2nd control system of the body, composed of endocrine glands and specialized endocrine cells

Overall, the endocrine system regulates complex processes such

The endocrine system releases chemicals called

are chemical substances secreted by endocrine cells into the extracellular fluids that regulate the metabolic activity of other cells in the body

classification of hormones

given hormone affects only certain tissue cells or organs, referred to as its target cells or target organs

HORMONE FUNCTION & REGULATION

Steroid and Thyroid hormones Hormones that are lipid-soluble molecules = diffuse through the plasma membrane

next step Once inside, the steroid hormone enters the nucleus and binds to a specific hormone receptor

Activates certain genes to transcribe messenger (mRNA) next step

a Once inside, the steroid hormone enters the nucleus and binds to a specific hormone receptor c Hormone-receptor complex then binds to specific sites in the cell's DNA b Activates certain genes to transcribe messenger (mRNA) e mRNA is translated in the cytoplasm d Protein synthesis

Protein or peptide hormones • NOT water-soluble and are unable to enter target cells directly • Instead, they bind to hormone receptors situated on the target cell's plasma membrane and use a second-system messenger system

Process: 1Activated receptor activates an enzyme 2CAMP stimulates a response/reaction inside the target cell 3Enzyme catalyzes reactions to produce second-messenger molecules (cyclic AMP or CAMP or cyclic adenosine monophosphate) 4 Hormone binds to the receptor protein on the plasma membrane

cyclic AMP or CAMP

The stimuli that activate endocrine glands fall into three (3) major categories:

common; endocrine glands are stimulated by other hormones

changes in blood levels of certain ions and nutrients stimulate hormone release

nerve fibers stimulate hormone release

These are ductless glands that produce hormones that they release into the blood or lymph

Pea-sized gland hanging by a stalk from the inferior surface of the hypothalamus • It has two functional lobes-the anterior pituitary (glandular tissue) and the posterior pituitary (nervous tissue)

It has two functional lobes

is not an endocrine gland in the strict sense because it does not make the peptide hormones it releases. • Instead, it acts as a storage area for hormones made by hypothalamic neurons.

released only during childbirth and nursing. It stimulates powerful contractions of uterine muscle during sexual relations, labor and breast feeding. It also causes milk ejection ("let- down reflex") in a nursing woman.

ADH

DIURESES

It causes the kidneys to reabsorb more water from the forming urine

also increases blood pressure by causing constriction of arterioles (small arteries) (Vasopressin)

Condition of excessive urine output due to hyposecretion of ADH S/Sx: continually thirsty and drink huge amounts of water

Master Endocrine Gland"

Master Endocrine Gland pituitary hormones (1) are proteins (or peptides), (2) act through second-messenger systems, and (3) are regulated by hormonal stimuli

General metabolic hormone • Direct effect on growth of skeletal muscles and long bones of the body, and thus it plays an important role in determining final body size Stimulates most target cells to grow in size and divide • Causes breakdown of fats for energy • Saves glucose to maintain blood sugar homeostasis

Hyposecretion of GH during childhood; Body proportions are fairly normal, but the person as a whole is a living miniature (with a maximum adult height of 4 feet

Hypersecretion of GH during childhood; Individual becomes extremely tall; height of 8 to 9 feet is common. Again, body proportions are fairly normal.

Hypersecretion of GH after long bone growth has ended during adulthood ⚫ Cause: result from tumor on pituitary gland Enlargement of facial bones particularly the lower jaw and bony ridges of underlying the eyebrows, feet and hands. • Enlargement of heart and other organs

Protein hormone structurally similar to growth hormone ⚫ Target organ/cell: Breast (mammary glands) • Stimulates and maintains milk production by the mother's breasts after childbirth

• They regulate the hormonal activity of the gonads (ovaries and testes

Female: stimulate follicle development in ovaries in women. As follicles mature, they produce estrogen and eggs are readied for ovulation. • Male: stimulates sperm development

Female: egg ovulation in women to produce progesterone and estrogen • Male: stimulates testosterone production in the testes

Hyposecretion of FSH, the lack of ability to successfully reproduce in both males and females

Hyposecretion of LH, inability to complete one full term of pregnancy

Also called as "thyroid- stimulating hormone" (TSH) Influences the growth and activity of the thyroid gland

Hormone that regulates the endocrine activity of the cortex portion of the adrenal gland

Small, cone-shaped gland that hangs from the roof of the third ventricle of the brain (EPITHALAMUS

primarily responsible for regulating your body's circadian rhythm to manage natural sleep cycle; peak level occurs at night and makes us drowsy and lowest levels occurs during daylight.

Located at the base of the throat; just inferior to the Adam's apple ⚫ Fairly large gland consisting of two lobes joined by a central mass or isthmus ⚫ Internally, it is composed of hollow structures called follicles which store a sticky colloidal material that form the thyroid hormone

The thyroid gland makes two (2) hormones:

Body's Major Metabolic Hormone

• It controls the rate at which glucose is "burned" or oxidized, and converted to body heat and chemical energy (ATP) It is also important for normal tissue growth and development, especially in the reproductive and nervous systems

⚫ It is an enlargement of the thyroid gland due to lodine deficiency in diet

calls" for the release. of thyroxine (T4), but as the peptide part of the molecule is made, the thyroid gland enlarges because the protein component is nonfunctional without iodine, thus, a continuous production of the peptide component

type of dwarfism and hypothyroidism in which adult body proportions remain child-like, with a proportionally longer torso and shorter legs compared to normal adults • Lack of thyroxine from birth or before birth; could be lack of thyroid gland or lack of iodine in mother ⚫ severe irreparable mental defects • Stunted growth • Reduced growth and function of many organs • Tx: Hormone replacement therapy in early diagnosis to prevent mental impairment

