Endocrine (youtube info)

What is the endocrine system?

A system made up of glands that secrete hormones directly into the bloodstream to regulate body functions.

hormones

Chemical messengers that regulate body processes like growth, metabolism, and reproduction.

What is the difference between endocrine and exocrine glands?

Endocrine glands secrete hormones directly into the blood (no ducts); exocrine glands use ducts to secrete substances to a surface (e.g., sweat, milk).

Can a gland have both endocrine and exocrine functions?

Yes. Example: The pancreas (endocrine = insulin, glucagon; exocrine = digestive enzymes).

Name the major endocrine glands.

Hypothalamus, pituitary, pineal, thyroid, parathyroid, thymus, adrenal glands, pancreas, ovaries, testes.

What does the hypothalamus do in the endocrine system?

Regulates the pituitary gland and produces hormones that control its activity.

What are the two parts of the pituitary gland?

Anterior pituitary and posterior pituitary.

What hormones does the posterior pituitary release?

Oxytocin (causes uterine contractions and milk ejection) and Antidiuretic hormone (ADH) which increases water reabsorption in kidneys.

What hormones are made by the anterior pituitary?

Growth Hormone (GH), Prolactin (PRL), Thyroid Stimulating Hormone (TSH), Follicle Stimulating Hormone (FSH), Luteinizing Hormone (LH), Adrenocorticotropic Hormone (ACTH).

What is the function of Growth Hormone (GH)?

Promotes growth and protein synthesis.

What is the function of Prolactin (PRL)?

Stimulates milk production in mammary glands.

What does TSH (Thyroid Stimulating Hormone) do?

Stimulates the thyroid gland to release thyroid hormones.

What is the function of FSH and LH?

Stimulate gonads to produce gametes and sex hormones.

What is the function of ACTH (Adrenocorticotropic Hormone)?

Stimulates the adrenal cortex to release hormones.

What hormone does the pineal gland release?

Melatonin — helps regulate sleep-wake cycle (circadian rhythm).

What hormones are made by the thyroid gland?

T4 (thyroxine), T3 (triiodothyronine), and calcitonin.

What do T3 and T4 do?

Regulate metabolism, growth, and development.

What does calcitonin do?

Lowers blood calcium levels.

What hormone does the parathyroid gland release?

Parathyroid Hormone (PTH) — raises blood calcium levels.

What is the function of the thymus gland?

Produces hormones (like thymosin) that stimulate T-cell development for immune function.

Where are the adrenal glands located?

On top of each kidney.

What are the two parts of the adrenal glands?

Adrenal medulla and adrenal cortex.

What hormones does the adrenal medulla release?

Epinephrine and norepinephrine — responsible for fight-or-flight response.

What hormones does the adrenal cortex release?

Cortisol (raises blood glucose and helps with stress/inflammation) and Aldosterone (reabsorbs sodium and helps regulate BP).

What hormones does the pancreas release?

Insulin (lowers blood sugar by allowing glucose into cells) and Glucagon (raises blood sugar by stimulating glycogen breakdown in the liver).

What hormones do the ovaries release?

Estrogen and progesterone.

What is the function of estrogen?

Promotes female secondary sex characteristics and uterine lining growth.

What is the function of progesterone?

Maintains the uterine lining for pregnancy and supports fetal development.

What hormones do the testes release?

Androgens, mainly testosterone.

What does testosterone do?

Promotes sperm production and male secondary sex characteristics.

What is hypothyroidism?

A condition where the thyroid is underactive and produces too little thyroid hormone.

What are symptoms of hypothyroidism?

Fatigue, slow heart rate, weight gain, low metabolism.

Why might TSH levels be high in hypothyroidism?

Because the pituitary is trying to stimulate the underactive thyroid to produce hormones.

What kind of doctor treats endocrine disorders?

An endocrinologist.