Hormones

Chapter 17

We have seen nerve impulse travel through neurons, how

hormones travel…….

The Endocrine Glands

Hence they are the Chemical Messengers

Why the action of hormones is specific to some target cells only?

Your hormones travel freely in blood?

Is fat intake important in terms of hormones….

• Hormones

– Peptide/Protein e.g., GH

– Lipid based e.g., Testosterone, Estrogen

– Amines (Tyrosine/Tryptophan) e.g., Epinephrine

Chemical classification of hormones

Do all hormones enter the cell?

........ soluble hormones trigger responses

without entering the cell.

…… soluble hormones trigger responses

after entering the cell.

Mechanism of Action

Hypothalamus

Pituitary

gland

Testes

(in males)

Ovaries

(in females)

Pancreas

Adrenal glands

Thyroid gland

Glands we shall study…

• Hypothalamus and Pituitary

• Adrenal Glands

• Thyroid

• Pancreas

Brain

Hypothalamus

Posterior pituitary

Anterior pituitary

Bone

Anterior and Posterior Pituitary

Name a gland that can produce multiple hormones…..

1. Name the hormone…..

How does it act?

An overactive thyroid

(hyperthyroidism) can cause a

person to feel too hot, while an

underactive thyroid (hypothyroidism)

can cause a person to feel too cold.

Negative Feedback

Life is

Homeostasis