Chapter 7 Flashcards
What is the skeletal system made up of?
Bones, cartilages, joints and ligaments.
What do ligaments do?
Ligaments connect bones and reinforce joints.
Axial skeleton
The axial skeleton consists of 80 bones.
Regions: Skull, Vertebral
Column and Thoracic Cage.
Main functions of the axial skeleton
- The axial skeleton supports the head, neck and trunk.
- It protects the brain (skull), vertebrae (vertebral column) and the organs (rib cage).
What 2 sets of bone make up the skull?
- Cranial bones (brain is enclosed in the cranial cavity)
- Facial bones.
Most skull bones are locked together except for the mandible which is able to move.
What are the joints in cranial bones called?
Sutures
Photo: Cranial and facial divisions of the skull
!!! Photo: The human skeleton Anterior view
The Cranium is divided into vault and base
Internally the base is divided into 3 fossae: anterior, middle and posterior fossae
The brain sits within these fossae, enclosed by the cranial vault. This area is known as the cranial cavity.
Superior view of the Cranial fossae
Other cavities contained in the cranium…
The middle and internal ear cavities.
The nasal cavity.
The orbits that house the eyeballs.
What are some named openings of in the skull, and what are some of their functions?
Fermina, canals fissures.
They provide passage ways for the spinal cord, major blood vessels, and the 12 cranial nerves.
Photo: Cross section of the skull including the cranial cavity…
!!! What are the 8 cranial bones?
Frontal bone
Parietal bones (2)
Occipital bone
Temporal bones (2)
Sphenoid bone
Ethmoid bone
Photo: Anterior view of the skull.
Photo: Posterior view of the skull…
Photo: Lateral aspect of the skull, external view…
Photo: Lateral aspect of the skull, internal view…
Photo: Temporal bone
Photo: Ethmoid bone
Photo: The sphenoid bone
!!! What are the 14 facial bones?
Mandible
Maxillary bones (2)
Zygomatic bones (2)
Nasal bones (2)
Lacrimal bones (2)
Palatine bones (2)
Vomer
Inferior nasal conchae (2)
Mandible is the largest and strongest of the facial bones.
Photo: Mandible, right lateral view
Photo: Bones of the nasal cavity.
Describe the Hyoid bone…
- The hyoid bone is not a bone of the skull.
- The hyoid bone lies in the anterior neck inferior to the mandible.
- The hyoid is the only bone in the body that does not articulate directly with another bone (it is anchored by ligaments).
- The hyoid bone acts as a moveable base the tongue, and a site of attachment for the muscles of swallowing and speech.
!! What are some special characteristics of the orbit cavity?
Orbits are cavities that encase the eyes and lacrimal glands.
Orbits are sites of attachment for eye muscles.
Orbits are formed by the parts of seven bones: frontal, sphenoid, zygomatic, maxilla, palatine, lacrimal and ethmoid.
Photo: bones that form the orbits
!! What are special characteristics of the nasal cavity?
The nasal septum and conchae are covered with a mucus-secreting mucosa that moistens and warms the entering air and helps cleanse it of debris. The conchae increases the turbulence of air flow which helps to trap airborne particles in the sticky mucus.
!! Characteristics of the paranasal sinuses.
Paranasal sinuses are formed from 5 skull bones:
frontal
sphenoid
ethmoid
paired maxillary
All of them contain mucosa-lined, air-filled spaces.
Functions of the paranasal sinuses:
warm and humidify air
help to lighten the skull
enhance resonance of voice.
!! General characteristics of the vertebral column.
It extends from the skull to the pelvis.
It functions to transmit weight of the trunk to lower limbs, surround and protect the spinal cord, and provide attachment points for ribs and muscles.
It’s flexible curved structure contains 26 irregular bones called vertebrae in 5 major regions.
!! 5 main regions of the vertebral column.
The 28” long vertebral column is broken into 5 regions:
1. Cervical - consists of 7 vertebrae
2. Thoracic - 12 vertebrae
3. Lumbar - 5 vertebrae
4. Sacrum - one bone formed from fusion of several bones; articulates with hip
5. Coccyx - fused bones that form terminus of column