Comparison of Upper and Lower Limbs

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Questions and Answers

What is the primary function of the clavicle?

To protect the vasculonervous package that supplies the upper limb

To serve as a movable support for the scapula and the free part of the limb (correct)

To facilitate deep breathing by elevating the ribs

To provide a wide range of motion for the upper limb

What is the shape of the clavicle?

S-shaped (correct)

Circular

C-shaped

Triangular

What is the composition of the clavicle?

Mainly cartilage

Pure spongy bone

Pure compact bone

A combination of spongy and compact bone (correct)

What is the significance of the clavicle being subcutaneous?

It allows for easy palpation Signup and view all the answers

How does the clavicle facilitate the movement of the scapula?

Through the 'escapulotoracic union' Signup and view all the answers

What is the function of the ligaments that connect the clavicle to the first rib?

To suspend the scapula Signup and view all the answers

Why is the inferior surface of the clavicle rough?

Because of the presence of ligaments Signup and view all the answers

What is the benefit of the clavicle's mobility?

It increases the range of motion of the upper limb Signup and view all the answers

What is the purpose of abducting the arm at an angle of approximately 15° when exploring the deltoid muscle?

To observe and palpate the deltoid muscle Signup and view all the answers

Which nerve innervates the deltoid muscle?

Axillary nerve Signup and view all the answers

What is the function of the redondo mayor muscle?

It adducts and rotates the arm medially Signup and view all the answers

What is the location of the redondo mayor muscle?

Inferolateral to the scapula Signup and view all the answers

What is the purpose of placing the arm in abduction when exploring the redondo mayor muscle?

To observe and palpate the redondo mayor muscle Signup and view all the answers

Which muscle is an important stabilizer of the humeral head in the glenoid cavity?

Redondo mayor muscle Signup and view all the answers

What is the nerve that innervates the redondo mayor muscle?

Inferior subescapular nerve Signup and view all the answers

What is the position of the arm when exploring the redondo mayor muscle?

Abduction Signup and view all the answers

Which dermatome is responsible for the sensation in the lateral aspect of the forearm and the thumb?

C6 Signup and view all the answers

Which spinal nerve segment is associated with the sensation in the medial aspect of the arm and forearm?

T1 Signup and view all the answers

Which dermatome is responsible for the sensation in the middle and ring fingers?

C7 Signup and view all the answers

Which spinal nerve segment is associated with the sensation in the base of the neck and the shoulder region?

C3, C4 Signup and view all the answers

What is the characteristic of the majority of the nerves in the upper limb?

They contain fibers from more than one spinal nerve or segment Signup and view all the answers

Which dermatome is responsible for the sensation in the little finger and the medial aspect of the forearm?

C8 Signup and view all the answers

What is the characteristic pain pattern in myocardial infarction?

Radiating downwards along the medial aspect of the left arm Signup and view all the answers

Which figure illustrates the distribution of the peripheral nerves (cutaneous nerves) of the upper limb?

Figure 3-19 Signup and view all the answers

What is the main reason for the sacrifice of stability in the upper limb?

To achieve greater mobility Signup and view all the answers

What is the primary function of the lower limbs?

To support the body's weight and transmit it to the ground Signup and view all the answers

How do the two pelvic bones connect to the sacrum?

Through the sacroiliac joints Signup and view all the answers

What is the main difference between the upper and lower limbs in terms of their connection to the axial skeleton?

The upper limbs are more mobile, while the lower limbs are more stable Signup and view all the answers

What is the role of the hand in the upper limb?

To facilitate the grasping and manipulation of objects Signup and view all the answers

How do the scapulae and clavicles connect to the axial skeleton?

Through the manubrium of the sternum Signup and view all the answers

What is the function of the sacroiliac joints?

To act as a rigid and stable joint Signup and view all the answers

What is the main characteristic of the upper limb that allows it to exercise some function in the desplazamiento?

Its ability to adopt a palmar or prehensile configuration Signup and view all the answers

What is the primary function of the spongy interior in the costillas?

Producing cells of the blood Signup and view all the answers

Which type of costillas connects directly to the sternum through their own cartilages?

Costillas verdaderas Signup and view all the answers

What is the main characteristic of the costillas flotantes?

They have cartilages that never connect to the sternum Signup and view all the answers

What is the function of the articular portion of the tubérculo?

To articulate with the transverse process of the corresponding vertebra Signup and view all the answers

How do the costillas falsas connect to the sternum?

Indirectly through the cartilage of the adjacent costilla Signup and view all the answers

What is the characteristic of the body of the costillas?

It is thin and flat Signup and view all the answers

What is the name of the ligament that inserts into the non-articular portion of the tubérculo?

Ligamento costotransverso Signup and view all the answers

How many types of costillas can be classified?

3 Signup and view all the answers

Study Notes

Comparative Analysis of Upper and Lower Limbs

Both upper and lower limbs are formed similarly, but their structure is distinct enough to provide different functions and capabilities.
The upper limb has sacrificed stability for greater mobility, but still possesses considerable force.

Connection to Axial Skeleton

Upper and lower limbs are connected to the axial skeleton (cranium, vertebral column, and thoracic cage) through the shoulder and pelvic girdles, respectively.
The pelvic girdle is formed by the two coxal bones, which connect to the sacrum (fig. 7-3).
The shoulder girdle consists of the scapulae and clavicles, which connect to the manubrium of the sternum.

Clavicle

Acts as a movable strut (support) for the scapula and the free part of the limb, allowing for maximum freedom of movement.
Permits the scapula to slide along the thoracic wall via the scapulothoracic joint, increasing the amplitude of limb movements.
Fixes the strut in place, especially after elevation, facilitating the ascension of the ribs for deep inspiration.
Transmits shocks (traumatic impacts) from the upper limb to the axial skeleton.
Protects the vasculonervous bundle that irrigates, drains, and innervates the upper limb.

Dermatomas of the Upper Limb

Segment of the spinal cord and description of dermatomes:
- C3, C4: region of the base of the neck, extending laterally over the shoulder
- C5: lateral aspect of the arm (i.e., superior aspect of the abducted limb)
- C6: lateral aspect of the forearm and thumb
- C7: middle and ring fingers (or the three middle fingers) and the central part of the posterior aspect of the forearm
- C8: little finger, medial aspect of the forearm, and the hand (i.e., inferior aspect of the abducted limb)
- T1: medial aspect of the forearm and arm
- T2: medial aspect of the upper arm and axillary skin

Redondo Mayor Muscle

A rounded muscle that runs laterally to the inferolateral third of the scapula.
Forms the inferior border of the lateral wall of the axilla.
Adducts and medially rotates the arm, and also participates in its extension from the flexed position.
Is an important stabilizer of the humeral head in the glenoid cavity.

Romboides Muscle

(Figure 3-28)

Escapulohumeral Muscles

Muscles that run from the scapula to the humerus and act on the shoulder joint.
(Figures 3-29 A-D)

Deltoides Muscle

(Figure 3-30)

Costillas, Cartílagos Costales, and Espacios Intercostales

Ribs are curved, flat bones that form the bulk of the thoracic cage.
Classified into three types: true ribs (1st-7th), false ribs (8th-10th), and floating ribs (11th-12th).
Each rib has a spongy interior that contains bone marrow (hematopoietic tissue), which produces blood cells.

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Description

This quiz compares the structure and functions of the upper and lower limbs, highlighting their similarities and differences.