Skeletal System- Skelly

Bone function

Bone function

support soft tissue, protects vital organs, stores calcium and lipids, manufactures blood cells, and serves as levers for the muscular system.

Osteon

basic structural unit of the bone (supporting column)

Lamellae

rings of calcified matrix which offers protection and circumferential interstitial

Center Canal

canals that run lengthwise through the bone containing blood vessels which supply nutrients + oxygen

Trabeculae

meshwork on bony structures; offers strength and flexibility to resist stress.

Osteoblasts

osteoclasts

bone resorption

osteocytes

bone cells within small spaces called lacunae; maintain bone matrix

Compact bone

dense bone (osteons) that forms the external portion of all bones.

Spongy Bone

inner layer of bone spaces (trabeculae) filled with bone marrow

Marrow

sponge-like material in the cavity of bones that function to produce blood cells (red) or store lipids (yellow)

Diaphysis

shaft or long, main, cylindrical portion of the bone

Epiphysis

extremities or ends of each bone

Periosteum

tough, fibrous membrane that surrounds the bone

Long bone

greater in length than in width, supports weight + facilitates movement (femur, humerus)

Short bones

wide as they are long; stability + movement (carpals, tarsals)

Flat bones

thin, plate-like. protect internal organs and muscle attachment (skull, ribs)

irregular bones

shapes that would not fit in any other category. protects internal organs (vertebrae, mandible, pelvis)

Sesamoid bone

small bone embedded within the tendon. protects tendons (patella)

How many bones are in the human body?

206 bones

Axial skeleton

made up of 80 bones including the skull, vertebrae, sternum, ribs, and hyoid bone

Axial Skeleton Function

central framework for attachment, protection of internal organs

Appendicular skeleton

Made up of 126 bones including pectoral girdles, upper/lower limbs, and pelvic girdle.

Appendicular skeleton function

allows the body to move and manipulate objects

Synarthrosis

immobile joint; protection of internal organs. ex: sutures of the skull

Amphiarthrosis

slight movement; weight bearing, stability. ex: vertebrae, pubic symphysis

Diarthrosis

free movement along an axis

Uniaxial

one ex: elbow

Biaxial

two . ex: knuckle

Multiaxial

multiple . ex: hip/shoulder

What are the types of structural joints?

Fibrous, Cartilaginous, Synovial

Suture

dense connective tissue. bind/sew bone together (skull)

Gomphosis

fastened with bolts (tooth to jaw)

Syndesmosis

fastened with a band; parallel bones connected by ligament. (radius, ulna, tibias, fibula)

Synchondrosis

joined by cartilage (hyaline).

temporary- epiphyseal growth plate

permanent- thoracic cage

Symphysis

growing together. fibrocartilage- strong union between bones with limited movement.

Joint cavity

fluid filled space which increases joint mobility (diarthrosis)

Articular capsule

connective tissue walls (ligaments) of joint cavity connecting bone to bone

Synovial Membrane

capsule + secretes synovial fluid for lubrication for friction protection

Articular Cartilage

hyaline connective tissue to cushion and prevents friction

Ligament

connects bone to bone. provides strength + support, limits ROM

Tendon

connect muscle to bone; help to resist forces + supports the joint

What are the types of synovial joints?

pivot, hinge, saddle, ball & socket, condyloid, plane

Pivot

uniaxial diarthrosis- rotation around a single axis. ex: c1, c2 vertebrae

Hinge

uniaxial diarthrosis. flexion + extension around a single axis. ex: elbow + knee

Saddle

biaxial diarthrosis- bone with bone convex + concave structure. ex: opposable thumb

Ball & Socket

multiaxial diarthrosis. anterior, posterior, medial, lateral rotation. ex: hips/shoulders.

Condyloid

biaxial diarthrosis- bending + straightening side to side. ex: knuckle/wrists

Plane

gliding joint for multiple movements. ex: tarsal bones, wrists.

What are the differences between the pelvis in males and females?

Male: narrower, pubic arch is less than 90 degrees, triangle shape

Female: wider, pubic arch is greater than 90 degrees, curved shape.

How is the skull of a female different than a male?

