Endocrine System

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Endocrine System : 

Priscilla DiNapoli Eddie McLaughlin Endocrine System

Endocrine System : 

Endocrine System Controls many body functions Releases special chemical substances called hormones into the bloodstream Hormones affect other glands in the endocrine system and other body systems Exocrine system Transports hormones via ducts to target tissues Consists of several glands located in various parts of the body Exocrine glands Secrete chemicals such as sweat, mucus, and digestive enzymes, into ducts that send the products to the appropriate location

Pituitary Gland : 

Pituitary Gland Pituitary gland: a small gland located on a stalk hanging from the base of the brain Known as the “master gland” Primary function is to control other glands Produces many hormones. Secretion is controlled by the hypothalamus in the base of the brain.

Pituitary Gland : 

Pituitary Gland The pituitary gland is divided into 2 areas, which differ structurally and functionally each area has separate types of hormone production. Posterior Pituitary: oxytocinthe (natural form of pitocin) stimulates uterus (contractions) causes “let down” of milk from the breast. antidiuretic hormone (ADH) (vasopressin) causes the kidney to retain water. Anterior Pituitary: thyroid-stimulating hormone (TSH) – stimulates the thyroid gland; raises metabolic rate growth hormone (GH) – less glucose usage, more fats used as energy adrenocorticotropin (ACTH) – stimulates the adrenal cortex to release its hormones follicle-stimulating hormone (FSH); Luteinizing hormone (LH) – stimulate maturation & release of eggs from ovary.

Pineal Gland : 

Pineal Gland Small mass of tissue near the center of the mammalian brain Secretes the hormone melatonin Modified amino acid Affects skin pigmentation Secreted at night; amount depends on length of night contains light-sensitive cells or nervous connections from the eyes Melatonin regulates functions related to light and seasons marked by changes in day length

Thyroid Gland : 

Thyroid Gland The Thyroid Gland lies in the anterior neck just below the larynx. Two lobes, located on either side of the trachea, connected by a narrow band of tissue called the isthmus. Sacs inside the gland contain colloid Within the colloid are the thyroid hormones: thyroxine (T4) triiodothyronine (T3) When stimulated (by TSH or cold temp) - released into the circulatory system and raise the metabolic rate. “C” cells within the thyroid produce the hormone calcitonin. Calcitonin lowers the calcium levels in the blood as part of calcium homeostasis.

Parathyroid Glands : 

Parathyroid Glands small, pea-shaped glands, located in the neck near the thyroid usually 4 - number can vary regulate the level of calcium in the body Secrete parathyroid hormone (PTH) – raises blood levels of Calcium; opposite to calcitonin Lack of calcium/PTH – convulsive contractions in skeletal muscle In the kidneys Stimulates reabsorption of calcium Activates conversion of vitamine D to its avtive form

Pancreas : 

Pancreas Pancreas has both endocrine and exocrine functions 1-2% endocrine cells Rest = exocrine cells Produces enzymes that are carried to the small intestine via the pancreatic duct Islets of Langerhans specialized tissues in which the endocrine functions of the pancreas occurs Each has a population of: alpha (? ) beta (?) each secretes an important hormone Alpha – glucagon Beta - insulin

Pancreas : 

Pancreas Alpha (?) cells release glucagon, essential for controlling blood glucose levels When blood glucose levels fall, ? cells raises the amount of glucagon in the blood stimulates the liver to release glucose stores stimulates the liver to manufacture glucose Beta Cells (?) release insulin Insulin raises the rate at which various body cells take up glucose lowers the blood glucose levels Insulin is rapidly broken down by the liver and must be secreted constantly.

Adrenal Glands : 

Adrenal Glands Adrenal glands 2 small glands found above the kidneys Adrenal Medulla –secretes the hormones norepinephrine and epinephrine (catecholamines – class of compounds synthesized from tyrosine The Adrenal Cortex secretes 3 classes of hormones, all steroid hormones: gluticocorticoids mineralocorticoids androgenic hormones gluticocorticoids: accounts for 95% of adrenal cortex hormone production Raises the level of glucose in the blood; ex: cortisol Released in response to stress, injury, or serious infection Mineralocorticoids: work to regulate the concentration of potassium and sodium in the body.

Gonads : 

Gonads Gonads and Ovaries: the endocrine glands associated with human reproduction. Female ovaries produce eggs Male gonads produce sperm Ovaries: located in the abdominal cavity adjacent to the uterus. Under the control of LH and FSH from the anterior pituitary they manufacture estrogen and progesterone sexual development preparation of the uterus for implantation of the egg Testes: located in the scrotum produce sperm for reproduction manufacture testosterone - promotes male growth and masculinization Controlled by anterior pituitary hormones FSH and LH.

Slide 12: 

Endocrine System

Slide 13: 

Stress and the Adrenal Glands

Hormonal regulation in Insects : 

Hormonal regulation in Insects 1. neuro secretory cells in the brain produce hormone (BH) which is stored in the corpus cardiacum until release 2. BH signals its main target organ, the prothoracic gland, to produce the hormone ecdysone 3. ecdysone secretion from the prothoracic gland is episodic, with each release stimulating a molt. Juvenile hormone (JH) determines the result of the molt. JH suppresses the molt. Endocrine and nervous system reactions

Disorders : 

Disorders Diabetes Mellitus one of the most common diseases in North America. Decrease in insulin secretion by the Beta (?) cells of the islets of Langerhans in the pancreas. Grave’s disease Hyperthyroidism – thyroid is overactive and grows twice the normal size Addison’s disease Adrenal gland disease – not enough steroid hormones produced Signs of conditions that often occur together with Addison's: goiter and vitiligo Cushing’s disease Increased production of cortisol This can be caused by taking glucocorticoid drugs, or by tumors that produce cortisol or adrenocorticotropic hormone(ACTH). Use of anabolic steroids Performance-enhancing drugs usually leads to cancer Increase in testosterone