Download The Endocrine System

The Endocrine System
Presented By:
Jess C.
Alex B.
Aleeya W.
Function
• The Endocrine System produces hormones that
control many body functions as well as help
maintain homeostasis.
Exocrine .vs. Endocrine
Exocrine
• Hormones release to an
external environment.
• Ducts carry hormones
Endocrine
• Hormones release to an
internal environment.
• Ductless
Hormones
• Hormones are substances that are secreted by
endocrine glands and are transported by blood.
• Most hormones are either steroids (synthesized
from cholesterol), or they are amines, peptides,
proteins, or glycoproteins (synthesized from
amino acids).
Steroid Hormones
Nonsteroid Hormones
Secretion Regulation
• The three types of hormone secretion regulation,
regulate using negative feedback.
I.
The Hypothalamus controls the anterior
pituitary gland’s release of hormones, which in
turn regulates other endocrine gland hormone
secretion.
II. The nervous system regulates some glands
directly.
III. Other glands respond to the changing of
internal environment.
Nervous System Gland Regulation
• The Nervous System controls glandular
secretion by either stimulating the gland directly
or by changing the internal environment,
initiating secretion.
Negative Feedback Mechanisms
• A Negative Feedback mechanisms is a loop
system in which the system responds to
perturbation in the opposite direction.
Locations
Pineal Gland
• The Pineal gland is regulated by the nervous
system directly.
• Pineal Gland secretes:
Melatonin – acts on certain brain regions and
helps regulate circadian rhythms.
Pituitary Gland
• The pituitary gland’s secretions are regulated by
both the nervous system and the hypothalamus.
• Anterior Pituitary secretes:
Growth Hormone (GH) – stimulates cells to increase in size.
Prolactin (PRL) – stimulates & sustains milk production.
Thyroid Stimulating Hormone (TSH) – controls thyroid gland
secretions.
Adrenocorticotropic Hormone (ACTH) – controls certain cortex
adrenal gland hormones.
Follicle-stimulating/luteinizing Hormone (FSH) (LH) – exert
actions on the gonads (reproductive organs).
Pituitary Gland (Continued)
• Posterior Gland secretes:
Antidiuretic Hormone (ADH) – decreases urine
formation.
Oxytocin (OT) – contracts smooth uterine wall
muscles.
Thyroid Gland
• Secretions are regulated by the other hormones
from the anterior pituitary gland, and changes in
the internal environment.
• Thyroid Hormones:
Thryoxine (T4) – Increases rate of energy released from
carbohydrates, increases protein synthesis rate, accelerates
growth.
Triiodothyronine (T3) – same as T4, 5 times more potent.
Calcitonin – inhibits release of calcium and phosphate ions from
bones.
Parathyroid Glands
• Secretions are regulated by changes in the
internal environment of the body.
• Parathyroid Hormone (PTH) – increases blood
calcium concentration and decreases blood
phosphate ion concentrations.
Adrenal Glands
• Adrenal glands are regulated by the nervous
system.
• Adrenal Medulla Hormones:
Epinephrine (adrenalin) –increases heart rate, skeletal
muscle vessels dilate, blood pressure rises, airways
dilate, breaks down glycogen to glucose, metabolism
increases.
Norepinephrine (noradrenalin) – increases heart rate,
blood flow to muscles increases, blood pressure
increases, airways dilate, metabolism increases.
Adrenal Glands (Continued)
• Adrenal Glands are regulated by the nervous
system.
• Adrenal Cortex Hormones:
Aldosterone – causes the kidney to conserve
sodium ions and excrete potassium ions.
Cortisol – increases blood concentration of amino
acids, increases the utilization of fatty acids as an
energy source, and increases the blood glucose
concentration.
Pancreas (Endocrine)
• The Pancreas’ secretions are regulated by
changes in the internal environment.
• Endocrine:
Glucagon stimulates the liver to break down
glycogen into glucose.
Insulin – stimulates the liver to form glycogen
from glucose.
Pancreas (Exocrine)
• The exocrine glands of the Pancreas secrete
digestive juices.
Reproductive Glands
• The secretions of these glands are regulated by
the hypothalamus and pituitary.
• Ovaries:
Estrogens – stimulate enlargements of accessory
organs.
Progesterone – promotes changes in the uterus
during a reproductive cycle.
Reproductive Glands (Continued)
• Testes:
Testosterone – increases growth of body hair,
enlargement of larynx and vocal chords,
thickening of the skin, increased muscular growth,
thickening of bones.
Disorders and Diseases
• Diabetes Mellitus – a metabolic derangement
that arises from lack of insulin or an inability of
cells to recognize it.
• The insulin deficiency of diabetes disturbs the
metabolism of carbohydrates, proteins, and fats.
• The disturbed metabolism leads to dehydration,
increased hunger, stunted growth, and other
adverse effects.