Skeletal System Flashcards
What forms the central axis of the body?
Axial skeleton
The axial skeleton includes the skull, vertebral column, and rib cage.
How many facial bones are there in the human skull?
Thirteen
These bones are solidly connected, forming most of the face.
What is the only movable bone in the skull?
Mandible
The mandible forms a movable joint with the skull.
How many auditory ossicles are found in each middle ear?
Three
There are six auditory ossicles in total, three in each ear.
How many cranial bones are there in total?
Eight
The cranial bones include: 1 Frontal, 2 Parietal, 2 Temporal, 1 Occipital, 1 Sphenoid, 1 Ethmoid.
What bone forms the forehead and upper eye sockets?
Frontal bone
The frontal bone protects the frontal lobe of the brain.
Fill in the blank: The _______ bones form the sides and roof of the cranium.
Parietal
There are two parietal bones that protect the brain’s top and sides.
What forms the back and base of the skull?
Occipital bone
The occipital bone contains the foramen magnum for the spinal cord to pass through.
Where are the temporal bones located?
Below the parietal bones on each side of the cranium
Temporal bones house the structures of the inner ear and protect the temporal lobe of the brain.
What are the features of the sphenoid bone?
Forms part of the cranium floor, lateral posterior eye orbits, and lateral cranium in front of temporal bones. Features: Sella turcica, optic foramen.
What is the shape and function of the sphenoid bone?
Bat-shaped, it forms part of the skull base and eye orbits. It connects with several other cranial bones.
What is the maxillae?
Upper jaw, anterior portion of hard palate, part of lateral walls of nasal cavity, floors of eye orbits.
What is the significance of the maxillae?
The upper jaw bone that forms the foundation of the face.
Example: The maxillae support the structure of the face.
What do the palatine bones form?
Form posterior portion of hard palate, lateral wall of nasal cavity.
What is the shape of the palatine bones?
L-shaped bones located at the back of the nasal cavity.
What is the function of the ethmoid bone?
Forms the anterior cranium, medial eye orbit, and roof of the nasal cavity.
What are the features of the ethmoid bone?
Features: Nasal conchae, perpendicular plate of the ethmoid.
Where is the ethmoid bone located?
Located between the eyes, it forms the roof of the nasal cavity and part of the eye orbits.
What is the role of the ethmoid bone?
It supports the structure of the nasal cavity.
What are zygomatic bones?
Cheek bones that also form the floor and lateral wall of each eye orbit.
Where are lacrimal bones located?
Medial surfaces of eye orbits.
What do nasal bones form?
Form bridge of nose.
What is the vomer?
In midline of nasal cavity, forms nasal septum with the ethmoid bone.
What are inferior nasal conchae?
Attached to lateral walls of nasal cavity.
What is the mandible?
Lower jawbone, the only movable skull bone.
What are paranasal sinuses?
Air-filled spaces located within certain skull bones, including the frontal, sphenoid, ethmoid, and maxilla bones.
What is the function of paranasal sinuses?
They help to lighten the skull, produce mucus, and enhance voice resonance.
What is the hyoid bone?
An unpaired, U-shaped bone in the neck that does not attach to the skull or any other bone.
What is unique about the hyoid bone?
It is the only bone that does not articulate with another bone.
What is the function of the hyoid bone?
It supports tongue muscles and serves as an attachment point for neck muscles that raise the larynx.
What is the coronal suture?
It connects the frontal bone to the parietal bones, running across the top of the skull from side to side.
What is the sagittal suture?
It runs along the midline of the skull, connecting the two parietal bones.
What is the lambdoid suture?
It connects the parietal bones to the occipital bone, located at the back of the skull.
What is the squamous suture?
It joins the parietal and temporal bones on the side of the skull.
What is the pterion?
A junction where the frontal, parietal, sphenoid, and temporal bones meet, one of the weakest points of the skull.
What is the lambda?
A point where the sagittal and lambdoid sutures intersect, forming a Y-shaped junction at the back of the skull.
