Doctor

20/02/2026

💪🦴 Muscles of the Back – The Body’s Structural Support and Movers
The back muscles are a complex network that provides posture, spinal movement, and upper limb mobility, while protecting the spinal cord. They are arranged in layers and divided into extrinsic (superficial & intermediate) and intrinsic (deep) muscles.
🔹 Extrinsic (Superficial & Intermediate) Back Muscles
These muscles connect the upper limbs and ribs to the spine, mainly involved in movement and respiration.
Superficial Group (Upper limb movement)
• Trapezius – elevates, retracts, and rotates the scapula
• Latissimus dorsi – extends, adducts, and medially rotates the arm
• Rhomboid major & minor – retract and stabilize the scapula
• Levator scapulae – elevates the scapula
Intermediate Group (Respiration)
• Serratus posterior superior – elevates ribs
• Serratus posterior inferior – depresses ribs
🔹 Intrinsic (Deep) Back Muscles
Also called true back muscles, these muscles maintain posture and move the vertebral column.
Superficial Intrinsic Layer
• Splenius capitis – extends head and neck
• Splenius cervicis – rotates and extends neck
Intermediate Layer – Erector Spinae Group
Powerful extensors of the spine, including:
• Iliocostalis – lateral column
• Longissimus – intermediate column
• Spinalis – medial column
Function: posture maintenance and bending movements
Deep Layer – Transversospinalis Group
• Semispinalis – extends vertebral column and head
• Multifidus – stabilizes vertebrae
• Rotatores – assist rotation of spine
🧠 Nerve Supply
All intrinsic muscles are supplied by posterior (dorsal) rami of spinal nerves.
⚡ Functions
✔ Maintain upright posture
✔ Facilitate movements: flexion, extension, rotation, lateral bending
✔ Stabilize vertebrae during motion
✔ Assist respiration (intermediate group)
⚕️ Clinical Importance
• Weak or atrophied back muscles → poor posture, low back pain
• Muscle spasm → restricted spinal mobility
• Injury can affect upper limb movement and stability

02/02/2026

4 Types of THYROID CANCER USMLE Will Test on Step 1, Step 2, & Step 3

1️⃣ Papillary Carcinoma
🔬 Most common (80%). best prognosis
They’ll give you young woman with painless nodule, history of childhood radiation, cervical lymphadenopathy.
⚠️ Spreads via LYMPHATICS but still excellent prognosis.
Histology: “Orphan Annie” eyes (clear nuclei), nuclear grooves, psammoma bodies.
🔍 Dx: Ultrasound → FNA shows characteristic nuclear features.
🏥 Tx: Total thyroidectomy + radioactive iodine (I-131) ablation + TSH suppression. >95% survival.

2️⃣ Follicular Carcinoma
🔬 Second most common. spreads via BLOOD
They’ll give you middle-aged patient with nodule.
FNA says “follicular neoplasm”. cannot distinguish adenoma from carcinoma on FNA.
⚠️ Spreads hematogenously to bone and lungs, NOT lymph nodes.
Need surgical excision to see capsular/vascular invasion.
🔍 Dx: FNA indeterminate → lobectomy required to diagnose.
🏥 Tx: Total thyroidectomy + radioactive iodine + TSH suppression.
🎯 FNA “follicular neoplasm” + need surgery to diagnose + mets to bone/lung = Follicular

3️⃣ Medullary Carcinoma
🔬 Parafollicular C cells. CALCITONIN
They’ll give you thyroid mass + elevated calcitonin + diarrhea.
Ask about MEN2A (pheo, hyperparathyroidism) or MEN2B (marfanoid, mucosal neuromas).
⚠️ 25% familial (RET mutation).
Histology shows amyloid deposits.
Screen for pheo BEFORE surgery in MEN2.
🔍 Dx: Elevated calcitonin. RET genetic testing. FNA with calcitonin stain.
🏥 Tx: Total thyroidectomy + lymph node dissection.
NO radioactive iodine. C cells don’t take it up.
🎯 Calcitonin elevated + amyloid + MEN2 = Medullary

4️⃣ Anaplastic Carcinoma
🔬 Undifferentiated. WORST PROGNOSIS
They’ll give you elderly patient (>60) with rapidly enlarging, rock-hard fixed mass causing dysphagia, hoarseness, stridor.
⚠️ Median survival 6 months.
Does NOT respond to radioactive iodine or TSH suppression.
🔍 Dx: FNA shows undifferentiated cells. CT for invasion.

