NMS 3

Question 1

Desxribe myofascial force transferrance through the leg

Answer 1

The most recognized pathway of force transmission from muscle fibers to bone is via the specialized myotendinous junction [1] and tendon, named myotendinous force transmission

Question 2

Describe the somatosensory system and pathways.

Answer 2

The somatosensory system is a complex system of sensory neurons and pathways that responds to changes at the surface or inside the body.

All afferent touch/vibration info ascends the spinal cord via the posterior (dorsal) column-medial lemniscus pathway via gracilis (T7 and below) or cuneatus (T6 and above).

Cuneatus sends signals to the cochlear nucleus indirectly via spinal grey matter, this info is used in determining if a perceived sound is just villi noise/irritation. All fibers cross (left becomes right) in the medulla.

Question 3

With reference to the somatic motor system, discuss how the Pyramidal and Extrapyramidal systems work together.

Answer 3

Pyramidal tracts – These tracts originate in the cerebral cortex, carrying motor fibres to the spinal cord and brain stem. They are responsible for the voluntary control of the musculature of the body and face
.
Extrapyramidal tracts – These tracts originate in the brain stem, carrying motor fibres to the spinal cord. They are responsible for the involuntary and automatic control of all musculature, such as muscle tone, balance, posture and locomotion

Question 4

Describe the tracts in the spinal cord and their function (you can use a diagram to illustrate your answer).

Answer 4

Spinothalamic

The lateral spinothalamic tract transmits pain and temperature.

The anterior spinothalamic tract (or ventral spinothalamic tract) transmits crude touch and firm pressure.

Posterior spinocerebellar tract – Carries proprioceptive information from the lower limbs to the ipsilateral cerebellum.
Cuneocerebellar tract – Carries proprioceptive information from the upper limbs to the ipsilateral cerebellum.
Anterior spinocerebellar tract – Carries proprioceptive information from the lower limbs. The fibres decussate twice – and so terminate in the ipsilateral cerebellum.
Rostral spinocerebellar tract – Carries proprioceptive information from the upper limbs to the ipsilateral cerebellum.

Question 5

Describe the basal ganglia and their function with regard to motor control.

Answer 5

Basal ganglia are strongly interconnected with the cerebral cortex, thalamus, and brainstem, as well as several other brain areas. The basal ganglia are associated with a variety of functions including: control of voluntary motor movements, procedural learning, routine behaviors or “habits” such as teeth grinding, eye movements, cognition,[1] and emotion.[2]

are involved in a number of parallel, functionally segregated cortical-subcortical circuits

A main role of the basal ganglia is the learning and selection of the most appropriate motor or behavioral programs

Question 6

Outline the primary visual pathway.

Answer 6

visual pathway. a pathway over which a visual sensation is transmitted from the retina to the brain. A pathway consists of an optic nerve, the fibers of an optic nerve traveling through the optic chiasm to the lateral geniculate body of the thalamus, and optic radiations terminating in an occipital lobe.

Question 7

With reference to the somatosensory system, describe the main types of mechanoreceptors, their function and associated neural pathways.

Answer 7

lamellar corpuscles - They are nerve endings in the skin responsible for sensitivity to vibration and pressure.
mellar corpuscles cause action potentials when the skin is rapidly indented but not when the pressure is steady, due to the layers of connective tissue that cover the nerve ending.

, tactile corpuscles,
responsible for sensitivity to light touch
Any physical deformation in the corpuscle will cause an action potential in the nerve.

Merkel nerve endings,
found in the basal epidermis and hair follicles. They are nerve endings and provide information on mechanical pressure, position, and deep static touch features, such as shapes and edges.

and bulbous corpuscles.
located between the dermal papillae and the hypodermis.
register mechanical deformation within joints, more specifically angle change,