16. Age Flashcards
What are the phases called associated with foetal growth/pubertal growth?
Foetal growth - hyperplasia (cell multiplication)
Pubertal growth - hypertrophy (cell expansion)
What are the 4 phases of growth and development - with years and key point?
Infancy (0-2yrs)
- skeletal growth greatest up to 4months.
Early childhood (3-8yrs)
- fine motor skills 3-5yrs
- body proportions refined 5-8yrs
Middle childhood (9-11yrs) - slow and steady physical development
Adolescence (12-18yrs)
- growth spurts= 2 years fast, 3 years slow
- testosterone and oestrogen influence anabolic effects
When does adolescence happen for girls vs boys?
Girls: 12-18yrs
Boys: 14-20 yrs
What causes a loss of coordination/injury in children?
Bones grow first and muscles/tendons become inflexible.
Longer limbs and lack of muscular structure.
At what age do girls have larger muscles than boys?
12-13yrs
Long bones ____ through ______ at ______ and increase in width through ________
Long bones length through addition of bone tissue at the epiphyseal plate and increase in width through appositional growth.
What age is ossification complete?
18-13 years
Describe appositional bone growth
- Osteoblasts lay down calcium and phosphate crystals around the shaft of the cartilage.
- Osteoclasts remove old bones that line the medullar cavity.
- Osteoblasts produce new bone tissue beneath the periosteum.
- Erosion of old bone along medullar cavity and deposition of new bone beneath the periosteum = increase diameter of the diaphysis/medullar cavity.
Describe longitudinal bone growth
- Cartilage is formed on epiphyseal side [top] of epiphyseal plate (growth plate)
- On diaphysial side [bottom] cartilage is ossified allowing the diaphysis to grow in length.
What does the growth hormone do?
- Elongation of limbs by osteoblasts and closure of epiphyseal plate
- Absorbs amino acids and protein
- Breakdown fat for energy
- Body fat levels decrease/increase among males/females
How does body composition change for teen females? %
Lean body mass falls from 80% to 74%
Body fat increases from 16% to 27%
What is testicular testosterone secretion associated with?
Increases in fat free mass
What are training-indued strength gains related to in children?
Neural mechanisms rather than hyperthropic factors
What happens to amount of red blood cells/haemoglobin concentration in pre and post puberty in males and females? %
RBCs: 47% boys and 42% girls
Haemoglobin: increases for boys, remains stable for women
What substrate do children rely on for exercise?
Fat (rather than glycogen as lower stores)
Why might children fatigue more easily with more likely to overheat during anaerobic work?
Unable to generate low blood pH and high blood lactate values linked to anaerobic work.
At what age do your tendons and ligaments completely fuse with the ephipyseal bone? and what might this increase risk of?
12-20 years
Osgood-Schlatters disease
When does strength peak and stay constant?
30yrs to 50 yrs
What percentage can you expect at age 70
- Decline in strength
- Muscle cross sectional area
30% decline strength
40% decline in muscle area
What is arteriosclerosis and what does this mean/cause?
Arteries lose their elasticity/become thicker.
Blood vessels are less capable of vasodilation causing rise in blood pressure.
What portion of skeleton is cartilaginous in a new-born baby?
What is the mineral content in a young adult?
2/3
2/3
Why does bone become brittle/hollow with age?
Increased proportion of inorganic mineral salts and higher rate of breakdown vs building of bone.
Why do bones become stiffer with age?
Collagen proteins loose their flexibility and bones absorb less energy before fractures.
What is Osteopenia/osteoporosis?
Osteopenia - bone poverty (reduced bone density due to synethsis lower than breakdown)
Osteoporosis - bone density is 50% below average mass of young adults.
What is sacropenia? and when does it begin?
Decline of muscle tissue with age.
40yrs, declines up to 50% by 80yrs.
What are the causes of sarcopenia? (6)
- Environment (reduced activty, protein, energy)
- Horemone (reduced insuline, testostrone)
- Inflamation
- Muscle repair rates
- Mitrocondria (less effective)
Duration of pregnancy in months/weeks/days
9 Months
40 Weeks
280 Days
Benefits of physical activity during and after prenancy
Decrease gestational diabetes
Decrease casearean
Decreased postpartum recovery
Prevention of pre-eclampia
Cardiovascular changes in pregnant women?
Relaxed blood vessels
Cardiac hypertrophy
Increased cardiac output 30% to 50% (week 32)
Heart rate increases 10-15 bpm (week 14-20)
Compression vena cava if lie on back (faint)
Blood volume increase 40%
Blood vessels dilate to reduce blood flow
RBCs increase 20-30%
Respiratory changes in pregnant women?
Metabolic rate increase Minute ventilation increase 50% Heat production/sweat rate increase Detect CO2 from respiration and tidal volume increased Decrease in pulmonary reserve Ribcage ligaments loosen Congested
Hormonal changes in pregnant women?
Progestorone and oestrogen cause depostion of fat
Relaxing of smooth muscles
Weight gain
Relaxation of pelvic ligaments/joints
Glucose levels decrease
Pancreas decrease insulin production (mother become resitant)
Muscoskeletal changes in pregnant women?
Disastasis recti (ab muscles seperate) Forward tilt pelvis Back pain (60% women)
Why are strong ab muscles important pregant women?
Support baby
Protect the back
Support uterus muscles during delivery
What are the 4 muscles of the pelvic floor?
Levator ani
Superficial transverse perinea
Bulbospongiosus
Ischiocavernosus
Where are the origin and insertion of the:
- Levator ani
- Superficial transverse perinea
- Bulbospongiosus
- Ischiocavernosus
- Levator ani
O - pubis and ischium
I - coccyx - Superficial transverse perinea
O - ischium
I - central tendon - Bulbospongiosus
O - central tendon
I - penis and clitoris - Ischiocavernosus
O - ischium
I - public arch
