bones/joints

skeletal system

includes joints, cartilage, ligaments, and bones; divided into the axial skeleton and the appendicular skeleton

206

how many bones are in an adult body?

axial skeletal

includes the skull, hyoid bone, vertebral column, thoracic cage, and sternum (80 bones)

hyoid bone

not connected by any other bone, joint, or ligament; used for speaking

appendicular skeleton

includes appendages, arms, and legs;functions: support, protection, movement, storage (fat & calcium/phosphorus), blood cell formation (marrow); the pink in the picture

long bones

longer than they are wide; mostly compact bone; includes all the bones of the limbs except the hands, wrist, and foot (ex. humerus)

short bones

cube-shaped, mostly spongy bone, includes: wrist and ankle, sesamoid bones (ex. talus)

sesamoid bones

forms within tendons (ex. kneecap)

flat bones

thin, flat, curved bones (ex. sternum)

irregular bones

bones that do not fit into the other groups (ex. vertebrae, hip bones)

ossification

means bone formation; all bones start as hyaline cartilage but gradually change to bone

compact bone

Hard, dense bone tissue that is beneath the outer membrane of a bone

spongy bone

composed of small needlelike pieces of bone and lots of open space and Layer of Bone tissue having many small spaces and found just inside the layer of compact bone

Hemopoiesis

formation of blood cells

diaphysis

shaft, makes up most of bone's length, composed of compact bone. Covered and protected by a fibrous connective tissue membrane (periosteum)

Epiphyseal plate

cartilaginous area at the ends of long bones where lengthwise growth takes place in the immature skeleton

Epiphyseal line

in adults; remnant of epiphyseal plate

Medullary cavity

cavity within the shaft of the long bones; filled with bone marrow

bone markings

markings present on a bone by blood vessels, tendons

periosteum

thin membrane that covers a bone

articular cartilage

covers joint surfaces of epiphysis

projection

grows out from bone surface

osteocytes

mature bone cells, found in lacunae

osteoblasts

bone forming cells

osteoclasts

Bone-destroying cells

lacunae

small spaces between the lamellae which contain osteocytes

lamellae

Concentric rings made up of groups of hollow tubes of bone matrix

osteon (Harversion system)

The unit of combact bone, also called a Haversian system. Osteons are essentially long cylinders of bone; the hollow center is called the central canal, and is where blood vessels, nervs, and lymphatic vessels are found. Compact bone is laid down around the central canal in rings (lamellae).

canaliculi

small hair-like canals extending from the central canal. Allow for diffusion of nutrients, waste products, hormones, etc. to lacunae.

appositional growth

"Growth from Outside": the increase in overall size where new compact bone is deposited just below the periosteum, and osteoclasts destroy bony connective tissue and enlarge the medullary cavity.

calcium levels in the blood and the pull of gravity

what are the 2 reasons bones are constantly remolding?

bone remolding

bony callus is remolded; strong permanent "patch" forms; weeks or months time to heal

fractures

breaking of hard tissue such as bone

reduction (related to fractures)

correcting a fracture by realigning the bone fragments

cranium and facial

what 2 sets of bones make up the human skull?

22; 14; 8

how many bones total are in the human skull? How many are facial? how many are cranial?

fontaness/soft spots

areas of cartilage in an infant skull are called what?

vertebral column

extends from the skull to the pelvis; made up of 26 irregular bones; surrounds and protects the spinal cord (before birth its 33 separate bones-9 fuse together to form sacrum and coccyx)

cervical vertebrae

7 vertebrae in the neck; includes the atlas and axis

thoracic vertebrae

next 12 bones in the vertebrae (T1-T12)

lumbar vertebrae

next 5 bones in the vertebrae (lower back)

intervertebral discs

made up of flexible fibrocartilage; separates each individual vertebrae; cushions and absorbs shocks; allows flexibility

slipped disc

when the discs are dry or the ligaments are weakened it will predispose people to a ____ __. Typically seen in older people; 90% water

12

how many pairs of ribs are there?

true ribs

first 7 pairs attached to the sternum by costal cartilage

false ribs

next 5 pairs are attached indirectly or not at all

floating ribs

2 false ribs that are not attached to the sternum

intercostal space

the space between the ribs; filled with intercostal muscle that aids in breathing

sternum

aka the breastbone; connects to the first 7 ribs; good place to obtain samples of blood forming tissue (ex. bone marrow)

shoulder girdle

composed of 2 spaculas and 2 collar bones

clavicle

"the collarbone" acts as a brace to hold the arm away from the top of the thorax; prevents shoulder dislocation

joints

aka articulations; hold bones together and used for mobility

functional joints

focuses on the amount of movement allowed by the joint (3 types: synarthoses, amphiarthroses, diarthroses)

osseous tissue

make up bones (aka bone tissue)

simple fracture

bone breaks cleanly but does not penetrate the skin

compound fracture

broken bone breaks through the skin

scoliosis

An abnormal lateral curvature, usually involving the thoracic vertebrae.

