Sensory Receptors Flashcards
What is the structure of cutaneous receptors?
The nerve endings are protected by a capsule
How is an action potential triggered in cutaneous receptors?
A membrane deformation activates stretch sensitive ion channels
What is the role of muscle spindles?
They monitor muscle length and the rate it changes at.
What 2 types of fibres is skeletal muscle made up of?
extrafusal and intrafusal muscle fibres
What are extrafusal muscle fibres?
regular muscle fibres
What are intrafusal muscle fibres?
Form muscle spindles
Contain specialised motor and sensory innervation
What do the intrafusal muscle fibres contain at the ends?
sarcomeres
What is a sarcomere?
A unit that contains the contractile units of a muscle (actin, myosin etc)
What are intrafusal muscle fibres controlled by?
gamma motorneurones
How is the muscle length monitored when it lengthens?
Ion channels open
What happens when an agonist muscle contracts?
The spindle contracts and causes the antagonistic muscle to lengthen which causes the spindles to increase their output of action potentials. This causes awareness of what is happening around the joint position.
What do golgi tendon organs do?
Monitor muscle tension by acting as stretch receptors in the tendons.
