By: Courtenay Parker
-Many functions in nervous system.-Help maintain body's homeostasis.
Major Organs and their functions
-Responsible for the direct control of the endocrine system through the pituitary gland.
-Contains special cells that secrete hormones
1. Thyrotropin-Releasing Hormone (TRH)
2. Growth Hormone-Releasing Hormone (GHRH)
3. Growth Hormone- Inhibiting Hormone (GHIH)
4. Gonadotropin-Releasing Hormone (GnRH)
5. Corticotropin- Releasing Hormone (CRH)
7. Antidiuretic Hormone (ADH)
2) Pituitary Gland- Small lump of tissue connected to the inferior portion of the Hypothalamus.
-Releases hormones that are carried through the body by blood vessels.
1. Posterior pituitary- not glandular tissue but nervous tissue.
-stores and releases cells created by neurosecretory cells.
2. Anterior pituitary- Produces six important hormones including:
1. Thyroid Stimulating Hormone. (TSH)
2. Adrenocorticotropic Hormone (ACTH)
3. Follicle Stimulating Hormone (FSH)
4. Luteinizing Hormone (LH)
5. Human Growth Hormone (HGH)
6. Prolactin (PRL)
-Produces Melatonin (Helps regulate the human sleep-wake cycle)
* Light sensitivity causes melatonin to be released only in the low light or darkness.
* increased Melatonin will causes humans to feel drowsy at nighttime when this gland is most active.
- Located at base of neck
- Wrapped around lateral sides of Trachea
-Produces three major hormones.
2. Triiodothyronine (T3)
3. Thyroxine (T4)
*Increased levels of T3 and T4 lead to increased cellular activity and energy usage in the body.
- Posterior side of Thyroid Gland
- Produce Parathyroid hormone (PTH)
- When calcium ion levels drop below a certain point, parathyroid hormone is released.
- Superior to kidneys
- Two distinct layers
1. outer adrenal cortex
2. inner adrenal medulla
1) Adrenal Cortex ( three classes)
-Glucocorticoids breakdown proteins and lipids to produce glucose.
-Mineralocorticoids group of hormones that help regulate the concentration of mineral ions.
-Androgens produced at low levels in the adrenal cortex to growth and activity of cells that are receptive to male hormones.
-inferior and posterior to stomach
-contains to endocrine and exocrine tissue
-Endocrine cells make up 1% of pancreas (Two types of cells)
1. Alpha cells- produce hormone glucagon- raises blood glucose levels
2. Beta cells- Produce hormone insulin- lowers blood glucose levels
-Produce sex hormones
1. Testes- Pair of ellipsoid organs found in scrotum of males
-produce testosterone in males after they start puberty
- hormone causes growth and increases strength
2. Ovaries- pair of almond shaped glands in the pelvic cavity found lateral and superior to the uterus.
-produce female sex hormones progesterone and estrogen
-progesterone is most active during ovulation and pregnancy
-estrogen function as primary female sex hormones
-found in chest, posterior to sternum
-produces hormone called thymosins- help train and develop T-lymphocytes during fetal development and childhood.
-T-lymphocytes help protect body from pathogens
-becomes inactive during puberty and is slowly replaced by adipose tissue throughout a persons life.
Treated by replacing or substituting to hormones of adrenal glands. Patients take hydrocortisone tablets.
2) Grave's disease- hyperthyroidism which causes high metabolism, rapid heartbeat, weight loss. Symptoms: Trouble sleeping, hand tremors, rapid heartbeat, and thinning of skin. Can be corrected by antithyroid medications that block the synthesis of thyroid hormones or by treatment with radioactive iodine.
3) Sterility- Hyposecretion of FSH and LF causing inability to reproduce. Symptoms: inability to conceive/reproduce. Minimally invasive surgery to distinguish if infertility is permanent. No treatment.
New studies are finding that not all women diagnosed with breast cancer need to be treated with a combination of Radiation therapy and endocine therapy. The 56th annual meeting held at the American Society for Radiation oncology's results brought about new concepts for treating estrogen or progesterone positive breast cancer. They found that older patients ( Group tested had median age 72) treated with radiation only had smaller, lower-grade tumors than patients who were treated with the combination. (Median age of the combination treatments group was 71). Patients treated with the combination were at slightly higher risk for tumors than the radiation only group. Studies conducted years later on the same patients found that patients treated with radiation alone had a disease-free progression of 92%. The combination group was not much lower at disease-free progression of 91%.