Run for your life Flashcards
What is an antagonistic pair
when one muscle contracts and the other one relaxes to induce a movement.
What are synovial joints?
- synovial fluid is present between the bones
Wht to tendons do?
connect muscle to bone
what do ligaments do
connect bone to bone
what occurs in arthritis
- swelling of joints - either bone ends rub together and cartilage in thinned (osteoarthritis)
- or bone erosion due to a swollen, inflamed synovial membrane
What are extensors and flexors?
extensors extend the limb
flexors bend the limb
Describe the size by size comparison of a bundle to muscle fibers
bundle of muscle fibers –> one muscle fiber —> myofibrils —> sarcomere
What does a sarcomere contain
a repeated unit of actin and myosin filaments
Describe/define the following terms:
- A Band
- I band
- H zone
- Z disk
- Region with overlapping of myosin and action filaments, including a myosin only area in the middle.
- Actin only area
- Only myosin filaments (in the middle of the A band)
- Z disk links adjacent sarcomeres together, zigzag line with actin molecules on either side, leading to 2 different sarcomeres
describe what happens to the Bands when a muscle contracts
- Z lines move closer together, I band gets smaller.
- A band remains the same
Describe the role of calcium ions in muscle contraction.
- bind to Tropomyosin is moved by troponin
- this exposes the myosin binding sites on actin.
Describe the changes that help muscle contraction occur after Ca2+ ions are bound.
- myosin heads can now bind to binding sides
- this causes the myosin to change shape
- actin filaments pulled over the myosin towards the M line
- sarcomeres therefore shorten.
explain the interaction between Ca2+ ions, Troponin and Tropomyosin
- Ca2+ binds to troponin, which causes it to change shape
- This causes tropomyosin to move away from the myosin binding site.
Describe how the concentration of Ca2+ ions around the myofibrils is controlled
- Ca2+ ions released from sarcoplasmic reticulum
- in response to action potential at neuromuscular junction
- Calcium channels open to allow ions to cross across the membrane
- Ca2+ ions taken back into the sarcoplasmic reticulum by active transport.
Name the 4 stages in order of aerobic respiration
- glycolysis
- link reaction
- Krebs cycle
- oxidative phosphorylation
Describe the cardiac cycle
- blood flows in through the vena cava, into the atria, increasing pressure.
- this opens the AV valves, causing atrial systole to take place.
- blood fills the ventricles, increasing pressure.
- AV valves close, and SL valves open out of the ventricles into the heart.
- diastole takes place.
what does myogenic mean in terms of the heart?
no external signal required to beat, beats on its own.
describe how a heart beat is coordinated.
- cells in the sinoatrial node become depolarised
- depolarisation spreads through the walls of the atria, causing atrial systole.
- Atrio ventricular node detect this depolarisation, sending impulses down the bundle of his (bundle of purkyne fibres) , and then down to the Purkyne fibres.
- after a slight delay (to ensure ventricles contract after the atria), this causes ventricular systole.
- ventricles contract from the apex upwards.
Why can’t the ventricles receive the depolarisation from the SAN?
atria and ventricles separated by a layer of non conducting tissue. (annulus fibrosus)
name 4 factors that effect heart rate
- low pH
- Stretch receptors
- decrease in BP
- Adrenaline
Describe the process of glycolysis
- glucose is phosphorylated to produce 2 pyruvate molecules, 2 ATPs and 2 NADH (end products)
- Glucose is phosphorylated to glucose bisphosphate.
- splits into triose phosphate, and this is oxidised to pyruvate. (NAD is reduced to NADH)
Describe the processes involved in the Link reaction.
- Pyruvate is oxidised (NAD–> NADH)
- simultaneously, it looses a Carbon (due to the coenzymeA)
- this produces CO2 and AcetylCoA and NADH as final products
Describe the processes involved in the krebs cycle
- acetylCoA reacts with a 4C compund to produce a 6C compound. In this process, CoA is reformed and goes back to the link reaction.
- the 6C compund is oxidised to a 5C compound - where NAD is reduced to NADH, and CO2 is produced
- this 5C compund is then resynthesised to the original 4C compound - producing 2NADH, 1FAD, and 1ATP molecule. (CO2 also produced)
Describe the processes involved in oxidative phosphorylation
- the Hydrogen carriers (NADH and FAD) are oxidised, producing electrons and H+ ions
- the electrons go through electron transport proteins, a series of redox reactions.
- the energy released from these reactions is used to actively pump H+ ions into the intermembrane space.
- H+ ions then diffuse back down an electrochemical gradient, through ATP synthase, which simultaneously produces ATP from ADP + Pi
- the H+ ions are accepted by oxygen, forming water.