Axial Skeleton and Vertebral Column

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Questions and Answers

What is the main function of the vertebral column?

To support the skull and trunk while allowing movement (correct)

To anchor the pectoral girdle

To provide attachment for thoracic muscles

To absorb all stresses during physical activity

How many vertebrae are typically found in the human vertebral column?

33 (correct)

Which curvature of the vertebral column is considered primary?

Pelvic curvature (correct)

Lumbar curvature

Thoracic curvature (correct)

Cervical curvature

What characterizes scoliosis?

An abnormal lateral deviation of the spine Signup and view all the answers

Which part of the vertebra serves as the weight-bearing portion?

Vertebral body Signup and view all the answers

What function do intervertebral discs serve?

To bind vertebrae and absorb shock while providing flexibility Signup and view all the answers

Which vertebral group contains the highest number of vertebrae?

Thoracic vertebrae Signup and view all the answers

What happens to intervertebral discs under stress?

They bulge laterally Signup and view all the answers

What is the primary function of the cervical vertebrae?

Support the head and allow its movement Signup and view all the answers

Which vertebrae are identified by the presence of transverse foramina?

Cervical vertebrae Signup and view all the answers

How many thoracic vertebrae correspond to the number of rib pairs?

12 Signup and view all the answers

What is the primary feature of lumbar vertebrae?

They are adapted for weight-bearing Signup and view all the answers

Which statement accurately describes the sacral vertebrae?

They protect the structures of the pelvic cavity. Signup and view all the answers

What structure is formed by the fusion of coccygeal vertebrae?

Coccyx Signup and view all the answers

Which is NOT a function of the pelvic girdle?

Protect the brain and spine Signup and view all the answers

What separates the greater pelvis from the lesser pelvis?

Pelvic brim Signup and view all the answers

What is the lower margin of the lesser pelvis called?

Pelvic outlet Signup and view all the answers

Which characteristic is true regarding the male pelvis compared to the female pelvis?

It is more robust due to muscle forces. Signup and view all the answers

What are the first seven pairs of ribs collectively known as?

True ribs Signup and view all the answers

Which of the following best describes the cranial cavity?

It is the largest cavity in the skull. Signup and view all the answers

Which type of ribs lack independent cartilaginous connections to the sternum?

False ribs Signup and view all the answers

What is the purpose of the paranasal sinuses?

To lighten the skull and add resonance to the voice. Signup and view all the answers

Which cranial bone includes the foramen magnum?

Occipital bone Signup and view all the answers

How many cranial bones are there in total?

22 Signup and view all the answers

Which part of the skull houses the temporal lobes?

Middle cranial fossa Signup and view all the answers

Which of the following bones articulates with the vomer?

Ethmoidal bone Signup and view all the answers

Which bone is NOT part of the splanchnocranium?

Frontal Signup and view all the answers

What are the two paired cranial bones?

Temporal and parietal Signup and view all the answers

What is the primary role of the dura mater?

To separate the brain from cranial bones. Signup and view all the answers

Which of the following defines the calvaria?

It refers to the dome of the top of the head. Signup and view all the answers

Study Notes

Axial Skeleton

The skeleton is divided into two parts: appendicular and axial.
Appendicular skeleton includes bones of the upper and lower limbs, and the pectoral and pelvic girdles.
Axial skeleton includes the cranium, vertebral column, ribs, and sternum.

Vertebral Column

Physically supports the skull and trunk.
Allows for movement.
Protects the spinal cord.
Absorbs stresses from walking, running, and lifting.
Provides attachment points for limbs, thoracic cage, and postural muscles.
Consists of 33 vertebrae.
Vertebral column consists of Cervical, Thoracic, Lumbar, Sacral, and Coccygeal vertebrae.

Vertebral Canal and Cranial Cavity

The vertebral canal is formed by the vertebral foramen.
Intervertebral discs are cartilaginous pads that cushion the vertebral column.
The vertebral canal (and cranial cavity) contains the spinal cord.

