Lab 5: Homeostasis

Mastrangelo lab #5

Homeostasis

Process in which human body maintains normal conditions and stability; requires communication between body systems / organs

Nervous System

Electrical Impulses deliver rapidly through the body

Endocrine system

Chemical Messangers (hormones) moved through vascular system; effects are slow moving and long lasting

Interstitial Fluid

15% of body weight; composition similar to plasma

Hypothalmus

Secretes hormones and connects to pituitary gland

Hypopheseal Portal System

Capillaries to veins to capillaries; connects to anterior pituitary (adenohypophysis)

Hypothalamo-hypophyseal tract

Neurons - connect to the posterior pituitary (neurohypophysis)

TRH, GnRH, CRH, SOM/GHIH and GHRH

Hypothalamic Hormones that target the anterior pituitary

OXY, AVP/ADH

Hypothalamic Hormones that target the posterior pituitary

Thyroid stimulating Hormone and Prolactin

TRH stimulates the release of…

LH and FSH

GnRH stimulates the release of…

ACTH

CRH stimulates the release of…

Growth Hormone

GHRH stimulates the release of…

Growth Hormone

SOM (GHIH) inhibits the release of…

Growth Hormone

(Anterior Pituitary) involved in growth and development; targets the liver and stimulates protein synthesis

Prolactin

(anterior pituitary) Regulates milk production; regulated by releasing and inhibiting factors

Oxytocin

(Posterior pituitary) “The love hormone” stimulates uterine contractions during birth, and implemented during arousal

Thyroid

Involved in metabolism regulation; stimulated by TSH from anterior pituitary

Adenopophysis (Anterior pituitary gland)

Releases FSH, LH, TSH, GH, PRL and ACTH

Thyroid

Target organ for TSH

Mamillary

Target organ for PRL

Ovaries / Testical

Target organs for FSH and LH

Adrenal Glands

Target Organ for ACTH

Whole body

Target organ for GH

Calcitonin

(Released by thyroid) Works with parathyroid hormone to regulate calcium balance

T3 and T4

Released by thyroid gland; negative feed back in blood controls levels to prevent further release of TRH from hypothalamus

Leuteinizing Hormone

Promotes Estrogen / Progesterone secretion in females (induces ovulation), Stimulates testosterone secretion in males

Follicle Stimulating Hormone

Promotes egg development in females / estrogen secretion; promotes sperm maturation in males

Adrenal Glands

Involved in stress response and water balance

Zona Glomerulosa

(Outer adrenal Layer) Responds to Vasopressin levels to secrete mineralcortocoids (aldosterone)

Zona Fasiculata

(middle layer-thickest) Responds to ACTH from anterior pituitary to secrete cortisol

Zona Reticularis

(Inner Adrenal Layer) Secretes androgens

Medulla

(innermost section of adrenal) Secrete catecholamines in response to hypothalamic stimulation

Pancreatic Artery

“Mixed Gland”- Both endocrine and exocrine functions

Pancreatic Exocrine Function

Produces digestive enzymes and sodium bicarb; empty into pancreatic duct / small intestine

Pancreatic Endocrine Function

Produces insulin and glucagon; pancreatic polypeptide and somatostatin; secreted into pancreatic vein / HPV

Alpha Cells

(pancreatic islets) secrete glucagon to increase blood / glucose levels

Beta Cells

(pancreatic islets) secrete insulin to decrease blood glucose levels

Delta Cells

Secrete Somatastatin - inhibits insulin and glucagon release

F Cells

Secrete Pancreatic Peptide

Ghrelin

Produced by G cells in stomach lining; increased ghrelin = increased appetite

Thymus

(immune system) secretes Thymosin to promote T-Cell maturation