University of Iowa - Human Anatomy - Exam 2

What are the bones of the skeleton?

Cartilages, Ligaments, and Connective Tissues

Cartilage

-Located throughout the body

ex. external ear, nose, ends of bones at moveable joints (articular cartilage), in trachea & larynx, maintaining the integrity of respiratory tubes, in between vertebrae, at the pubic symphysis (by pelvis along mid-line)

What are the three types of cartilage?

Hyaline: Glass

Elastin: Flexible

Fibrocartilage: Toughest (inter-vertebral disk)

Growth of Cartilage

Appositional Growth: From the outside

-Chrondroblasts

Interstitial Growth: From the inside out

-Chondrocytes

What tissues are the bones composed of?

Bone, nervous tissue, blood tissue, cartilage, and epithelial tissue.

What are the primary functions of bones

Support, movement, protection, mineral storage, blood cell formation, and energy storage

Long Bones

Most limb bones (humerus)

Short Bones

Wrist & ankle bones

Flat bones

Sternum

-cranial bones, rib, sternum, scapula

Irregular bones

vertebrae and pelvis

Diaphysis

(shaft of the bone)

Epiphysis

each end of bone, covered with articular cartilage

Medullary Cavity

filled with bone marrow

Periosteum

Outer covering of the bone

Endosteum

lines inner portion of the bone and medullary cavity

Epiphyseal line

Remnant of the growth plate

Compact bone

found on the superficial aspect of the bone

Spongy bone

trabeculae

-spaces between the traebeculae are filled with marrow

Compact bone (microscopic view)

Osteons: groups of cylinders to help bone resist stresses

-each of the cylinders/tubes is a lamella

-central canal/haversion canal (eye holes)

-perforating canals: openings perpendicular to central canals

Spongy bone (microscopic view)

Each traebecula contains several layers of lamellae and osteocytes

Bone cells/Bone tissue

Osteogenic cells (undifferentiated stem cells)

Osteoblasts (deposit osteoid)

Osteocytes: When they are embedded into bone matrix

-originate from osteoblasts that migrate into and become trapped in the bony matrix

-sense strain and forces on bone, so they can direct adaptation

Osteoclast: break down bone

-constantly working to liberate calcium or to adjust for bone not being used

Osteogenesis/Ossification

Bone tissue formation

2 types of bone tissue formation

intramembranous - flat bones

endochondral - long bones

-continues into early adulthood

-bones increase in both length and width

Appositional growth - growth by adduction of bone tissue to its surface

Intramembranous bone formation

Osteoblasts aggregate around the surface of the bone being formed

-deposit osteoid = mostly type I collagen

-becomes mineralized to become bone

Endochondral bone formation (step 1)

nonspecific tissue condenses and is signlaed to differentiate

Endochondral bone formation (step 2)

mineralization of the outside of diaphysis

Endochondral bone formation (step 3)

diaphysis cavity begins to become hollow/cavity is formed (programmed cell death)

Endochondral bone formation (step 4)

Blood vessels penetrate and bring in osteoblasts and osteoclasts

-still a layer of chondrocytes on each end "growth plates"

Endochondral bone formation (step 5)

Chondrocytes being driven indirectly by GH and other factors, which stimulate mitotic division

Endochondral bone formation (step 6)

Secondary ossification center is formed

Endochondral bone formation (step 7)

Cartilaginous growth plate gone (osteoblasts responsible for final destruction of chrondrocytes) - lay down osteoid

Primary

Diaphysis

Secondary

Epiphysis

Bone remodeling

bone is dynamic living tissue

spongy bone - replaced every 3-4 years

compact bone - replaced every 10 years

bone resorption via osteoclasts

bone depostion via osteoblasts

in children - depositon exceeds resortion

in young adults - deposits = resorption

in older adults - resorption exceeds depostion

Articular surfaces

head - bony expansion

neck - narrow arrow distal to the head

facet - smooth surface

condyle - rounded projection

Depressions and Openings

Foramen - round or oval opening

Groove - furrow

Fissure - narrow slit

Notch - indentation

Fossa - shallow depression

Meatus - canal

Sinus - cavity within a bone

2 types of bone fractures

simple, compound (punctures the skin)

Types

comminuted - tibia shattered (bone shattered)

compression - compression of the bone; osteoporosis

spiral - fracture

Epiphyseal - causes epiphysis to separate from diaphysis

Depressed/depression - depression of the bone

Greenstik/buckle - a slight bend or break of the bone but it does not puncture the skin

Fracture healing process (1)

Hematoma formation: blood in the area

Fracture healing process (2)

Fibrocartilage Callus Formation: a soft callus forms, which later is replaced by dense connective tissue - called the fibrocartilaginous callus

Fracture healing process (3)

Bony callus formation

Fracture healing process (4)

Bone redmodeling

Osteoporosis

Bone tissue deteriorate/breaks down at a faster rate tan it is being produced

- compact bone becomes thinner, spongy bone has fewer trabeculae

Osteomalacia

inadequatley mineralized (soft)

Rickets

Osteomalicia in children

What are osteomalacia and rickets both caused by?

