Mass Transport + Gas Exchange In Humans Flashcards
Explain how the highest blood pressure produced in the left ventricle
Stronger contractions as it has thicker muscular wall
Explain the role of the heart in the formation of tissue fluid
Ventricles contract forming high hydrostatic pressure
Which forces water out of the capillaries
Describe and explain adaptation of alevolar epithelium
• 1-cell thick, which reduces the diffusion distance , so a increases the rate of diffusion
Explain how the constant flow of blood aids gas exchange in the lungs
• maintaining the concentration gradient
• By replacing oxygenated blood with deoxygenated blood
Explain and describe how the elastic tissue in the wall helps to even out the pressure of blood flowing
through the artery or during exhalation
stretches as a result of high pressure/surge of blood;
then recoils
Which helps to push air out
Apart from lung cancer and other cancers, name 2 other diseases whose risk factors are increased by smoking
•Heart disease
•Diabetes
Describe and explain 2 adaptations of alveoli that enable rapid gas exchange
• Large number of alveoli- so that there is an increase in surface area
• Alveolar epithelium is only one cell thick- so there is a reduces diffusion distance, increasing the rate of diffusion
• A large network of capillaries- so that there is a short diffusion distance
Describe the pathway taken by a CO2 molecule from the blood to outside the air
•Across the endothelial wall of the capillary
• across the alveolar epithelium into the alveolar space
• It then travels up the bronchioles and up the bronchi
• Into the trachea and out the mouth/nose
An oxygen concentration gradient is maintained between the alveoli and the lung capillaries. Describe and explain how this is maintained
• Ventilation brings in air with a high Oxygen concentration
• Circulation removes blood with a high oxygen concentration
Explain how the volume of the thorax increases
• external intercostal muscles contract
• diaphragm contracts, moving the rib cage up
How are red blood cells adapted to carry oxygen?
- concave shape gives a big surface area for absorbing oxygen. it also helps them pass smoothly through capillaries to reach body cells
- packed with haemoglobin which absorbs oxygen
- they have no nucleus to leave even more room for haemoglobin
Explain how the stain allows you to distinguish between white and red blood cells
White blood cells have a nucleus that stains whereas red blood cells do not
Suggest how a blockage in the lymphatic system could cause lymphoedema
Excess tissue builds up
Explain how cardiac output could stay the same even when their resting heart rate had decreases
Cardiac output= stroke volume x heart rate
Stroke volume increases
Units dm3min-1
Effect of flow of blood between aorta and pulmonary artery could cause death
Less oxygenated blood flows through aorta
Less oxygen delivered to cells
Not enough oxygen for aerobic respiration
Tissue doesn’t grow properly
Explain four ways in which the structure of the aorta is related to its function
Elastic tissue stretches when ventricles contract to prevent pressure rising to high when blood flows past
Recoils to maintain pressure
Has Muscle for contraction
Thick wall to withstand pressure
Smooth endothelium reduces friction
Aortic valve prevents back flow of blood