Exchange Surfaces And Breathing Chapter 3.1 Flashcards
What factors effect the need for an exchange systems ?
3
1-size
2-SA:V
3-level of activity
What’s the formula for a)surface area of cylinder
B) volume of cylinder
A) (piDxheight )x 2pi ^2
B) pi r^2 x height
SA of sphere ?
Volume of sphere ?
SA: 4pi r squared
Volume : 4/3 pi r ^3
How should you write SA:V ratio
X:1
What are the features if s good exchange system ?
4
1-large SA
2-thin barrier ( reduce Diffusion distance )
3-Good Blood supply( maintain Concentration gradient )
4-Good ventilation
Outline the mammalian has exchange order ?
4
Trachea —> bronchi —> Bronchioles —> Alveoli
How are alveoli good exchange surfaces ?
4
- large SA:V ratio
- layer of moisture ( surfactant ) stops them sticking together
- alveolus wall is thin ( squamous epithelium )
- good blood supply ( may capillaries )
What makes the lungs a good exchange surface ?
4
- large SA:V
- good blood supply
- constantly ventilated so concentration gradient in air is maintained
- many alveoli increases SA
What happens in inhalation ?
- diaphragm
- ext int Costel muscles
- v
- air
- diaphragm moves DOWN and contracts
- Ext intercostal muscles = ribs rises
- Volume increases
- pressure decreases
- Air moves in
What happens in exhalation? (6)
- diaphragm
- ext intercostal muscles
- interval intercostal muscles
- v
- p
- air
- diaphragm moves up
- ext intercostal muscles lOWERS RIBS
- Internal intercostal muscles push out Air forcefully
- volume decreases
- pressure increases
- air moves out
Why do humans need lungs ?
3
- large organism ( diffusion distance is too big )
- High metabolic activity
- small SA:V
Why do active organisms need a specialised exchange system ?
( 3)
- respiration ( energy )
- aerobic respiration works best
- NEED O2 from Lungs
What are the physiological changes that occur during Excersize ?
(4)
1- volume of air breathed out rises
2-breath rate increases
3-concentration gradient maintained at higher level
4-muscle repaired more
What are the properties of the airways ?
3
- large enough to allow airflow
- supported = prevent collapse
- Flexible = movement
What do the trachea and bronchi both have (tissues ) ?
5
- cartilage
- smooth muscle
- elastic fibres
- goblet cells
- epithelium
What does a bronchiole not have ?
1
- cartilage
What do alveoli have ?
1
- elastic fibres
What are the main cells and tissues that work together in lungs ?
- goblet cells
- ciliates cells
- elastic fibres
- smooth muscle
- cartilage
What does :
A) ciliates epithelium do ?
B) glandular tissue do ?
C)smooth muscle do ?
A-cilia wafts mucus
B-produces mucus
C-supports airway
What does : A) elastic tissue do ? B) blood do ? C) nervous tissue do ? D) connective tissue do ?
A-elastic tissue recoils and dilates airway ( expels Air )
B-blood transports gases
C-nervous tissue carries messages to coordinate actions
D-connective tissue holds other tissues together
What’s the Oxygen uptake?
Volume of O2 absorbed by lungs in 1min
What’s tidal volume ?
Volume of air inhaled and exhaled in one breath , usually measured at rest
What vital capacity
- greatest volume of air that can be expelled after taking the deepest breath
What does vital capacity depend on ?
3
1-size of person
2-age / gender
3-level of exercise
How do you investigate breathing.
SPIROMETER
How does a spirometer work?
2 points
- breath in
-breath out
1-Oxygen filled chamber with moveable lid with Pen attached ( recorded on rotating drum ) -person breathe out via tube -person breaths IN ( lid goes down ) -person breaths out ( kid goes up ) 2- results = spirometer trace
What’s soda like for in spirometer?
Absorb CO2
What are precaution to take when using a spirometer ?
5
- subject is healthy - no asthma
- soda like is fresh and functioning
- no air leak
- mouth piece sterilised
- water chamber isn’t tooo high
Why does total volume of air decrease in chamber ?
3
- Air Breathed our by Person is O2 and CO2
- CO2 is absorbed by soda lime so only O2 left
- O2 used up by respiration
How do you calculate ventilation rate ?
Tidal volume x breathing rate
How do fish breathe ?
2
- water enters mouth and passes through gills
- countercurrent flow
Outline the gill structure.
- gills made of gill filaments or primary lamellae( increase SA)
- Gill plates
- each gill supported by gill arch
- lots of capillaries on gill plates p
How are fish ventilated?
9
- mouth opens
- Buccal cavity is lowered
- v increases
- p decreases
- water sucked in
Mouth closes
- floor of buccal cavity raised
- v decreases
- p increases
- water forced out of gill filaments
Each gill has a bony flap ( OPERCULUM)
When p increases this opens and water leaves the
How are insects ventilated?
Structure ?
(4)
O2 in via spiracle -trachea -tracheole -tracheal fluid Oxygen travels down conc gradient to cells ! (High—> low)
How do insects pump gases ?
2
- rhythmic body movements
- movement of wings
Why are so many blood vessels important in lungs?
3
- many small blood vessels = larger SA than 1 or 2
- CO2 carried to lungs
- O2 constantly carried away ( gradient )
