Anatomy Flashcards
A thoracic cord lesion
A thoracic cord lesion causes spastic paraperesis, hyperrflexia and extensor plantar responses (UMN lesion), incontinence, sensory loss below the lesion and ‘sensory’ ataxia.These features typically manifest several weeks later, once spinal shock (in which areflexia predominates) has resolved.
How can a spinal cord injury can produce both upper and lower motor neuron injuries
depending on the level and extent of the injury.
UMN & LMN lesion in spinal cord
Upper Motor Neuron (UMN) Injury:
If the injury occurs in the cervical or thoracic region of the spinal cord, it may affect the UMNs that originate in the brain and travel down the spinal cord to connect with LMNs at various levels below. This type of injury usually results in spastic paralysis, characterized by muscle stiffness or tightness (spasticity) and overactive reflexes (hyperreflexia).
Lower Motor Neuron (LMN) Injury: If the injury occurs at the level of the lumbar or sacral spinal cord or the the lower end of the spinal cord, it can directly affect the LMNs that exit the spinal cord at these levels. These neurons normally innervate the muscles of the lower limbs and pelvic region. LMN injuries from this cause often result in flaccid paralysis, characterised by weak, floppy muscles, reduced or absent reflexes, muscle atrophy, and sometimes muscle twitches (fasciculations)
Feature of spinal shock
Areflexia
Function of filum terminale
filum terminale ANCHORS the cord to the FIRST coccygeal vertebra.
Division of spinal cord
- The spinal cord is incompletely divided into two symmetrical halves by a dorsal median sulcus and ventral median fissure.
What is Rexed laminae
The Rexed laminae (singular: Rexed lamina) comprise a system of ten layers of grey matter (I–X), identified in the early 1950s by Bror Rexed to label portions of the grey columns of the spinal cord.
Similar to Brodmann areas, they are defined by their cellular structure rather than by their location, but the location still remains reasonably consistent.
Relation of superficial temporal and maxillary artery with parotid gland
They are anterior
Lymphatic of parotid gland
Deep cervical
Which nerve is passing through the parotid gland and innervating it
Greater auricular
function of the middle pharyngeal constrictor
swallowing
origin of middle pharyngeal constrictor
from the lesser and greater cornu of the hyoid
axillary sentinel node location
Typically in the axillary fat pad, in the level I or level II lymph nodes of the axilla.
The axillary lymph nodes are divided into three levels based on their location in relation to the pectoralis minor muscle:
Level I: Located below and lateral to the lower edge of the pectoralis minor muscle
Level II: Located behind the pectoralis minor muscle
Level III: Located above and medial to the upper edge of the pectoralis minor muscle
Origin,Path & Function of thoracodorsal nerve
Origin
The TDN originates from the POSTERIOR cor
CORD of the brachial plexus, at the apex of the axilla.
Path
The TDN runs posteriorly to the axillary vein, along the posterior wall of the axilla, and then along the posterolateral chest wall.
Function
The TDN’s primary function is to provide motor innervation to the latissimus dorsi muscle, which helps to extend, adduct, and internally rotate the shoulder.
Surgical importance of middle or long subscapular nerve.
The TDN is also known as the middle or long subscapular nerve.
The TDN is important to identify during axillary surgery, and surgeons may use it as a nerve graft.
