not yet assessed Flashcards
didn't come up in paper 1 or 2
outline the composition of the trachea in the mammalian gas exchange system, relating to its functions. (2)
- incomplete rings of cartilage: provides structural strength
- ciliated epithelium: goblet cells secreting mucus to trapped unwanted particles/pathogens
outline the composition of the bronchi in the mammalian gas exchange system, relating to its functions (2)
- small incomplete cartilage rings: support/structure
- smooth muscle: enables widening/narrowing to adapt to changing volumes of air
outline the composition of the bronchioles in the mammalian gas exchange system, relating to its functions (1)
- smooth muscle: regulates air flow by widening/narrowing
outline the composition of the alveoli, and its adaptations relating to its functions.
(5)
- elastic muscle: elastic recoil of lungs to force air out
- layers of flattened ciliated epithelial cells
- rich blood supply= rich o2 supply
- small but large in numbers= large s.a. for gas exchange
- thin walled= short diffusion dist
outline the order of structures air moves through in the insect gas exchange system.
1) air enters through spiracles
2) down tracheae
3) through tracheoles
4) tracheal fluid
outline the adaptations present in an insects gaseous exchange system
- tracheae have rings of chitin
- large number of tracheoles
- air sacs that act as reservoirs- inflated and deflated w/ abdominal movements
outline how air is pumped into an insects gaseous exchange system, referring to volume changes
- air is actively pumped into system by muscular pumping movements of thorax & abdomen
- these movements increase vol & decrease pressure (air moves in)
- or these movements decrease vol and increase pressure (air forced out)
outline the general structure of the gaseous exchange system in bony fish. outline some of their adaptations
- gill filaments in stacks- tips of adjacent filaments overlap which + resistance to flow of water & slows movement :. increasing gas exchange time
- lamellae: which have rich blood supply & large SA
- water flows over gills which are covered by operculum (flap)
- countercurrent exchange system
outline how to dissect a fish to view the gill filaments properly
(2)
- cut off operculum (can now see gill arch)
- cut out one gill filament out of 4 : can count n/of gill filaments
outline how to view an insects gaseous exchange system by dissecting a locus (6 steps)
- secure onto surface using pin
- pull out abdomen as far as it will stretch & pin
- remove limbs & wings
- cut along both sides of abdominal wall using forceps & scissors
- pull back flap of abdominal wall & remove
- submerge remains in saline solution
what is the light band in myofibrils
Do they change during contraction, if so how?
where actin and myosin don’t overlap.
also known as I bands
- the light band narrows, because the actin and myosin overlap more
what is the dark band in myofibrils
Do they change during contraction, if so how?
where the actin and myosin overlap
- remains the same width during contraction
what is the Z line in myofibrils
do they change during contraction, if so how?
darker line found at the centre of each light band
the Z lines move closer together, because the light bands narrow
what is the H zone in myofibrils
do they change during contraction, if so how?
the H zone is a lighter coloured region found at the centre of each dark band
the H zone narrows because the muscles become more compacted
outline the structure of myosin
(3)
long rod fibres with globular heads
the heads contain a binding site for each actin & ATP
the heads of the myosin protrude from all the tails wrapping around each other to form the filament
