) secreted by the ________.

TSH, hypothalamus

________ is the primary hormone secreted by the testes, and it is also secreted in small quantities by the adrenal gland in both males and females

Testosterone

Define: Cervix:

The passage that forms the lower part of the uterus.

The ______ cells of the pancreas that secrete insulin also detect levels of glucose.

beta

Steroid hormones are classified as hormones made from ___________

cholestorol

FSH (produced in the anterior pituitary)

helps control the menstrual cycle and the production of eggs by the ovaries

Binding of the ___________ to the receptor triggers change in the receptor that signals molecules within the target cell.

hormone

The production and secretion of the major anterior pituitary hormones are regulated by the __________________

hypothalamus

Whether in the cytoplasm or the nucleoplasm (inside the cell nucleus), steroid hormones affect ________ in their target cellls.

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