• Hypothyroidism or hyposecretion of thyroxine (T4) occurring in adults ⚫ Characterized by both physical and mental sluggishness (but no mental impairment) ⚫ Cause/s: viral infection, cancer, radiation exposure, autoimmune disease • S/sx: puffiness of the face, fatigue, poor muscle tone, . low body temperature (the person is always cold), obesity, and dry skin • Medx: Oral thyroxine (T4)

Hyperthyroidism generally from a tumor on the thyroid gland Thyroid gland enlarges (+) Exophthalmos - bulging of the eyes • 5/sx: high metabolism, heat intolerant, rapid heartbeat, weight loss, nervous and agitated behavior ⚫ Tx: surgical removal of tumor or part of the affected thyroid gland or use of thyroid- blocking drugs or radioactive-iodine to destroy some of the thyroid cells

Decreases the blood calcium ion level by causing calcium to be deposited in the bones • Released directly to the blood in response to an increasing level of blood calcium ions

Tiny masses of glandular tissue most often found on the posterior surface of the thyroid gland ⚫ Typically, there are two (2) parathyroid glands on each thyroid lobe • It secretes parathyroid hormone (PTH

Most important regulator of calcium ion (Ca++) homeostasis of the blood • Parathyroids release PTH to stimulate the osteoclasts when calcium in the bloodstream drops below a certain level • PTH also stimulates the kidneys and intestines to absorb more calcium ions (from urinary filtrate and food)

uncontrollable spasms or rapid muscle twitching when calcium ions fall too low

massive bone destruction; large punched-out holes in the bone matrix (X-ray). Fragile and brittle bones.

Located in the upper thorax, posterior to the sternum • Large in infants and children, decreases in size throughout adulthood and by old age, it is composed mostly of fibrous connective tissue and

thymus Produces a hormone called

essential for normal development of a special group of white blood cells. (T lymphocytes) and the immune response

Also called "suprarenal glands" are two glands curved over the top of the kidneys like triangular hats

two parts of adrenal glands

-outer; made of glandular -inner; made of neural tissue

three major groups of steroid hormones produced by the adrenal cortex

three major groups of steroid hormones produced by the adrenal cortex

Regulates mineral (or salt) content of the blood, particularly sodium (Na+) and potassium (K+) ions • Water and electrolyte balance • When aldosterone increases, the kidney reabsorb increasing amounts of sodium (Na+) ions and secrete more potassium (K+) into the urine. When sodium is reabsorbed, water follows

enzyme produced by the kidneys to release aldosterone when blood pressure drops

Promote normal cell metabolism and help the body resist long-term stressors, primarily by increasing the blood glucose level High glucocorticoids = fats and proteins are broken down and converted to glucose • Controls inflammation and reduces pain

High glucocorticoids

Also called "Adrenal Androgens

male sex hormones (mostly

-female sex hormones

increase in body hair in a masculine pattern such as a beard in females

Low levels or hyposecretion of all adrenal cortex hormones, especially aldosterone and cortisol

Hypersecretion of cortisol and androgens due to a tumor on the adrenal cortex

hormones of adrenal medulla

Autonomic Nervous System (ANS) stimulates

Located close to the stomach in the abdominal cavity Both an exocrine gland and an endocrine gland

masses of endocrine (hormone-producing

Two (2) important hormones produced of pancreas

Released from the pancreatic islets ⚫ Helps the cells absorb glucose, reducing blood sugar and providing the cells with glucose for energy • Without insulin, cells are unable to use glucose as fuel and they will start malfunctioning

Insulin moves sugar from the blood into your cells to be stored or used for energy • With diabetes, your body either doesn't make enough insulin or can't effectively use the insulin it makes ⚫(N) blood glucose: 80 to 120 mg/100ml

blood glucose: 80 to 120 mg/100ml

Occurs when the pancreas is unable to produce enough insulin • Tends to develop at a young age Cannot be prevented Require insulin therapy

Occurs due to insulin resistance (ie. when the body does not respond well to insulin) Tends to develop at an older age Can be prevented with lifestyle changes Can be managed with lifestyle modifications alone if diagnosed early

Released from the pancreatic islets • Acts an antagonist of insulin • When blood sugar levels are too low, the pancreas releases glucagon instructs the liver to release stored glucose, which causes blood sugar to rise

hormone of ovaries

paired, slightly larger than almond-sized organs located in the pelvic cavity

-development of sex characteristics in women (growth and maturation of the reproductive organs

menstrual cycle

endocrine glands

• A temporary organ formed in the uterus of a pregnant woman • Produces several protein and steroid hormones that help maintain the pregnancy and pave the way for delivery of the baby In the 3rd month of pregnancy, the placenta is the one producing estrogen and progesterone, while the ovaries become inactive for the rest of the pregnancy

early pregnancy; stimulates to continue production of estrogen and progesterone so that the lining of the uterus is not sloughed off during menstruation

hormone that works with estrogen and progesterone in preparing the breasts for lactation.

hormone produced in a pregnant woman during labor; it causes the mother's pelvic ligaments and the pubic symphysis to relax and become more flexible, which eases birth passage.

adh produce at?

oxytocin produce at?

growth hormone produce ?

contisone