Locomotive And Movement (17.3 - 17.5)

What does the skeletal system consist of?

The skeletal system consists of a framework of bones and a few cartilages

Why is the skeletal system significant?

It plays a significant role in movement by providing support and attachment points for muscles.

How do bone and cartilage differ in structure?

Bone has a very hard matrix due to calcium salts, while cartilage has a slightly pliable matrix due to chondroitin salts.

How many bones make up the human skeletal system?

The human skeletal system is made up of 206 bones.

Into how many principal divisions is the skeletal system grouped? Name them.

Two principal divisions: the axial skeleton and the appendicular skeleton.

What does the axial skeleton include?

The axial skeleton comprises 80 bones, including the skull, vertebral column, sternum, and ribs.

How many bones form the skull?

The skull is composed of 22 bones, including 8 cranial bones and 14 facial skeletal elements.

What is the hyoid bone, and where is it located?

The hyoid is a U-shaped bone present at the base of the buccal cavity and is included in the skull.

What are the ear ossicles?

Each middle ear contains three tiny bones: Malleus, Incus, and Stapes, collectively called ear ossicles.

What connects the skull to the vertebral column?

The skull region articulates with the superior region of the vertebral column with the help of two occipital condyles, making it dicondylic.

What is the vertebral column? How many vertebrae does it have?

The vertebral column consists of 26 serially arranged vertebrae and forms the main framework of the trunk.

Describe the vertebral column's regions

The vertebral column is differentiated into cervical (7), thoracic (12), lumbar (5), sacral (1-fused), and coccygeal (1-fused) regions.

What is the function of the vertebral column?

The vertebral column protects the spinal cord, supports the head, and serves as the attachment point for ribs and back musculature.

How many pairs of ribs are there, and how are they classified?

There are 12 pairs of ribs classified as true ribs (first 7 pairs), false ribs (8th-10th pairs), and floating ribs (11th-12th pairs).

What forms the rib cage?

The rib cage is formed by the thoracic vertebrae, ribs, and sternum.

What constitutes the appendicular skeleton?

The appendicular skeleton includes the bones of the limbs and their girdles, with each limb made up of 30 bones.

Name the bones of the forelimb.

Humerus, radius, ulna, carpals (8), metacarpals (5), and phalanges (14).

What is the longest bone in the human body?

The femur, or thigh bone, is the longest bone in the human body.

What are the bones of the hind limb?

Femur, tibia, fibula, tarsals (7), metatarsals (5), and phalanges (14).

What is the patella?

The patella, or kneecap, is a cup-shaped bone covering the knee ventrally.

Describe the pectoral girdle

Each half of the pectoral girdle consists of a clavicle and a scapula. The scapula is a triangular flat bone with a ridge (spine) and a depression (glenoid cavity) that articulates with the humerus.

What is the pelvic girdle?

The pelvic girdle consists of two coxal bones, each formed by the fusion of ilium, ischium, and pubis, with a cavity called the acetabulum for articulation with the thigh bone.

What are joints?

Joints are points of contact between bones or between bones and cartilages, facilitating movement.

What are the three types of joints?

Fibrous, cartilaginous, and synovial joints.

Describe fibrous joints

Fibrous joints do not allow any movement and are found in flat skull bones joined by sutures.

What are cartilaginous joints?

Joints where bones are joined by cartilage, allowing limited movement, such as between vertebrae.

What are synovial joints?

Synovial joints are characterized by a fluid-filled synovial cavity between articulating bones, allowing considerable movement. Examples include ball and socket, hinge, and pivot joints.

What is myasthenia gravis?

An autoimmune disorder affecting the neuromuscular junction, causing fatigue, weakness, and skeletal muscle paralysis.

What is muscular dystrophy?

A genetic disorder leading to progressive degeneration of skeletal muscle.

Define tetany.

Rapid muscle spasms due to low calcium levels in body fluids.

What is arthritis?

Inflammation of joints.

What causes osteoporosis?

Age-related loss of bone mass and increased fracture risk, commonly due to decreased estrogen levels.

What is gout?

Inflammation of joints caused by the accumulation of uric acid crystals.