Anatomy Chapter 5 Test

Axial skeleton

bones that form from the longitudinal axis of the body

Appendicular skeleton

the bones of the limbs and girdles

5 functions of the bones

support, protection, movement, storage, blood cell formation

Movement

Skeletal muscles attached to bones by tendons

Storage

fat stored in the internal cavities, stores calcium and phosphorous

Blood cell formation

within the marrow cavities

Classification of Bones

the adult skeleton has 206 bones

2 types of bone

compact, spongy

4 types of bone structures

long, short, flat, irregular

Compact bone

dense and looks smooth and homogeneous

Spongy bone

composed of small needlelike pieces of bone and lots of open space

Long bones

typically longer than they are wide, shaft with heads at both ends, mostly compact bone

Short bones

generally cube-shaped, mostly spongy bone

Flat bones

thin, flattened, and usually curved, 2 thin layers of compact bone with a layer of spongy bone between them

Irregular bones

don't fit into other categories

Diaphysis

makes up most of the bone's length, compact bone

Periosteum

covers diaphysis

Sharpey's fibers

perforating, secures diaphysis to the bone

Epiphyses

the end of the long bone

Epiphyseal line

in adult bones only

Yellow marrow (medullary) cavity

primarily a storage area for adipose tissue

Red marrow

found only in the spongy bone of flat bones and some epiphyses of some long bones in adults

Bone markings

reveal where muscles, tendons, and ligaments were attached and where blood vessels and nerves passed

Projections

grow out from bone surface

Depressions

indenations in the bone

Osteocytes

mature bone cells

Lacunae

cavity where osteocytes are found

A network of connecting canals

connects all the bone cells to the nutrient supply through the hard bone matrix

2 types of strong and supportive tissues

cartilage and bone

Embryos

where the skeleton is primarily amde of hyaline cartilage

Ossification

bone formation

Osteoblasts

bone forming cells

Hyaline cartilage

mostly turns into bone by birth

Articular cartilages

covers bone ends

Epiphyseal plates

lengthwise growth in long bones

Bones remodeled in response to 2 factors

calcium leven in the blood, the pull of gravity and muscles on the skeleton

Calcium levels-

too low, parathyroid hormone released, activates osteoclasts to break down bone matrix, releases calcium into blood
too high, calcium deposited in bone matrix

The pull of gravity and muscles

body increases in size and weight, determines where bone matrix is to be broken down or formed

2 types of bone fractures

closed and open

Closed (simple) fracture

bones break cleanly does not penetrate skin

Open (complex) fracture

broken bone ends penetrate through skin

Reduction

"setting" a bone, the realignment of broken ends

4 steps of bone repair

hematoma, fibrocartilage callus, bony callus, bone remodeling

Hematoma

blood filled swelling forms

Fibrocartilage callus

contains cartilage matrix, body matrix, and collagen fibers, closes/conects gap

Bony callus

made of spongy bone, forms

Bone remodeling

equal strength

Two set of bones in Skull

cranium and facial bones

Sutures

all but one of the bones in the skull are joined together by sutures

Cranium

encloses and protects the brain

Facial bones

hold eyes in place, connected to facial muscles

8 bones that make up the cranium

frontal bone, parietal bone, external acoustic meatus, styloid process, zygomatic process, mastoid process, jugular foramen, carotid canal

Frontal bone

the top front of the skull, forehead

Parietal bone (2)

The back top of the skull

Temporal bones (2)

the part of the skull where the ears are located

External acoustic meatus

canal that leads to the eardrum

Styloud process

sharp, needlelike projection- attachment point of many neck muscles

Zygomatic process

bridge that joins chekbone

Mastoid process

rough projection full of air cavities, and attachment site of some neck muscles

Jugular foramen

opening that allows passage of the jugular vein, drains from the brain

Carotid canal

internal carotid artery, supplies blood to the brain

Occipital bone

towards tha back of the head, at the bottom

Foramen magnum

large opening at the base of the occipital bone, connectin to spinal cord

Sphenoid bone

In front of the temporal bones, in front of the ears

Ethmoid bone

In between the eye socket and the nose

8 main facial bones

maxillae, palatine bones, zygomatic bones, lacrimal bones, nasal bones, vomer bone, inferior nasal conchae, mandible

Maxillae

fuse to form the upper jaw

Sinuses

drain into the nasal passages

Palatine bones

form the posterior aspect of the hard palate

Zygomatic bones

the cheekbones

Lacrimal bones

fingernail-sized bones forming part oof the medial walls of each orbit

Nasal bones

small rectangular bones forming the bridge of the nose

Vomer bone

on the medial line of the nasal cavity and fors the bony nasal septum

Inferior nasal conchae

thin, curved bones projecting from the lateral walls of the nasal cavity

Mandible

lower jaw bone

Hyoid bone

only bone of the body that does not articulate directly with any other bone

Fetal skull

large compared to body, ¼ of length

Fontanels/soft spots

fibrous membranes connecting cranial bones

Vertebral Column (Spine)

extends from the skull to the pelvis

Function of the vertebral column

supports the skull, transmits weight through the pelvis to the lower limbs

Vertebrae

26 bones in the vertebral column are connected and reincofced by ligaments

Intervertebral discs

separates the spine, is pads of flexible fibrocartilage

structure of vertebral column

S-shaped structure

Primary curvatures of vertebral column

thoracic and sacral regions

Secondary curvatures of vertebral column

curvatures in cervical and lumbar regions

Abnormal spinal curvatures of vertebral column

scoliosis, kyphosis, lordosis

Body of vertebrae

disclike part

Vertebral arch

arch formed from joining all posterior extensions

Vertebral foramen

canal for spinal cord

Transverse processes

two lateral projections of the vertebral arch

Spinous process

single projection

Superior and inferior articular processes

allow vertebrae to form joints with adjacent vertebrae

How many cervical vertebrae are there

7 cervical vertebrae

Atlas: 1st cervical vertebra

has no body, allows you to nod

Axis: 2nd cervical vertebra

large upright process, allows you to rotate head side-to-side

C3 through C7

smallest and lightest vertebrae, contains foramina for arteries

How many thoracic vertebrae are there

12

Thoracic vertebrae (T1 to T12)

articulate with the ribs, spinous process is long and hooks downward

How many lumbar vertebrae are there

5

Lumbar vertebrae (L1 to L5)

massive blocklike bodies