B5d: Respiratory systems Flashcards
Why are amphibians and fish restricted to their habitats(3)
because of their methods of gaseous exchange
- amphibians does not have waterproof skin, so it would lose too much water if it lived in a dry habitat, so they are confined to moist habitats
- fish gills work by forcing water across filaments, and the gill filaments would stick together if they weren’t in water and the fish would suffocate, so they can only live in water
How do humans breath in(inspirate)(3)
intercostal muscles and diaphram contracts, ribs move up and out and diaphram moves down, increasing the chest volume
-causes the lung to expand and the pressure within to decrease
higher outside pressure causes air to enter the lungs
How do humans breath out(expirate)(3)
intercostal muscles and diaphram relaxes, ribs move down and inward and diaphram moves up, decreasing the chest volume
-causes the lung to contract and the pressure within to increase
higher pressure within the lungs forces the air out
What is the total lung capacity
total volume of air you can fit in your lungs
What is the tidal air
volume of air you breathe in or out at rest
What is the residual air
the air left in your lungs after you breathe air which cannot be forced out
What is the vital capacity air(2)
the amount of usable air/maximum volume of air that can be breathed in or out
total lung capacity - residual air
Where and how does gaseous exchange occur(2)
occurs within the alveoli(air sacs)
occurs due to diffusion between the air and the blood capillaries around the alveoli since there is a concentration gradient
How are gaseous exchange surfaces (e.g. alveoli) adapted for gas exchange(5)
very large surface area to increase the rate of diffusion
moist surface to help oxygen and carbon dioxide dissolve
permeable surface to help gases exchange easily
thin lining(one cell thick) so gases don’t have to diffuse very far
good blood supply to maintain the concentration gradient
How does the respiratory system protects itself from disease(3)
the trachea and bronchi are lined with mucus(produced by goblet cells) and ciliated cells
- mucus catches dust and microbes before they reach the line
- cilia sweeps microbe-filled mucus away from the lungs as phlegm
Describe some causes of lung diseases and describe the examples(2+2+2)
Industrial causes
-abestos causes a disease called abestosis, which is where inflammation and scarring in the lungs limits gas exchange
Genetic causes
-cystic fibrosis which is inherited, causes the lungs to produce too much mucus in the bronchioles, making breathing difficult
Life style
-smoking causes lung cancer, where cells grow rapidly and divide out of control, forming a tumour and reducing the surface area in the lungs
Why is the respiratory system prone to diseases
the lungs are a dead end, meaning microbes can’t easily be flushed out
What are some symptoms of asthma
difficulty breathing, wheezing, tight chest
How can the symptoms of asthma be relieved
inhaling a drug from an inhaler
Describe what happens during an asthma attack(4)
lining of airways becomes inflamed
fluid builds up in airways
muscles around bronchioles contract constricting airways.
all of these makes it difficult to breathe
