3.3 Skeletal system organisation

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Questions and Answers

How many bones are in the axial skeleton?

80 (correct)

206

Which of the following is NOT a component of the axial skeleton?

Sternum

Ribs

Shoulder blades (correct)

Vertebrae

What is the total number of rib bones in the human skeletal system?

24 (correct)

Which structure is formed by the 24 vertebrae?

Vertebral column Signup and view all the answers

How many bones comprise the hyoid structure in the human skeleton?

1 Signup and view all the answers

What are the total number of bones in the axial skeleton?

80 bones Signup and view all the answers

Which of the following is NOT a function of the axial skeleton?

Facilitates limb movement Signup and view all the answers

How many regions are in the vertebral column?

5 regions Signup and view all the answers

Which type of rib is characterized as being directly attached to the sternum?

True ribs Signup and view all the answers

What is a key structural difference between the male and female pelvis?

Width Signup and view all the answers

Which of the following is NOT part of the axial skeleton?

Humerus Signup and view all the answers

The axial skeleton does NOT include which of the following?

Pelvic bones Signup and view all the answers

How many bones make up the adult skull?

22 bones Signup and view all the answers

What is the primary function of intervertebral disks in the vertebral column?

To absorb shocks Signup and view all the answers

Which of the following describes the cervical vertebrae?

There are 7 cervical vertebrae located in the neck. Signup and view all the answers

What is the main role of the thoracic cage?

To support the thoracic cavity and protect organs Signup and view all the answers

Which of the following is NOT a component of the vertebral column?

Clavicle Signup and view all the answers

How many total vertebrae are found in the adult vertebral column?

26 vertebrae Signup and view all the answers

Which bones can be found articulating with the thoracic vertebrae?

Ribs Signup and view all the answers

What characterizes the sacral and thoracic spinal curves?

Both are primary curves accommodating organs Signup and view all the answers

Study Notes

The Skeletal System

The skeletal system in adults has 206 bones, divided into the axial and appendicular skeletons.
The axial skeleton provides support and protection for vital organs, and consists of 80 bones.
- The skull, made up of 22 bones (8 cranial and 14 facial) houses and protects the brain.
- Some bones are air-filled to reduce weight, assist with speech production, and moisten and clean incoming air.
- The vertebral column, or 'spine,' protects the spinal cord, supports the head and body, and has 4 spinal curves: cervical, thoracic, lumbar, and sacral.
- The vertebral column is made up of 26 bones: 24 vertebrae, the sacrum, and the coccyx.
- The thoracic cage, which supports the chest cavity, is composed of thoracic vertebrae, ribs, and the sternum.
The appendicular skeleton is responsible for movement, and includes 126 bones.
- The pectoral girdle connects the arms to the body and consists of the clavicles (collarbones) and scapulae (shoulder blades).
- The upper limbs include the arms, forearms, wrists, and hands. They have bones like the humerus, ulna, radius, carpal bones, metacarpals, and phalanges.
- The pelvic girdle consists of the hip bones, providing support and stability for the lower limbs.
- The lower limbs (legs, ankles, and feet) are responsible for locomotion and weight-bearing with bones like the femur, patella (kneecap), tibia, fibula, tarsals, metatarsals, and phalanges (toes).
- The pelvic girdle is made up of two hipbones (ossa coxae), connecting the lower limbs to the axial skeleton.

The Thoracic Cage

The thoracic cage is composed of the thoracic vertebrae, ribs, and sternum, forming the skeleton of the chest.
Ribs are classified as true ribs (1-7), false ribs (8-12), and floating ribs (11-12).
The sternum is a flat bone located in the midline of the chest wall.
The xiphoid process of the sternum attaches to the diaphragm and rectus abdominis muscles.

The Vertebral Column

The vertebral column protects the spinal cord, supports the head and body, and consists of 26 bones.
Vertebrae are classified into five regions: cervical (7), thoracic (12), lumbar (5), sacrum (1), and coccyx (1).
The intervertebral disks are fibrocartilage pads that separate the vertebral bodies, absorbing shocks and cushioning the vertebrae.
The vertebral canal is a hollow passageway that encloses the spinal cord.
Vertebral foraminae are gaps between adjacent vertebrae, allowing for nerve connections.

Differences in Male and Female Pelvis

The female pelvis is generally smoother, lighter, has less prominent muscle/ligament attachments, and has a wider angle of opening, compared to the male pelvis.

The Appendicular Skeleton

The appendicular skeleton makes movement and manipulation of objects possible.
It consists of the limbs and supportive girdles.

The Pectoral Girdle

Also known as the shoulder girdle, it connects the upper limbs to the axial skeleton.
Consists of two clavicles and two scapulae.
The only point of attachment to the axial skeleton is the manubrium of the sternum.