ST120Concorde Career College, Portland

Define the term endocrine.Describe the functions of the

endocrine system.List and identify the structures of the

endocrine system and describe the function of each.

List the endocrine hormones, the source of each, and the effect each has on the body.

Describe the effect of the hypothalamus on the endocrine system.

Describe the mechanism by which the endocrine system helps to maintain homeostasis.

Describe common diseases, disorders, and conditions of the endocrine system including signs and symptoms, diagnosis, and available treatment options.

Demonstrate knowledge of medical terminology related to the endocrine system verbally and in the written form.

Exocrine - ducts Lacrimal glands Salivary glands Sweat glands Sebaceous

glands Pancreas

Endocrine - secretes directly into bloodstream

The term endocrine refers to a gland that secrets directly into the

bloodstream.

The term exocrine refers to a gland that secrets directly onto a surface

or through a duct.

The endocrine system produces hormones as directed by the nervous system.

Hormones are messengers, delivered via the bloodstream, that have certain effects of various cells, functions, or organs.

Amino acid compounds

Steroids

Hormone secretion is regulated by a negative feed back system

Pineal

Pituitary Anterior lobe Posterior lobe

(AKA - Pineal Body)

Small, flattened, cone-shaped structure located posterior to the midbrain and connected to the roof of the 3rd ventricle.

Produced by the pineal glandMelatonin is primarily produced at

night (during darkness)Melatonin influences the sleep/wake

cycle and seems to delay the onset of puberty

Small gland approximately the size of an olive or a cherry located in the sella turcica of the sphenoid bone

Attached to the hypothalamus by the infundibulum (stalk-like structure)

Divided into anterior and posterior lobes

Considered to be the “Master Gland” because it’s hormones regulate other glands.

AKA - Hypophysis -tropin - Suffix that indicates

hormones that stimulate other glands.

1. Growth Hormone (GH)

2. Thyroid Stimulating Hormone (TSH)

3. Adrenocorticotropic Hormone (ACTH)

4. Prolactin (PRL)5. Follicle Stimulating

Hormone (FSH)6. Luteinizing

Hormone (LH)

General InformationMessages (“releasing hormones”)

from the hypothalamus are received in the anterior pituitary gland via a portal system

Produced in the anterior pituitaryAKA - SomatotropinActs on most body tissues (primarily

bone and soft tissues)Produced throughout the lifespan

Produced in the anterior pituitaryAKA - thyrotropinStimulates the thyroid gland to

produce thyroid hormones

Produced in the anterior pituitaryStimulates the adrenal cortex

Produced in the anterior pituitaryStimulates milk production

(lactation)

Produced in the anterior pituitaryClassified as a gonadotropinFemale - Stimulates ova

development in the ovariesMale - Stimulates sperm cells in the

testes

Produced in the anterior pituitaryFemale - Causes ovulation and sex

hormone secretionMale - Hormone is referred to as

interstitial cell stimulating hormone (ICSH) and causes sex hormone secretion

1. Antidiuretic Hormone (ADH)

2. Oxytocin

General Information Posterior pituitary hormones are produced

in the hypothalamus and stored in the posterior pituitary

Hormone release is controlled by nerve impulses that travel through a special pathway (tract) between the hypothalamus and the posterior pituitary

Relationship of Hypothalamus and Pituitary

Gland

Posterior pituitary hormonePromotes reabsorption of water from

the kidneys thereby decreasing the amount of urine excreted

Posterior pituitary hormoneCauses uterine contraction and milk

let down (ejection) from the breasts

Gigantism - Overproduction of GH during childhood.

Acromegaly - Overproduction of GH during adulthood.

Large stature Usually very

weak

Widening of the bones of the hands, feet, and face

Largest endocrine gland Located in the neck Two main lobes (right and left lateral) Connected by a narrow band called the

isthmus A third lobe, of conical shape, called the

pyramidal lobe, frequently arises from the upper part of the isthmus, or from the adjacent portion of either lobe

Thyroxine (T4) Principal thyroid hormone Increases metabolism; required for normal

growth and mental capacity Triiodothyronine (T3)

Secondary thyroid hormone Increases metabolism; required for normal

growth and mental capacity Calcitonin

Decreases calcium level in the blood

Thyroid produces T4 and T3 in response to a signal (TSH) from the pituitary gland

Overgrowth of the thyroid glandSmooth appearanceMay or may not cause

overproduction of hormonesDue to lack of iodine in the diet

AKA neonatal hypothyroidism

Failure of fetal thyroid to form

Results in lack of physical growth and mental development

Thyroid test required at birth to detect

Lifetime treatment with thyroid supplement

Atrophy of the thyroid in an adult

Skin becomes dry and a peculiar swelling occurs

Patient becomes mentally and physically sluggish

Easily treated with hormone replacement therapy

Most cases due to Grave’s disease

Exophthalmos Thyroid storm Treat either with

Chemical suppression Destruction of thyroid

tissue (radioactive iodine)

