Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
53 Cards in this Set
- Front
- Back
components of motor system
|
muscles and motor neurons
|
|
charles sherrington
|
mentioned the importance of the execution of actions muscles do.
|
|
can locomotion be possible without the brain?
|
yes, because there is certain amount of circuitry present in the spinal cord, which can perform locomotion.
|
|
Sherrington and Graham Brown
|
elicited that the rhythmic movement of the hind legs of cat and dog was possible, after severing spinal cord from the rest of the body.
|
|
summation of motor system
|
the spinal cord consists of certain motor programs, which are processed, executed and modified by the descending commands from the brain.
|
|
the division of motor control
|
a. the spinal cord's command and the control of the spinal cord muscle contraction.
b. the brain and the control of spinal cord's motor programs. |
|
the two major types of muscles
|
striated and smooth
|
|
characteristics of the smooth muscle
|
it lines the digestive tract, and the nerves that innervate it are from the ANS. it plays a major role in peristalisis, and the control of blood pressure.
|
|
types of striated muscle
|
cardiac and skeletal
|
|
cardiac muscle
|
it is the heart muscle. it is involuntary and does not need any innervation. It is innervated from the ANS
|
|
Skeletal muscle
|
it is the bulk muscle mass present in the body. it is enclosed in a connective tissue which becomes the tendons at the end of the muscle. it is innervated by the CNS.
|
|
why is it called the somatic sensory system?
|
it called so because the skeletal muscle is derived from the embryological 33 somites. thus these cells, and the parts of nervous system coordinating movement are called, somatic motor system
|
|
why is it important
|
because it is generated by voluntary control and generates behavior.
|
|
flexion
|
the movement in the direction of closing the knife is called flexion
|
|
extension
|
the movement in the direction of opening the knife is called extension
|
|
the major flexion muscle
|
brachialis, whose tendons insert into humerus at one end and at ulna at the other end.
|
|
what are the flexor muscles?
|
the major flexor muscles are the brachialis, biceps brachii, and the coracobrachialis.
|
|
what are synergists?
|
the three muscles working together namely the brachialis, biceps brachii, and the coracibrachialis.
|
|
what are the extensor muscles?
|
triceps brachii, and the anconeus.
|
|
the major flexion muscle
|
brachialis, whose tendons insert into humerus at one end and at ulna at the other end.
|
|
why are they antagonisits?
|
because the two muscles work in opposite direction.
|
|
what are the flexor muscles?
|
the major flexor muscles are the brachialis, biceps brachii, and the coracobrachialis.
|
|
the important point about the muscles is that
|
they can only pull but not push.
|
|
what are synergists?
|
the three muscles working together namely the brachialis, biceps brachii, and the coracibrachialis.
|
|
axial muscles
|
these muscles, act on the trunk
|
|
what are the extensor muscles?
|
triceps brachii, and the anconeus.
|
|
proximal muscles
|
these move the shoulder, girdle, pelvis and knee
|
|
why are they antagonisits?
|
because the two muscles work in opposite direction.
|
|
distal muscles
|
these move the hands, feet and digits
|
|
the important point about the muscles is that
|
they can only pull but not push.
|
|
the importance of axial musculature
|
the maintenance of posture
|
|
axial muscles
|
these muscles, act on the trunk
|
|
proximal muscles
|
these move the shoulder, girdle, pelvis and knee
|
|
distal muscles
|
these move the hands, feet and digits
|
|
the importance of axial musculature
|
the maintenance of posture
|
|
the importance of proximal muscles
|
locomotion
|
|
importance of distal musculature
|
manipulation of the objects
|
|
which neurons innervate the somatic musculature?
|
the somatic motor neurons in the ventral horn.they are also called, lower motor neurons to distinguish from the higher motor neurons providing input to the spinal cord
|
|
lower motor neuron's function by Sherrington?
|
the final common pathway for the control of the behavior.
|
|
what is the ventral root?
|
the axons of the lower motor neuron bundle together to form the ventral root
|
|
what is a spinal nerve
|
the ventral root, joins with the dorsal root to form the spinal nerve
|
|
types of spinal nerves
|
cervical, thoracic, lumbar and sacral
|
|
the 50 muscles of the arm are innervated by
|
the C3-T1. represented by the swelling of the ventral horns.
|
|
the leg musculature control
|
by the L1-S3.
|
|
the characteristics of the cervical, and lumbar-sacral
|
they mainly innervate the distal and proximal musculature.
|
|
characteristic nerves innervating the axial musculature
|
they are found at all the levels. cervical, thoracic, lumbar and sacral.
|
|
the arrangement of the lower motor neurons in the ventral horn.
|
the cells innervating the axial musculature are medial to the ones innervating the distal muscles. the cells innervating the flexors are dorsal to the extensors. the distal muscles are lateral.
|
|
the two types of lower motor neurons
|
alpha motor neurons and the gamma motor neurons
|
|
motor unit
|
one alpha motor neuron and the muscles fibers innervated by it are called the motor unit.
|
|
motor neuron pool
|
the collection of alpha motor neuron innervating a single muscle is called the motor neuron pool.
|
|
the graded control of muscle contraction by alpha motor neurons
|
the first way the CNS controls is by varying the firing rate of the motor neurons.
the second way is by CNS recruiting additional synergistic motor units. |
|
Control by variation of firing rate
|
the neurotransmitter used is ACh. the alpha motor neuron communicates by releasing ACh. since it is very reliable, ACh released due to one pre synaptic potential, causes a post synaptic potential, causing a twitch. a sustained contraction due to sustained action potentials will causes temporal summation of post synaptic activity. the rate of firing is thus a very important way of grading muscle contraction.
|
|
what is a twitch?
|
a rapid sequence of contraction and relaxation in the muscle fiber.
|