Heart And Lungs Questions Flashcards
Breathing out as hard as you can is called forced expiration.
Describe and explain the mechanism that causes forced expiration. (4)
- internal intercostal muscles contract and diaphragm muscles relax
- volume of thorax decreases and pressure of thorax increases
- air is forced out of lungs and pushed out down pressure gradient
People in group B were recovering from an asthma attack.
Explain how an asthma attack caused the drop in the mean FEV (volume of air a person can breathe out in one second) showed. (4)
- muscles around the walls of bronchioles contract
- lining overproduces sticky mucus
- diameter of airways reduced
- flow of air down bronchioles reduced
Scientists investigated the effects of ageing and long-term cigarette smoking on FEV1 and on the development of emphysema.
Scientists determined the mean FEV1 value of 25-year-olds in the population.
Suggest 2 precautions that should have been taken to ensure that this mean FEV1 value was reliable. (2)
- people are healthy
- large sample size
Explain the importance of determining a mean FEV1 value of 25-year-olds in this investigation. (2)
- for comparison
-takes into account outliers
The mean FEV value of non-smokers decreases after the age of 30.
Use your knowledge of ventilation to suggest why. (1)
- intercostal muscles are less effective
One of the sever disabilities of emphysema is that walking upstairs becomes difficult.
Explain how a low FEV1 value could cause this disability. (3)
-less CO2 removed
-less O2 uptake
-less aerobic respiration/ ATP
Describe the pathway taken by an oxygen molecule from an alveolus to the blood. (2)
-across epithelial cells of alveolus
- across the endothelial cells of capillary wall
Explain how one feature of an alveolus allows efficient gas exchange to occur. (2)
- epithelial cells of alveolus are one cell thick
- short diffusion distance
Describe and explain the mechanism that causes lungs to fill with air. (3)
- diaphragm muscle contracts and external intercostal muscles contract
-cause volume increases and pressure decrease in thorax
-air enters as it moves down pressure gradient
Scientists used a DNA staining solution and not iodine solution to stain lung tissue.
Suggest why. (2)
- no starch in lung tissue
- make nucleus visible as it contains DNA
Scientists investigates the link between lung disease asthma and three risk factors. They studied a large number of people. They recorded if the people has asthma and if they
-were obese
-burned wood indoors as fool
-lived in a house with a cat or dog
The scientists used a statistical test to calculate the probability of the link between asthma and each risk factors being due to chance.
Obese : (smaller than) 0.001
Burned wood indoors : =0.06
Lived with a cat or dog : (smaller than) 0.05
A student who looked at these results concluded that all three risk factors are linked with asthma. Evaluate this conclusion. (3)
IN SUPPORT:
-risk with asthma and living with dog/cat is statistically significant
-link with obesity is highly significant
NOT SUPPORTED:
-risk with asthma and burned wood indoors isn’t statistically significant/ due to chance
Describe and explain one feature of the alveolar epithelium that makes the epithelium well adapted as a surface for gas exchange. (2)
- permeable
- allows diffusion of o2 and co2
Tidal volume si the volume of air inhaled and exhaled during a single breath when a person is resting. The tidal volume in a person with emphysema is reduced compared with tidal volume in a healthy person.
Suggest and explain how a reduced tidal volume affects the gas exchange of co2 between the blood and alveolus. (3)
-less CO2 exhaled out of lungs
-so reduced diffusion gradient between blood and alveoli
-less movement of CO2 out of blood
A student is dissecting a sheep’s heart. He prepared a risk assessment on:
-carrying a scalpel
-using a scalpel
Complete Table 3 by giving 3 control measures the student must use to reduce the risk associated with carrying and using a scalpel. (2)
Source: sharp knife
Hazard:
Control measures to reduce risk:
Source: sharp knife
Hazard: danger
Control measures to reduce risk:
- Cut heart in direction away from him
- Cut onto a hard surface
- Use sharp blade
FIGURE 6= (16-18.6 ) is pre-high blood pressure, ( 18.6-22) high blood pressure
16bp and above steadily increases risk of cardiovascular disease
FIGURE 7= treatment 1: mean blood pressure after treatment went down by 1.7, treatment 2: went down by 4
Scientists investigated the correlation between patients bp and risk if developing cardiovascular disease, they put them into groups, shown in figure 6.
In a separate investigation a doctor measured the effect of bp medicines (treatment 1 and 2) on treating a large no of patients with a mean by of 22.
Using the info in figure 6 and 7 evaluate the effect of these treatments on reducing risk of developing cardiovascular disease in patients with a mean by of 22 kph. (4)
- treatment 2 is more effective than 1 as 1 reduces by by 1.7 but 2 reduces it by 4
- 1 doesn’t bring persons bp out of high category so still at high risk
- 2 bring person down to pre-high bp so still at a higher risk than normal
- neither treatment achieves a low risk bp
- no statistics test so dont know if changes in by are due to chance
Describe how humans breathe in and out. (5)
IN:
- diaphragm muscle contracts and diaphragm flattens
- external intercostal muscles contracts and ribcage is pulled up and out
- volume increases and pressure decreases in thorax
OUT:
- diaphragm muscle relaxes and diaphragm moves up
- external intercostal muscles relax and ribcage moves down and in
- volume decreases and pressure increases in thorax
This question is about the flow of blood through the heart.
Give the order of the structures through which blood will pass as it enters the heart and flow through the left ventricle, numbering 1-6. (2)
- Pulmonary vein
- Left atrium
- Left atrioventricular valve
- Left ventricle
- Left semi-lunar valve
- Aorta
Name the type of blood vessel that controls blood flow to muscles and explain how these blood vessels change blood flow during exercise. (3)
-artériole
-muscle relaxes
-vasodilation increases blood flow
Describe how oxygen in the air reaches capillaries surrounding alveoli in the lungs.
Details of breathing aren’t required . (4)
- down trachea, bronchi and bronchioles
- down pressure gradient
- down diffusion gradient
- across alveolar epithelium
- across capillary endothelium
Describe the gross structure of the human gas exchange system and how we breath in and out. (6)
(Describe and explain trachea, bronchi, bronchioles and alveoli)
INSPIRATION:
- external intercostal muscles contracts and diaphragm muscle contracts
- increases volume and lowers pressure of thorax
EXPIRATION:
- internal intercostal muscles contracts and diaphragm muscle relax
- decreases volume and increase pressure in thorax
