L16: Sex-based Physiological Differences

Question 1

Why were females often excluded from studies in exercise science?

Answer 1

Because of ignorance on physiological differences and the complexity associated with hormone fluctuations

Question 2

What are chromosomes and why is the 23rd pair of chromosomes important?

Answer 2

Chromosomes are bundles of DNA holding the code required to make every protein in the human body.

The 23rd pair of chromosomes determine a person’s sex (male, female, or intersex)

Question 3

What proportion of the population is intersex?

Answer 3

3%

Question 4

Besides sex, what is the 23rd pair of chromosomes responsible for?

Answer 4

Hormone and organ development

Question 5

What are the sex hormones in males and females, and what hormones do they produce?

Answer 5

Males: testes (testosterone)
Females: ova (estrogen)

Both males and females produce testosterone and estrogen. The only difference is the production site and interaction with the body

Question 6

What are 3 characteristics of the male heart that differ from the female heart?

Answer 6

1. Larger
2. Thicker walls
3. Higher resting stroke volume

Question 7

Why do females tend to have a higher resting heart rate?

Answer 7

Female hearts tend to be smaller and weaker than male hearts, so they have to work harder to pump blood throughout the body

Question 8

What are 3 characteristics of the male vascualr system that differ from the female vascular system?

Answer 8

1. Larger lipid core
2. Greater plaque development
3. Higher risk of CVD

Question 9

How does atherosclerosis differ between males and females?

Answer 9

In females, atherosclerosis tends to form smaller plauques. However, since females tend to have smaller blood vessels, these plaques are still a health risk

Question 10

At what ages does CVD significantly increase for males and females respectively?

Answer 10

Males: 50
Females: 60

Question 11

What are 2 characteristics of the male vascular system that differ from the female vascular system?

Answer 11

1. Larger airways (trachea, bronchi, lungs, etc)
2. More alveoli (more space for gas exchange)

Question 12

What is the difference between a pyramidal and prismatic ribcage?

Answer 12

Males have a pyramidal ribcage that is wider and forms more of a pyramid shape

Females have a prismatic ribcage that is narrower and forms more of a barrel shape

Question 13

On average, how much larger is the male brain than the female brain (evan after adjusting for height)?

Answer 13

10 - 15%

Question 14

In what 3 parts of the brain do males tend to have more grey matter than females?

Answer 14

1. Hippocampus
2. Amygdala
3. Motor areas

Question 15

In what part of the brain do females tend to have more grey matter than males?

Answer 15

Mostly in the pre-frontal cortex.

They also tend to have mroe complex white matter connections

Question 16

What proportion of testosterone do females produce compared to males?

Answer 16

7 - 10% of testosterone as males

Question 17

How does body composition differ between males and females?

Answer 17

Males: more muscle mass and visceral fat (but lower body fat percentage)

Females: More adipose tissue and subcutaneous fat

Question 18

How does fat distribution differ between males and females?

Answer 18

Males: stored in the upper body (apple shape)

Females: Stored in the lower body (pear shape)

Question 19

During pregnancy, how does the females body alter energy use?

Answer 19

Fat oxidation increases to spare bloodd glucose for the foetal brain

Question 20

How does energy use differ between males and female during exercise?

Answer 20

Males: tend to prefer carbohydrates
Females: tend to prefer fats

Question 21

If males are more predisposed to Type 2 diabetes than females, why do females have a higher rate of obesity?

Answer 21

Males are more likely to have insulin insensetivity but females are more likely to store fat

Question 22

What happens to insulin sensetivity with age?

Answer 22

It increases, espically after puberty

Question 23

Why does a decline in estrogen production cause an imbalance in osteoclasts and osteoblasts?

Answer 23

Estrogen promotes osteoblast apoptosis (cell death)