Anatomy-- unit 4: skeletal system

What are the functions of the skeletal system?

support

protection

movement

blood cell formation

storage of minerals & fat

Osteoblasts

add bone tissue to the external surface of the diaphysis

Osteoclasts

removes bone tissue from inside surface of diaphysis

Osteocytes

mature bones cells

maintain bone health and structure

Chondrocytes

produce and maintain the ECM (extracellular matrix)

sythnsize collagen & proteoglycan

What are the two sub-skeletons that our skeleton can be divided into?

axial & appendicular

What parts are in axial skeleton?

skull, vertebral column, rib cage, sternum, hyoid

What parts are in appendicular skeleton?

arms, legs, girdle

What is the function of the axial skeleton?

protection of vital organs

What is the function of the appendicular skeleton?

movement

How many bones are in the human body?

206

Function of red marrow

production of blood cells

Where is red marrow found

in flat bones of body & ends of long bones

Function of yellow marrow

store energy in the form of fat

Location of yellow marrow 

in the central hallow cavity (medullary cavity) of long bones

What are the two types of bone tissue

Compact and spongy bone

Compact bone structure

outer layer

dense and solid

arranged in circular units called osteons

haversian canal in the center contains blood vessels, lymphatic vessels, and nerves

Spongy (cancellous) bone structure

Inner layer

a lattice-like structure of slender bony spikes called trabeculae that create open spaces

Compact bone function

resist pressure and shocks and protect the spongy tissue

Spongy bone function

reduces bone weight and density while providing structural support

Compact bone location

on the outer layer of all bones

Spongy bone location

at end of long bones

inner layer of all bone

Function of articular cartilage

reducing friction during joint movement

Location of articular cartilage

hip, knee, elbow, shoulder

Five types of bones

Long

Short

Flat

Irregular

Sesamoid

Example of long bone

Femur, humerus, tibia

Example of short bone

carpals and tarsals

Example of flat bone

skull, ribs, scapula

Example of irregular bone

vertebra, mandible, hips

Example of sesamoid bone

only patella

What is the term for bone formation?

ossification/osteogenesis

What are the two ways bones can develop

intramembranous ossification

endochondral ossification

What is endochondral ossification

a temporary hyaline cartilage model is replaced by bone

What is intramembranous ossification

when bone is created from fibrous connective tissue called mesenchyme without a cartilage model

example of endochondral ossification

long bones

example of intramembranous ossification

flat bones of skull, clavicle, mandible

Which is the more common bone formation

endochondrial 

What is the line called where bone growth occurs?

epiphyseal plate

What is the epiphyseal plate made up of

cartilage that later solidifies into bone

What are the two types of bone growth

Epiphyseal (intersitial) Growth & Appositional growth

Bursa

a fluid-filled sac in the body

act as cushions between joints, tendons, and muscles

Intervertebral disc

fibrocartilaginous cushions located between the vertebrae of the spinal columns

shock absorber & allow flexibility

Fontanelle

soft spots in an infant's skull covered by tough, fibrous membranes

to allow the skull to mold during birth

Synovial fluid

thick, lubricating liquid

within a joint capsule, reduces friction

in the highly movable joint

Suture

fibrous joints in the skull that connect its bones

allow for brain growth and movement during birth

Endosteum

a thin layer of connective tissue that lines the inner surface of bones

houses cells crucial to bone reformation & growth

Articulation

a joint

where two or more bones meet

Ligament

fibrous connective tissues that connect bones to bones, providing stability and support to joint

ACL

Periosteum

a dense, fibrous membrane that covers most of the bones in the body

Trabeculae

thin, beam-like structures that form a network within spongy (cancellous) bone.

Tendon

fibrous connective tissues that connect muscles to bones, enabling movement

Achilles

Meniscus

two crescent-shaped fibrocartilage pads located on the inner (medial) and outer (lateral) sides of the knee joint

Osteon

the fundamental structural and functional unit of compact bone, a cylindrical structure that provides strength and support

How does calcium phosphate affect bones

makes bones hard and strong by forming the mineral component, hydroxyapatite

How does testosterone affect bones

supports bone formation and growth

How does estrogen affect bones

regulates bone breakdown (resorption)

how does thyroid hormone affect bones

it controls the growth of the bone

how does somatropin affect bones

stimulates bone remodeling by increasing both bone formation and resorption

how does parathyroid hormone affect bones

increases activity of osteoclasts that break down bone

this releases calcium and phosphate into bloodstream

Describe the process of remodeling

Constant process in which osteoclasts remove bone tissue and osteoblasts replace it

chipping little pieces at a time

How often does bone get replaced in our skeleton

every 10 years

Carpal tunnel syndrome

Overuse of the wrist

When the median nerve, which runs through the carpal tunnel in the wrist, becomes compressed

Osteoarthritis

degenerative of joint cartilage disease

wear and tear

Kyphosis

abnormal curvature of the spine (humpback)

Gout

a type of arthritis; deposits of uric acid crystals in the joints

Sprain

 stretched or torn ligament

Rheumatoid arthritis

a chronic systemic inflammatory disease of smaller joints and surrounding tissues, autoimmune

Fracture

a crack or break in bone

Lordosis

exaggerated inward curvature of the lumbar spine (swayback)

Osteogenesis Imperfecta

brittle bone disease

Osteoporosis

a condition in which bones thin (become porous) over time due to a lack of calcium (calcium phosphate)

Scoliosis

an abnormal S-shaped curvature of the spine

Tendonitis

Inflammation of the tendons

Interstitial growth

growing in length

Appositial Growth

growing in width and diameter

What are the three classifications for joints

Synarthroses

Amphiarthroses

Diarthroses (synovial)

Synarthroses Joint

No movement joint

Example of synarthroses joint

sutures, between teeth, and jaw

Amphiarthroses Joints

bone joined by cartilage

Examples of amphiarthroses joints

ribs, epiphyseal plates, intervertabral discs, sternum

Diarthroses (synovial) joints

bones seperated by fluid

synovial fluid is present

Examples of diarthroses joints

hips, knees