Quick Revision Flashcards
What are the three types of muscle?
Cardiac muscle, smooth muscle and skeletal muscle
What is the difference between the three types of muscle?
Neither cardiac nor smooth muscles are under conscious control, so we remain largely unaware of their contractions. However skeletal muscles make up the bulk of body muscle and act under voluntary control.
Muscles are made up of millions of tiny muscle fibres, called _________.
Myofibrils.
What are myofibrils?
Tiny muscle fibres that make up individual muscles.
Why would a muscle was made up of individual cells joined end to end be inefficient?
Because the junction between adjacent cells would be a point of wellness and reduce the o weakly strength of the muscle.
How is a muscle adopted, instead of having all its individual cells joined end to end?
The separate cells become fused together into muscle fibres.
What is a sarcoplasm?
A muscle cell’s cytoplasm
What are transverse (t) tubules?
Where the sarcolemma fold inwards across the ms or fibre and stick into the sarcoplasm.
What is the sarcloemma?
The cell membrane of muscle fibres.
What do T tubules do?
They help to spread electrical impulses throughout the sarcoplasm so they research all parts of the muscle fibre.
The sarcoplasm contains a sarcoplasmic reticulum. What is this for?
This stores and releases calcium ions that are needed for contraction.
Muscles that work together to move an incompressible bond are called antagonistic pairs.
The contracting muscle is called the ________.
Whilst the relaxing muscle is called the _________.
Contracting - agonist
Relaxing - antagonist
Myofibrils contain…
- thin myofilaments: made of actin
- thick myofilaments: made of myosin
What would a myofibrils look like under a microscope?
A pattern of alternating dark and light bands.
In myofibrils, there are alternating dark and light bands. Outline the light bands.
lIght bands contain the thIn actin filaments only - the I-bands.
In myofibrils, there are alternating dark and light bands. Outline the dark bands.
dArk bands contain the thick myosin filaments, and some overlapping thin actin filaments - A-bands.
What is a Z-line?
The end of each sarcomere
What is an M-line.
The muddle of each sarcomere.
What is the H-zone?
Around the M-line is the H-zone. This contains only myosin filaments.
How is muscle contraction explained?
By the sliding filament theory.
Outline the sliding filament theory.
Myosin and actin filaments slide over one another to make the sarcomeres contract.
This simultaneous contraction means that the myofibrils and muscle fibres contract.
Sarcomeres return to their original length as the muscle relaxes.
What is the primary response?
The production of antibodies, and memory cells produced by T and B cells.
What is the secondary response?
Clonal selection occurs faster. Memory B cells are activated and divide into plasma cells that produce the appropriate r