lordosis

Abnormal anterior curvature of the lumbar spine (sway-back condition)

kyphosis

An exaggerated posterior curvature of the thoracic spine that causes significant back pain and limited mobility.

synarthroses

immovable functional joints

ampiarthroses

slightly moveable functional joints

diarthroses

freely moveable functional joints

fibrous joints

bones used by fiber tissue (ex. skull sutures are connected by connective tissue fibers)

cartilaginous joints

bones ends connected by fiber cartilage (ex. intervertebral joints of the spine)

synovial joints

bone ends are separated by a joint cavity containing synoival fluid (ex. knee)

dislocation

Displacement of a bone from its normal location in a joint

hyperextension

Excess extension of the parts at a joint, beyond the anatomical position (bending the head back beyond the upright position).

plane joints

(synovial joint) the articular surfaces are essentially flat, and only short slipping or gliding movements are allowed (nonaxial); doesn't involve rotation around any axis (ex. intercarpal joints of the wrist)

hinge joints

(synovial joint) cylindrical end of one bone fits into a trough-shaped surface on another bone. Angular movement is allowed in just one plane (ex. elbow joint, ankle joint, and joints between the phalanges of the fingers); are uniaxial (allow movement around one axis only)

pivot joints

(synovial joint) the rounded end of one bone fits into a sleeve or ring of bone/possibly ligaments. Can only turn around its long axis which makes pivot joints uniaxical joints

condyloid joint

(synovial joint) the egg-shaped articular surface of one bone fits into an oval concavity in another. both are oval. Allows for the moving bone to travel (1) from side to side and (2) back and forth, but the bone cannot rotate around its long axis; movement occurs around 2 axis (biaxial) (ex. knuckle joints)

saddle joint

(synovial joint) each articular surface has both convex and concave areas, like a saddle; biaxial joint that allows essentially the same movements as condylar joints

ball and socket joints

the spherical head of one bone fits into a round socket in another bone; multiaxial joints that allow movement in all axes, including rotation and are the most freely moving synovial joint (ex. shoulder and hip)

calcium

when ____ level drop in the blood, osteoclasts break down bone matrix and release calcium ions back into the blood

communited

bone breaks into many fragments (found in elderly)

compression

bone is crushed; most common in vertebrae with the osteoporosis bones

depression

broken bone is pressed inward

impacted fracture

clean break in the transverse plane (cross section); often seen in stress fractures

spiral fracture

ragged break when excessive forces are applied (ex. sports/abuse)

hematoma formation

blood vessels rupture; blood filled swelling

fibrocartilage callus

tissue repair; new capillaries; "splint" the broken bone which closes the gap

bony callus

osteoblasts and osteoclasts come to the area and multiply; fibrocartilage is gradually replaced

Hydroxyapatite

Hardy crystals consisting of calcium and phosphate that form the bone matrix.

Osteoporosis

A condition in which the body's bones become weak and break easily.

Intramenbranous Bones

bone that forms from membrane like layers of primitive connective tissue

endochondral bones

bone that begins as hyaline cartilage that is subsequently replaced by bone tissue

intramembranous ossification

Process of replacing embryonic connective tissue to form intramembranous bone

mesenchymal cells

Stem cells that respond to injury or infection.Differentiate into fibroblasts, macrophages, etc.

endochondral ossification

Process of transforming hyaline cartilage into endochondral bone.

Chrondrocytes

cartilage cells

primary ossification center

area in center of diaphysis, where bone tissue first replaces cartilage

secondary ossification center

area of the epiphyses, where spongy bone forms later in development

zone of resting cartilage

- Layer closest to end of epiphysis
- Resting cells; anchor epiphyseal plate to epiphysis

zone of proliferating cartilage

rows of young cells, undergoing mitosis

zone of hypertrophic cartilage

- Rows of older cells left behind when new cells appear
- Thicken epiphyseal plate, lengthening the bone
- Matrix calcifies, cartilage cells (chondrocytes die)

zone of calcified cartilage

thin layer of dead cartilage cells and calcified matrix

bone resorption

removal of bone, action of osteoclasts

bone deposition

formation of bone by osteoblasts

vitamin D

calcium absorption; deficiency causes rickets, osteomalacia

vitamin A

osteoblast & osteoclast activity; deficiency retards bone development