Biology 30 Endocrine System

Pituitary

Master gland of the endocrine system

Where is LH and FSH secreted?

What do they stimulate?

Secreted by the anterior pituitary glad

They stimulate the gonads to secrete sex hormones (ovaries and testes)

What is a hormone?

A chemical messenger

Glucagon

secreted from the pancreas and causes glucose to be released from the liver

Insulin

Secreted from the pancreas, causes glucose to be removed from the blood

Aldosterone

Reduces the excretion of sodium from the body— produced from the adrenal cortex

Cortisol

long term stress hormone, produced from the adrenal cortex

What hormone is secreted by the parathyroid gland and raises blood calcium levels

PTH- parathyroid hormone

Calcitonin

Secreted by the thyroid gland and REDUCES blood calcium levels— REGULATES CALCIUM LEVELS

Thyroxine

Secreted by the thyroid gland and stimulates metabolism

what hormone induces sleep

melatonin

ADH

Antidirutic hormone is secreted by the posterior pituitary and promotes water retention by the kidneys. Inhibited by alcohol

Oxytocin

Produced by the posterior pituitary and stimulates uterine contractions and “milk let down” reflex; can induce contractions during labour

What is the hormone secreted by the anterior pituitary and stimulates the gonads to produce sperm and ova?

FSH- follicle stimulating hormone

What is the hormone that is secreted by the anterior pituitary and stimulates the thyroid?

TSH— Thyroid stimulating hormone

Primary hormones of the anterior pituitary

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

Primary hormones of the posterior pituitary

• Oxytocin (uterine contractions, bonding)
• Antidiuretic Hormone (ADH / Vasopressin) (water retention)

Hypothalamus

The "control center." Secretes releasing/inhibiting hormones and antidiuretic hormone (ADH) to control the pituitary gland

Anterior vs. Posterior Pituitary

Anterior = synthesizes and secretes 7 hormones (e.g., GH, TSH, ACTH). Posterior = stores/releases ADH and oxytocin produced by the hypothalamus

Thyroid

Butterfly-shaped gland in the neck. Controls metabolism and blood calcium (calcitonin)

Adrenal Gland

Cortex (outer) secretes steroids like cortisol and aldosterone; Medulla (inner) secretes catecholamines (epinephrine, norepinephrine)

Type I vs Type II diabetes

Cushings syndrome vs Addisons disease

Cushing's = excess cortisol (moon face, buffalo hump). Addison's = deficit of cortisol and aldosterone (hypotension, hyperpigmentation)

Hypothyroidism symptoms

low metabolism, weight gain, fatigue

Hypothyroidism

thyroid does not produce enough thyroid hormones for proper bodily function

Hyperthyroidism

thyroid produces too much hormones to have normal bodily functions

Hyperthyroidism symptoms

high metabolism, weight loss, anxiety

Negative feedback loop

The most common loop: A stimulus causes a hormone to be released— target cells respond— the response decreases the original stimulus to bring the body back to homeostasis

Positive feedback

a process in which an initial change causes further change in the same direction, amplifying the original signal

example: oxytocin production is labour

wheres the thyroid

D

wheres the pancreas

H

what is structure “B”

hypothalamus

what is structure “G”

Adrenal Gland

what is structure “E”

parathyroid glands

where is the pituitary gland

C

what is a tropic hormone

a hormone released to stimulate the release of other hormones. it is released from the thyroid, anterior pituitary and the hypothalamus

what is the relation between thyronxine and TSH

They are in a negative feedback loop, so when one is high the other is low