3.1 exchange surfaces Flashcards
what is ventilation?
the refreshing of air in the lungs so there is a higher oxygen concentration in the blood, and a lower carbon dioxide concentration
what are intercostal muscles?
the muscles between the ribs, the contraction of the external intercostal muscles raises the ribcage
what are the alveoli?
the folds of the lung epithelium, where gas exchange takes place in the lungs
what are the bronchi and bronchioles?
smaller airways leading to the lungs
what is the diaphragm?
a layer of muscle beneath the lungs
what is the trachea?
the main airway leading from the back of the mouth to the lungs
what are the feature of a good exchange surface?
- large surface area
- thin barrier
- good blood supply
what are the airway requirements?
- LARGE enough for sufficient flow without obstruction
- DIVIDE INTO SMALLER AIRWAYS
- STRONG to prevent collapsing
- FLEXIBLE to allow movement
- be able to STRETCH and RECOIL
What are goblet cells?
cells that secrete mucus
what is smooth muscle?
involuntary muscle that contracts without the need for conscious thought
what are elastic fibres?
protein fibres that can deform and recoil to their original size
what are ciliated epithelium?
a layer of cells with hair-like extensions called cilia
what are organelles?
the small structures within cells, each with a specific function
what is surface area to volume ration?
a calculation used by biologists to define the limits on size of an organism
what are 3 main factors that affect the need for an exchange surface?
- size
- level of activity
- SA:V
what is cartilage?
a form of connective tissue
what are some precautions when using a spirometer?
- sterile equipment
- enough oxygen
- fresh supply of soda lime
- constant temperature
- equipment that is functioning properly
what is respiratory minute volume?
the volume of air inhaled or exhaled from a persons lungs in one minute
tidal volume X breathing rate
what is dead space?
the air in the bronchioles, bronchi and trachea
whatt is vital capacity?
the greatest volume of air that can be expelled from the lungs after one breath
what is a spirometer?
a device that can measure the movement of air into and out of the lungs
what is tidal volume?
the volume of air inhaled or exhaled in one breath
what is oxygen uptake?
the volume of oxygen absorbed by the lungs in one minute
what is breathing rate?
the number of breaths per minute
what structures are in the trachea?
- large C-shaped cartilage
- smooth muscle
- elastic fibres
- goblet cells
- ciliated epithelium
what structures are in the bronchi?
- smaller, less regular cartilage
- smooth muscle
- elastic fibres
- goblet cells
- ciliated epithelium
what are the structures in the alveoli?
- elastic fibres
what are the structures in the bronchioles?
- elastic fibres
- ciliated epithelium
- smooth muscle
- some cartilage
what are some features of the alveoli?
- moist alveolar surface
- large surface area
- thin wall
what is the process of ventilation in bony fish?
- mouth opens, operculum closes
- buccul cavity floor is lowered
- volume increases, pressure decreases in buccal cavity
- water rushes into mouth
- opercular cavity expands
- buccul cavity floor is raised
- water moves from buccul cavity over the gills into opercular cavity
- mouth closes, operculum opens
- the sides of the opercular cavity move inwards, pressure increases
- water rushes out of the fish through the operculum.
what is countercurrent flow?
the flow of blood through the capillaries in the opposite direction to the flow of water
why is countercurrent flow important?
it maintains an oxygen conentration gradient
what is the process of ventilation in insects?
- air enters via the spiracles
- air is transported through the tracheae
- the tracheae divides into tracheoles
- the ends of the tracheoles are filled with fluid
more oxygen can be absorbed when the insect is active as the tracheal fluid withdraws to allow a larger surface area for diffusion
how do flight muscles help with ventilation in insects?
specialised air sacs in the trachae are squeezed
how does wing movements help with ventilation in insects?
alters the volume and pressure of the thorax
how do specialised breathing movements help with ventilation in locusts?
the abdomen expands so the spiracles at the front open and air enters then leaves from the spriacles at the back
what type of circulatory system do insects have?
open circulatory system
