Temporomandibular joint

It is a condylar variety of synovial joint, present in the buccal region. Temporo-mandibular joint helps in chewing.

Bones involved - 

1. Temporal

2. Mandibular

Articular surface - 

A. Upper articular surface is formed by the temporal bone.

1. Articular tubercle of temporal bone.

2. Anterior part of mandibular fossa of temporal bone.

3. Posterior non articular part formed by head of mandible of temporal bone.

B. Lower articular surface is formed by mandible bone.

Note - The articular surfaces are covered with fibrocartilage and the joint cavity is divided into upper and lower parts by an inter articular disc.

Ligaments of TMJ -

1. Fibrous capsule

2. Lateral TM ligament

3. Sphenomandibular ligament

4. Stylomandibular ligament

Relations - 

A. Lateral - 

1. Skin and fasciae

2. Parotid gland

3. Facial nerve (only temporal branch)

B. Medial 

1. Tympanic plate

2. Spine of sphenoid bone

3. Auriculo temporal and chorda tympani nerves

4. Middle meningeal artery

C. Anterior 

1. Lateral pterygoid

2. Masseteric nerves and artery

D. Posterior

1. Parotid gland

2. Superficial temporal vessels

3. Auriculotemporal nerves

E. Superior

1. Middle cranial fossa

2. Middle meningeal vessels

F. Inferior

1. Maxillary artery

2. Maxillary vein

Blood supply of TMJ - 

1. Superficial temporal artery and vein.

2. Maxillary artery and vein.

Nerve supply of TMJ - 

1. Auriculotemporal nerve.

2. Masseteric nerve.

Movements of TMJ - 

1. Depression 

2. Elevation

3. Protrusion

4. Retrusion

5. Lateral or side to side movements (during chewing)

Main muscles producing movements of TMJ - 

1. Depression - 

a. Lateral pterygoid

2. Elevation -

a. Masseter

b. Temporalis

c. Medial pterygoid 

3. Protrusion -

a. Lateral and medial pterygoid

b. Superficial oblique fibres of masseter

4. Retraction - 

a. Posterior horizontal fibres of temporalis

b. Deep vertical fibres of masseter

5. Lateral movements - 

A. Right side movement - 

 

a. Left lateral and medial pterygoid

b. Right temporalis 

c. Right masseter

B. Left side movement -

a. Right lateral and medial pterygoid.

b. Left temporalis

c. Left masseter

Clinical anatomy - 

1. Dislocation of mandible during excessive opening of mouth.

2. During operations of TMJ, facial and  auriculotemporal and mandibular division of trigeminal nerves should be taken care.

Shoulder joint

It is a ball and socket variety of synovial joint. 

Bones involved in shoulder joint

1. Scapula

2. Humerus

Articular surface involved in shoulder joint

1. Glenoid cavity of scapula

2. Head of the humerus

Factors providing stability of shoulder joint 

1. Rotator cuff muscles 

Click here to know more about rotator cuff muscles

2. Glenoid labrum

Movements of shoulder joint

1. Flexion

2. Extension

3. Adduction

4. Abduction 

5. Medial rotation

6. Lateral rotation

7. Circumduction (not a particular movement but rather it is a combination of all six movements)

Ligaments of shoulder joint

1. Capuslar ligament

2. Transverse humeral ligament

3. Coracohumeral ligament

4. Glenoidal labrum

Bursae present in shoulder joint

1. Subacromial bursae

2. Subscapularis bursae

3. Infraspinatus bursae

Relations

1. Superiorly

Coracoacromial arch, subacromial bursae, supraspinatus and deltoid muscle.

2. Inferiorly 

Long head of triceps brachii, axillary nerves and posterior circumflex humeral artery.

3. Anteriorly 

Subscapularis, coracobrachialis, short head of bicep brachii and deltoid muscles

4. Posteriorly

Infraspinatus, teres minor and deltoid muscles.

5. Within the joint

Long head of biceps brachii.

Blood supply 

1. Anterior and posterior humeral vessels.

2. Suprascapular vessels.

3. Subscapular vessels.

Nerve supply

1. Axillary nerve.

2. Musculocutaneous nerve.

3. Suprascapular nerve.

Click here to check my playlist on nerves of upper limb.

Main muscles producing movements of shoulder joint.

1. Flexion

a. Pectoralis major 

b. Anterior deltoid

2. Extention

a. Posterior deltoid

b. Lattisimus dorsi

3. Adduction

a. Pectoralis major

b. Lattisimus dorsi

c. Biceps brachii

d. Triceps brachii

4. Abduction 

From - 

a. 0° to 15° - Supraspinatus

b. 15° to 90° - Middle Deltoid

c. 90° to 180° - Serratus anterior and trapezius

5. Internal rotation

a. Pectoralis major

b. Anterior deltoid

c. Lattisimus dorsi

d. Teres major

6. External rotation 

a. Posterior deltoid

b. Infraspinatus

c. Teres minor

Clinical anatomy 

1. Frozen shoulder

2. Shoulder joint dislocatiom

3. Shoulder tip pain

Pain gate theory diagram.

