Intro to limb anatomy

Question 1

Nerve plexuses

Answer 1

• All are from ventral rami (contain SS, SM, sym/post)
• Brachial plexus: ventral rami of C5-T1
• Lumbosacral plexus: ventral rami of L3-S3

Question 2

Movements of limbs 1

Answer 2

• Movement definitions are different depending on which part of a limb is being talked about (upper vs lower)
• For forearms only: supination is palms face up, pronation is palms face down
• For upper limbs (rotation around elbow): flexion is anterior movement of arm, extension is posterior movement of arm

Question 3

Movements of limbs 2

Answer 3

• For upper limbs (rotation around shoulder): flexion is anterior movement of arm, extension is posterior movement of arm
• For lower limb (rotation around knee): flexion is posterior movement of leg, extension is anterior movement of leg
• For lower limb (rotation around hip): flexion is anterior movement of leg, extension is posterior movement of leg

Question 4

Various directions of movements

Answer 4

• Flexion: anterior movement (except around knee/ankle: posterior movement)
• Extension: posterior movement (except around knee/ankle: anterior movement)
• Abduction: away from body, laterally
• Adduction: toward body, medially
• Medial rotation
• Lateral rotation

Question 5

Movements of the glenohumeral (shoulder) joint

Answer 5

• Primary abductors: supraspinatus and deltoid muscles
• Primary lateral rotators: infraspinatus, teres minor, and posterior deltoid
• Primary medial rotators: pectoralis minor, latissimus dorsi, teres major, and subscarpularis
• Flexion: coracobrachialis, anterior deltoid, short head of biceps, and upper part of pectorals major
• Extension: teres major, latissimus dorsi, long head of triceps, and posterior deltoid

Question 6

Movements around the hip joint

Answer 6

• Abductors: gluteus medius, gluteus minimus, and tensor fascia latae (TFL)
• Lateral rotators: piriformis, obturator internus, obturator externus, and quadratus femoris
• Flexors: iliopsoas, sartorius, rectus femoris, abductor muscles

Question 7

Joints

Answer 7

• Fibrous joints: made of dense connective tissue, found in interosseous membranes (sutures of skull)
• Synovial joints: have various components such as joint cavity, hyaline cartilage on bony surfaces, joint capsule (SS innervation), synovial lining membrane (secretes synovial fluid), synovial fluid