Lachmans TEST REVIEW (PERSONAL Back/Thorax) (Part 1)

Question 1

Why is the spinal cord not subject to injury from disk herniation below L2?

Answer 1

Because the spinal cord ends at L2; below that level is the cauda equina in the subarachnoid space.

Question 2

What anatomical structures are found within the subarachnoid space below L2?

Answer 2

Cauda equina and filum terminale.

Question 3

What is the cauda equina made of?

Answer 3

Dorsal and ventral nerve roots that extend down from the lumbar and sacral segments.

Question 4

Where does the subarachnoid space end?

Answer 4

S2

Question 5

What spinal roots form the sciatic nerve?

Answer 5

L4-S3

Question 6

What physical maneuver stretches the sciatic nerve and may cause pain in nerve root compression?

Answer 6

Raising the extended leg in the lateral position.

Question 7

Through which anatomical landmarks does the sciatic nerve pass in the thigh?

Answer 7

Between the greater trochanter and the ischial tuberosity.

Question 8

What are the three ligaments pierced during a midline lumbar puncture (LP)?

Answer 8

Supraspinous, interspinous, and ligamentum flavum.

Question 9

Where does the epidural space extend from and to?

Answer 9

From the foramen magnum to the sacral hiatus.

Question 10

How is CSF accessed and evaluated?

Answer 10

By piercing into the subarachnoid space and analyzing clearness, color, cell count, and protein levels.

Question 11

A herniated disk at L1/L2 affects which spinal nerve and what are the motor and sensory findings?

Answer 11

Spinal Nerve Affected: L2

Motor Finding: Weakness of hip flexors

Sensory Disturbance: Groin and anterior thigh

Question 12

What are the effects of a herniated disk at L2/L3?

Answer 12

Spinal Nerve Affected: L3

Motor Finding: Weakness of knee extensors

Sensory Disturbance: Anteromedial thigh

Question 13

Which spinal nerve is affected by an L3/L4 herniated disk, and what deficits are seen?

Answer 13

Spinal Nerve Affected: L4

Motor Finding: Weakness of ankle dorsiflexors

Sensory Disturbance: Anterior leg and medial foot

Question 14

What are the findings in an L4/L5 disk herniation?

Answer 14

Spinal Nerve Affected: L5

Motor Finding: Weakness of big toe extensor

Sensory Disturbance: Dorsum of the foot

Question 15

Describe the findings of a herniated disk at L5/S1.

Answer 15

Spinal Nerve Affected: S1

Motor Finding: Weakness of ankle plantar flexors

Sensory Disturbance: Lateral foot

Question 16

What structures form the walls of the axilla?

Answer 16

Anterior wall: Pectoralis major and minor

Posterior wall: Subscapularis, teres major, latissimus dorsi

Medial wall: Serratus anterior

Lateral wall: Intertubercular sulcus of the humerus

Question 17

What passes through the axilla?

Answer 17

Contents: NAVL — Nerve (brachial plexus), Artery (axillary), Vein (axillary), and Lymph nodes

Lymph drainage regions: Anterior/posterior chest wall, scapular region, upper limb

Drainage path: Subclavian trunk → Thoracic duct (left) or Lymphatic duct (right)

Question 18

Name the five groups of axillary lymph nodes and their drainage areas.

Answer 18

Anterior nodes: Drain anterior chest wall and breast

Posterior nodes: Drain posterior chest wall

Lateral nodes: Drain upper limb

Central & Apical nodes: Receive drainage from the above 3 groups

Efferent drainage from apical nodes: Into subclavian trunk

Question 19

Which lymph nodes are commonly involved in breast cancer spread?

Answer 19

Anterior, central, and apical nodes

Supraclavicular nodes may also receive drainage

Question 20

What is Axillary Lymph Node Dissection (ALND) and its boundaries?

Answer 20

ALND: Surgical removal of all nodal tissue in the axilla

Boundaries:

Superiorly: Axillary vein

Inferolaterally: Latissimus dorsi

Medially: Pectoralis minor

Posteriorly: Subscapularis

Question 21

What are accessory lymphatic channels and their clinical significance?

