Parathyroid Glands

Sam Pandey and Ben CherryP:61/13/13

Location

We normally have 4 parathyroid glands total

Located in the neck Exist behind the Thyroid gland Exist in groups of two Two on the left of the thyroid and two

on the right

Hormones

Parathyroid Gland secretes two main hormones

The Parathyroid Hormone (PTH)-Positive hormone

Calcitonin-Negative hormone

Effects on human body

Both PTH and calcitonin regulate calcium levels

PTH increases the level of calcium and phosphorous if level is low (osteoclast activation)

PTH acts upon both bones and kidneys

Withdraws calcium from urine Calcitonin inhibits osteoclasts

Roles on homeostasis

Parathyroid hormone controls calcium

Calcium plays an enormous role in maintenance of homeostasis

Effects neuromuscular excitability, blood clotting, cell membrane permeability and functioning of certain enzymes

Calcium is very important…

Facts about calcium

The most important roles of calcium are…

Provide means for electrical impulses to travel

Provide electrical energy to nervous system

Provide electrical energy to muscular system

Provide strength to skeletal system

Positive Feedback Mechanisms Low blood calcium level leads to… Increased secretion of PTH Further osteoclast activation Increase in bone matrix breakdown Calcium transported to bloodstream Blood-calcium level increase Ultimately achieving normal BCL

Negative feedback (antagonistic) High blood calcium leads to… Increased secretions in calcitonin

(antagonistic hormone) Reduced or inhibits osteoclast

activity Decrease in bone matrix breakdown Ultimately achieving normal BCL

Trouble

Hyperparathyroidism- a disease in which the parathyroid gland secretes too much PTH.

Blood calcium levels soar Life threatening Can kill in an average of 20 years

Hyperparathyroidism

Symptoms Constipation Lethargy Muscle weakness Muscle spasms Osteoporosis Coma Death

Hypoparathyroidism

A rare condition in which body secretes low levels of PTH

Low production of PTH ultimately leads to low ionized levels of calcium in blood

Also causes increased levels of phosphorous

Lethal if not treated

Symptoms

Hypocalcemia Increased neuromuscular irritability Muscles spasms Convulsions Seizures Tingling sensations Painful menstruation death

Treatments

Hyperparathyroidism is very curable if dealt with correctly

Surgeries are available Cure rates are usually in the 90-

100% range Hypoparathyroidism is not curable

by surgery Pills and other supplements are

available Patients must take these

supplements often times throughout their life

Sources

Anthony’s Textbook of Anatomy & Physiology

http://www.parathyroid.com/parathyroid.htm

http://www.mayoclinic.org/diseases-conditions/hypoparathyroidism/basics/definition/con-20030780

http://www.medicinenet.com/hyperparathyroidism/article.htm