Mass Transport in Animals

Flashcards about Mass Transport in Animals

What is the function of valves in the heart?

Prevent blood from flowing backwards, ensuring unidirectional flow.

What are atrioventricular valves?

Bicuspid and tricuspid valves that are located between the atria and ventricles.

How does the heart contract?

Every time the heart beats, the chambers contract.

What are the risk factors for a heart attack?

Smoking and high blood pressure.

What happens during the diastole phase of the cardiac cycle?

Atria and ventricles are relaxed, and valves are closed.

What is atrial systole?

Atria contract, decreasing volume and increasing pressure, pushing blood into the ventricles.

What happens during ventricular systole?

Ventricles contract, decreasing volume and increasing pressure, causing semilunar valves to open.

Define cardiac output.

Volume of blood pumped by a ventricle in one minute.

How is cardiac output calculated?

Heart rate multiplied by stroke volume.

What does an electrocardiogram (ECG) do?

Attaches electrodes to the chest to measure electrical activity of the heart, plotting activity against time.

What are the characteristics of arteries?

Thick muscle layer that contracts and relaxes to control blood flow, and a thick elastic layer that stretches and recoils to maintain high BP.

What are the characteristics of arterioles?

Thicker muscle layer to reduce blood flow into capillaries and a thinner elastic layer to maintain high pressure.

What are the characteristics of veins?

Thin muscle layer because blood flow doesn't need to be controlled, thin elastic layer because low BP is needed, and valves.

What are the characteristics of capillaries?

Lining layer is thin for short diffusion distance, lumen is narrow, and numerous and highly branched for a large surface area for exchange.

What is tissue fluid?

Liquid surrounding cells containing water, glucose, and ions, controlling the exchange of substances between blood and cells.

How is tissue fluid formed?

Forces water and small substances out of the capillary, forming tissue fluid, which is then returned to the blood via osmosis.

What is haemoglobin?

A protein that transports oxygen around the body.

What type of blood cells contain hemoglobin?

Red blood cells.

How many molecules of oxygen can each iron ion bind to?

Each iron ion is able to bind to one molecule of O₂ .

What is oxyhaemoglobin?

When iron binds with O2.

What does positive cooperativity enable?

Rapid O2 association and dissociation.

Why is the partial pressure high in alveoli?

Due to a high concentration in alveoli and a low concentration in RBC.

What does a small change in partial pressure result in?

Small change in partial pressure = large change in % saturation.

Explain the shift of the curve in the Bohr effect based on concentration of CO2

When CO₂ concentration is high, changes to the right. When CO₂ concerntration is low it chagnes to the left.

What can changing acidity (pH) change?

The shape of the haemoglobin molecule.

How does CO2 influence the acidity of blood?

More CO2 = more acidic; low CO2 = less acidic.

What is Haemoglobin Affinity?

How readily haemoglobin associates with oxygen.