Cervical Vertebrae (Neck)

Seven cervical vertebrae (C1-C7).
Relatively small, compared to the other vertebrae types in the spine.
Their function is primarily to support the head and permit movement.
The first two (C1 and C2) have unique structures for this purpose- transverse foramina.

Thoracic Vertebrae (Chest)

Twelve thoracic vertebrae (T1-T12).
Each thoracic vertebrae has ribs attached to them.
Their function is supporting the thoracic cage, enclosing the heart and lungs.

Lumbar Vertebrae (Lower Back)

Five lumbar vertebrae (L1-L5).
Their most distinctive feature is a thick, stout body, adapted to bear the weight of the upper body.

Sacrum and Coccyx

Five sacral vertebrae (S1-S5) fuse together into a single structure, the sacrum.
The sacrum is located on the posterior wall of pelvic cavity, and protects the organs within.
Four (sometimes five) coccygeal vertebrae (Co1-Co5) fuse into the coccyx.

Pelvic Girdle or Pelvis

The pelvis is a bowl-shaped structure made of sacrum, coccyx, and two hip bones (coxal bones).
The pelvic girdle supports the trunk and lower limbs.
It encloses and protects the viscera, including the lower colon, bladder, and reproductive organs.
The pelvis is composed of the greater (false) pelvis above the pelvic brim and the lesser (true) pelvis below.
The pelvic inlet and outlet define the boundary between the false pelvis and the true pelvis.

Pelvic Structure

The pelvis has a bowl-like shape.
The greater (false) and lesser (true) pelvis are separated by a somewhat round margin called the pelvic brim.
The greater pelvis forms the walls of the lower abdominal cavity, whereas the lesser pelvis encloses the pelvic cavity.

Pelvic Inlet and Outlet

The opening of the lesser pelvis, through which the infant's head passes during birth, is called the pelvic inlet.
The lower margin of the lesser pelvis is called the pelvic outlet.

Sex Differences in the Pelvis

The male pelvis is more robust (heavier and thicker) than the female pelvis.
The female pelvis is adapted for childbirth.

Thoracic Cage

Consists of thoracic vertebrae, sternum, and ribs.
Its roughly conical shape provides enclosure for lungs and heart.
Provides attachment for pectoral girdle and upper limb.

Sternum

A bony plate anterior to the heart.
Divided into three sections: manubrium, body, and xiphoid process.
Connects to the ribs via costal cartilages.

Ribs

Twelve pairs of ribs.
First seven ribs are true ribs, directly attached to the sternum.
Ribs 8-10 are false ribs, attached to the sternum indirectly through costal cartilage.
Ribs 11-12 are floating ribs, lacking anterior connection to the sternum.

Skull and Cranial Cavity

The skull is the most complex part of the skeleton; consisting of 22 bones (and sometimes a little more).
The skull is composed of 2 main divisions: neurocranium (cranial bones) and splanchnocranium (face bones).
The neurocranium encloses the brain and comprises 8 bones.
The splanchnocranium forms the face and consists of 14 bones.
The cranial cavity contains the largest cavity, encasing the brain, along with other cavities.

Cranial Fossae

The cranial base, or floor, has 3 depressions called cranial fossae.
The anterior cranial fossa is shaped to accommodate the frontal lobes.
The middle cranial fossa is shaped like outstretching bird wings, accommodating the temporal lobes.
The posterior cranial fossa encases the cerebellum.

Paranasal Sinuses

Several cavities within the skull called paranasal sinuses, are named after the bones they are located in.
These sinuses are connected to the nasal cavity, lined with mucous membranes, and filled with air.
They lighten the skull, enhance voice resonance, and aid in humidifying and warming inhaled air.

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Description

This quiz covers the key components and functions of the axial skeleton, including the vertebral column. It explores the cervical, thoracic, lumbar, sacral, and coccygeal vertebrae, along with the roles of the vertebral canal and cranial cavity. Test your knowledge on the structure and purpose of these essential parts of the human skeleton.