The Endocrine System The Glands That Run the

The Endocrine System The Glands That Run the Body

The Endocrine System Purpose ◦ To produce, secrete, and regulate hormones Done by the glands of the endocrine system ◦ Glands – Produce, secrete, and regulate hormones and enzymes

Endocrine Glands

Hormones Purpose ◦ To run the body’s metabolism, or normal functions Hormones are secreted by the glands directly into the blood stream ◦ This means that all hormones go to every part of the body, not just to one organ Hormones: ◦ Influence the flow of substances through cell membranes ◦ They often work together This means that a hormonal imbalance may interfere with normal body functions

Thymus Gland Location – Below the thyroid and above the heart Purpose – Initiate antibody formation in the blood Not always classified as an endocrine gland

Thyroid Gland Location – ◦ 2 lobes located on either side of the trachea Purpose – ◦ Secretes iodine-based hormones that regulate metabolism, physical and mental growth, oxidation, heart rate, blood pressure, temperature, glucose absorption, and the utilization of glucose

Thyroid Gland - Abnormalities Hyperthyroidism Secretion of too much thyroid hormone, characterized by difficulty concentrating, nervousness, weight loss, extreme appetite, sweating, irregular periods, and goiter Hypothyroidism Secretion of too little thyroid hormone, characterized by depression, fatigue, weight gain, heavy menstrual periods, thin, brittle hair and nails, puffy face, hands, and feet

Parathyroid Gland Location – 4 small glands positioned next to the thyroid gland Purpose – Secretes hormones that regulate the use of calcium in bone growth, muscle tone, and nerve activity

Parathyroid Abnormalities Hyperparathyroidism ◦ Secretion of too much parathyroid hormone, causing elevated blood calcium levels which can lead to cataracts, long bone fractures, back pain, tumor growth, and kidney stones Hypoparathyroidism ◦ Secretion of too little parathyroid hormone, causing decreased blood calcium levels which can lead to cataracts, loss of teeth, seizures, and muscle spasms

Pituitary Gland Location – Base of the brain Purpose – Regulates: ◦ ◦ ◦ ◦ Skeletal growth Development of reproductive organs Secretions from testes and ovaries Stimulation of mammary glands to produce milk Blood pressure Performance of smooth muscle Reabsorption of water in the kidneys Functioning of adrenal cortex, which is more active during times of stress

Pituitary Gland Abnormalities Disorders can result in: ◦ Infertility ◦ Giantism ◦ Dwarfism

Pineal Gland Location – Base of the brain Purpose – Exact purpose is unknown, but it is very active in regulating metabolism Abnormalities – can result in insomnia, anxiety, elevated estrogen/progesterone, immunity suppression, and lowered body temperature

Adrenal Gland Location – Above the kidneys Purpose – ◦ Secretes cortisol, which regulates metabolism and the balance between salt and water ◦ Secretes adrenaline (epinephrine), which increases heart rate and stimulates the liver and nervous system

Adrenal Gland Abnormalities Can result in many different disorders and diseases Common signs and symptoms include fatigue, poor appetite, dizziness, weight loss, and nausea

Pancreas Location – Anterior to the stomach Purpose – Secretion of insulin to control sugar levels in the blood Abnormalities can lead to diabetes and malnutrition

Ovaries Location – Suspended from pelvic wall on each side of the uterus Purpose – ◦ Secretes estrogen, which produces female characteristics and initiates female bodily functions ◦ Secretes progesterone, which affects the endometrial lining of the uterus

Testes Location – Suspended in the scrotum from the groin Purpose – Secrete testosterone, which controls the growth of body hair and beard, body size, and deepening of the voice