Anatomy and Physiology

Skeletal System

What is a long bone

Bone that has a shaft and 2 ends and is longer than it is wide.Have a thick outside layer of compact bone and an inner medullary cavity containing bone marrow. The ends contain spongy bone and an epiphyseal line.

Parts of a long bone

 Articular cartilage, spongy bone, space occupied by red marrow, endosteum, compact bone, medullary cavity, yellow marrow, periosteum, proximal epiphysis, epiphyseal disks, diaphysis, femur, distal epiphysis. 

Examples of long bones

 Humerus, radius, femur, fibula, tibia, phlanges (90 bones)

What are short bones

Roughly cubed shaped and contain mostly spongy bone. Outside surface is a thin layer of compact bone.

Examples of short bones

Carpals, tarsals (32 bones)

What are flat bones

 Made up of a layer of spongy bone between two thin layers of compact bone. They have a flat shape, not rounded. 

Examples of flat bones

Sternum, ribs, skull (12 bones)

What are irregular bones

They are primarily spongy bone that is covered with a thin layer of compact bone.

Examples of irregular bones

Vertebrae and sacrum (33 bones)

Bones in Axial skeleton

Skull, middle ear bones, hyoid bone, vertebral column, thoracic cage

Hyoid bone

Only bone that doesn’t articulate with any other bone

Thoracic cage

Bones of thorax

\# of bones in Axial skeleton

80

\# of bones in Appendicular skeleton

126

Pelvic girdle

Bones of the hip

Pectoral girdle

Bones of the shoulder

Bones in Appendicular skeleton

Pectoral girdle, upper limbs, pelvic girdle, lower limbs

Number of ribs

12 pairs

True ribs

First 7 pairs attach directly to the Sternum

False ribs

Last 5 pairs attach indirectly to the Sternum

Cervical vertebrae

C1-C7

Thoracic vertebrae

T1-T12

Sacrum

1 or 5

Coccyx

1 or 4-5

\# of bones in vertebral column

 26-33

Fontanels (or *soft spots*)

An infant is born with two major soft spots on the top of the head called fontanels. These soft spots are spaces between the bones of the skull where bone formation isn't complete. This allows the skull to be molded during birth. The smaller spot at the back usually closes by age 2 to 3 months.

Sinusitis

Inflammation of the sinuses

Sinus infections

Follows a cold, flu, or allergy response; Infection in sinuses; Thick green mucus, headache, sinus pain

Sinus pressure

discomfort and pain in the spaces behind the nose, cheeks, and eyes

Sinus headaches

Caused by pressure that is the result of fluid accumulation in the sinus cavities

Differences between the male and female pelvic cavity

female pelvis is broader, shallow, the intet is wider for birth

Scoliosis

Sideways curvature of the spine

Kyphosis

Increased front to back curve of the spine (forward rounding) (higher)

Lordosis

Curve of the lower back area of the spine (lower)

Hip fracture (involves the femur)

A break in the upper portion of the femur (thighbone)

Heel spurs

Extra bone forming forming on our heel bone (excess growth becomes painful)

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Bunions

Lump on toes (shoes don’t fit)

Epiphysis

Found at end of bone and articulates (forms a joint) with another bone

articular cartilage

Covers the articulating part of epiphysis. Is made of a layer of hyaline cartilage

spongy bone/cancellous bone

 Found in the epiphyses. Has thin layers of compact bone on their surfaces. Consists of numerous bony plates. Irregular connecting spaces found between plates (Reduce the weight of bone)

red bone marrow

 blood cell forming tissue in spaces within the bone

Marrow

 soft connective tissue that fills the medullary cavity

compact bone

Makes up wall of diaphysis

medullary cavity

Is a semi-rigid tube (hollow chamber) within the diaphysis (is continuous with the spaces of the spongy bone)

yellow marrow

fat storage found in certain bone cavities

periosteum

Tough, vascular covering of fibrous tissue. Covers the bone except for the articular cartilage on the ends of the bones. Helps repair bone tissue, Osteoblasts found here

epiphyseal plates/growth plates

Cartilaginous layer within the epiphysis of the long bone that grows

proximal epiphysis

Is end of bone nearest to the body

diaphysis

Is the shaft of the bone. Located between the epiphyses

distal epiphysis

 is end of bone farthest from the body

Processes

 bony projections which provide sites where ligaments and tendons attach

Grooves and openings

 form passageways for blood vessels and nerves

Depression

a depression of one bone may articulate with the process of another bone

Osteon/Haversian System

Compact bone consits of these cylinder shaped units (haversian system). many of these units cemented together form the substance of compact bone

