Module 3: Section 1 - Exchange and Transport Flashcards
alveoli?
tiny air sacs that consist of
epithelial cell layer
elastic fibres
collagen
bronchi?
divisions of trachea that consist of small tubes
suppoted by incomplete rings of cartilage
cartilage?
rings are incomplete to bend
strong & flexible to stop organs from collapsing
connective tissue
provide support
smooth muscle?
involuntary muscle
found in walls of trachea and bronchi
controls organs diameter in tubes so when relaxed they widen
cilliated epithelium (cillia)?
beats bacteria containing mucus upwards away from alveoli towards throat (swallowed) to prevent infection
tiny-hair like cillia
goblet cells?
secrete mucus into trachea lining
mucus traps harmful microorganisms and dust particles preventing enter to lungs
elastic fibres?
allow alveoli to stretch as air is inhaled + recoil as air is exhaled
found in trachea, bronchi, brochioles
bronchioles?
small divisions of bronchi
trachea?
primary airway which carries air from nasal cavity to the chest
ventilation?
movement of fresh air into lungs and stale out via expiration/inpiration
what does trachea contain?
C cartilage
smooth muscle
elastic fibres
goblet cells
cilliated epithelium
what does bronchi contain?
Small cartilage
smooth muscle
elastic fibres
goblet cells
cilliated epithelium
what does alveoli contain?
elastic fibres
squamous epithelium
what does bronchioles contain?
smooth muscle
elastic fibres
goblet cells
cillia
why do we need exchange surfaces?
to exchange mats such as urea water and oxygen ACROSS PLASMA MEMBRANES
squamous epithelium?
Flat, scale-like epithelial cells
thin walls for quick diffusion pathway
diffusion is quick when? why?
the SA:V is greater
diffusion is slow when? why?
the SA:V is smaller
as larger organisms cells have no direct contact with external environment so diffusion distance is larger
why do larger organisms have specialised exchange surfaces?
as they have higher metabolic rate and smaller SA:V so require more oxygen and glucose
adaptations for alveoli?
layer of squamous epithelium cells for quick diffusion pathway
partially permeable to allow certain gases across
ventiliation of air for a steep diffusion gradient
large SA to increase rate of gas exchange
good blood supply so gas exchange can be transported
ribcage?
consist of ribs that enclose the thorax (chest)
diaphragm?
sheet of muscle that moves the ribcage up and out when it contracts
external intercostal muscles?
found between the ribs
pull the ribcage up and out when they contract
internal intercostal muscles?
found between the ribs pull the ribcage down and in when they contract
pleural cavity?
found in thoracic cavity
double membrane
filled with pleural fluid that lubricates lungs
adheres to thoracic cavity and lungs via water cohesion so lungs expands whilst breathing
inspiration?
active process requiring energy for muscle contraction
expiration?
a passive process
events of inspiration?
- external intercostal muscles contract while internal intercostal muscles relax, moving the ribcage up and out
- The volume of the thoracic cavity increases
- diaphragm contracts and flattens, further increasing the volume of the thoracic cavity
- lung pressure decreases below atmospheric pressure
- Air flows into the lungs down the pressure gradient
events of expiration?
- external intercostal muscles relax, moving ribcage down and in
- The volume of the thoracic cavity decreases
- diaphragm relaxes and unflattens, further decreasing the volume of the thoracic cavity
- lung pressure increases above atmospheric pressure.
- Air is forced out of the lungs down the pressure gradient.
What is tidal volume
The air inhaled and exhaled when at rest
What is breathing rate
How many breaths are take (usually in a minute)
What is oxygen consumption
the rate at which an organism uses up oxygen
What is a spirometer
its a machine that can give readings of tidal volume, vital capacity, breathing rate and oxygen uptake
How does a spirometer work
1) It has an oxygen-filled chamber with a moveable lid
2)The person breaths through a tube connected to the oxygen chamber
3) as the person breathes in and out , the lid of the chamber moves up and down
4) These movements are recorded by a pen attached to the lid of the chamber and this writes on the rotating drum
What is residual volume
Volume that remains in the lungs so they don’t collapse
Why do fish have special adaptations
there is a lower concentration of oxygen in water than in air
how are fish gills ventilated
1) fish opens its mouth, lowering the floor of the buccal cavity and the volume of the buccal cavity increases decreasing the pressure in the cavity
2) When the fish closes its mouth the floor of the buccal cavity raises again and the volume inside the cavity decreases and the pressure increases and the water is forced out across the gill filaments
3) Each gill is covered by a bony flap called operculum, the increase in pressure forces the operculum on each side of the head to open
what is ventilation?
the total volume of air inhaled in 1 minute
describe insects structure
rigid exo-skeleton with waxy coating that is impermeable to gases
small openings called spiracles along the thorax and abdomen
what are spiracles?
small pores that allow gases to diffuse into the body
these lead into the tracheae
can open/close via sphincters
spiracles pathway? aka structure in insects
cant afford diagrams ;(
exo-skeleton/spiracle -> tracheae -> tracheole
what are tracheae?
air filled tubes that carry O2 in the body
these have rigid rings of chitin to keep tracheae open
what are tracheoles?
smaller versions (NO CHITIN) of tracheae that have thin permeable walls that delive O2 directly to exchange surface
contain tracheal fluid (dissolves O2)
what happens during activity in an insect?
-lactic acids builds
-this loers water potential in cells
-water leaves the tracheoles into the cells via osmosis
-this allows more SA to be exposed for gass exchange
what are the ventilation mechanisms in insects?
mininum 2
-Mechanical active ventilation
-Collapsible air sacs
-Wing movement
-Thoracic muscle vibration
describe - Mechanical active ventilation
muscles around tracheae contract and relax to change the volume of the thorax and abdomen, causing the tracheae to push air in and out of the spiracles.
describe - Collapsible air sacs
inflate and deflate to ventilate the tracheal system and can increase the volume of air moved through the system.
describe - Wing movement
pumps air to ventilate the tracheal system.
describe - Thoracic muscle vibration
pumps air to ventilate the tracheal system.
Bony fish - Structure?
large, active so higherlevels of O2 needed
low SA:V
Bony fish - Gills - Structure?
Covered by the operculum (bony flap) - maintains flow of water over gills
Gills consist of stacked filaments called gill lamellae
Gill lamellae surrounded by good blood supply
what are the adaptations of gills?
The lamellae provide a large surface area.
The lamellae membranes are thin to minimise diffusion distance.
The gills have a good blood supply to maintain steep diffusion gradients.
The countercurrent flow of blood and water creates even steeper concentration gradients.
what is the counter-current system?
the flow of blood and water in opposite directions
how does the counter-current system function?
O2-rich blood meets H2o across gills maximising diffusion of O2 to blood (H2O flowing away = O2 weak H2O)
O2-poor blood meets O2-reduces H2O allowing for diffusion into the blood (H2O flowing towards = O2 H2O)
