lies within the abdominopelvic cavity in the loop formed betwen the inferior border of the stomach and the proximal portion of the small intestine.
roughly 99% of the pancreatic volume, consist of clusters of gland cells (pancreatic acini, and their attached ducts.
consists of small groups of cells scattered among the exocrine cells.
pancreatic islets (Islets of Langerhans)
the endocrine cluster of cells
produce the hormone glucagon.
released by ALPHA CELLS, raises blood glucose levels by increasing the rates of glycogen breakdown and glucose release by the liver.
produce the hormone insulin.
a peptide hormone realeased by beta cells when glucagon concentration exceed normal levels (70-110mg/dl also stimulated by elevated levels of some amino acids.
When blood glucose levels rise
beta cells secrete insulin, which then stimulates the transport of glucose across plasma membrane.
When blood glucose levels decline
Alpha cells secrete glucagon, which stimulates glycogen breakdown and glucose release by the liver.
The effectos of insulin on its target cells
(1) the acceleration of lucose uptake, (2) the acceleration of glucose utilization and enhance ATP production (3) the stimulation of glycogen formation (4) the stimulation of amino acid absorption and protein sytheisis (5) the stimulation of triglyceride formation in adipose.
the effects of glucagon
stimulating the breakdown of Glycogen in skeletal muscle and liver cells, Stimulating the production of Glucose in the liver.
When sugar drops below 70
serious problems can occur.
inhibits insulin and glucagon secretion, slows rate of nutrient absorption and enzyme secretion along digestive tract. Stimulated by a protein rich meal.
Inhibits gallbladder contraction, regulates production of pancreatic enzymes
Hormone: secretin, gastrin etc.
Target: Organs of the digestive system, other regions
Hormonal effects: Coordinate digestive activities
Hormone: Erythropoietin (EPO), calcitrol
Target: red bone marrow, intestinal lining, bone, kidneys
Hormonal effects: STimulates RBC production, stimulates Ca and phosphate absorption, stimulates Ca+ release from the bones, inhibits PTH secretion
Hormone: Natriuretic peptides (ANP, BNP)
Target: kidneys, hypothalmus, suprarenal gland
Hormonal Effects: Increased water and salt loss at kidneys, decrease thirst, suppress secretion of ADH and aldosterone.
Hormone: Thymosins (many)
Target: Lymphocytes and other cells of the immune response.
Hormonal effects:Coordinate and regulate immune response.
Hormonal effects: Suppression of appetite, permissive effects on GnRH and gonadotropin synthesis.
A condition caused by the hyposecretion of glucocorticoids and mieralcocorticoids, characterized by an inability to mobilize energy reserves and maintain normal blood glucose levels.( symptoms = low blood glucose, low blood sodium, weight loss, dehydration, weakness Na/K+ imblalance.
due to the hypersecretion of ACTH, group of symptoms attributed to the excessive production of cortisol by the adrenal cortex; this syndrome may be a result of a pituitary tumor or a primary adrenal gland dysfunction; symptoms include abnormally pigmented skin, "moon face," pads of fat on the chest and abdomen, " buffalo hump" (fat on the upper back), and wasting away of muscle
An irregular enlargement of the thyroid gland.
General adaptation syndrome (GAS)
The pattern ofhormonal and physiological adjustments with which the body responds to all forms of stress.
the principle estrogen
steroid hormone produced in the ovaries of females under FSH and LH stimulation.
the most important androgen
Nurse (sustentacular) cells
in the testes and support the differeniation and physical maturationn of sperm.
is a peptide hormone released by the kidneys in response to low oxygen levels in kidney tissues. stimulates the production of RBC by bone marrow.
(natrium=sodium, ouresis=making water) secreted when blood volume becomes too great and cells are stretched excessively, oppose the effects of angiotensin II.
Endocrine cells in the heart
muscles cells in the atria (chambers that receive blood form the veins) and the ventricles (chambers that pump blood to the rest of the body)
Atrial natriuretic peptide
A peptide hormone secreted by cardiac atrial cells in response to atrial distension (increased blood flow); causes increased renal sodium excretion and as such lowers blood pressure (antagonizing aldosterone).
Brain natriuretic peptide
Released continuously at low levels by heart. high levels assoc w/hypertension, CHF and HIV related cardiomyopathies and atherosclerosis.
Hormonal effects: inhibits secretion of FSH
(opposing) Ex: Insulin and Glucagon
Hormonal responses to stress
Alarm phase, resistance phase, exhaustion phase.
Low blood calcium
PERFORMING: Tapping on the face at a point just anterior to the ear and just below the zygomatic bone.
POSITIVE RESPONSE: Twitching of the ipsilateral facial muscles, suggestive of neuromuscular excitability
caused by HYPOCALCEMIA.
PERFORMING: Inflating a sphygmomanometer cuff above systolic blood pressure for several minutes
POSITIVE RESPONSE: Muscular contraction including flexion of the wrist and metacarpophalangeal joints,
hyperextension of the fingers, and flexion of the thumb
on the palm, suggestive of neuromuscular excitability
caused by HYPOCALCEMIA.