A1 Lungs And Health Studies Flashcards
Where does the air move during inspiration?
Air moves into the lungs down trachea, bronchi, bronchioles and then the alveoli
What happens to the lung volume during inspiration?
Increases- to let air into the lungs
What happens to the pressure in the lungs during inspiration?
The pressure decreases lower than atmospheric pressure
What happens to the external intercostal muscles during inspiration?
They contract to push ribcage up and out
What happens to the diaphragm during inspiration?
It contracts to flatten out
Where does the air move during expiration?
Air moves out of the alveoli, bronchioles, bronchi and trachea and mouth
What happens to the lung volume during expiration?
Decreases- to force air out of the lungs
What happens to the pressure in the lungs during expiration?
The pressure increases greater than atmospheric pressure
What happens to the external intercostal muscles during expiration?
They relax and pull ribcage back down
What happens to the diaphragm during expiration?
It relaxes and returns to domed shape
What happens to the internal intercostal muscles during forced expiration?
They contract
Fick’s Law: Rate of diffusion=
Surface area X Difference in concentration / Diffusion distance
How does oxygen get into the blood?
It moves through the trachea, bronchi, bronchioles and then alveoli, it then diffuses across the alveolar epithelium and capillary endothelium. Finally it diffuses through the red blood cell membrane and then bind with the haemoglobin
How are alveoli adapted?
Short diffusion distance due to its one cell thick wall, large surface area as there are millions of alveoli, good blood supply by the surrounding capillaries so maintains a high concentration gradient
What is breathing a result of?
A difference in pressure between the lungs and the atmospheric pressure this is called a pressure gradient
How does air get to the alveolar air space?
Down a pressure gradient (generated by muscle contraction)
How does oxygen get to haemoglobin?
It diffuses through the alveolar epithelium
What is the definition of tidal volume?
Is the volume of breaths with each normal breathe (the average is between 0.4-0.5 dm^3)
What is ventilation rate?
The number of breaths per minute (the average is 15)
What is FEV?
Forced expiratory volume is the volume of air that can be breathed out in 1 second
What is FVC?
Forced vital capacity is the volume of air that can be breathed out forcefully after a deep breath
What is pulmonary ventillation?
It is the volume of air ventilated by the lungs in a minute
What is the equation for pulmonary ventillation?
Tidal volume x ventilation rate
What is the cause of asthma?
Smoking, air pollution and genetic pre-disposition
What are the symptoms of asthma?
Temporary breathing difficulties, asthma attacks and wheezing
How is gas exchange slowed by asthma?
Tidal volume is reduced which decreases the concentration gradient
What are the risk factors for asthma?
Pollen , dust and genetics
What is the cause of turberculosis?
Bacterial infection
What are the symptoms of turberculosis?
Coughing , fever and chest pain
How gas exchange is slowed by turberculosis?
Scar tissue makes alveoli thicker which increases the diffusion distance
What are the risk factors of turberculosis?
Poor diet , AIDS and HIV
What is the cause of Emphysema?
Smoking and occupation
What are the symptoms of Emphysema?
Difficulty breathing and dry coughing
How gas exchange is slowed by Emphysema?
Reduced elasticity of the lungs prevents exhalation which reduces the concentration gradient
What are the risk factors of Emphysema?
Smoking
What is the cause of lung cancer?
smoking and carinogen exposure
What are the symptoms of lung cancer?
Breathing difficulty and weight loss
How is gas exchange slowed by lung cancer?
Reduced tidal volume due to tumours
What are the risk facors of lung cancer?
Smoking
What is the cause of pulmonary fibrosis?
Occupation and genetic pre dispostion
What are the symptoms of pulmonary fibrosis?
Dry cough and breathing difficulties
How is gas exchange slowed by pulmonary fibrosis?
Scar tissue increases diffusion distance and reduces elasticity
What are the risk factors of pulmonary fibrosis?
Coal and dust
Do small or big organisms have a large surface area?
Small
What increases when surface area to volume ratio increases?
Oxygen uptake increases
What are endotherms?
Organisms that control body temperature internally
What replaces heat loss?
Respiration