Surgical removal

Routine blood test

Specialty blood test (radioactive iodine uptake)

Radionuclide scan (thyroid scan)

Four tiny glands located posterior to the thyroid gland

Embedded in the thyroid capsule

Responsible for production of parathyroid hormone (PTH)

One of three substances that regulate calcium metabolism PTH

▪ Promotes release of calcium from bone▪ Causes kidney to retain calcium

Calcitonin▪ Lowers amount of calcium in circulation by allowing deposit

in bone Hydroxycholecalciferol

▪ Active hormonal form of vitamin D▪ Produced in the liver and kidneys▪ Increases absorption of calcium from the small intestine to

raise blood calcium levels All three substances work together to regulate calcium levels in

the blood, maintain bone, and other functions (e.g., strong teeth)

Positive Trousseau’s sign may indicate hypocalcemia due to hypoparathyroidism

Positive Chvostek’s sign may indicate hypocalcemia due to hypoparathyroidism

Caused by inadequate PTH production, damage to, or removal of the parathyroid glands

Excess PTH causes removal of calcium from the bone causing weakening/kidney stones

Two small glands Located above

each kidney Outer portion -

cortex Inner portion -

medulla

Cortex Medulla

Three main groups of hormones Glucocorticoids Mineralocorticoids Sex hormones

(gonadocorticoids)

Main hormone (95%) - cortisol (aka - hydrocortisone)

Maintains carbohydrate reserve by promoting conservation of glucose instead of protein

Glucocorticoid production increases during times of stress

Suppress inflammatory response

Main hormone (95%) - AldosteroneRegulation of electrolyte balanceControl reabsorption of sodium and

secretion of potassium by the kidneys

Influences development of secondary sex characteristics Male - hair growth on body, deepening of

voice, maturation of sperm cells Female - breast development, changes

in shape of pelvis

(Hypofunction of Adrenal Cortex)

Muscle atrophy Weakness Unusual skin

pigmentation Electrolyte

imbalance

(Hypersecretion of Cortisol)

Obesity with round face

Bruises easily Muscle weakness Bone loss Elevated blood

sugar

Before and after treatment

Released in response to sympathetic stimulation

Fight or flight hormones Increase blood pressure Convert stored glycogen to glucose Increase heart rate Increase metabolism Dilate bronchioles

Epinephrine (aka Adrenaline) and Norepinephrine Increase blood pressure and heart rate Activate cells influenced by sympathetic

nervous system and others

Both an endocrine and exocrine gland

Located within the abdomen

Produces two primary hormones Insulin Glucagon

•Alpha cells producing glucagon (15–20% of total islet cells)

•Beta cells producing insulin and amylin

(65–80%) •Delta cells producing somatostatin

(3–10%) •PP cells producing pancreatic polypeptide

(3–5%) •Epsilon cells producing ghrelin

(<1%)

Produced in the beta cells of the islets of Langerhans

Responsible for transport of glucose across plasma membranes where it is metabolized for energy

Insulin increases the rate that the liver changes glucose into fat

Lowers blood sugar level Increases rate that amino acids are converted

into proteins

Produced in the alpha cells of the islets of Langerhans

Works with insulin to regulate blood sugar levels Causes the liver to release stored glucose into

the bloodstream Increases the rate at which glucose is made from

proteins in the liver

Failure of the islet cells to produce an adequate supply of insulin

Two types Type I Type II

May be controlled with diet, exercise, insulin replacement therapy

Male Testes

▪ TestosteroneFemale

Ovaries▪ Estrogens▪ Progesterone

Stimulates growth of primary sex organs (testes, penis)

Supports development of secondary sex characteristics

Stimulates growth of primary sex organs (uterus, tubes)

Supports development of secondary sex characteristics

Stimulates development of secretory portions of mammary glands

Prepares uterine lining for implantation of fertilized ovum

Aids in maintaining pregnancy

Mass of lymphoid tissue in the mediastinum above the heart

Produces Thymosin Assists in maturation of T lymphocytes

after they leave the thymus and reside in the lymph nodes throughout the body

Stomach secretes a hormone that simulates digestive activity

Kidneys secret erythropoietin which stimulates red blood cell production in the bone marrow when a decrease in oxygen is detected

Atria of the heart produce a substance called atrial natriuretic peptide (ANP) in response to increases filling of the atria. ANP increases loss of sodium by the kidneys and lowers blood pressure

Placenta produces several hormones during pregnancy including HCG (measured during a pregnancy test)

Produced by most body tissuesAct near site of production

Blood vessel constriction and dilation Bronchial constriction and dilation Intestinal constriction and relaxation

(increased and decreased peristalsis) Many additional functions that are not

fully understood