Table of Contents
- 1 Why is bone mass lost in space HBS?
- 2 What bone cells liquefy bone matrix?
- 3 How do astronauts deal with bone loss in space?
- 4 What causes bone loss in astronauts?
- 5 When blood calcium levels drop below homeostatic levels is released calcium released from bones?
- 6 When ca2+ levels drop receptors increase the production of?
- 7 What to do about muscle atrophy in space?
- 8 What happens to your body when you go to space?
Why is bone mass lost in space HBS?
Bone mass is “lost in space” refers to the loss of bone material of astronauts in space. In the weightless environment of the space, the bones don’t have to support the body against the gravity. So without using their bones, the bones of the astronauts in space weaken, they are “lost in space”.
What bone cells liquefy bone matrix?
skeletal
| Question | Answer |
|---|---|
| bones cells that liquefy (break down) bone matrix and release calcium to the blood(bone destroying cells located in the bone) | osteoclasts |
| hollow tube of compact bone | diaphysis |
| the hollow area inside the diaphysis of a bone that contains yellow bone marrow | medullary cavity |
| ends of the bone | epiphysis |
When blood calcium levels drop below homeostatic levels what is released?
When blood calcium is low, the parathyroid gland secretes parathyroid hormone. This hormone causes effector organs (the kidneys and bones) to respond. The kidneys prevent calcium from being excreted in the urine.
Where do large tubercles occur?
The head articulates with the glenoid cavity of the scapula to form the glenohumeral (shoulder) joint. The margin of the smooth area of the head is the anatomical neck of the humerus. Located on the lateral side of the proximal humerus is an expanded bony area called the greater tubercle.
How do astronauts deal with bone loss in space?
Bone loss and kidney stones are well-known as essential problems for astronauts to overcome during extended stays in space. Crew members engage in physical exercise for 2.5 hours a day, six times a week (15 hours a week) while in orbit to avoid these issues.
What causes bone loss in astronauts?
On Earth, you experience a constant gravitational pull towards the centre of the planet. But when astronauts travel into outer space, they experience a condition called weightlessness or microgravity. This is what causes bone loss.
What builds bone matrix?
Osteoblasts synthesize the bone matrix and are responsible for its mineralization. They are derived from osteoprogenitor cells, a mesenchymal stem cell line. Osteocytes are inactive osteoblasts that have become trapped within the bone they have formed. Osteoclasts break down bone matrix through phagocytosis.
Which of the following stimulates osteoclast activity?
Parathyroid hormone stimulates osteoclast activity, meaning the answer is d).
When blood calcium levels drop below homeostatic levels is released calcium released from bones?
The parathyroid glands produce and secrete PTH, a peptide hormone, in response to low blood calcium levels (Figure 2). PTH secretion causes the release of calcium from the bones by stimulating osteoclasts, which secrete enzymes that degrade bone and release calcium into the interstitial fluid.
When ca2+ levels drop receptors increase the production of?
When blood calcium levels drop below a certain point, the calcium-sensing receptors in the parathyroid gland are activated, and the parathyroid glands release parathyroid hormone (PTH) into the blood.
Where is the tubercle?
On a rib, tubercle is an eminence on the back surface, at the junction between the neck and the body of the rib. It consists of an articular and a non-articular area.
What happens to an astronaut’s body if they don’t exercise?
If astronauts don’t exercise, their bodies start losing bone and muscle. Bone and muscle loss mean decreased size and strength, and can reduce an astronaut’s ability to do work because it makes them weak.
What to do about muscle atrophy in space?
The only way to minimize muscle atrophy in space is through intensive exercise, particularly strength training exercises, combined with an adequate diet. Astronauts on the International Space Station spend 2 1/2 hours per day exercising to combat the effects of muscle atrophy.
What happens to your body when you go to space?
Spacefarers typically experience bone loss in the lower halves of their bodies, particularly in the lumbar vertebrae and the leg bones. Diminishing bone mass also triggers a rise in calcium levels in the blood, which increases the risk of kidney stones.
How often do astronauts exercise on International Space Station?
Astronauts on the International Space Station spend 2 1/2 hours per day exercising to combat the effects of muscle atrophy.