Quadriceps muscle.

There are four muscles present in the anterior compartment of thigh. Those four muscles provides stability to the knee joint and helps in extention of knee. 

Name of quadriceps muscles - 

1. Rectus femoris

a. Origin - From anterior inferior iliac spine and groove above brim of acetabulum.

b. Insertion - Base of patella. 

c. Nerve supply - Femoral nerve (L1, L2,          L3).

d. Action - Extension of knee.

2. Vastus lateralis

a. Origin - Upper part of intertrochanteric         line of femur.

b. Insertion - Lateral and upper border of        patella.

c. Nerve supply - Femoral nerve.

d. Action - Extention of knee.

3. Vastus medialis

a. Origin - Lower part of intertrochanteric         line of femur.

b. Insertion - Upper and medial border of        patella. 

c. Nerve supply - Femoral nerve. 

d. Action - Extention of knee. 

4. Vastus intermedius

a. Origin - Upper 2/3rd anterior and lateral      surfaces of shaft of femur

b. Insertion - Lateral border of patella.

c. Nerve supply - Femoral nerve. 

d. Action - Extention of knee.

NOTE - 

Vastus medialis has also two  parts

1. Vastus medialis longus(VML)

2. Vastus medialis oblique(VMO) 

VMO exercises are very helpful in knee pain specially in arthritis

VMO isometric contraction

Femoral artery.

Femoral artery is a continuation of external iliac artery after passing through the inguinal ligament.  

Femoral artery has three divisions -

1. Superficial

Superficial femoral artery has following three branches -

a. Superficial epigastric artery

b. Superficial external pudendal artery

c. Superficial circumflex iliac artery

2. Deep

Deep femoral artery has following three branches - 

a. Deep external pudendal artery

b. Muscular artery

c. Profunda femoris artery

3. Descending genicular artery 

It is itself a branch of femoral artery which supplies to the knee joint.

Diagram of femoral artery -

Rotator cuff

It is a fibrous sheath formed by four tendons which strengthens the capsule of shoulder joint from all sides except inferiorly. 

Rotator cuff muscles also stabilises humeral head to keep it in its position so there is stable range of motion of shoulder joint.

Note :- As the rotator cuff muscles doesn't strengthens the capsule joint from inferior side so dislocation of the humerus occurs most commonly in a downward direction.

Origin and insertion of rotator cuff muscles.

Muscles of rotator cuff muscle arises from scapula and are inserted into lesser and greater tubercle of humerus.

 Rotator cuff muscles name -

1. Subscapularis

2. Supraspinatus

3. Infraspinatus

4. Teres minor

Clinical - 

1. Rotator Cuff Tear - 

Tearing of the muscles or tendons of rotator cuff.

2. Rotator Cuff Tendinitis - 

Acute inflammation of the tendons of rotator cuff.

3. Rotator Cuff Tendinopathy -

Chronic degeneration of the rotator cuff tissue.

4. Impingement syndrome -

Biomechanical dysfunction of the shoulder complex with causes abnormal wear and tear on the rotator cuff soft tissue.

5. Bursitis -

Inflammation of the bursa around the rotator cuff muscle. 

Femoral triangle.

It is a femoral trigone present in the supero medial part of anterior thigh.

It can be seen during - 

1. Flexion of hip joint.

2. Abduction of hip joint

3. Internal rotation of hip joint

BOUNDARY OF FEMORAL TRIANGLE

1. Lateral - 

Sartorius muscle

2. Medial -

Adductor longus muscle 

3. Base -

Inguinal canal (present between anterior superior iliac spine and pubic tubercle).

4. Apex - 

It is a point where the lateral and medial boundary meet.

ROOF OF FEMORAL TRIANGLE

1. Skin

2. Superficial fascia

3. Deep fascia

FLOOR 

1. Medial - Adductor longus

2. Lateral - Iliopsus (Psoas major and iliacus)

CONTENTS

1. Femoral nerve and its branches such as pectineus nerve and genito femoral nerve.

2. Femoral artery.

3. Femoral vein.

4. Lymph node.

5. Great saphenous vein.

6. Flexor sheath

NOTE :- The contents of femoral traingle is divided into three compartments for artery, vein and lymph. The three compartments are called media, lateral and intermediate compartment. The compartments are tied together by a flexor sheath. Flexor sheath holds the artery, vein and lymph nodes as there is higher pressure of blood in them.