• second messenger system
• uses chemical messages (hormones)
Hormones control several major processes:
• Reproduction
• Growth and Development
• Mobilization of Body Defenses
• Homeostasis
• Regulation of Metabolism
CHEMISTRY OF HORMONES
• Amino Acid-Based Hormones
* Proteins
* Peptides
* Amines
• Steroids
* made from cholesterol
• Prostaglandis
* made from highly active lipids
EFFECTS CAUSED BY HORMONES
• Changes in plasma membrane permeability or electrical state
• Activation or inactuvation of enzymes
• Synthesis of proteins, such as enzymes
• Stimulation of mitosis
STIMULI THAT ACTIVATES ENDOCRINE
• Hormonal
• Humoral
• Neural
PITUITARY GLAND
• Major organ of Endocrine System
• size of grape
• protected by sphenoid bone
* Anterior Pituitary
- Glandular tissue
* Posterior Pituitary
- Nervous tissue
ANTERIOR PITUITARY
• 6 Hormones
- 2 (Non - endocrine)
- 4 (tropic hormones)
Hormones
1. Prolactin (PRL)
- maintains milk production
- males
2. Adrenocorticotropic (ACTH)
- adrenal cortex
3. Thyroid-stimulating Hormone (TSH)
- influences growth of thyroid
4. Gonadotropic Hormones
- hormonal activity of gonads
• Follicle-stimulating Hormone (FSH)
- follicle and sperm development
• Luteinizing Hormone (LH)
- triggers ovulation
- testosterone production
- interstitial cell-stimulating hormone (ICSH)
5. Growth Hormone
- amino acids priduce proteins
- General metabolic hormone
*Pituitary dwarfism
* Pituitary gigantism
POSTERIOR PITUITARY
• Oxytocin
- contraction of uterus
- causes milk ejection
• Antidiuretic Hormone (ADH)
- urine production (diuresis)
- vasopressin
THYROID GLAND
• base of throat
• two lobes and connecting isthmus
• Thyroid Hormone
- major metabolic hormone
* Thyroxine (T4)
- thyroid follicles
* Triiodothyronine (T3)
- conversion of T4
• 2 Hormones (Thyroid and Calcitonin)
• Calcitonin (Osteoclast)
- decreses blood calcium
- 9-11 mg/100ml
PARATHYROID GLAND
• produces PTH
• increases calcium
• located back of thyroid
ADRENAL GLANDS
• Cortex
- outer glandular region in 3 layers
- produces mineralocorticoids
* Mineralocorticoids (Outer)
- target organ is kidney
- regulates mineral content
* Glucocorticoids (Middle)
- normal cell metabolism
- help resist long-term stressors
- ACTH
* Sex Hormones (Inner)
- Androgens (male)
- Estrogen (female)
* Cortisone and cortisol
- stress hormone
• Medulla
- inner neural tissue region
* Catecholamines
- deal with short-term stressors
- Epinephrine and Norephrine
PANCREATIC ISTETS
• pancreas is mixed gland
* Insulin
- decreases glucose
- allows glucose to cross plasma membranes (beta)
* Glucagon
- increases glucose
- enter blood from alpha cells
PINEAL GLAND
• Third ventricle
• Secretes melatonin
- circadian rhytm (body clock)
THYMUS GLAND
• Posterior to sternum
• Largest in infants
• Produces thymosin (T lymphosites)
- matures WBC and develop immune system
OVARIES
• Estrogens (Female)
- produced by Graafian Follicles or Placenta
- female characteristics
• Progesterone
- corpus luteum
- menstrual cycle
TESTES
• produce several androgens
• Testosterone
OTHER HORMONE
• parts of small intestine
• parts of stomach
• kidneys
• heart
PLACENTA
• maintain pregnancy
• produces HC6