lesson 4 - function of respiration

Question 1

What is the respiratory system?

Answer 1

The network of organs and tissues that help you breathe and carry out gas exchange. It includes the airways, lungs, and blood vessels.

Question 2

How does the respiratory system provide oxygen to the body?

Answer 2

During gas exchange, oxygen in the air enters the lungs and travels through the bronchi, bronchioles, and to the alveoli. At the alveoli, the oxygen diffuses through the alveolar cells and the vascular endothelial cells into the blood. At the same time, carbon dioxide diffuses from the blood into the alveoli and is released through exhalation.

Question 3

The two factors needed for respiration

Answer 3

1. Respiratory surface - The area where gases are exchanged with the environment
2. Moisture - Since gases need to be dissolved in water in order to be utilised

Question 4

What is diffusion?

Answer 4

A passive transport mechanism of the movement of molecules from an area of high to low concentration to reach equilibrium

Question 5

What are the factors that affect the rate of diffusion?

Answer 5

1. Diffusion Distance (the smaller the distance between the air in the alveoli and the blood in the capillary, the faster the rate of diffusion)
2. Concentration Difference (difference of molecules between the alveolus and blood entering the lung; larger the concentration difference, the quicker the rate of diffusion)
3. Surface Area (when surface area is decreased, it makes it harder for oxygen to enter; larger surface area = quicker rate of diffusion)

Question 6

What type of respiratory system, environmental/habitat, and specialised structure for respiration do humans have?

Answer 6

Type of respiratory system = Lungs

Environmental/habitat = Terrestrial

Specialised structure for respiration = Internal lungs with a branching structure to increase surface area and prevent water loss

Question 7

What is the countercurrent exchange mechanism?

Answer 7

Blood flows through the gills of aquatic creatures in the opposite direction to the flow of oxygen containing water.

Question 8

Difference between respiration and ventilation?

Answer 8

Respiration is the gas exchange in and out of a cell, while ventilation is the movement of air in and out of an organism (inhale, exhale)

Question 9

What is gas exchange?

Answer 9

Gas exchange is the delivery of oxygen from the lungs to the blood, and the elimination of carbon dioxide from the blood to the lungs

Question 10

An advantage and a disadvantage of aquatic respiratory systems

Answer 10

Advantage: Keeping the surface moist is no issue

Disadvantage: Oxygen concentrations in the water are low, especially in warmer and saltier environments

Question 11

An advantage and a disadvantage of terrestrial respiratory systems

Answer 11

Advantages: Oxygen diffuses faster in air, and air contains much more oxygen as compared to water

Disadvantage: Surfaces must be internal to avoid loss of water due to evaporation

Question 12

What is air pressure controlled by

Answer 12

Diaphragm and rib muscles (intercostal - muscles between ribs)

Question 13

Organs involved in breathing and what they do

Answer 13

1. The diaphragm: a dome-shaped layer of muscle which separates the thoracic cavity from the abdominal cavity
2. Rib (intercostal) muscles: Helps controlling inhalation and exhalation and is found along the inside of the rib cage

Both work together to move air in and out of the lungs

Question 14

Stages of respiration

Answer 14

1. Breathing (inhalation and exhalation)
2. External respiration (gas exchange)
3. Internal respiration
4. Cellular respiration

Question 15

What happens in stage 1 of breathing (inhalation)

Answer 15

1. Inhalation - Drawing in oxygen-rich air from the outside. Intercostal muscles and the diaphragm contract to expand the chest cavity. Diaphragm lowers to decrease the pressure in lungs, and air is drawn in (area of high –> low pressure)

Question 16

What happens in stage 2 of breathing (exhalation)

Answer 16

2. Exhalation - Expelling carbon dioxide-rich air from inside the body to outside. The intercostal muscles and diaphragm relax to contract the chest cavity. The diaphragm rises to increase the air pressure in lungs, and the air is then pushed out

Question 17

What is the medulla oblongata?

Answer 17

The medulla oblongata is the location where the brain and spinal cord connect which makes it a channel for nerve signals to send to and from your body. It helps with processes such as heartbeat, breathing, and blood pressure.