Chapter 6 Flashcards
Why is the volume of oxygen that has to be absorbed and the volume of carbon dioxide that has to be removed large?
They are large organisms with a lot of respiring cells
They have high metabolic rates so require a lot of respiration
What do lungs do?
Ensure efficient gas exchange occurs
Why are lungs located in the body?
Because air isnt dense enough to support and protect the delicate structures
The body would loose a great deal of water and dry out
What are the lungs protected by?
Ribcage
What are the lungs made up of?
A series of highly branched tubules - bronchioles - ending in tiny sacs called alveoli
What is the structure and function of the trachea?
A flexible airway supported by rings of cartilage which prevents it from collapsing when the air pressure decreases when breathing in
The walls are made of muscles and lined with ciliated epithelial cells
What is the structure and function of the bronchi?
2 division of the trachea with each division leading to 1 lung
They produce mucus to trap dirt particles and cilia move it towards the throat
What is the structure and function of the bronchioles?
Are a series of branching subdivisions of the bronchi.
The walls ate made up of muscle and lined with epithelial cells which allows then to constrict so that they can control the flow of air in and out of the alveoli
What is the structure and function of the alveoli?
Small air sacs at the end of the bronchioles. Between the alveoli there are some collagen and elastic fibres what allow the alveoli to stretch as they fill with air and string back to expel carbon dioxide rich air
What is the approximate size of the alveoli ?
100 micrometres to 300 micrometres in diameter
What is the gas exchange surface in the lungs?
The alveolar membrane
What is ventilation?
The idea of moving air in and out of the lungs to maintain a steep concentration gradient
Which intercostal muscles contract and which relaxed in inspiration?
External intercostal muscles contract
Internal intercostal muscles relax
Which intercostal muscles contract and which relaxed in expiration?
Internal Intercostal muscles contract
External intercostal muscles relax
Which 3 muscles are needed for pressure changes in the lungs?
Diaphragm
Internal intercostal muscles
External intercostal muscles
Is inspiration active process or a passive process?
Active
Is expiration active process or a passive process?
Passive
Explain the process of inspiration
External intercostal muscles contract and internal intercostal muscles relax
The ribs are pulled upwards and outwards
The diaphragm muscles contract and it flattens
These increase the volume so the pressure of the lungs decreases
The atmospheric pressure is now greater than the lung pressure so air is forced into the lungs
Explain the process of expiration
The internal intercostal muscles contract and the external intercostal muscles relax
The ribs move downwards and inwards
The diaphragm relaxes so it is pushed upwards by the contents of the abdomen that had been compressed earlier
The decreased volume of the thorax increases the pressure in the lungs so the atmospheric pressure is less so air is forced out of the lungs
What is pulmonary ventilation rate?
How much air is taken in and out of the lungs in a given time
What is the calculation to work out pulmonary ventilation rate?
Pulmonary ventilation rate = tidal volume x breathing rate
What is the unit of pulmonary ventilation rate?
Dm3min-1
Is diffusion of gases between alveoli and blood slow or fast?
Very fast
What 2 things happen to red blood cells that pass through capillaries? What affect does this have on the diffusion of the gases?
They are slowed because it is so narrow and the diffusion distance decreases because they are flattened against the side of the capillary. Increased diffusion because diffusion time has increased and also diffusion distance decreased.
The walls of the alveoli and capillaries are _______. What affect does this have on the rate of diffusion of gases?
One cell thick. The distance over which diffusion is very short which means the rate is increased.
Alveoli and pulmonary capillaries have a very _____ _____ _____. What affect does this have on the rate of diffusion of gases and why?
Large surface area. Increased rate because the area over which diffusion can take place is increased so more gas can diffuse out or in in a given time.
What is the purpose of breathing movement? What affect does this have on the rate of diffusion of gases and why?
It constantly ventilates the lungs. Increases rate of diffusion because creates a steep concentration gradient of gases to be maintained
What affect does the heart pumping have on rate of diffusion and why?
Constantly circulates blood throughout the body. Increases rate of diffusion because creates a steep concentration gradient of gases to be maintained
List as many factors of the rate of diffusion of gases in the body as possible
- Alveoli and capillary walls are only 1 cell thick
- Blood and air are constantly circulated around the body.
- There are loads of alveoli with a large overall surface area for diffusion
- Rich blood supply to alveoli
- Red blood cells are pushed against capillary walls which increases diffusion time and decreases diffusion distance
How do you calculate the area of a triangle?
1/2 bxh
How do you calculate the area of a circle?
Pi x radius squared
How do you calculate the area of a parallelogram?
B x h (height not length)
How do you calculate the area of of a trapezoid?
H(a+b)
2
How do you calculate the area of a rhombus?
B x h
How do you calculate the volume of a sphere?
4 x pi x radius to the power of 3
How do you calculate the surface area of a sphere?
4 x pi x radius squared
How do you calculate the volume of a cone?
1/3 x pi x radius squared x height
What substances can be taken in from the environment?
Water Oxygen Glucose Carbon dioxide Proteins Carbohydrates Lipids
What substances can be given out to the environment?
Water
Carbon dioxide
Urea
Oxygen
Define metabolite
A substance formed in or necessary for metabolic reactions
Energy cannot be —— or —- only —-
Created
Destroyed
Transferred
which has a larger surface area to volume ratio?
A mouse or an elephant?
A mouse
Is heat lost more easily from a mouse or an elephant? Why?
A mouse because it has a bigger SA:V
What makes a good exchange area?
A large SA
thin
Selectively permeable
Has a steep concentration gradient
How can a steep concentration gradient be maintained?
With: A rich blood supply Indirect active transport Digestion Movement of environmental medium Internal transport system eg blood
Why do big multicellular organisms such as a mouse need a transport system?
To allow substances to come into contact with all cells in the organism, as they are too larger to rely on diffusion alone
Explain the surface area to volume ratio of single celled organism
Large SA:V
How is gas exchanged in single celled organisms?
Oxygen is absorbed via diffusion
Carbon dioxide diffuses out of the body
What is the internal networks of tubes called?
Tracheae
What does the tracheae divide into?
What are these?
Tracheoles
Small deadens tubes that extend throughout the body
How is oxygen brought into the body of insects?
Via spiracles
What are the 3 ways that gases move in and out of the tracheal system in insects?
Down a concentration gradient
Mass transport
The ends of the tracheoles are filled with water
