**Core Concept:** The humerus is a long bone in the upper extremity, forming part of the human shoulder joint. It has two major parts: the shaft (or shafts) and the head. The attachment sites for muscles are crucial for understanding muscle function and pathologies.

**Why the Correct Answer is Right:** The correct answer is D) "There is no attachment of the long head of biceps brachii."

The long head of the biceps brachii is a muscle of the upper arm that originates from the supraglenoid tubercle of the scapula (shoulder blade) and inserts onto the neck of the humerus. The other options are true:

A. The short head of biceps brachii does attach to the supraglenoid tubercle of the scapula and also to the coracoid process of the scapula.
B. The brachialis muscle attaches to the inner part of the humerus (anteromedial aspect) and the ulna (ulnar head).
C. The brachioradialis muscle attaches to the olecranon process of the ulna and the radius.

**Why Each Wrong Option is Incorrect:**

A. The short head is not considered incorrect as it attaches to the supraglenoid tubercle of the scapula and the coracoid process of the scapula.
B. Brachialis does attach to the humerus, but not specifically to the neck of the humerus.
C. Brachioradialis does attach to the olecranon process of the ulna and the radius, not just the humerus.

**Why the Correct Answer is Right:**

The long head of the biceps brachii is the one muscle that does not attach to the humerus, specifically to the neck of the humerus. This is important to remember as it affects the path of the long head of the biceps brachii muscle during contraction, which can lead to tendonitis or inflammation in the biceps tendon in the elbow joint (bicipital tendinitis).

**Why Each Wrong Option is Incorrect:**

A. The short head is not considered incorrect, as it attaches to the supraglenoid tubercle of the scapula and the coracoid process of the scapula.
B. Brachialis does attach to the humerus, but not specifically to the neck of the humerus.
C. Brachioradialis attaches to the olecranon process of the ulna and the radius, not just the humerus.

**Why the Correct Answer is Right:**

The long head of the biceps brachii attaches to the neck of the humerus, allowing it to pull the humerus during contraction, causing the elbow joint to flex (bend) at the elbow joint.

**Clinical Pearls:**

1. Understanding the correct attachment sites of muscles is essential for diagnosing and treating muscle strains, tendinitis, or bicipital tendinitis, which