Week 7 HUBS1406 - Endocrine system

Basal metabolic rate - amount of energy per unit time that a person needs to keep the body functioning at rest.

The thyroid gland uses iodine from the foods you eat to make two main hormones: Triiodothyronine (T3) Thyroxine (T4)

Triiodothyronine (t3) and thyroxine (t4) both help to regulate body temp, metabolism and heart rate.

Triiodothyronine (T3) and Thyroxine (T4) are made in the pineal gland

The pituitary gland and hypothalamus both control the thyroid.

The pineal gland and hypothalamus both control the thyroid.

The Endocrine system maintains homeostasis

The Endocrine works collectively with the nervous system.

The Nervous system acts quickly in the body by using neurotransmitters.

Hormones bind to their target cell

Hormones don’t always have to secrete into blood stream, it can secrete to nearby cell

Some Hormones bind to lipids because they are protein bound hormones.

Examples of amino acid-derived hormones include epinephrine and norepinephrine

Most lipid hormones are steroid hormones, which are usually ketones or alcohols and are insoluble in water.

Steroid hormones (ending in ‘-ol’ or ‘-one’) include estradiol, testosterone, aldosterone, and cortisol.

The amino acid – derived hormones (ending in ‘-ine’) are derived from tyrosine and tryptophan and include epinephrine and norepinephrine (produced by the adrenal medulla).

Peptide hormones consist of a polypeptide chain; they include molecules such as oxytocin (short polypeptide chain) or growth hormones ( proteins ).

Amino acid-derived hormones and protein hormones are water-soluble and insoluble in lipids.

Amino acid-derived hormones and protein hormones are water-soluble and soluble in lipids.

Amino acid hormone – binds to receptor membrane

Peptide hormone – binds to receptor membrane

Lipid (steroid) hormone - binds to cytoplasm

Insulin helps to keep your blood sugar level from getting too high (hyperglycemia) or too low (hypoglycemia).

Insulin is a hormone made by the pancreas that allows your body to use sugar (glucose) from carbohydrates in the food that you eat for energy or to store glucose for future use.

The pancreas releases glucagon when the concentration of insulin (and indirectly glucose) in the bloodstream falls too low.

Glucagon causes the liver to convert stored glycogen into glucose, which is released into the bloodstream.

Glycogen is mainly stored in the liver and the muscles and provides the body with a readily available source of energy if blood glucose levels decrease.

Glycogen is mainly stored in the liver and the muscles and provides the body with a readily available source of energy if blood glucose levels decrease.

Hypothalamus – production of antiduiretic hormone and oxytocin

The hypothalamus plays a crucial role in many important functions, including:
- releasing hormones
- regulating body temperature
- maintaining daily physiological cycles
- controlling appetite
- managing of sexual behavior
- regulating emotional responses

The pituitary gland produces prolactin, which acts on the breasts to induce milk production. The pituitary gland also secretes hormones that act on the adrenal glands, thyroid gland, ovaries and testes, which in turn produce other hormones.

Through secretion of its hormones, the pituitary gland controls metabolism, growth, sexual maturation, reproduction, blood pressure and many other vital physical functions and processes.

Pituitary glands – anterior (secretes ACTH, TSH, GH, PRL, FSH, LH) and posterior lobe (secretes oxytocin and ADH)

Pineal gland – secretes melatonin

Thyroid gland also secretes calcitonin

Parathyroid gland - posterior to thyroid, there are 4 of them – regulates calcium and phosphate

Thymus gland - posterior, there are 4 of them – regulates calcium and phosphate

Thymus – secretes thymosin - stimulates the development of disease-fighting T cells

Erythropoietin (EPO) is a hormone produced primarily by the kidneys. It plays a key role in the production of red blood cells (RBCs), which carry oxygen from the lungs to the rest of the body.

The Thymus secretes erythropoietin

The adrenal cortex—the outer part of the gland—produces hormones that are vital to life, such as cortisol (which helps regulate metabolism and helps your body respond to stress) and aldosterone (which helps control blood pressure).

The adrenal medulla—the outer part of the gland—produces hormones that are vital to life, such as cortisol (which helps regulate metabolism and helps your body respond to stress) and aldosterone (which helps control blood pressure).

The adrenal medulla, the inner part of an adrenal gland, controls hormones that initiate the flight or fight response. The main hormones secreted by the adrenal medulla include epinephrine (adrenaline) and norepinephrine (noradrenaline), which have similar functions.

The adrenal cortex, the inner part of an adrenal gland, controls hormones that initiate the flight or fight response. The main hormones secreted by the adrenal cortex include epinephrine (adrenaline) and norepinephrine (noradrenaline), which have similar functions.

Leptin is a hormone released from fat cells in adipose tissue.

The hypothalamic–pituitary–thyroid axis (HPT axis for short, a.k.a. thyroid homeostasis or thyrotropic feedback control) is part of the neuroendocrine system responsible for the regulation of metabolism.

The hypothalamic–pineal–thyroid axis (HPT axis for short, a.k.a. thyroid homeostasis or thyrotropic feedback control) is part of the neuroendocrine system responsible for the regulation of metabolism.

Thyrotropin is a hormone secreted by the pituitary gland which regulates the production of thyroid hormones.

Corticotropin-releasing hormone (CRH) is secreted by the hypothalamus in response to stress.

Adrenocorticotropic hormone (ACTH) is made in the pituitary gland. It is needed for your adrenal glands to work properly and help your body react to stress. ACTH stimulates the release of another hormone called cortisol from the cortex (outer part) of the adrenal gland.

Follicle stimulating hormone is produced by the pituitary gland. It regulates the functions of both the ovaries and testes. Lack or insufficiency of it can cause infertility or subfertility both in men and women.

Luteinising hormone is produced by the pituitary gland and is one of the main hormones that control the reproductive system.

Progesterone is a hormone released by the corpus luteum in the ovary. It plays important roles in the menstrual cycle and in maintaining the early stages of pregnancy. It may also be involved in the growth of certain cancers.

Growth hormone is a small protein made in part of the brain called the pituitary gland.

Oxytocin is produced in the hypothalamus and is secreted into the bloodstream by the posterior pituitary gland.

Blood clotting is also a positive feedback loop

Prolactin produces breast milk

Endocrine means ‘ductless gland’

Exocrine means ducted gland