The female brow ridge/superciliary arch is less protruded than a male. The female eye margin is sharper than a male’s. The female mastoid process is smaller than a male’s. The female mandible is rounder than the male’s.

Intramembranous

The replacement of sheet-like connective tissue membrane with bony tissue

Bones formed in Intramembranous

compact + spongy, certain flat bones, irregular and clavicle.

Process of formation in intramembranous

mesenchyme gather together to begin to differentiate into specialized cells. osteoblasts secrete osteoid + hardened mineral salts. osteoblasts turn to osteocytes + osteogenic cells to osteoblasts. osteoids = periosteum

Endochondral

involves replacement of hyaline cartilage with bony tissue.

Endochondral bones formed

most bones, femur, vertebrae, tibia, metacarpals.

Endochondral fate of cartilage template

template is calcified, the chondrocytes become hypertrophic + undergo apoptosis

Endochondral process of formation

cartilage scaffolds that are arranged in zones gradually replaced by bone.

Compact bone structure

dense and strong bone tissue that can withstand compressive forces. consists of closely packed osteons or haversian systems.

Compact bone location

found under periosteum + in diaphysis of long bone

Compact bone function

provides support + protection to the bone

Spongy bone structure

made up of tiny cross hatchings supports called trabeculae

spongy bone location

within the ends of the long bone, pelvic bone, ribs, skull, vertebrae

spongy bone function

helps reduce stress + provide strength to bone

What are the types of cells found in bone tissue?

osteogenic, osteoblasts, osteocytes, osteoclasts

Osteogenic cells function

develop into osteoblasts. located in deep layers of periosteum + marrow

ostoecytes function

maintain mineral concentration of matrix

what are some types of bone fractures?

stable, open, transverse, oblique, comminuted

stable fracture

broken ends lined up

open fracture

skin pierced by bone, bone visible

transverse fracture

horizontal line fracture

oblique fracture

fracture at angle

comminuted fracture

bone shattered into 3 or more pieces.

What are the steps of repair for bone fractures?

hematoma- forms clot to stop the blood flow to bone

granulation tissue- gives stability + bone bridging tissue

bony callus- forms bridge if bone is not connected

bone remodeling- bone becomes stronger for a period of time (months or years) after fracture

Osteoporosis symptoms

silent disease, no symptoms until bone broken

bones may become so fragile that fractures occur spontaneously or result of minor falls

Who is at risk for osteoporosis

women are at higher risk than men, especially women in menopause.

aging, body size (more slender build are at greater risk), family history, changes to hormones, and lifestyles are also risk factors.

Histological effect of hormones

involved in controlling bone growth, maintaining bone once formed and remodeling.

treatment and lifestyle changes for osteoporosis

medication- vitamin, dietary supplement, bone health + hormone treatment

diet- calcium rich food, vitamin D

exercise- physical activity at least 2 hours, 2x a week. weight bearing and balance exercises

How does exercise affect bone tissue?

greater bone density

stimulates deposition of more bone tissue

resistance training is important to slow down bone loss due to aging

thicker bones

how does diet/nutrition affect bone tissue?

Vitamin D facilitates calcium absorption

Vitamin K helps with bone mineralization and Vitamin D in bone growth regulation.

magnesium supports bone health

fluoride stabilizes + strength

omega 3 reduces inflammation (interferes with osteoblasts)

overall enhances production of new tissue

Fibrodysplasia ossifican progressiva (FOP) cause

genetic mutation of gene (ACVRI) in bone morphogenic protein during embryonic formation of skeleton

FOP affected population

1 in 2 million people are at risk. no population is more prone than the other

FOP histological effect

extra skeleton bone is normal then develops through series of tissue differentiation events during embryonic skeletal development.

underlying genetic mutation alters signals that regulate induction of cell differentiation.

FOP symptoms

episodes of muscles swelling

inflammation, rapid ossification after trauma to muscle

difficulty speaking

eating malformed big toes at birth

scoliosis or kyphosis

gradual replacement of muscles, tendons, ligaments into bone at neck

hearing impairment.

what is the role of red bone marrow?

produces red blood cells.