Ossos dos Membros Superiores: Sistema Esquelético 5/5

Summary

This educational video provides a detailed exploration of the bones in the human upper limb. It covers the shoulder girdle (clavicle and scapula), the arm (humerus), the forearm (radius and ulna), and the hand (carpals, metacarpals, and phalanges). The speaker explains each bone's location, function, and anatomical relationship, offering useful study tips for visualizing and understanding bone positioning. The content is designed for students learning human anatomy, with a focus on clarity and visual guidance for the wrist and hand bones, emphasizing both proximal and distal bone arrangements.

Takeaways

• 😀 The upper limb skeleton includes bones from the shoulder girdle, arm, forearm, wrist, and hand.
• 😀 The shoulder girdle (cintura escapular) consists of the clavicle and scapula, connecting the upper limb to the axial skeleton.
• 😀 The clavicle articulates with the sternum medially and the acromion of the scapula laterally, forming a key part of the shoulder.
• 😀 The scapula is a posterior bone that articulates with the humerus at the glenoid cavity, forming the shoulder joint.
• 😀 The humerus is the single bone in the upper arm, the longest bone of the upper limb.
• 😀 The forearm has two bones: the radius (lateral, near the thumb) and the ulna (medial, near the pinky).
• 😀 The anatomical position helps in distinguishing the radius (lateral) and ulna (medial), with the thumb serving as a key reference.
• 😀 The wrist contains eight small carpal bones, arranged in two rows: proximal (scaphoid, lunate, triquetrum, pisiform) and distal (trapezium, trapezoid, capitate, hamate).
• 😀 The hand has five metacarpal bones, with each corresponding to a finger, numbered from 1 (thumb) to 5 (pinky).
• 😀 The fingers have phalanges: the thumb has two (proximal and distal), while the other fingers have three (proximal, middle, distal).

Q & A

What bones make up the shoulder girdle or scapular belt?

The shoulder girdle consists of two bones: the clavicle and the scapula. The clavicle connects medially to the sternum and laterally to the acromion of the scapula.

How does the humerus relate to the scapula?

The humerus is the long bone of the upper arm that articulates with the scapula at the glenoid cavity, forming the shoulder joint.

What are the differences between the ulna and the radius in the forearm?

The ulna is the medial bone of the forearm, located closer to the body’s midline, while the radius is the lateral bone, positioned on the thumb side in the anatomical position.

What does the term 'anatomical position' refer to when discussing the radius and ulna?

In the anatomical position, the body stands upright with arms at the sides and palms facing forward. In this position, the radius is lateral (on the outside of the forearm) and the ulna is medial (closer to the body).

How are the carpal bones in the wrist organized?

The carpal bones are arranged in two rows of four. The proximal row includes the scaphoid, lunate, triquetrum, and pisiform. The distal row includes the trapezium, trapezoid, capitate, and hamate.

What is the function of the scapula in relation to the humerus?

The scapula plays a crucial role in shoulder movement, as it provides the articulation surface for the humerus at the glenoid cavity, allowing for a wide range of arm motions.

How many metacarpal bones are there in the human hand?

There are five metacarpal bones in the hand, one for each finger, numbered from 1 (the thumb) to 5 (the little finger).

What is the primary difference between the thumb and the other fingers in terms of phalanges?

The thumb has two phalanges: a proximal and a distal phalanx, whereas each of the other fingers has three phalanges: proximal, middle, and distal.

What is the significance of the 'pisiform' carpal bone?

The pisiform is the smallest carpal bone in the proximal row and is shaped like a pea, hence the name 'pisiform'. It is important in the function of the wrist joint.

What is the 'amato' carpal bone, and why is it named that?

The hamate carpal bone is also called 'amato' because of its hook-like structure, which gives it the appearance of a 'hook'. This shape is significant for the attachment of ligaments in the hand.