The Endocrine System

yup.

Water Soluble Hormones

Proteins, peptides and amino acids

• can’t cross the phospholipid membrane (its made of fat!)

• binds to external receptor cites

Fat Soluble Hormones

Steroids, usually.

• Can cross phospholipid membrane

• interacts with receptor cites within cell

Hormones

chemicals that affect

• metabolism within cells (ex.insulin)

• growth and development of body parts

• homeostasis (also insulin)

Tropic Hormones

Targets are other endocrine glands (causes other glands to release)

Ex. thyroid stimulating hormone (TSH) → Thyroid

Non-Tropic Hormones

Non-Endocrine Targets

Ex. Insulin → your body cells!

Posterior Pituitary Gland

Stores and releases hormones made by the hypothalamus

Anterior Pituitary gland

makes and releases its own hormones

Human Growth Hormone (hGH)

FROM: produced and secreted by the anterior pituitary

WHAT: promotes bone and muscle growth by:

• increasing cell division, muscle growth, release of stored fats and other important changes during puberty

• theres more of it in you as a child than as an adult

Hypersecretion

too much secretion

Hyopsecretion

too little secretion

Pituitary Dwarfism

What: do not grow very much, very short individuals in adulthood. Normally proportioned though.

Why: too little growth hormone during childhood

hyposecretion of the human growth hormone

Gigantism

What: growing super tall, beyond seven feet. beyond what human beings typically grow healthily to.

Why: too much human growth hormone during childhood.

hypersecretion of the human growth hormone

Acromegaly

What: the enlargement of hands, head/forehead, jaw, feet in adulthood

Why: too much growth hormone during adulthood.

hypersecretion of human growth hormone

Thyroid Gland

Releases thyroxine and calcitonin. Is attached to trachea (does nothing to impact breathing though). Regulates metabolism, growth, and development.

Parathyroid Glands

4 glands embedded in posterior surface of thyroid gland

releases parathyroid hormone, which regulates calcium levels in the blood

Thyroxine

FROM: the thyroid

WHAT: increases metabolic rate throughout all body cells

• it controls heat production and regulation too.

• increase of release when it’s cold → shivering

• decrease in release when it’s hot

(break down of sugars is a catabolic, exothermic reaction)

Myxedema

What: cold all the time, fatigued, dry skin, hair loss, weight gain, sleepy

Why: hyposecretion of thyroxine in adults

Cretinism

What: abnormal mental and physical development, growth impairment

Why: hyposecretion of thyroxine in children.

Grave’s Disease (Hyperthyroidism)

What: jitteriness, weight loss, fast heart rate, feel warm all the time, mood swings, hair loss

Why: hypersecretion of thyroxine

fixed by removing parts of the thyroid.

Goiter

What: Iodine deficiency.

Why: The thyroid keeps getting sent TSH and it doesn’t know what to do with it because you don’t got enough iodine to make thyroxine

The thyroid swells in efforts to produce more thyroxine (w/out iodine)

can be prevented by consuming iodized salt!

Calcitonin

FROM: the thyroid

WHAT: Deposits calcium in bones, kidneys release it (send it too ur pee). Decreases blood calcium levels.

Parathyroid Hormone

FROM: the parathyroid

WHAT: Releases calcium in bones, increases the absorption of calcium in the kidneys and intestines.

opp of calcitonin (antagonistic)

Adrenal Glands

WHERE: On top of the kidneys. There’s the outer adrenal cortex and the inner adrenal medulla.

Produce cortisol (stress hormone) and aldosterone (regulates electrolyte balance)

Adrenal Medulla

Short term stress response. Sympathetic response, it secretes epinephrine and norepinephrine.

Adrenal Cortex

Long term stress response. Produces glucocorticoids such as cortisol (regulates metabolism and energy levels), and mineralcorticaids such as aldosterone (regulates self + water balance)

Cortisol

FROM: the adrenal cortex

WHAT: Raises blood glucose by increasing the breakdown of fats and proteins

allows long term response to stress

Aldosterone

FROM: the adrenal cortex

WHAT: Increases blood pressure by increasing the intake of Na+ ions, and consequently, water (osmosis).

Addison’s Disease

What: bronzing of skin (low cortisol), dehydration (low aldosterone)

Why: Adrenal insufficency. Adrenal cortex hyposecretes (not enough) adrenal hormones.

Cushing’s Disease

What: Neck and face become round and swollen with fluid

Why: hypersecretion of cortisol by the adrenal cortex

Insulin

Targets: All cells, liver and muscles

Effect: Decreases blood glucose by increasing cell permeability to glucose and conversion of blood glucose into liver and muscles glycogen

Glucagon

Targets: All cells, liver and muscles

Effect: Increases blood glucose by decreasing cell permeability to glucose and conversion of stored glycogen into glucose

Pancreas

Regulates blood sugar

Hormones: glucagon and insulin

Made up of Islets of Langerhans (Alpha cells + Beta cells)

Does NOT require pituitary

Hypothalamus

Regulates body temperature, hunger, and thirst, and helps control the pituitary gland

Islets of Langerhans

Located within the pancreas, they produce insulin and glucagon

Antidiuretic Hormone (ADH)

Produced by the hypothalamus and released by the posterior pituitary gland, it regulates water balance in the body.

Oxytocin

Produced by the hypothalamus and released by the posterior pituitary gland, it stimulates uterine contractions during childbirth and milk letdown during lactation.

Thyroid-Stimulating Hormone (TSH)

Produced by the pituitary gland, it stimulates the thyroid gland to produce thyroid hormones.

Adrenocorticotropic Hormone (ACTH)

Produced by the pituitary gland, it stimulates the adrenal glands to produce cortisol

Hypothyroidism

A condition where the thyroid gland produces too little thyroid hormone, leading to symptoms such as fatigue and weight gain.

Diabetes Mellitus

A group of conditions characterized by high blood sugar levels, often due to insulin deficiency or resistance.

Hyperparathyroidism

A condition where the parathyroid glands produce too much parathyroid hormone, leading to high calcium levels in the blood.