Endocrine and Nervous Systems

Dr Atef MasadPhD Biomedicine

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• The endocrine system and the nervous system work together to control the metabolic activity of the body.

• Endocrine glands are DUCTLESS. This means that the hormones produced are put into the bloodstream to be taken to other parts of the body.

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• The hormones of the endocrine system produce specific effects on body functions very slowly. This is due to the slow release of the chemicals (hormones).

• By contrast, the nervous system brings about very fast changes. This is because the nervous system does not use chemical messengers, it uses electricity.

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Combining Forms for Endocrine

Aden/o gland adenoma

Adrenal/o

Adren/o adrenal gland

adrenalectomy

adrenal

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Calc/o calcium calcemia

Gluc/o

Glyc/o sugar, glucose

glucogenesis

hyperglycemia

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Pancreat/o pancreas

pancreatitis

Thym/o thymus

thymoma

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Thyroid/o thyroid gland

thyroidectomy

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• Although all the major hormones circulate within the bloodstream, each on has a specific TARGET organ.

• Dysfunction of a gland may result in hyposecretion or hypersecretion of the hormone.

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Characteristics of Hormones

• Are chemical substances produced by specialized cells.

• Are slowly released in minute amounts directly into the bloodstream.

• Are produced by endocrine glands• Are inactivated or excreted by the kidney

or liver.

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Specific Glands

• PITUITARY

• Located in the brain.• Two parts to this gland: anterior anter/o posterior poster/o• The anterior and posterior parts are called

LOBES.• Also known as the HYPOPHYSIS. anterior lobe: adenohypophysis posterior lobe: neurohypophysis

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Hormones of the pituitary gland:

Adenohypophysis: Growth Hormone (GH) Thyroid Stimulating Hormone (TSH) Adrenocorticotropic Hormone (ACTH) Follicle-Stimulating Hormone (FSH) Leutinizing Hormone (LH)

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Neurohypophysis:

Antidiuretic Hormone (ADH)

Oxytocin

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• Overproduction of GH produces a condition called GIANTISM.

• Underproduction of GH produces a condition called DWARFISM

• Recall, that the combining form for extremities is ACR/O; therefore, the word denoting enlargement of the extremities is ACROMEGALY. This condition is a result of the hypersecretion of GH after puberty. This disorder is characterized by enlarged bones of the hands, feet, and head.

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• What is ACRODERMATITIS?

inflammation of the skin of the extremities

• What is ACROHYPERHIDROSIS?

excessive perspiration of the extremities

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• THYROID GLAND

Located on the front and sides of the trachea just below the larynx.

It has two lobes that are separated by a thin strip of tissue called the ISTHMUS.

The combining forms for the thyroid gland are thyr/o thyroid/o

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Hyperthyroidism

excessive

Thyroid gland

condition

Therefore, hyperthyroidism is a condition of excessive secretion of the thyroid gland.

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Thyrotoxicosis

Thyroid gland

poison

condition

Therefore, thyrotoxicosis is a condition of the thyroid gland that is poisonous.

This condition is also known as HYPERTHYROIDISM

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Hormones of the Thyroid Gland

ThyroxineTriiodothyronine: 1. regulates metabolism 2. increases energy production from food. 3. increases rate of protein synthesis

Calcitonin: decreases the reabsorption of calcium and

phosphate from bones to blood.

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PARATHYROID GLANDS

- Located on the posterior surface of the thyroid gland.

- Named because they are found “around” the thyroid gland.

- There are 4 parathyroid glands that produce PARATHYROID HORMONE (PTH) or PARATHORMONE.

- This hormone increases the reabsorption of calcium and phosphorus from bone to blood.

- This works opposite of the CALCITONIN from the thyroid gland.

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ADRENAL GLANDS

-also known as the SUPRARENAL GLANDS as they are found on top of the kidneys.

-Hormones produced are: 1. Epinephrine (adrenaline): increases heart rate

and force of contraction, dilates bronchial tree, increases the conversion of glycogen from the liver to glucose, and increases the use of fat for energy.

2. Norepinephrine (noradrenaline): raises blood pressure and constricts blood vessels.

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3. Aldosterone: regulates the amount of salt in the body.

4. Cortisol: Regulates the metabolism of carbohydrates, proteins, and fat.

5. Androgens: maintain secondary sex characteristics

These three hormones are produced by the ADRENAL CORTEX. The previous two are produced by the ADRENAL MEDULLA.

• medull/o = inner part/medulla

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PANCREAS (ISLETS of LANGERHANS)

- located posterior to the stomach.- hormone producing cells are called ISLETS.- Produce INSULIN (decreases blood sugar levels)

and GLUCAGON (increases blood sugar levels).

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The Nervous System

• Two parts:

1. Central Nervous System: Brain and Spinal Cord

2. Peripheral Nervous System: Nerves that arise from the brain (cranial nerves) and spinal cord (spinal nerves)

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• NEURONS are the basic unit of the nervous system. They are specialized cells that:

1. respond to stimuli

2. detect stimuli

3. conduct electrochemical impulses

4. release chemical regulator.

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• GLIAL CELLS1. Do not carry impulses2. Support and protect neurons3. Line certain brain and spinal cord structures4. Are phagocytic5. Attach neurons to their blood supply

Of importance because they are common sites of tumors.

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Combining Forms

Cerebr/o cerebrum

Encephal/o brain

Gli/o glue or gluelike glial cell tissue

mening/oMeningi/o meninges

Myel/o spinal cord or bone marrow

Neur/o nerve04/21/23 26Dr Ate Masad