• Endocrine glands are glands of the endocrine system that secrete their products, hormones, directly into the blood rather than through a duct.

Hormones

Hormones• Secreted by the endocrine glands.• Chemicals that circulate via the

bloodstream to specific parts of the body and affect their functioning and growth.

• Not all hormones are secreted by glands.Ex:secretin.

• Not all hormones are proteins.• They can be peptides, steroids, amino acids and derivatives of catecholamine.

Thyroid gland• Located at the base of the neck on

either side of the wind pipe.• Necessary for optimal development

and growth of CNS and other body systems.

• Secretes thyroxin-regulates the rate of metabolism.

• Hypothyroidism -cretinism-retarded physical and

mental growth, poor body proportions, low metabolic activity, a broad nose, dry skin, poor mental activity.

-Myxoedema-thick, puffy skin, dry, brittle hair, sluggish mental activity, increased body fat and weight.

• Hyperthyroidism-nervousness, irritability, fatigue, fast heart beat, weight loss.

Goiter or grave’s disease• Enlarged thyroid gland characterised

by swelling under the skin at the front of the neck.

• Increased heart beat and metabolism, reduction in weight, high blood pressure

-overactive, unstable, tense, nervous.

-insomnia.

Parathyroid glands

• Located on either side of TG• regulates calcium absorption and

metabolism.• Secretes parathormone hormone. -regulates calcium level in the blood. -small variations-muscles and nerve

impairment, affects behavior. -necessary for cartilage models to

become bones. -under secretion or over secretion

affects skeletal bones and teeth. -removal-tremors, cramps,

convulsions and muscular twitching.

Thymus gland

• Located in the region where the throat joins the chest.

• Large gland at childhood starts shrinking around puberty and reduces to the minimum during adulthood.

• Stimulates the vertical growth and withholds premature sexual development.

• Plays an important role in the development of the child’s immune system.

Adrenal glands• Play an important role in

determining a person’s mood, energy level and ability to cope with stress.

• Located above kidneys.- Each gland has:• Adrenal medulla (inner)• Adrenal cortex (outer)

Adrenal medulla :• Helps cope with physical and

emotional stress.• Closely related to the sympathetic

nervous system, control physical reactions induced by emotion.

• Secretes-epinephrine (adrenalin)-increase heart rate, facilitates blood flow to muscles and brain, relaxation of smooth muscles, conversion of glycogen to glucose in the liver. Norepinephrine (noradrenalin)-stimulates to release adrenocortical hormone.

Adrenal cortex :• Secretes a number of hormones-

aidosterone, cortisol (minor aches and pains), cortisone (rheumatoid arthritis), 17-ketosteroids (sex hormones) etc.

• Secreted more under stress.• Destruction-Addison’s disease-

irritability, increased fatigue, loss of appetite.

Pancreas

Neurotransmitters

• Different parts of your brain share information and organize plans for action through a code system.

• Chemicals called neurotransmitters are emptied from tiny sacs into the space between nerve cells.

• These chemicals cross that space and bind to receptors on other nerve cells.

• The binding process triggers an electrical stimulus in the receiving cells.

• A hormone is a substance that is secreted by an organ or part of the body, into the blood stream, and is thereby transported to another body part (or it may act on the organ that secreted it), to illicit an action.• A neurotransmitter is any specific

chemical that crosses a synaptic space after being transmitted from a presynaptic cell, and acts on a post-synaptic cell.

• Hormone is a compound produced by an endocrine gland and released into the bloodstream where it can find it's target cells at some distance from it's actual site of release.• A neurotransmitter is a compound

released from a nerve terminal. These nerve terminals are in direct apposition with their target cells to ensure rapid and specific delivery of the signal.

ADRENALINA hormone or a neurotransmitter?????