anatomy unit 2 lecture objective notes

Functions of the skeletal system

Support, movement, protection, producing blood cells, and storage of minerals and fat.

Types of bones by shape

Classified as long, short, flat, irregular, and sesamoid.

Long bone example

Examples include humerus, femur.

Short bone example

Examples include carpals and tarsals.

Flat bone example

Examples include skull bones, ribs, sternum.

Irregular bone example

Examples include vertebrae and pelvis.

Sesamoid bone example

Example includes the patella.

Gross features of a long bone

Includes compact bone, spongy bone, periosteum, endosteum, and marrow cavities.

Compact bone

Dense bone that forms the outer layer of bone.

Spongy bone

Lightweight bone found inside bones that provides support.

Articular cartilage

Smooth tissue that covers the end of bones at joints.

Periosteum

A dense layer of vascular connective tissue enveloping bones.

Endosteum

Membrane lining the medullary cavity of a bone.

Medullary cavity

Central cavity of bone containing yellow and red marrow.

Yellow marrow

Fatty tissue that stores lipids.

Red marrow

Tissue that produces blood cells.

Epiphysis

The end part of a long bone.

Diaphysis

The shaft or central part of a long bone.

Metaphysis

The region where the diaphysis and epiphysis meet.

Epiphyseal line

Growth plate area between the epiphysis and diaphysis.

Nutrient foramen

Small openings in bones for blood vessels.

Bone tissue components

Includes osteons, calcified matrix, osteocytes, osteoblasts, and osteoclasts.

Osteon

The basic structural unit of compact bone.

Calcified matrix

Bone tissue's rigid structure consisting of mineral deposits.

Haversian canal

Central canal containing blood vessels in osteons.

Volkmann canal

Channels that carry blood vessels perpendicular to the Haversian canals.

Osteocytes

Mature bone cells that maintain the bone matrix.

Canaliculi

Small channels that connect osteocytes allowing nutrient exchange.

Osteoblasts

Bone-forming cells.

Concentric lamellae

Layers of bone matrix around Haversian canals.

Osteoclasts

Cells that break down bone tissue.

Osteogenic cells

Stem cells that differentiate into osteoblasts.

Lacuna

Small cavities in bone that house osteocytes.

Bone lining cells

Cells that cover the surface of bone.

Trabeculae

Supporting struts in spongy bone.

Mesenchymal cells

Stem cells that can differentiate into various types of connective tissue.

Bone marking: process

A projection or projection from a bone.

Bone marking: spine

A sharp, slender projection on a bone.

Bone marking: condyle

A rounded surface at the end of a bone.

Bone marking: epicondyle

A projection situated above a condyle.

Bone marking: tubercle

A small, rounded projection on a bone.

Bone marking: tuberosity

A large, rounded projection.

Bone marking: trochanter

Very large, blunt, irregularly shaped process.

Bone marking: trochlea

A smooth, grooved articular process shaped like a pulley.

Bone marking: crest

A narrow, prominent ridge.

Bone marking: line

A narrow ridge of bone.

Bone marking: head

A bony expansion carried on a narrow neck.

Bone marking: neck

A narrowing of a bone.

Bone marking: fossa

A shallow depression in a bone.

Bone marking: facet

A small, flat surface on a bone.

Bone marking: fissure

A narrow, slit-like opening in a bone.

Bone marking: foramen

An opening, hole, or passage in a bone.

Bone marking: meatus (canal)

A canal-like passageway.

Bone marking: sinus

An air-filled cavity in a bone.

Bone marking: groove/sulcus

A furrow or trench in a bone.

Bone marking: ramus

An arm-like bar of bone.

Bone marking: notch

An indentation at the edge of a structure.

Endochondral bone formation

Process of bone development from cartilage.

Intramembranous bone formation

Bone development directly from connective tissue.

Interstitial bone growth

Growth that occurs within the bone length.

Appositional bone growth

Growth occurring on the surface of a bone.

Effects of exercise on bone

Increases bone density and strength.

Epiphyseal plate bone growth

Area for lengthwise growth of long bones.

Roles of human growth hormone

Stimulates growth, increases height until growth plates fuse.

Roles of estrogen and testosterone in bone growth

Promote bone maturation and closure of growth plates.

Calcitonin

Hormone that reduces blood calcium levels.

Parathyroid hormone

Hormone that increases blood calcium levels.

Compact vs. spongy bone

Compact bone is dense, spongy bone is lighter with trabecular structure.

Axial skeleton

Includes skull, vertebral column, and rib cage.

Appendicular skeleton

Includes the limbs and girdles.

Types of skull bones

Cranial bones protect the brain; facial bones form the face.

Frontal sinus

Air-filled cavity in the frontal bone.

Sphenoidal sinus

Sinus located behind the eyes in the sphenoid bone.

Maxillary sinus

Largest sinus located in the maxilla.

Ethmoidal air cells

Group of small sinuses within the ethmoid bone.

Joints

Locations where two or more bones meet, allowing for various movements.

Ligaments

Connective tissues that connect bones to other bones at joints.

Tendons

Connective tissues that attach muscles to bones.

Axial skeleton functions

Supports the head, neck, and trunk; protects the brain and spinal cord.

Appendicular skeleton functions

Facilitates movement and interaction with the environment through limbs.

Cartilage

Flexible connective tissue found in joints, the rib cage, and nose.

Synovial fluid

Fluid in synovial joints that reduces friction and nourishes cartilage.

Foramina

Plural of foramen; openings in bones for nerves and blood vessels.

Bone remodeling

The process of bone maintenance through resorption and new bone formation.

Osteoporosis

A condition where bones become weak and brittle due to loss of tissue.

What is a simple fracture?

A fracture where the bone breaks cleanly and does not penetrate the skin.

What is a compound fracture?

A fracture in which the bone breaks and pierces through the skin.

What is a comminuted fracture?

A fracture where the bone is shattered into many pieces.

What is a greenstick fracture?

An incomplete fracture in which the bone bends and cracks on one side, common in children.

What is a transverse fracture?

A fracture that occurs straight across the bone.

What is an oblique fracture?

A fracture that occurs at an angle across the bone.

What is a spiral fracture?

A fracture caused by a twisting force that results in a spiral-shaped break.

What is an avulsion fracture?

A fracture that occurs when a muscle or ligament pulls away a piece of bone.

What is a stress fracture?

A small crack in the bone that often develops due to repetitive force or overuse.

What is a pathologic fracture?

A fracture that occurs due to a disease that weakens the bone, such as osteoporosis.

Step 1: Hematoma formation

A blood clot forms at the fracture site to stabilize the break and begin the healing process.

Step 2: Fibrocartilaginous callus formation

Soft callus forms as cartilaginous tissue bridges the fracture gap, providing temporary stabilization.

Step 3: Bony callus formation

The soft callus is replaced by a bony callus as osteoblasts produce new bone tissue.

Step 4: Bone remodeling

Dead bone and callus are removed, and the new bone is remodeled to restore original shape and strength.