Q. 26 - Biology

Question

What are the major differences between the pelvic girdle and the pectoral girdle that allow the pelvic girdle to bear the weight of the body? 

Step-by-Step Solution

Answer

• Conversely to the pectoral girdle, which is only tenuously linked to the ribcage, the pelvic girdle is firmly fastened to the body by powerful ligaments. 
• Compared to the pectoral girdle, which has shallow sockets for the scapula, the pelvic girdle's sockets are deep, allowing the femur to be more stable. Because the head and neck are so hefty, most tetrapod's carry 75% of their weight on their front legs; the shoulder joint's benefit is greater range of motion.
• Exoskeletons and hydrostatic pressure can both shield interior organs from damage. 
  Compare the methods the skeletons use to carry out these tasks.

Step 1 : Introduction

The difference between the pectoral and pelvic girdles is primarily due to the following factors: the type of bones that contribute to formation, bone association, and articulations. The two types of bones that contribute to shoulder muscle or pectoral girdle formation are the collar bone (clavicle) and the shoulder blade (scapula). 

Step: 2 Pelvic girdle

• The pelvic girdle's anterior portion is made up of the pubis. 
• When standing or sitting, the major function of the pelvic girdle is to support the upper body's weight and distribute it to the lower limbs. 
• The pubic symphysis, a cartilaginous joint, articulates well with pelvic girdle, a flattened, atypically formed bone. 

Step: 3 Pectoral girdle

• The clavicle and scapula are the two principal bones that make up the pectoral girdle.
• The clavicles in humans connect the sternum (breastbone) medially and the scapulae laterally; the scapulae are connected to the trunk only via muscles, though.