Bone Densitometry Basics: Osteology

The study of bones

Osteology

Bones are made up of

Collagen protein and minerals

What is a calcium rich mineral?

hydroxyapatite

Bone mass is _____ % of body's weight

20%

____ is a living tissue that repairs itself

bone

What is the standard anatomical position?

Body erect, feet slightly apart, palms facing forward with thumbs pointing away from body

Why use the standard anatomical position?

Used to discuss location and orientation of bones

What are the 3 planes of refernce?

Sagittal, coronal, and Axial/transverse

Which two planes of reference are the absolute reference?

Sagittal and Coronal planes

Which plane is a relative reference?

Transverse/ axial plane

What is a relattive reference plane?

Has no fixed location, need to set a reference when describing the bone.

What are the 4 directional references?

Medial, Lateral, Proximal, Distal

What is included in the axial skeleton?

Torso, head, skull, ribs, spine, sternum

What is the area of bone that connects with another bone via cartilage, fibrous tissue or synovial fluid?

Articular surface

What is a natural prominence, appendage, or outgrowth of a bone?

Process

What is a bony projection not as pronouced as a process called?

Eminence

What is a rounded articular process that rests/ rotates, and slides against another bone?

Condyle

What is an attachment point for back muscles for standing and lifting?

Spinous Process

What is a large rounded eminence of variable shape that is an attachment for muscles and tendons?

Tuberosity

What are small articular surfaces on bones that connect without forming a complete joint?

Facets

The depressed area of bone that is broad and shallow

Fossa

What is a long pit/ furrow running along the side of a bone that acts as a channel for veins, tendons, and muscles. Hard to palpitate

Groove

Give an example of a groove in the body

Ribs

Term what describes the opening through a bone

foramen

What are the 4 sinus cavities in the cranial bone?

Frontal, ethmoid, maxillary, and sphenoid.

The sinuses are connected to the nose via openings called _____

ostium

Joints are padded with what material? (3)

cartilage, fibrous tissue, synovial fluid

We categorize joints by ____ and _____

range of motion, structure

The structure of joints is grouped by

the type of tissue binding them

Range of motion of joints in based on _____?

the kind of movement

____ joints are connected by relatively dense, tough tissue

fibrous

The two types of ranges of motion for fibrous joints are ___________ and _________

Synarthrosis and syndesmosis

What is the range of motion of synarthrosis?

Immovable, nearly immovable

What is the range of motion for syndesmosis?

Slightly moveable

What is the purpose of fibrous joints?

permanently bind 2 or more bones together

What are the three types of fibrous joints?

sutures, syndesmoses, gomphoses

What type of fibrous joint is found in the skull, not fused until after birth, and the cartilage is replaced by fibrous tissue?

Sutures

What type of fibrous joint is immobile and keeps teeth in their sockets?

gomphoses

What type of fibrous joint is slightly mobile that connects two bones using a ligament?

Syndesmoses

Give an exam of a syndesmoses fibrous joint

radius and ulna, tibia and fibula

What type of joints have slightly mobile articulation?

Cartilaginous Joints

What range of motion describes cartilaginous joints?

Amphiarthroses

Amphiarthroses means what?

little movement

What are the two types of cartilaginous joints?

Symphyses and synchondroses

Give an example of a symphyses cartilaginous joint

Pubic symphysis

What type of cartilaginous joint is described as slightly less rigid than a fused bone allowing minor bending and compression and slightly flexible?

Symphyses

What type of cartilaginous joint is described as little movement, strong bond

Synchondroses

Give an example of a synchondroses cartilaginous joint

First rib and sternum connect

Synchondrosis cartilaginous joints in children and adolescents form temporary joints called?

Epiphyseal growth plates

What type of joint is described as fully mobile?

Synovial Joint

Another term for synovial joint?

Diarthroses

Type of joint that is described as a rounded protrusion articulating with a cup like depression

Ball and socket joint

Type of joint that allows movement forward and backward, side to side but does not rotate

Condyloid Joints

Give an example of a condyloid joint

Between radius and carpal bones of the wrist

A joint described as a concave/ convex structure

Saddle Joint

Example of a saddle joint

Between the trapezium and first metacarpal

Type of joint where the range of motion is on one axis

Hinge Joints

Example(s) of a hinge joint

elbow and knee

Type of joint with only rotational movement

Pivot Joints

examples of pivot joint

radius and ulna, atlas and axis

Type of joint positioned between flat surfaces of adjacent bones

Gliding Joints

Examples of gliding joints

carpals, tarsals, vertebrae

Long bones are made up of what two types of bone tissue?

cortical bone and trabecular bone

What type of bone tissue accounts for 80% of the skeletal weight?

Cortical bone

What type of bone tissue can be described as a smooth, hard mineral that is solid, dense and hard. Provides strength to the skeleton

Cortical Bone

What mineral and protein is cortical bone made of?

hydroxyapatite mineral and collagen protein

What happens to cortical bone when hydroxyapatite dissolves or becomes weakened?

Bone becomes flexible, rubbery, useless for support

What happens to cortical bone is collagen is burned/dried out?

Bone becomes fragile and brittle

What type of bone tissue can be described as porous, thin, needle like strands with a spongy structure similar to a honeycomb.

Trabecular bone

Trabecular bone accounts for what % of the weight of the skeleton?

20%

Where is trabecular bone found (3)?

1) End of the shafts of long bones

2) Vertebral bodies

3) Center of flat bones.

True or false, Trabecular bone has the same composition of cortical bone

true

What is the function of trabecular bone?

1) Houses bone marrow

2) Supplies and produces RBC

3) Reserves fats and minerals

What is the name of the cavity that is in the center of long bones?

Medullary Cavity

What is the medullary cavity filled with?

Yellow bone marrow, reserve of fat cells

What is the medullary cavity surrounded by?

Cortical/ compact bone

The ends of long bone are filled with what type of bone marrow?

Red bone marrow

When someone is young, the ends of long bones contain more ____ marrow and less _____ marrow.

More Red, Less Yellow

When someone is old, the ends of long bones contain more _____ marrow and less ______ marrow.

More yellow, less red

What is the term of the protective layer that surrounds bone?

Periosteum

What is the function of the Periosteum?

Supplies nutrients to bones, contains bone forming cells

What is the term of the inner layer of the medullary cavity?

Endosteum

What is the function of the endosteum?

It lines the medullary cavity and contains bone-forming cells

What are the names of the two basic microscopic structures of bone?

Woven Bone and Lamellar Bone

What is the type of microscopic structure of bone that is the first bone to develop in the fetus?

Woven Bone

What is Woven Bone made of?

Collagen fibers arranged at random

What is lamellar bone?

Secondary bone - this remodels woven bone

What is the term for small cavities housing living bone cell in lamellar bone?

Lacunae

What is the term for tiny channels that connect lacunae to each other and nourish bone cells?

Canaliculi

What system overcomes the limitation of lamellar bone being arranged too tightly for nutrients to diffuse through it

Haversian System

What type of bone cell builds/ creates new bone cells?

Osteoblasts

What type of bone cell regulates bone repair and maintenance?

Osteocytes

What type of bone cell resorbs old bone?

Osteoclasts

What type of bone cell is regulated by hormone concentrations?

Osteoclasts

What type of bone cells regulates calcium concentration in bone?

Osteoclasts

What are the two methods of bone growth in embryo?

Intramembranous ossification and endochondral ossification