20/01/2026

Lung sounds are the audible vibrations created as air moves through the respiratory system, and they are heard during auscultation with a stethoscope. These sounds offer valuable clues about airway openness, lung tissue health, and the presence of fluid, inflammation, or obstruction.

Normal lung sounds include tracheal, bronchovesicular, and vesicular patterns, each reflecting airflow through specific regions of the lungs. Abnormal lung sounds such as crackles, wheezes, rhonchi, stridor, and pleural friction rubs often indicate conditions like pneumonia, asthma, heart failure, or pleural irritation.

Changes in pitch, loudness, or location can show altered ventilation or airway narrowing. Because lung sounds often change before physical symptoms develop, auscultation remains essential for effective diagnosis and clinical monitoring.

17/01/2026

Anatomy of Digestive System

30/12/2025

Forearm muscle supply

20/12/2025

Head and Neck Anatomy

06/12/2025

Superficial Muscles of the Upper Body 📖🔍
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▪️ Understanding the superficial muscles of the upper body is essential for any medical and sports professional.
▪️ These muscles lie close to the skin and are responsible for major movements of the shoulders, arms, chest, and back.
▪️ They also play a vital role in posture, stabilization, and functional performance.
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1) Trapezius :
- Location : Upper back and neck .
- Function : Elevates, depresses, retracts, and rotates the scapula; helps extend the neck.
- Note : Crucial for posture and scapular stabilization.
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2) Latissimus Dorsi :
- Location : Mid to lower back, extending to the upper arm
- Function : Extends, adducts, and internally rotates the arm; supports pulling movements.
- Note : Known as the “lats,” important for pulling strength.
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3) Pectoralis Major :
- Location : Front of the chest .
- Function : Flexes, adducts, and internally rotates the arm.
- Note : Main pushing muscle of the chest.
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4) Deltoid :
- Location : Shoulder .
- Function : Abducts the arm; anterior fibers flex and internally rotate; posterior fibers extend and externally rotate.
- Note : Gives the shoulder its rounded shape.
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5) Biceps Brachii :
- Location : Front of the upper arm .
- Function : Flexes the elbow and supinates the forearm.
- Note : Frequently trained in upper body workouts.
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6) Triceps Brachii :
- Location : Back of the upper arm .
- Function : Extends the elbow joint; assists in shoulder extension.
- Note : The main opposing muscle to the biceps; essential for pushing movements .
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7) Brachialis :
- Location : Deep to the biceps brachii .
- Function : Primary flexor of the elbow joint.
- Note : Important for arm strength.
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8 ) Brachioradialis :
- Location : Lateral side of the forearm .
- Function : Flexes the elbow, especially in a neutral grip ( when your palm is facing inward (like a handshake position).
- Note : Supports grip and forearm stability.
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9) Flexor & Extensor Muscles of the Forearm :
- Location : Anterior and posterior compartments of the forearm.
- Function : Control wrist and finger movements, including flexion, extension, pronation, and supination.
- Note : Essential for grip strength, functional hand use, and wrist stability.
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10) Serratus Anterior :
- Location : Lateral chest wall, attached to ribs .
- Function : Protracts and stabilizes the scapula against the rib cage.
- Note : Known as the “boxer’s muscle.”
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13/11/2025

Hip Muscles Anatomy - Anatomy
A variety of hip muscles surround the hip joint, and act to accelerate, decelerate, and stabilize the hip joint.

11/11/2025

07/11/2025

Amniotic Fluid Index (AFI), It is a quantitative measurement of the amount of amniotic fluid surrounding the fetus in the uterus, assessed using ultrasound.

24/10/2025

Injection Techniques