Answer 21

Connect to: Parasternal nodes

Allow: Direct metastasis to the contralateral breast

Obstruction risk: May reverse flow and involve nodes in atypical areas (e.g., inguinal region

Question 22

Which nerves are vulnerable during axillary lymph node dissection?

Answer 22

Long thoracic nerve (C5–C7): Innervates serratus anterior

Thoracodorsal nerve (posterior cord): Innervates latissimus dorsi

Intercostobrachial nerve (branch of 2nd intercostal): Sensory function

Question 23

What does the upper pharynx consist of, and what happens at the C4 level?

Answer 23

Upper pharynx (naso- and oropharynx): Shared aerodigestive pathway

At C4: Bifurcates into the larynx (airway) and laryngopharynx (digestive)

Question 24

What structures form at the C6 level?

Answer 24

Laryngopharynx continues as the esophagus

Larynx continues as the trachea

Question 25

At what vertebral level does the trachea bifurcate, and what are the differences between the R and L bronchi?

Answer 25

Bifurcation level: T4 Right main bronchus: More vertical and wider — more prone to aspiration Left main bronchus: More horizontal and narrower

Question 26

How many lobar and segmental bronchi are there in each lung?

Answer 26

Right lung: 3 lobar bronchi (upper, middle, lower) Left lung: 2 lobar bronchi (upper, lower) Each lung: 10 segmental bronchi Each supplies a bronchopulmonary segment, separated by connective tissue septa

Question 27

What is the path of food that triggers the cough reflex?

Answer 27

Food may enter the aditus of the larynx Travels into: Vestibule → Ventricle → Infraglottic space

Question 28

hat nerve initiates the cough reflex, and what sequence of events follows?

Answer 28

Nerve: Internal branch of the superior laryngeal nerve Sequence: Glottis closes Abdominal muscles contract Diaphragm relaxes Intrathoracic pressure increases Pressure builds in the infraglottic space Glottis bursts open → expels the foreign body

Question 29

What muscles move the bolus from mouth to oropharynx, and their innervation?

Answer 29

Palatoglossus – Vagus nerve (CN X) Hyoglossus – Hypoglossal nerve (CN XII) Styloglossus – Hypoglossal nerve (CN XII)

Question 30

Which muscles elevate the pharynx during swallowing, and how are they innervated?

Answer 30

Palatopharyngeus – Vagus nerve (CN X) Salpingopharyngeus – Vagus nerve (CN X) Stylopharyngeus – Glossopharyngeal nerve (CN IX)

Question 31

Which muscles occlude the nasopharynx by lifting the soft palate, and their innervation?

Answer 31

Levator palati – Vagus nerve (CN X) Tensor palati – Trigeminal nerve (CN V3)

Question 32

What muscle occludes the oral cavity during swallowing, and its innervation?

Answer 32

Palatoglossus – Vagus nerve (CN X)

Question 33

Which muscles constrict the pharynx, and what nerve innervates them?

Answer 33

Superior, middle, and inferior pharyngeal constrictors – Vagus nerve (CN X)

Question 34

What muscles close the glottis by adducting the vocal folds, and how are they innervated?

Answer 34

Lateral cricoarytenoid Interarytenoid → Both are innervated by the recurrent laryngeal branch of the Vagus nerve (CN X)

Question 35

What muscle obstructs the laryngeal aditus using the epiglottis, and its innervation?

Answer 35

Aryepiglotticus – Vagus nerve (recurrent laryngeal branch)

Question 36

When does the embryonic heart tube form and where is it located?

Answer 36

Week 4: The embryonic heart tube forms as a midline structure.

Question 37

What major heart developments occur during weeks 5–6 of embryonic development?

Answer 37

Ventricular septation: Division of ventricles into left and right Truncus arteriosus division: Forms ascending aorta and pulmonary trunk via the aorticopulmonary septum

Question 38

What is the developmental error in Tetralogy of Fallot (TOF)?

Answer 38

Cause: Dextropositioning (rightward displacement) of the aorticopulmonary septum Effect: Pulmonary stenosis (narrow trunk) Overriding aorta (receives blood from both ventricles) Right ventricular hypertrophy (due to pressure overload) Ventricular septal defect (VSD)