Chapter 15 Endocrine system

Thymus

A lymphoepithelial organ in the upper part of the middle of the chest, just behind the breastbone. It is the site of T-cell development.

Adrenal glands

A pair of endocrine glands that sit just above the kidneys and secrete hormones that help arouse the body in times of stress

Pancreas

An organs in the abdominal cavity with two roles. The first is an exocrine role: to produce digestive enzymes and bicarbonate, which are delivered to the small intestine via the pancreatic duct. The second is an endocrine role: to secrete insulin and glucagon into the bloodstream to help regulate blood glucose levels.

Anterior pituitary gland

Controlled by hypothalamic-releasing and hypothalamic-inhibiting hormones

What's the difference between the endocrine glands versus exocrine glands?

Endocrine glands secrete their products directly into the bloodstream, while exocrine glands secrete products into ducts that release their products into cavities or outside the body.

Ovaries

Estrogen

What are hormones and describe the main types described during lecture

Hormones are chemical signals that promote change throughout the body. Prostaglandins are hormones that result in local changes, pheromones are chemical signals that influence the behavior of others, peptide hormones are those that bind to receptors on the outside of the cell causing signal changes inside, and steroid hormones are those that enter the cell and bind to receptors inside the cell resulting in changes to gene activity and protein synthesis.

Pineal gland

Is a pea-sized gland which produces melatonin, which is a hormone that the modulation of wake/sleep patterns and photoperiodic (seasonal) functions.

Thyroid gland

It is a large gland located below the larynx. Iodine is needed in the diet to allow the thyroid gland to produce its hormones

Testes

Male gonads

Hypothalamus

Regulates internal environment through the autonomic nervous system Helps control heartbeat Helps control body temperature Helps control water balance Controls glandular secretions

Parathyroid glands

Small glands embedded in the surface of the thyroid gland Produces parathyroid hormone (PTH) Causes blood Ca2+ level to increase by promoting osteoclast activity Promotes reabsorption of Ca2+ by the kidneys

Posterior pituitary gland

Stores and secretes antidiuretic hormone (ADH) and oxytocin that are produced by the hypothalamus ADH regulates water balance by reabsorbing water into the bloodstream. Oxytocin causes uterine contractions during childbirth and allows milk to be released during nursing.

Describe the role of the anterior pituitary gland and know the hormones it produces/secretes, note any disorders.

The anterior pituitary gland is under control of the hypothalamus via the inhibiting and releasing hormones. Here, there are several hormones produced and secreted by the APG. Thyroid-stimulating hormones targets the thyroid to secrete thyroid hormones, adrenocorticotropic hormone targets the adrenal gland to secrete cortisol, gonadotropic hormones target gonads (ovary or testes) to secrete hormones and/or produce sperm and egg, prolactin stimulates mammary gland development and milk production, melanocyte stimulating hormone stimulates skin color changes, and growth hormone stimulates growth of muscles and bones. Irregular secretions of GH can lead to dwarfism (under secretion) or gigantism (hyper secretion

Describe the role of the hypothalamus and know the hormones it produces/secretes, note any disorders.

The hypothalamus has many roles, but its major role is controlling glandular secretions by secreting releasing or inhibiting hormones.

Describe the role of the parathyroid gland and know the hormones it produces/secretes, note any disorders.

The parathyroid gland secretes parathyroid hormones that function to stimulate osteoclastic activity thereby removing calcium from bones and adding to the blood stream.

Describe the role of the posterior pituitary gland and know the hormones it produces/secretes, note any disorders.

The posterior pituitary stores and secretes 2 hormones produced by the hypothalamus. ADH regulates water balance by promoting water reabsorption in the kidneys, while oxytocin stimulates uterine contractions and promotes secretion of milk during nursing.

Describe the role of the thyroid gland and know the hormones it produces/secretes, note any disorders.

The thyroid gland needs a sufficient among of iodine to function and produce the thyroid hormones. Insufficient iodine leads to an enlargement of the thyroid known as a goiter. Thyroid hormone is important to regulate metabolism. Also, calcitonin is produced by the thyroid that promotes calcium absorption by the bones thereby reducing the available calcium in the blood. Students should know what congenital hypothyroidism and myxedema (hypothyroid secretion) as well as hyperthyroidism known as exophthalimic goiter.

Peptide hormones

bind to a receptor on the outside of the plasma membrane causing chemical changes to occur inside the cell

Pheromones

chemical signals that influence the behavior of other individuals.

Adrenal medulla:

controlled by the nervous system,Inner portion of the adrenal glands,produces 'flight or fight response'

What is the endocrine system, and how does it function?

is a system of the body comprised mainly of glands that secrete hormones into the bloodstream. These messages act on target cells by binding to specific receptors that cause slow, prolonged changes to the cell target cells.

Steroid hormones

lipids that enter a cell and affect gene activity and thus protein synthesis.

Prostaglandins

local hormones that affect neighboring cells and thus are not carried in the bloodstream.

Adrenal cortex:

portions are controlled by ACTH from the anterior pituitary,Outer portion of the adrenal glands, Produces hormones that provide a long-term response to stress

Endocrine glands

secrete their products directly into the bloodstream

Exocrine glands

secrete their products into ducts that carry these products to other organs or outside the body

hormones

that move through the bloodstream to target cells

What does the thyroid gland produce?

thyroid hormone (TH) which regulates metabolism, which is the breakdown or build-up of molecules. calcitonin which helps lower blood Ca2+ levels by stimulating the deposition of calcium in the bones

glands,

tissues capable of releasing (secreting) contents.