Bone and muscle deterioration
Without gravity effects
Skeletal muscle not required to maintain posture
Muscle groups differs moving in weightless environment than in terrestrial
No weight on back or leg muscle
Weakens over time and gets smaller
With no regular exercise
Astronauts loses 20% of their muscle mass in 5-11 days
Muscle fibres also changes
Slow-twitch endurance fibres that maintain posture are replaced by fast-twitch rapidly contracting fibres(insufficient for any heavy labour)
Bone metabolism also changes
In microgravity there is very little mechanical stress
Results in loss of bones tissue
1.5% per month
Hip
Femur
From lower vertebrae
Decreases load on bones
Makes bones frail
Resulting in symptoms resembling osteoporosis
Increases osteoclast activity due to microgravity
Osteoclast: breaks bones into minerals that are absorbed by body
Osteoblast are not consecutively active so causes bones to demenished without recovery
Particularly seen in pelvic region
As this region Carrie's biggest lead with gravity present