Bone Physiology - Function of the Bone Flashcards
What is the Axial skeletal consist of ?
- Skull
- Vertebrae
- Thoracic cage
What does the appendicular skeleton consist of?
Upper limbs
Lower limbs
Which type of skeleton protects the
- brain
- heart
- liver
- lungs
Axial skeleton
What is the function of the appendicular skeleton?
Movement
What mineral in the body does the bone store and release ?
Calcium !!
and phosphate
What is calcium important for in the body
- Muscle Contraction
- Nerve Impulse
- Blood clotting
When calcium levels are too high in the blood what happens ?
Calcium gets deposited in the bone by osteoblasts
When calcium levels are too low in the blood what happens ?
Calcium is released from the bone and added to the blood by osteoclasts.
How much of the calcium within the body is depositied within the bone ?
99% in the bone
1% in the blood
What are the three types of bone cells ?
- Osteoclasts
- Osteoblasts
- Osteocytes
Where is alkaline phosphate released from?
Osteoblasts
What is the effect of low ALP on the bones ?
- SOFT BONES EASILY FRACTURES
Where is ankylosis protein released from ?
Osteoblasts
What do pyrophosphates do ?
They inhibit calcium-phosphate formation and growth
What does decreased ankylosing protein lead to?
Ankylosing spondilitis
If you have low calcium levels what is this called ?
What symptoms may you get with this ?
Hypocalcaemia
Muscle spasms
What is it called when calcium levels are too high?
What may happen with this ?
hypercalcaemia
cardiac arrhythmia
What are the three hormones important for calcium homestasis ?
- Calcitonin released from the thyroid gland.
- Parathyroid hormone released from the parathyroid gland
- Vitamin D3
When hypocalemia occurs, what hormone is produced in response to this?
Parathyroid hormone released from the parathyroid gland.
In response to hypocalcemia, PTH is released; where does this hormone act, and what does it do?
- Acts on the bone - Osteclats stimulates to release calcium ions from the bone.
- Kidney - Kidney absorb calcium ions and calcitrol - THEN THIS INCREASES INTESTINAL REABSOPRTION OF CALCIUM !!!!
- Inrestinal response - Increase absorption.
What does calcitrol do during hypocalcemia ?
Calcitrol stimulates intestinal reabsoption of calcium.
What two things are essential for the body to get vitamin D?
- The cholesterol under our skin
- This is then synthesised by the sun to produce vitamin D3.
What hormone is released in response to hypercalcemia ?
CALCITONIN FROM THE THYROID GLAND.
How does calcitonin work in response to hypercalcemia?
Is PTH and calcitonin controlled by positive or negative feedback cycles ?
The release of both hormones (PTH and Calcitonin) is controlled by negative feedback cycles
