Skeletal System 1

What are the different types of bone?

Compact bone and spongy bone

Where do you find compact bone?

External surface of all bones

What is the structure of compact bone?

Very hard, collagen and calcium matrix, full of osteons

What is an osteon?

Elongated concentric pillars running lengthwise down the bone, each with a central canal

Where is spongy bone formed?

In the epiphysis of long bones, and within the bones of the skull, ribs and vertebrae

What is the structure of spongy bones?

No osteons, irregular spongy bone called trabeculae, open cavity

What are trabeculae?

Irregularly arranged lamellae, and osteocytes interconnected by canaliculi, the sponge of spongy bone

What is in the cavity of spongy bone?

Red bone marrow

What does red bone marrow do?

Hematopoietic, makes red blood cells

What are lamellae in osteons?

Rings of the bone marrow, regular and circular (tree trunk) in compact bone, Swiss cheese in spongy bone

What are lacunae in osteons?

Spaces between rings of lamellae, filled with osteocytes

What are canaliculi?

Canals between lacunae that carry capillaries to cells, perpendicular to bone

What is the central cavity of osteons?

Inside the concentric rings of lamellae, for nerves and blood vessels

What are perforating canals in osteons?

Connect blood and nerve supply of periosteum with the central canals and medullary cavity, perpendicular to bone

What are our two skeletons?

Axial and appendicular (teeth also)

What is our axial skeleton?

Bones in the central core of the body

What bones are in the axial skeleton?

Skull, hyoid, vertebral column, thorax (ribs, sternum)

How many bones are in the axial skeleton?

80

How many bones are in the skull?

28, 8 cranial, 14 facial, 6 ossicles

What cranial bones are paired?

Parietal, temporal

What are the cranial bones?

Frontal, 2 parietal, ethmoid, sphenoid, 2 temporal, occipital

Where is the frontal bone?

Forehead of skull

Where are the parietal bones?

Top of the skull, one on each side

Where is the ethmoid bone?

Behind the nose

Where is the sphenoid bone?

Base of the brain, behind ethmoid

Where are the temporal bones?

One at each temple, sides of the skull

Where is the occipital bone?

Back of the head

What are the unpaired facial bones?

Mandible, Vomer

What are the facial bones?

Mandible, 2 maxillae, 2 nasal, 2 zygomatic, 2 lacrimal, vomer, 2 inferior nasal conchae, 2 palatine

What bones form the hard palate?

2 Maxillae, 2 palatine

Where is the mandible?

Your lower jaw

Where are the maxillae?

Upper jaw

Where are your nasal bones?

Spine of nose

Where are your zygomatic bones?

Cheekbones

Where are your lacrimal bones?

By your tear ducts

Where is your vomer?

Behind maxillae in nose area, inferior to ethmoid and inferior nasal conchae

Where are your inferior nasal conchae?

Under ethmoid behind nose

Where are your palatine bones?

Back of hard palate inside mouth

What is your hyoid bone?

attached with tongue and associated muscles, assists in swallowing

Where is the hyoid bone?

Attaches under chin, does not articulate with any other bone

How many vertebrae do we have?

26

What is the spinous process of a vertebrae?

Middle projection pointing back

What are the transverse processes of vertebrae?

Two lateral spines of the vertebra

What are the superior and inferior articular processes?

Four small spines that point up and down and connect the vertebrae to each other

What are the laminae in vertebrae?

Arches between spinous and transverse processes

What are the pedicles in vertebrae?

Connections between body and transverse processes

What is the vertebral foramen?

The space in the middle for the spinal cord

What is the body of vertebrae?

Thick anterior region, actual column part, does not touch other vertebrae

What are the five regions of the vertebral column?

Cervical, thoracic, lumbar, sacrum, coccyx

Where are the cervical vertebrae?

Along your neck

How many cervical vertebrae are there?

7

What are unique about cervical vertebrae?

Transverse foramen (hole) through transverse processes for vertebral arteries, smallest and lightest

What is the atlas vertebrae?

C1, has no body or spinous process, articulates with the skull

What does the atlas vertebrae do?

Allows for flexion and extension of the neck

What is the axis vertebrae?

C2, has a knoblike dens (odontoid process) that projects up to be the body of the atlas, articulates with atlas

What does the axis vertebrae do?

Creates a pivot joint for lateral movement

Where is the thoracic region of vertebrae?

Upper back/ribs

How many thoracic vertebrae are there?

12

What are unique about the thoracic vertebrae?

Long, slender spinous processes, costal facets in body and transverse processes for ribs

Where are the lumbar vertebrae?

Lower back below ribs

How many lumbar vertebrae are there?

5

What is unique about the lumbar vertebrae?

Large thick bodies, short rectangular spinous process

What do the lumbar vertebrae do?

Support upper body, limited rotation of lower back

What is the sacrum?

1 vertebrae made of five fused vertebrae

Where is the sacrum?

Pelvic girdle, articulates with ilium and 5th lumbar vertebrae

How are vertebras numbered?

Increase in number as you descend the body

What is the coccyx?

3-5 fused vertebrae, tailbone, attached to sacrum, counts as one vertebrae

What is the intervertebral foramen?

Lateral openings between processes and body, parallel with the body, exit for spinal nerves

What parts of the spinal cord are concave posteriorly?

Cervical and lumbar

What sections of the spinal column are convex posteriorly?

Thoracic and sacrum

What is scoliosis?

Lateral bend of spinal column

What is kyphosis?

Extensive dorsal thoracic curve, hunchback

What is lordosis?

Extensive lumbar curve, hips forward of pregnant women