List two structures of the ventilatory system.

Describe the function of the conducting airways in maintaining a healthy state.

Explain the variability in VO₂max in the following groups: trained and untrained.

Explain the variability in VO₂max in the following groups: young and old.

Explain the variability in VO₂max in the following groups: male and female.

Describe the source and role of insulin and glucagon in the body.

With reference to specific hormones, discuss the relationship between the hypothalamus and the pituitary gland.

nose ✔

mouth ✔

pharynx ✔

larynx ✔

trachea ✔

bronchi ✔

bronchioles ✔

lungs ✔

alveoli ✔

they enable the easy flow of gases easily / provide a low resistance pathway for air flow and gas exchange ✔

as the air comes into the body it is warmed by the surrounding tissues ✔

the incoming air is moistened by the cells that line the conducting airways as they excrete mucus in order to trap particles / pathogens / excrete mucus to improve gas exchange ✔

the cells lining the conducting airways have special macrophage cells for defence against foreign bodies ✔

the cells lining the air ways have cilia for removal of any foreign bodies
OR
hairs in the nasal cavity filter particles from the air ✔

Award [1 max] for list.

<endurance> training can improve VO₂max ✔

<endurance> training causes physiological adaptations such as increased cardiac output✔

gains in VO₂max will be greater the less trained you are ✔

Award [2 max] for each part.

in general VO₂max increases with maturation <due to an active healthy lifestyle> ✔

VO₂max begins to decline after maturation ✔

the rate of decline in VO₂max is determined by an active healthy lifestyle ✔

Award [2 max] for each part.

relative VO₂max is lower in females compared to males <even in highly trained athletes>✔
due to:

females have a larger % fat in body mass
OR
females have a lower hemoglobin concentration (10–14 % more in males)
OR
females generally have smaller heart / lungs / blood volume ✔

Award [2 max] for each part.

Accept in the converse.

insulin:
made by the pancreas / beta cells ✔

is released into the blood stream to affect many cells ✔

is released when blood glucose levels are high ✔

allows cells (muscle, liver, fat) to take up glucose / glycogenesis / lipogenesis✔

glucagon:
produced by the pancreas / alpha cells ✔

released into the blood stream ✔

is released when blood glucose levels are too low ✔

promotes glycogenolysis / gluconeogenesis / lipolysis ✔

Award [3 max] for each.

the hypothalamus and pituitary gland work together to maintain homeostasis of the body ✔

hypothalamus controls the pituitary gland
OR
hypothalamus sends releasing hormones to the pituitary gland to stimulate the release of the specific hormone ✔

e.g. GHRH and GH ✔

hormones for the <posterior> pituitary are sent down from the hypothalamus for release ✔

e.g. ADH is sent directly from the hypothalamus to the pituitary <for release> ✔

the release is controlled via negative feedback ✔

Generally answered articulately and accurately.

Most candidates have an accurate understanding of the functions of the conducting airways, but their knowledge is superficial. Very few candidates were able to describe them.

Most candidates were able to outline the difference in VO₂max between trained and untrained individuals but were unable to explain why.

Most candidates were unable to specifically explain the variability with age. Many candidates understood that VO₂max can decline with age but were unable to make reference to the changes in VO₂max from child to maturation and therefore were unable to access any marks. Very few candidates could explain the variability accurately.

Out of the three questions, this was answered the best with many candidates able to outline the main variability between the sexes and provide a suitable explanation.

Answered well with many candidates scoring four marks or above. Candidates were generally able to identify where the hormones were produced and the reasons for their release. Fewer candidates were able to identify where the hormones were released and the effect of their release.

Many candidates were able to outline the control of the pituitary gland by the hypothalamus and provide an appropriate reference to the release of a hormone; however few candidates achieved more than two marks.