Circulatory System, Respiratory System and Immunity Flashcards
What can be found in tyre of the lungs? (from top to bottom)
- The trachea
- The right and left bronchus
- The bronchioles
- Alveoli
- Intercostal muscles
- Ribs
- Diaphram
What happens when you inhale?
- External muscles contract
- Ribs move up
- Diaphragm muscles contracts
- Diagram lowers
- Volume of the chest increases
- Pressure in the chest decreases
- Air pressure in the lungs is lower than atmospheric pressure
- Air rushes into to the lungs
What happens when you exhale?
- External muscles relax
- Ribs move down
- Diaphragm muscles relax
- Diagram raised
- Volume of the chest decreases
- Pressure in the chest increases
- Air pressure in the lungs is higher than atmospheric pressure
- Air rushes out of the lungs
How are alveoli adapted for gas exchange via diffusion between air in the lungs and blood in the capillaries?
- Large surface area
- Moist surface to allow oxygen to dissolve
- A thin lining to allow fast diffusion of gases
- Lots of blood capillaries surrounding them
Give 3 examples of chemicals in cigarettes:
- Carbon monoxide
- Tar
- Nicotine
What does carbon monoxide do to you?
It combines with haemoglobin in red blood cells, which reduces the capacity to carry oxygen - forms carboxyhemoglobin - eventually suffocating you to death
What does tar do to you?
It is a carcinogen (chemical that can cause cancer), forms a sticky layer in the lungs - coats the bronchi, bronchioles, trachea and alveoli - smokers cough - difficulty with gas exchange
What is nicotine?
It is a stimulant. It causes the release of more of the neurotransmitter dopamine at the synapses of nerves in the reward centre of the brain. It is not particularly harmful itself but increases exposure to cigarette smoke
Give 3 side effects of nicotine:
- Increases heart rate
- Increases blood pressure
- Decreases appetite
Give 3 consequences of smoking:
- Cancer
- Emphysema
- Bronchitis
How does smoking cause cancer?
Cancer carcinogenic chemicals cause the DNA in cells to mutate, and thus divide uncontrollably
How does smoking cause Emphysema?
- Destruction of alveoli for gas exchange causes the surface area of the lungs to hugely decrease
- Patient feels short of breath
- Chemicals in cigarettes also break down elastic proteins structures in the lungs, reducing their elasticity and so causes the bronchioles and alveoli to collapse
How does smoking cause Bronchitis?
- The cilia lining the trachea are paralysed by hot smoke and the chemicals in it
- This irritates the passages to the lungs
- Passages become inflamed and narrow
- Production of Mucas by the goblet cells in the trachea increases, but the mucus cannot be removed so infections occur (bacteria becomes trapped in the trachea)
- Lack of cilia and increased mucus causes cough reflex, referred to as smokers’ cough
Why are smokers more susceptible to lung infections such as bronchitis and emphysema then a non smoker?
- The cells lining the trachea and bronchi produce a sticky mucus which traps dirt particles and bacteria
- Fine hairs called cilia move the mucus up and out of the lungs, the heat and chemicals from the cigarette smoke paralyses the cilia (they cannot be killed, they are hair like extensions on cells!)
- Smokers are more likely to get lung infections such as bronchitis (sufferers get a chesty cough) and emphysema (sufferers become breathless because the walls between their alveoli break down so there is a smaller area for gas exchange).
What happens when you smoke during a pregnancy?
- If a woman smokes during pregnancy, they is a lack of oxygen given to the baby
- This affects the baby’s growth and development so it is likely to be underdeveloped
- It is also more likely to be mentally unwell
Describe the effect of exercise on your body and your breathing:
- During exercise, there is an increase in physical activity and muscle cells respire more than they do when the body is at rest
- The heart rate increases during exercise. The rate and depth of breathing increases - this makes sure that more oxygen is absorbed into the blood, and more carbon dioxide is removed from it
How can the rate of breathing be measured?
- The rate of breathing can be measured by counting the number of breaths in one minute
- The depth of breathing can be measured using a spirometer (a device that measures the volume of air inhaled and exhaled)