Biceps/Triceps/Knee/Ankle

JERKS and ROOTS

ALL: Reflexes goes to spinal cord and bypass the brain

Biceps (C5-C6)-->Elbow Flexion

Triceps (C7-C8)-->Elbow Extension

Knee Jerk/Patellar Reflex (L3-L4)-->Knee Extension

Ankle Jerk (S1-S2)

Definition of Afferent and Efferent Reflexes

Afferent (Sensory)-->Goes to Spinal Cord

Efferent (Motor)-->Produces the Reflex

Fractures of the Humerus

Surgical Neck Fracture-->Axillary Nerve damaged and Abduction of arm up to 90 degrees (deltoid)

Middle of Shaft Fracture--> Radial Nerve damaged leads to Wrist Drop and compromised extension of elbow

Bicipital Groove

(intertubercle groove)

Spiral Groove/Radial Groove

Bicipital Groove-->Long Head of Biceps Brachii

Spiral Groove-->Radial Nerve and Deep Brachial Artery and Vein.

What is Cleidocranial Dystosis?

Condition where there are problems with the ossification of the clavicle and skull.

(Clavicle: Between the latter concave 1/3 and medial convex 2/3)

Enchondral Ossification

vs.

Intramembraneous Ossification

Enchondral: Mesenchyme goes to hyaline cartilage then invaded by osteoblasts.

->Growth and epiphyseal plates

->Goes until 20-21 years old

Intramembraneous: Directly invaded by osteoblasts no cartilage involved

Biceps Brachii Muscle

Musculocutaneous Nerve (C5-C6)

Branching from the lateral cord of the Brachial Plexus

Serratus Anterior Muscle

Long Thoracic Nerve (C5, C6, C7)

Main Function

->Main elevation of the arm above 90.

->Protracts (Abduction) of the scapula against thoracic wall, rotates scapula laterally to elevate arm (Glenoid Cavity faces upward)

->An accessory muscle during respiration by lifting the ribs.

Origin->Lateral Aspect of the first 8-9 ribs.

Insertion->Medial Border of the Scapula from Superior to Inferior Angle

Winged Scapula

Muscles Involved: Serratus Anterior (Main) and sometimes Rhomboid (Palsy)

Condition: Can't elevate arms above 90 degrees.

Cause: Complete Masectomy and removal of some lymph nodes creating lesions on Long Thoracic Nerve.

Coracobrachialis Muscle

Musculocutaneous Nerve (C5,C6,C7)--Brachial Plexus

Main Function: Flexion (Anteversion) and Adduction of the Arm.

Origin: The Coracoid Process on the Scapula

Insertion: Medial Surface of the upper part of Humerus.

Pectoralis Minor Muscle

Medial Pectoral Nerve (C8-T1)

Main Function: Pulls scapula forward and downward. Rotation of the scapula so glenoid cavity faces down.

Origin: Anterior Surface of the first (3-5) ribs.

Insertion: The coracoid process of the scapula.

*Pectoralis Minor is deep to the Pectoralis Major.*

Pectoralis Major Muscle

(Superficial Muscle on the Upper Part of the

Thoracic Wall Anteriorly)

Lateral and Medial Pectoral Nerve (C5-T1)

(Originates from Brachial Plexus Lateral/Medial cords)

Main Function: Adduction and Medial Rotation of the Arm. Lowers the arm when raised. Clavicular part assists in anteversion of arm. This muscle also expands during forced respiration.

Origin: 3 sites. The Clavicle Medially. Sternum/Upper Costal Cartilages. Abdominal portion from Rectus Sheath.

Insertion: All the muscle fibers merge into crest of Greater Tubercle.

Rotator Cuff Injury