Skeletal Tissue

What you should know before studying the skeletal system

• This lesson will focus on the two types of specialized connective tissue that make up the majority the skeletal system. These tissues are bone and cartilage. Bone differ in size and shape based on their function. There are two broad types of bone tissue, compact bone and cancellous or spongy bone. Bones also differ on the amount of each type of bone tissue that comprises them.

Compact bone is dense and solid in appearance.Cancellous or spongy bone is open spaced with

needle-like structures.

General Functions of theSkeletal System

• Support for the organs and tissue• Storage of minerals (inorganic ions) and lipids. Minerals

are important in the regulation of osmotic concentrations of body fluids and as cofactors in enzymatic reactions. Calcium is the most abundant mineral and is used in a variety of ways through out the body including bone density, nerve signal transmittance and muscle contraction. Bone stores energy in the lipids found in yellow marrow.

• Production of blood. Red marrow that fills the cavities of many bones produces, red blood cells, white blood cells and other blood elements.

• Protection of soft organs and tissues.• Leverage to change the magnitude and direction of the

forces generated by skeletal muscles.

Four Broad Types of Bone Shapes

• Long bones are long, slender bones such as those found in the arm and legs. The femur is the largest and heaviest bone of the body

• Short bones are small, box-like bones such as those found in the wrist (carpel) and ankles (tarsal)

• Flat bones are generally broad, thin bones with flattened curved surface such as those found in the skull, shoulder blades and ribs.

• Irregular bones are bones such as the vertebrae that don’t generally fit into the above categories

Bone Marking (Surface Features)

• Bone markings are important surface features that allow for the identification of the bone which may include the bones function.

• Bone markings provide anatomical information that can be helpful to anthropologist, criminologist and pathologist.

• Bone markings can indicated age and gender of an individual

Process

• A projection or bump usually for muscle attachment.

Ramus

• Extension of a bone making an angle with the rest of the structure

Trochanter

• Large, rough projection for muscle attachment on the femur.

Tuberosity

• Small, rough oblong projection

Tubercle

• Small, round projection (Small Tuberosity)

Crest

• Prominent ridge

Line

• Low ridge

Spine

• Pointed process

Head

• Expanded articular end of an epiphysis, separated from the shaft by a neck

Neck

• Narrow connection between the epiphysis and the diaphysis

Condyle

• Smooth, rounded articular process (bump)

Epicondyle

• Process near a condyle (Bump on a bump)

Trochlea

• Smooth, grooved articular process shaped like a pulley

Facet

• Small, flat articular surface

Fossa

• Shallow depression, receives an articulating bone

Notch

• V-like depression in the margin of a flat area

Sulcus

• Narrow groove

Foramen

• Rounded passageway (hole) for blood vessels or nerves

Canal

• Passageway through a bone

Fissure

• Elongate cleft, crack like hole for blood and nerves

Meatus

• Tube like opening or channel

Sinus or Antrum

• Chamber within bone usually filled with air