Muscles and Nerves Flashcards
Muscle functions
Movement - Skeleton - Intestines - Heart & blood vessels Static support Heat production
Types of muscle:
skeletal
- attached to skeleton
- locomotion
- Voluntary
Types of muscle:
cardiac
- heart
- blood circulation
- involuntary
Types of Muscle:
smooth
- walls of vessels and organs
- move substances and restrict flow
- involuntary
skeletal muscle contains
- epimysium
- perimysium
- endomysium
- blood vessel
- fascicle
- muscle fibre
tendons are
- dense connective tissue
- do not shorten
- can alter force of direction
- some muscles share common tendons
Muscles in action
muscles that pass over a joint will act on that joint.
- they can act on more than one joint as they pass over more than one joint
some muscles can have
more than one action.
some maintain posture and oppose gravity.
eg- erector spinae, deltoid
Muscles work as part of the system
Elbow joint:
flexors and extensors work in opposition
Muscles work as part of the system
shoulder joint:
stabilised by joint action of rotator cuff muscles
Muscles work as part of the system
hand:
forearm arm muscles for powerful grip
intrinsic hand muscles for precision
Limbs: muscle compartments
Arm:
flexor and extensor
Limbs: muscle compartments
Forearm:
flexor pronator and extensor supinator
Muscles of the same compartment usually
supplied by the same nerve.
eg- radial nerve supplies all extensors in the upper limb
Nervous system:
structural differences
CNS
- brain and spinal cord
PNS
- 12 Cranial and 31 spinal nerves
Nervous system:
Functional divisions
Somatic (voluntary)
Autonomic (involuntary)
- Sympathetic (fight or flight)
- Parasympathetic (rest and digest)
sensory is
afferent neurons
motor is
efferent neurons
1st spinal nerves exits between
skull and C1
roots can be
either sensory or motor
sensory comes in from dorsal horn (from skin)
motor exits from ventral root (to muscle)
spinal nerves can be
sensory and motor
rami can be
sensory and motor
in the somatic pathway the motor fibres
do not synapse
in the autonomic pathway, he motor fibres
synapse at the ganglion
Sympathetic trunk/chain is formed by
sympathetic ganglia
sympathetic ganglia is where
most sympathetic motor fibres synapse.
(except fibres to the abdominopelvic viscera)
note that fibres dont follow the same course
ventral ramus is
posterior to the dorsal ramus
difference between the parasympathetic and sympathetic nerves
- location of outflow of nerves
- location of ganglia
- transmitters and receptors used
Myotomes & Dermatomes are
- Areas supplied by a single spinal nerve
- Can be used clinically to test for lesions at specific levels of the spinal cord
cutaneous nerve maps are
combination of fibres from different spinal nerves
dermatomes
are strips of the body that are supplied by the same nerve.