2 Main Control Systems in the Body

Nervous System Endocrine System

enables the body to adjust to maintains control over long

changes in the environment distances and for long periods

quickly of time

▫  The endocrine system carries out its control via the work of hormones.

HORMONES ð

▫  Very ______quantities of each type of hormone are produced and ______into the ______(no more than 10-12 mol/L).

▫  However, the potency (or impact) of hormones is magnified many times by their ability to affect key metabolic processes in the target cells.

Factors in Hormone Production and Function:

Hormone production increases or decreases in response to changing metabolic needs of the body

ð e.g. fluid balance, infection, stress

The impact of a specific hormone on the activity of target tissues is a function of:

§  ______

§  ______

§  ______

§  ______

ð Hormones regulate endocrine activity by means of ______loops.

ð Hormones ______affect all cells. Cells have specific types and numbers of receptors for specific hormones.

2 types of endocrine system Hormones – Steroid and Protein hormones

Type / Steroid / Protein
Structure
Water Solubility
Method of Transport into Target Cells
METHOD OF ACTION

Components of the Endocrine System:

§  The endocrine system is comprised of hormone-producing glands and tissues of the body.

▫  Endocrine gland ð ______

▫  Exocrine gland ð______

(e.g. sweat glands; salivary glands)

ENDOCRINE GLANDS

Organ / Function
Endocrine only / Mixed
Hypothalamus
Pituitary
Parathyroid
Thyroid
Thymus
Heart
Stomach
Adrenal Gland
Kidney
Pancreas
Intestines
Skin
Ovaries
Testes

The Pituitary Gland: “The Master Gland”

§  Found at the stalk of the hypothalamus

§  ______(some are produced by the hypothalamus)

§  Controls other endocrine glands

§  Composed of two lobes:

1.  ______:

▫  ______

▫  Hormone release occurs when necessary, often stimulated by the hypothalamus (specialized nerves between hypothalamus and pituitary)

▫  e.g. Antidiuretic hormone ð regulates body water

▫  e.g. Oxytocin ð uterine contractions during labour

2.  ______:

▫  Produces own hormones

▫  Still has strong nerve connection with the hypothalamus

The Hypothalamus

§  connected to the pituitary gland

§  ______

______

The hypothalamus and pituitary gland control many critical physiological processes ---- e.g. metabolic rate, appetite, kidney function, reproduction etc., AND they secrete hormones that influence the activity of other hormone-producing glands.