Lecture 12 Flashcards
what does the sarcoplasmic reticulum store?
Intracellular storage of Ca++ ions
What is a neuromuscular junction?
A chemical synapse formed by the contact between a motor neuron and a muscle fibre.
What is the T-tubule?
An access point for extracellular calcium.
Calcium interacts with _______, which shifts the _________and exposes the ________binding sites.
Calcium interacts with troponin, which shifts the tropomyosin and exposes the myosin binding sites.
True or False?
Motor unit displays ALL or NONE activation of fibres.
TRUE
Force of contraction in a whole muscle depends on what characteristics of motor units?
SIZE of motor units
NUMBER of motor units
RATE OF FIRING of motor units
Force of contraction in a whole muscle depends on what characteristics of a muscle cell?
- length
- number
- arrangement
Force of contraction in a whole muscle depends on what characteristics of a muscle?
The muscle attachments, length and role.
When looking at an anatomical level, which five things are involved?
- bones = lever
- joint = pivot or fulcrum
- muscle contraction = pull
- load = external or internal
What is concentric muscle action?
Active muscle shortening, develops tension, change in joint position.
What is isometric muscle action?
Active, no change in muscle length, develops tension no change in joint position.
What is eccentric muscle action?
A muscle lengthening, develops tension, change in joint position.
What are the 4 types of muscle roles?
- agonist
- antagonist
- stabiliser
- neutraliser
How do agonists act?
Concentrically
How do antagonists act?
Eccentrically.