Vitamin D or calcium phosphate deficiency in diet. Can be treated by drinking Vitamin D fortified milk.

Osteosarcoma

More common in younger individuals

-10-25 years of age

-long bones

-tumors erode meduallary cavity and the compact bone

-most deaths occur from secondary tumors in the lungs

-pain and swelling

-Treatment = amputation

Axial Skeleton

206 bones in the human skeleton

- axial: 80 bones in the skull, vertebral column, and throacic cage

Appendicular Skeleton

Bones of upper and lower limbs as well as their attachment points (pectoral girdle, pelvic girdle) to the axial skeleton

Scoliosis

abnormal lateral curvature (middle/high school females)

Kyphosis

Hunchback - extreme throacic curvature (more common in people with osteoporosis)

Lordosis

Swayback - extreme lumbar curvature (excessive weight in the abdominal area), common in pregnant women and older aged men

Spinal ligaments

Anterior and posterior longitudinal ligaments

-run the length of the vertebral column

-prevent hyperextension and hyperflexion of the back

Ligamentum flavum - one of many ligaments that runs from vertebrae to vertebrae

Intervertebral disk

-pads between vertebrae

-make up about 25% of the total length of the spine

-Help absorb shock/compression

Structure

-nucleus pulosis

-Anulus fibrosus

Herniated disk/slipped disk

Caused by heavy lifting

Anulus fibrosus ruptures, allowing nucleus pulposis to protrude (puts pressure on spinal nerve roots causing pain

Treatment - heat, pain killers, physical therapy and surgery if needed

C1

Atlas

C2

Axis

illium

Forms the superior portion of the innanimate bone (acetabulum = lateral, greater sciatic notch = posterior)

Ischium

Posterior/inferior side

Coxal bone

Pubis

anterior portion of the pelvis

Pelvic brim

separates false (greater) pelvis from true (lesser) pelvis

False pelvis

superior to brim

True pelvis

inferior to brim

Medial longitudinal arch

relatively high - runs anterior to posterior

Lateral longitudinal arch

relatively low - runs anterior to posterior

Transverse arch

runs medial to lateral

Joints/articulations (classifications)

Synarthoses (no movement allowed); sutures

Amphiarthorses (slighly moveable); vertebral column)

Diarthroses (freely movable); hip, shoulder, wrist

Cartilaginous joints

Connected by cartilage

Not highly moveable

2 types

-synchondrosis: hyaline cartilage connects the bones (ribs costal cartilage)

-symphysis - fibrocartilage connects bones (pubic symphysis)

Fibrous joints

connected by fibrous tissue

very little motion

3 types

-sutures (skull)

-syndesmoses (ulna and radius)

-gamphoses (tooth)

Gliding

flat surfaces of two bones slide across one another

Angular

change angle between bones

Flexion

antebrachial up to shoulder; decreasing angle

Extension

increasing angle

Hyperextension

extension beyond normal degree

Abduction

movement away from the midline

Adduction

movement towards the midline

Circumduction

movement in a circle

Rotation

movement about an axis

-occurs between C1 and C2 as well as the spone

-occurs at hip

Protraction

moving a body part forward

Retraction

movement in a backward motion

Elevation

movement in a superior direction

Depression

lowering inferior direction

Supination

palm faces anteriorly (radius and ulna are parallel)

Pronation

Palms posterior (radius crosses over ulna)

Opposition

independently touch tips of fingers with thumbs

Inversion

sole of foot medially

Eversion

sole is lateral

Dorsiflexion

Pointing toes up

Plantar flexion

point toes down

Plane joints

articulating surfaces are flat or slightly curved

Hinge

convex and concave surfaces articulate

Pivot

cylindrical surface of the bone articulate with ring of the bone and ligament

-rotation around central axis

Condyler

head articulates with cavity of another bone

Saddle

concave surface in one direction and convex in another. ex; back and forth side to side

Ball-and-Socket

Ball shaped head of one bone articulates wit cup shaped cavity of another. ex; hip and shoulder

Stabilizing factor

articular surfaces (bony structures)

ligaments (bone to bone)

muscles (muscle to bone)

Temporomandibular joint (TMJ)

jaw, modified hinge joint, pain due to muscle lightening

Humeroulnar joint

elbow joint

Hip joint

Ball and , wide R.O.M

Acetabulum labrum - rim of fibrocartilage - helps maintain articulation between head of femur and cetabulum

Ligaments - illiofemoral ligament

Muscle tendons

Knee joint

Largest most complex join, allowing flexion and extension

12+ bursae

- subcutaneous prepatellar bursa - commonly injured if the knee is bumped

- stabilized by tendons of many major muscle, especially quadriceps femoris

Menisci - C shaped rings of cartilage

-lateral and to medial meniscus