What is the vertebral column?
The vertebral column (spine) is the central axis of the skeleton, running from the skull’s base to just beyond the pelvis.
How many bones are in the vertebral column?
It consists of 26 bones, divided into five regions.
What are the four major curvatures of the spine?
The spine has four major curvatures: cervical, thoracic, lumbar, and sacrococcygeal.
Which regions of the spine curve anteriorly?
Cervical and lumbar regions curve anteriorly (inward).
Which regions of the spine curve posteriorly?
Thoracic and sacrococcygeal regions curve posteriorly (outward).
What are the functions of the vertebral column?
Supports body weight, protects the spinal cord, allows spinal nerves to exit the spinal cord, provides attachment for muscles, and enables movement of the head and trunk.
How many cervical vertebrae are there?
7 cervical vertebrae.
How many thoracic vertebrae are there?
12 thoracic vertebrae.
How many lumbar vertebrae are there?
5 lumbar vertebrae.
How many sacrum and coccyx are there?
1 sacrum and 1 coccyx.
What is the atlas?
Atlas: 1st vertebra, supports the head.
What is the axis?
Axis: 2nd vertebra, allows head rotation.
What are the characteristics of Cervical Vertebrae?
Small, with transverse foramina for blood vessels. Bifid (split) spinous process and flexible for head movement.
What are the characteristics of Thoracic Vertebrae?
Larger, with facets for rib articulation. Spinous processes are long and angled downward.
What are the characteristics of Lumbar Vertebrae?
Largest, with thick bodies for weight-bearing. Short, broad spinous processes for muscle attachment.
What is the Sacrum?
A fused bone of five vertebrae, forming the back of the pelvis. Supports body weight and connects to the pelvic girdle.
What is the Thoracic Cage?
Commonly called ‘rib cage’. Protects the heart and the lungs within the thorax. Contains 12 pairs of ribs.
What is the sternum also known as?
The sternum is also known as the “breastbone”.
What are the three parts of the sternum?
The three parts of the sternum are the Manubrium, Body, and Xiphoid Process.
What are true ribs?
True ribs are attached to both the vertebrae and the sternum. Ribs 1-7 are considered true ribs.
What are false ribs?
False ribs are attached to the vertebrae and the ribs above them. Ribs 8-12 are considered false ribs.
What are floating ribs?
Floating ribs are a subset of false ribs that do not attach at all to the sternum. They are attached to the vertebrae and the muscles in the abdominal wall, specifically Ribs 11-12.
What bones make up the appendicular skeleton?
The appendicular skeleton consists of the Pectoral Girdle (4 bones), Upper Limb (60 bones), Pelvic Girdle (2 bones), and Lower Limb (60 bones).
What is the function of the pectoral girdle?
The pectoral girdle provides attachment for muscles that move the upper arm and forearm and attaches the upper extremities to the axial skeleton.
What is the scapula commonly known as?
The scapula is commonly known as the shoulder blade.
Where is the scapula located in relation to the ribs?
The scapula is located at the 2nd to 7th rib and is approximately 5 cm from the vertebral column.
What is the glenoid cavity?
The glenoid cavity is where the humerus attaches to form the shoulder joint.
What are the coracoid process and acromion?
The coracoid process and acromion are muscle attachment sites, such as for the biceps brachi and deltoid.
What is the clavicle also known as?
The clavicle is also known as the collarbone.
What are the ends of the clavicle called?
The clavicle has a sternal (medial) end and an acromial (lateral) end.
What does the conoid tubercle provide?
The conoid tubercle provides attachment for the conoid ligament.
What does the costal tuberosity provide?
The costal tuberosity provides attachment for the costoclavicular ligament.
Where does the sternal end of the clavicle attach?
The sternal end of the clavicle attaches to the manubrium of the sternum.
Where does the acromial end of the clavicle attach?
The acromial end of the clavicle attaches to the acromion of the scapula.
