-
pancreas
both an exocrine and endocrine gland
-
acini
the arrangement of exocrine cells in the pancreas. They produce digestive enzymes, which flow into the gastrointestinal tract through a network of ducts
-
pancreatic islets or islets of langerhans
scattered among the exocrine acini are endocrine tissue with the different cell types
-
Alpha or A cells
secrete glucagon which increases blood glucose levels when it falls below normal. cells in the pancreatic islets
-
Beta or B cells
cells in the pancreatic islets. about 70% of the islets. they secrete insulin which helps lower blood glucose levels when it is too high
-
Delta or D cells
cells in the pancreatic islets. They secrete somatostatin which is exactly like the growth inhibiting hormone of the hypothalamus
-
ovaries
paired oval bodies located in the female pelvic cavity, produce several steroid hormones including two estrogens and progesterone.
-
Estrogen and progesterone
these female sex hormones along with FSH and LH regulate the menstrual cycle, maintain pregnancy, and prepare mammary glands for lactation.
-
inhibin
a protein hormone that inhibits secretion of follicle-stimulating hormone (FSH)
-
relaxin
a peptide hormone produced during pregnancy which increases the flexibility of the pubic symphysis and helps dilate the uterine cervix during labour and delivery.
-
testes
the male gonads are oval glands the lie in the scrotum. They mainly secrete testosterone and androgen or male sex hormone
-
testosterone
stimulates descent of the testes before birth, regulates production of sperm and stimulates the development and maintenance of male secondary sex characteristics.
-
Pineal glands
is a small endocrine gland attached to the roof of the third ventricle of the brain at the midline. It has secretory pinealocytes and secretes melatonin
-
pinealocytes
the secretory cells in the masses of neuroglia in the pineal gland
-
melatonin
an amine hormone derived from serotonin and secreted by the pineal gland. it contributes to the setting of the body's biological clock. More is released in darkness so it is said to promote sleepiness
-
thymus
is located behind the sternum between the lungs. The hormones it produces are thymosin, thymic humoral factor (THF), Thymic factor (TF) and thymopoietin. They promote the maturation of T-cells, a type of white blood cell that destroys microbes and foreign substances
-
eicosanoids
two types: prostalglandnis or PGs and Leukotrines or LTs. They are found in virtually all body cells except the red blood cells. They exist only briefly in the blood
-
leukotrines
stimulate chemotaxis (attraction of a chemical stimulus) of white blood cells and mediate inflammation
-
Prostaglandnis
alter smooth muscle contraction, glandular secretions, blood flow, reproductive processes, platelet function, respiration, nerve impulse transmission, lipid metabolism, and immune responses
-
growth factors
play an important role in tissue development and repair. They cause growth by stimulating cell division. They include insulin, thymosin, thyroid hormones, human growth hormone and prolactin
-
Stress response or general adaptation syndrome (GAS)
the changes in the body elicited by stress which are controlled mainly by the hypothalamus. It occurs in three stages
-
Fight or flight response
first stage of stress response. It is initiated by nerve impulses to the hypothalamus to the sympathetic division of the ANS. Non essential body functions are inhibited
-
resistance reaction
stage two of stress response, is initiated in large part by the hypothalamic releasing hormones and is a longer lasting response. The hormones involves are the corticotropin-releasing hormones, growth-hormone releasing hormone and thyrotropin-releasing hormone. This stage helps the body continue fighting a stressor long after the fight or flight response dissipates.
-
exhaustion
stage three of stress response. The resources of the body may eventually become so depleted that the cannot sustain the resistance stage and exhaustion ensues. Prolonged exposure to high levels of cortisol and other hormones involved in the resistance reaction causes the wasting of muscles, suppression of immune system, ulcers and failure of pancreatic beta cells.
|
|