THE ENDOCRINE SYSTEM

• Identify the principle endocrine glands in humans • Describe the function of the hormones of the principle endocrine

glands and how they maintain homeostasis through feedback

Goals for this lesson:

Key Words:

• Homeostasis • Hypothalamus/ pituitary

complex • Thyroid • Parathyroid • Adrenal Glands • Epinephrine • Antidiuretic hormone

(ADH)

• Thyroid-stimulating hormone (TSH)/ thyroxin

• Calcitonin/ parathyroid hormone (PTH)

• Adrenocorticotropic hormone (ACTH)/ cortisol

• glucagon/ insulin • Human growth hormone

(hGH)

• Hormones • Negative feedback • Positive feedback • Releasing hormone • Inhibiting factor • Aldosterone • Islet cells • Pancreas

What is the endocrine system?

Definition: A network of glands that secrete hormones that will have an

effect on the body or on an individual organ.

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Simplified: The Endocrine system is what is controlling most of our

internal environment. It also plays a role in our emotions and how we feel.

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What is Homeostasis?The tendency of a system, especially the physiological system of higher animal, to maintain internal stability.

!Our nervous system and endocrine system work

together to maintain homeostasis

Mapping the Endocrine System - The glands

The pituitary gland:

- Works with the hypothalamus as the control centre. Is responsible for coordinating the endocrine and nervous systems

- Has two lobes (the posterior and the anterior)

The hypothalamus:

- The part of the brain associated with homeostasis

- Works with the pituitary gland

- Creates RELEASING HORMONE and INHIBITING FACTOR that sends signals to the pituitary gland

Releasing hormone: signals the release of a stored hormone

Inhibiting factor: stops the production of a hormone

The Thyroid Gland

- Regulates metabolic processes

- Consists of two-lobes

- Contains the parathyroid glands

The Parathyroid glands

- Found in the thyroid gland

- There are 4 of them

- Regulate blood calcium and phosphate levels

The Adrenal Glands

- Located above the kidneys

- Each gland is made up of two glands encased in one shell

- Creates hormones that act along-side the autonomic nervous system

- The inside (ADRENAL MEDULLA) produces hormones during stressful situations, the outside (ADRENAL CORTEX) produces hormones to help the body recover after stress

The Pancreas:

- Contains islet cells, also known as islets of Langerhans, which produce hormones which help to control blood sugar levels

The Testes and the Ovaries:

- Sex glands that we will learn more about during our next unit (Reproduction)