Osteonic canal

contains blood vessels and nerve fibers

haversian canal / central canal

contains blood vessels and nerve fibers

Lacunae

space containing the osteocyte or bone cell

Osteocytes

The cells residing within the bone matrix and comprising 90% to 95% of the all bone cells

Lamellae

Bone matrix is deposited in thin layers called the lamellae which gorms concentric ptterns around tiny longitudinal tubes called haversian canals / central canals

Canaliculi

Bone cells also have many cytoplasmic processes that extend outward and pass through very small tubes in the extracelluar matrix called canaliculi. allow materials to move rapidly between blood vessels and bone cells

Perforating canals/Volkmann’s canals

Canals that run at right angles to the central canals, provide pathways for blood vessels and nerve fibers to connect central canals with the periosteum (outside the bone)

Trabeculae

Supporting bundles of bony fibers in cancellous (spongy) bone

Autologous transplan

Using some of the patient's own bone marrow that was harvested before treatment began

Allogeneic transplant

Stem cells are acquired from a donor who has been determined to be human leukocyte antigen (HLA)-matched to the recipien

Bone Development & Growth

Bones grow longitudinally and determine the height of an individual *and* grow thicker and wider to support the weight of the adult body

Where does Longitudinal bone growth occur

At the epiphyseal plate/disk/disc (or growth plate)

How do bones grow taller

Cartilage next to the epiphysis contines to multiply and grow toward the diaphysis

Osteoblasts

Cartilage next to the diaphysis however, is invaded by ___ and becomes ossified. This helps bones grow taller.

Lengthen

As long as the cartilage contunes to form within the epiphyseal plate/disk the bone continues to

Longitudinal bone growth __ when the epiphyseal plate/disk becomes __

Stops/Ossified

Epiphyseal plate/disk is sensitve to the effects of certain hormones especially

 Growth and sex hormone 

Stimulates the growth at the epiphyseal plates, making a child taller

Growth hormone

Bones continue to grow in ___ even after longitudinal bone growth stops

Thickness and width

Bones are continuously being

Reshaped

Bone remodeling is accomplished by the combined actions of

 Osteoblasts: bone-forming cells

osteoclasts: bone destroying cells

Osteoblasts

Within the periosteum continusously deposit bone on the external bone surface

Osteoclasts

Found on the inner bone surface surronding the medullary cavity, breaks down bone tissue. thus they holllow out the interior of the bone

Osteoclasts and Osteoblasts

They create a large wide hollow bone that is strong but not too heavy

Factor that stumulates bone growth is

Weight bearing

__ keeps calcium in the bone and increases bone mass

Exercise

Intramembranous bones

Ossification that involves the replacement of thin membrane with bone; like in flat bones of skull

Endochondral bones

Develop from cartilage

Bone remodeling

this is how bones are continually being reshaped – in thickness and width

What happens if the epiphyseal plate is injured/damaged?

It can result in a shorter or crooked limb. A growth plate fracture affects the layer of growing tissue near the ends of a child's bones. Growth plates are the softest and weakest sections of the skeleton — sometimes even weaker than surrounding ligaments and tendons.

What happens if a bone is broken or fractured?

Occurs when a force exerted against a bone is stronger than the bone can bear. This disturbs the structure and strength of the bone, and leads to pain, loss of function and sometimes bleeding and injury around the site.

What happens if there is a dislocation?

When extreme force is put on a ligament, causing the ends of 2 bones to come apart. A dislocation can cause pain, swelling, and weakness.

First Way

Immovable joints, Slightly movable joints, Freely movable joints

Second Way

Fibrous joints, Cartilaginous joints, Synovial joints

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Synovial Joints

All freely movable joints are synovial joint

Articular cartilage

 Ends of long bones are covered with a thin layer of hyaline layer resists wear and minimizes friction when it is compressed as the joint moves

Joint capsule

 A tubular joint capsule holds together the bones of a synovial joints

has 2 distinct layers: an outer layer of dense connective tissue and ligaments that reinforce the joint capsule and help bind the articular ends of the bones)

Synovial membrane

The inner lining of the joint capsule (shiny, vascular lining of loose conective tissue) secrets synovial fluid

Synovial fluid

moistens and lubricates the smooth cartilaginous (consistency of uncooked egg white - clear viscous fluid)

Bursa/bursae *(plural*)

fluid-filled sacs found in certain joints

bursae is commonly located between ______ which _____

tendons and underlying bony promisenses

cushion and aid in the movement of tendons that glide over these bondy part or over other tendons

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example of bursae

patella of the knee or olecranon process of the elbow

Supporting ligaments

Join articulating bones together and stabilize joint

Hinge joint

The convex surface of one bone fits into the concave surface of another bone

Example of hinge joint

Elbow, joints of the phalanges

What does hinge joint allow

Movement in one direction only