Lab 9: The Skeletal System Flashcards
What makes up the skeletal system?
The entire framework of bones and their cartilages, joints and ligaments
How many bones does a human have?
How many in each of the 2 skeleton systems?
206 named bones.
- axial skeleton (80) skull, vertebral column and thoracic cage.
- appendicular skeleton (126) upper/lower limbs, girdles
5 types of bones
- how are they classified?
- location
Classified: based on their shape
long
- Cylinder-like shape, longer than it is wide
- Femur, tibia, fibula, metatarsals, humerus, ulna, radius, metacarpals, phalanges
short
- Cube-like shape, approximately equal in length, width, and thickness
- Carpals, tarsals
flat
- Thin and curved
- Sternum, ribs, scapulae, cranial bones
irregular
- Complex shape
- Vertebrae, facial bones
sesamoid
- Small and round; embedded in tendons
- Patellae
fontanels
-function?
- areas of fibrous connective tissue stil exist between the cranial bones at birth.
- “soft spots” of a baby’s skull
- provide flexibility for the skull to compress as it passes through the birth canal
Sutures
-how many in adults
- immoveable joints in the adult skull
* four major ones: coronal, sagittal, squamous, and lambdoid sutures
Function of facial bones
form the face, hold the teeth and anchor the muscles of facial expression.
What is the only movable bone in the skull?
mandible
Which structure passes through the foramen magnum?
spinal chord
The occipital condyles rest upon which bone?
atlas vertebra
How many bones form the face? Name them.
14 Bones:
Maxilla (2) Zygomatic (2) Mandible (1) Nasal (2) Palatine (2) Inferior nasal concha (2) Lacrimal (2) Vomer (1)
How many bones form the eye orbit? Name them.
7 Bones:
maxilla zygomatic bone lacrimal bone palatine bone frontal bone ethmoid bone sphenoid bone
Hyoid Bone
- isolated U-shaped bone, just below the mandible
- function: attachment point for the muscles of the tongue and larynx
- only bone of the body that does not directly articulate with any other bone.
vertebral column
Function
• protect spinal cord
• supports head
• attachment point for ribs/pelvic girdle/muscles of the neck and back.
Function of the curvature (S-shape) in the vertebral column
- increase its strength
- help maintain balance when upright
- absorb shocks when moving
- help protect the vertebrae from fracture
Cervical Vertebrae
- 7 vertebrae
- smallest and lightest
- first are: atlas: & axis
- transverse foramen
- spinous process is bifid (Except C1, C2 and C7)
Atlas
- C1
* allow you to nod your head “yes”.