Topic 7 Test Flashcards
What are tendons?
Non-elastic tissue which connects muscles to bones.
Tendons are crucial for transmitting the force generated by muscles to bones, allowing for movement.
What is the function of ligaments?
Elastic tissue that joins bones together and determines the amount of movement possible at a joint.
Ligaments provide stability to joints while allowing for flexibility.
Define joints.
The area where two bones are attached for the purpose of permitting body parts to move, made of fibrous connective tissue and cartilage.
Joints can be classified into different types based on their structure and movement capabilities.
What are skeletal muscles?
Muscles attached to bones, arranged in antagonistic pairs.
Skeletal muscles are responsible for voluntary movements and are under conscious control.
What are antagonistic muscle pairs?
Pairs of muscles which pull in opposite directions; as one muscle contracts, the other relaxes.
This mechanism allows for coordinated movement and control of joints.
What is the role of extensors in muscle movement?
Extensors act to straighten the joint.
They are essential for movements such as standing up or straightening the arm.
What do flexors do?
Flexors act to bend the joint.
Flexors are important for actions like bending the elbow or knee.
Provide an example of an antagonistic muscle pair.
Triceps and biceps in the arm.
When the triceps relaxes, the biceps contracts to lift the arm.
Process of Sliding Filament Theory
- Calcium ions are released from the sarcoplasmic reticulum when a nerve stimulates the muscle.
- Calcium binds to troponin, changing its shape and exposing myosin binding sites.
- Myosin heads attach to these sites and pull, causing the muscle to shorten.
- When ATP binds to myosin, it changes shape and resets to its original position.
- ATP is broken down into ADP and Pi, preparing myosin for the next contraction.
- If stimulation stops, ATP helps move calcium ions back into the sarcoplasmic reticulum.
What are the stages of respiration?
It has four stages:
• Glycolysis
• Link Reaction
• Kreb’s Cycle
• Oxidative Phosphorylation
Describe Glycolysis
Glycolysis is the first process of both aerobic and anaerobic respiration. It occurs in the cytoplasm.
In this process glucose is phosphorylated to produce 2 molecules of pyruvate, 2 molecules of ATP and 2 molecules of NADH.
** in anaerobic, pyruvate is reduced to lactate using NADH
Describe the Link Reaction
Where pyruvate is bound to coenzyme A producing acetyl coenzyme A with the release of NADH.
- occurs in mitochondrial matrix
Describe the Krebs Cycle
Acetyl-CoA then enters the Krebs cycle, where it donates 2 carbons to the 4 carbon compound oxaloacetate, producing citrate.
CoA is restored for use in the link reaction. Citrate is oxidised and carbon dioxide, ATP, reduced NAD and reduced FAD are produced.
- occurs in mitochondrial matrix
Describe oxidative phosphorylation
ATP is synthesised via chemiosmosis in the electron transport chain in mitochondria. This process generates the majority of ATP in aerobic respiration.
What is the process of oxidative phosphorylation
Reduced coenzymes carry hydrogen ions and electrons to the
Inner mitochondrial membrane
electron transport
chain, which occurs on the inner mitochondrial membrane.
• Electrons are carried from one electron carrier to another in a series of redox reactions: the electron carrier which passes the electron on is oxidised, whereas the electron carrier which receives it is reduced.
• Hydrogen ions are actively transported across the membrane into the intermembrane space - using the energy released from redox reactions. As a result, the concentration of the hydrogen ions in the intermembrane space is high.
• Hydrogen ions diffuse back into the mitochondrial matrix, down the electrochemical gradient through the protein ATP synthase.
• ATP is produced on stalked particles using ATP synthase.
• The hydrogen ions and electrons are then combined with oxygen to produce water.
How is the heart described
myogenic - has the ability to initiate its own contraction
Cardiac Cycle
- Depolarisation originates in the Sinoatrial Node.
- Depolarisation spreads through the atria - causing atrial systole. .
- Bundle of His splits into two branches
- It cannot spread directly to the ventricles due to the region of nonconductive tissue - the annulus fibrosus.
- Instead, it stimulates another region of conducting tissue known as the Atrioventricular Node.
- A slight delay occurs between atrial systole and atrial diastole / ventricular systole (in which the ventricles fill with blood).
- The AVN passes depolarisation into the conducting fibres known as the Bundle of Hisalled Purkyne Fibres. These spread up through the ventricles to initiate ventricle systole.
ECGs
Electrical changes in the heart are caused by the spread of a wave of depolarisation which can be measured and detected with an electrocardiogram (ECG). Some diseases affect the wave of depolarisation within the heart thus affecting the ECG pattern therefore ECG can be used in the diagnosis of various heart diseases including cardiovascular heart diseases.
calculate cardiac output
Cardiac output = stroke volume x heart rate
Factors increasing heart rate
- Low pH caused by high carbon dioxide concentration, detected by chemoreceptors, receptors send impulses to the medulla oblongata where the cardiovascular centre is located
• Stretch receptors respond to muscle movement
• Decrease in blood pressure
• Adrenaline is a hormone released to stimulate the fight or flight response - The relevant receptor sends an impulse to the Cardiac Control Centre in the medulla oblongata. An impulse is then sent to the Sinoatrial Node along a sympathetic neurone, depolarisation occurs and noradrenaline is released at the SAN. This results in increased heart rate.
Calculate Ventilation Rate
Ventilation rate = tidal volume x number of breaths per minute
Factors affecting ventilation rate
• Increase in carbon dioxide concentration in blood which causes pH to drop
• Impulses from stretch receptors in muscles and tendons caused by exercise
• Voluntary control
Slow Twitch Muscle Fibres
- Muscle fibres that contract slowly.
- Muscles you use for posture, e.g. those in the back, have a high proportion of them.
- Good for endurance activities, e.g. maintaining posture, long-distance running.
- Can work for a long time without getting tired.
- Energy’s released slowly through aerobic respiration.
- Lots of mitochondria and blood vessels supply the muscles with oxygen.
- Reddish in colour because they’re rich in myoglobin
- a red-coloured protein that stores oxygen.
Fast Twitch Muscle Fibres
- Muscle fibres that contract very quickly.
- Muscles you use for fast movement, e.g. those in the eyes and legs, have a high proportion of them.
- Good for short bursts of speed and power, e.g. eye movement, sprinting.
- Get tired very quickly.
tion. ne
Energy’s released quickly through anaerobic respiration using glycogen (stored glucose). - There are few mitochondria or blood vessels.
in - Whitish in colour because they don’t have much myoglobin (so can’t store much oxygen).
