L12: Physiological Development in Youth

Question 1

What is the difference between chronological and biological age?

Answer 1

Chronological age: Age measured in years since birth

Biological age: Age of cells measured using various biomarkers

Question 2

In what part of life is metabolism highest?

Answer 2

At birth before steadily declining

Question 3

In what part of life does metabolism rise slightly before declining again?

Answer 3

During puberty (10 - 16)

Question 4

Why are there 2 growth spurts in most organs?

Answer 4

One during childhood, another during puberty

Question 5

Why does the growth rate of the brain plateau earlier than other organs?

Answer 5

In the first two years of life, the brain is already 50% grown

Question 6

Why do reproductive organs only have 1 growth spurt?

Answer 6

It is of no use during childhood, so it will only develop during puberty

Question 7

Why does the lymphoid grow twice as large as an adult’s before shrinking to a regular size?

Answer 7

During childhood, the lymphoid is larger as it is exposed to more pathogens and quickly building the immune system

Question 8

When do males and females tend to reach their full height, and when is their peak rate of height/weight growth?

Answer 8

Full height:
Males: 18
Female: 16

Peak rate:
Males: 14
Females: 12

Question 9

Besides genetics, what 3 other factors influence the growth of the muscoskeletal system?

Answer 9

1. Physical activity
2. Nutrition (protein and calcium)
3. Sunlight (Vitamin D)

Question 10

How does Vitmain D interact with calcium in the body?

Answer 10

Vitmain D helps the body better absorb calcium

Question 11

When does fat-free mass (lean body tissue) plateau for males and females?

Answer 11

Males: 20
Females: 15

Question 12

What is the average fat percentage for 20 year old males and females?

Answer 12

Males: 15%
Females: 25%

Question 13

What are growth plates in bones?

Answer 13

Growth plates are composed of cartilage which elongate throughout childhood and adolescence. The body eventually replaces this with bone

Question 14

In what 3 ways do bones in children differ from bones in adults?

Answer 14

1. Smaller, more cartilage
2. Less rigidity (tendency for incomplete fractures)
3. More haversian canals for blood vessels

Question 15

By what proportion do the number of alveoli increase from birth to adulthod?

Answer 15

10 fold increase (50 million - 500 million)

Question 16

For what 3 reasons do children tend to have a higher breathing than adults?

Answer 16

1. Smaller lungs
2. Smaller tidal volume
3. Higher breathing frequency

Question 17

For what 4 reasons do children tend to have a higher heart rate than adults?

Answer 17

1. Smaller heart
2. Weaker contractile force
3. Less stroke volume
4. Higher heart rate

Question 18

When does growth rate of the nervous system begin to plateau and decline?

Answer 18

Plateau: 20
Decline: After 60 and 80

Question 19

What is the difference between the amygdala and the cortex?

Answer 19

Amygdala: Responsible for emotions, impulses, and instinctive behaviour
Cortex: Responsible for speech, decision making, and motor skills

Question 20

When does the pre-frontal cortex finish developing?

Answer 20

After puberty at 25

Question 21

Besides the gondal hormones, what 3 other homrones change significantly during puberty?

Answer 21

1. Dopamine
2. Seratonin
3. Melatonin

Question 22

How do the physical activity guidelines differ between adolescents and adults?

Answer 22

Adolescents need to be more active, preferably everyday