lecture 9: endocrine system

Endocrine System

Endocrine System

A system that coordinates the activity of organs through hormones, which are chemical messengers released into the blood from glands.

Hormones

Chemical messengers that have specific target cells and can be peptides, steroids, or amino acid derivatives.

Homeostasis

The process of maintaining a stable internal environment, controlled by the autonomic nervous system and the endocrine system.

Exocrine Glands

Glands that excrete products into ducts leading to body cavities or surfaces, such as salivary and gastric glands.

Endocrine Glands

Ductless glands that secrete hormones directly into the blood, including the pituitary, thyroid, and adrenal glands.

Hormone Receptors

Specific proteins on target cells that hormones bind to, influencing cell activity.

Down-regulation

A process where the number of hormone receptors decreases in response to excess hormone levels.

Up-regulation

A process where the number of hormone receptors increases in response to hormone deficiency.

Pituitary Gland

Often referred to as the master endocrine gland, it controls many other endocrine glands and is regulated by the hypothalamus.

Hypothalamus

A brain region that produces releasing and inhibiting hormones that regulate the pituitary gland.

Growth Hormone (GH)

A hormone that regulates metabolism, stimulates growth, and promotes the release of insulin-like growth factors.

Thyroid Stimulating Hormone (TSH)

A hormone that stimulates the growth and activity of the thyroid gland, increasing thyroid hormone production.

Adrenocorticotropic Hormone (ACTH)

A hormone that stimulates the output of steroid hormones from the adrenal cortex.

Prolactin (PRL)

A hormone that stimulates lactation and prevents pregnancy during breastfeeding.

Follicle Stimulating Hormone (FSH)

A hormone that stimulates the production of gametes and increases estrogen production in females.

Luteinising Hormone (LH)

A hormone that triggers ovulation and increases progesterone secretion in females.

Melanocyte Stimulating Hormone (MSH)

A hormone involved in skin pigmentation, produced in response to UV light.

Oxytocin

A hormone that contracts the uterus during childbirth and promotes bonding between mother and baby.

Antidiuretic Hormone (ADH)

A hormone that reduces urine output by stimulating water reabsorption in the kidneys.

Diabetes Insipidus

A condition characterized by a deficiency of ADH, leading to excessive urination and thirst.

Cushing Syndrome

A disorder caused by prolonged exposure to high levels of cortisol, leading to various symptoms including weight gain and hypertension.

Addison’s Disease

A condition of adrenal insufficiency characterized by weakness, fatigue, and hyperpigmentation of the skin.

Type I Diabetes

An autoimmune condition resulting in the destruction of insulin-producing beta cells in the pancreas.

Type II Diabetes

A condition characterized by insulin resistance and often associated with obesity and lifestyle factors.

Thyroid Hormones

Hormones produced by the thyroid gland that regulate metabolism, growth, and development.