IBS - SKELETAL SYSTEM

Skeleton system contains ___ named bones.

206

Most bones are _____.

• paired

Axial skeleton includes the bones of…

skull, vertebral column, ribcage

What skeleton protects, supports, or carry other body parts?

• Axial skeleton

Appendicular skeleton consists of…

Bones of the upper and lower limbs and the girdles.

Which skeleton is responsible for the locomotion of the body?

• Appendicular skeleton

How many bones are in the axial skeleton?

80 bones

Skull Bones

• Cranium - 8

• Face - 14

• Hyoid bone - 1

• Auditory ossicles - 6 bones

How many bones are in the vertebral column?

26

Thorax Bones

• Sternum - 1

• Ribs - 24

How many bones are in the appendicular skeleton?

126 bones

Pectoral (shoulder) girdles

• Clavicle - 2

• Scapula - 2

Pelvic (hip) girdle

• Pelvic/coxal - 2

UPPER LIMBS

• Humerus — 2

• Ulna — 2

• Radius — 2

• Carpals — 16

• Metacarpals — 10

• Phalanges — 28

LOWER LIMBS

• Femur — 2

• Patella — 2

• Fibula — 2

• Tibia — 2

• Tarsals — 14

• Metatarsals — 10

• Phalanges — 28

Carpals are the …

• wrist

Metacarpals are the …

• palm

Tarsals are the …

• ankle

Metatarsals are the …

• feet

What are long bones?

• greater length than width

• shaft plus two ends, often expanded

Examples of long bones:

• all limb bones

NOT patella, wrist and ankle bones

What are short bones?

• roughly cube shaped

• nearly equal in length and width

Examples of short bones:

• bones of the wrist (carpal) and ankle (tarsal)

What are flat bones?

• thin, flattened

• usually a bit curved

Examples of flat bones:

• sternum, scapulae, ribs, most skull bones

What are irregular bones?

• complex shapes, cannot be defined clearly

Examples of irregular bones:

• vertebrae, hip bones

What are sesamoid bones?

• special short bone that form in a tendon

• vary in size and # in diff individuals

Examples of sesamoid bones:

• patella, pisiform

What are sutural bones?

• small bones located in sutures (joints) between cranial bones

Every bone has two layers that are called…

• Compact bone

• Spongy bone

The compact layer of the bone is:

• dense outer layer, looks smooth and solid to naked eye

The spongy layer of the bone is:

• internal layer

• consists of trabeculae = porous, spaces between are filled with red or yellow bone marrow

What is diaphysis in bone structure?

• bone’s shaft or body

• long, cylindrical, main portion

What is epiphysis in bone structure?

• proximal and distal ends of the bone

What is metaphysis in bone structure?

• region between the diaphysis and epiphysis

What is articular cartilage in bone structure?

• thin layer of hyaline cartilage

• covering the part of the epiphysis

✓ Reduces friction at movable joints

What is periosteum?

• tough connective tissue covering

• associated with blood supply

✓ Protects the bone, assists in fracture repair, helps nourish bone

tissue, and an attachment point for ligaments and tendons

What is the function of the periosteum?

• protects the bone, aids in fracture repair, helps nourish bone tissue, and an attachment point for ligaments and tendons

What is the medullary cavity or marrow cavity?

• hollow, cylindrical space within diaphysis

• contains fat yellow bone marrow and blood vessels

What is the endosteum?

• thin membrane that lines medullary cavity

• contains a single layer of bone-forming cells and small amount of connective tissue

What is the structure of short, irregular, AND flat bones?

• ALL share a simple design

• outer thin plate of compact bone

• periosteum covering the compact bone

• inner spongy bone

• endosteum covering the spongy bone

What do short, irregular, AND flat bones NOTHAVE?

• diaphysis, epiphyses, medullary cavity

Spongy bone of a typical flat bone is called the…

diploë

BONE MARKINGS: (Heads, trochanter, spine, tubercle, crest, line, tuberosity, condyle, ramus)

Projections

BONE MARKINGS: (Fossae, fissure, groove)

Depressions

BONE MARKINGS: (Foramina, sinus, meatus).

Openings

Bones have surface markings adapted ____

• for specific functions

Depressions and openings allow …

• passage of soft tissues (blood vessels, nerves, ligaments, and tendons)

• form joints

Processes, projections or outgrowths help…

• to form joints

• serve as attachment points for connective tissue (ligaments and tendons)

Hematopoietic tissue of bone marrow:

• reproduces red blood cells

• found within the red marrow cavities

  ➢ Trabecular cavities of spongy bone of long bones

  ➢ And in the diploë of flat bones

In new born infants, red bone marrow is located…

• in medullary cavity and spongy bone cavities

Location of hematopoietic tissue in ADULT long bones…

• fat-containing medullary cavity extends

• little red marrow is present in the spongy bone cavities

• hemopoiesis occurs only at heads of the femur and humerus, diploë of flat bones and in some irregular bones

Function of bones - support:

• structural framework that supports the body

• provide attachment points for the tendons of the muscles

Function of bones - protection:

• protects the internal organs from injury

Function of bones - movement:

skeletal muscles attach to bones by tendons

✓ Use bones as levers to move the body and its parts

→ walking, grasping, breathing

Function of bones - mineral homeostasis:

• (storage and release)

• reservoir for minerals, calcium and phosphate

• stored minerals are released into the bloodstream and maintain critical mineral balances

Function of bones - blood cell production:

• hemopoiesis occurs in the red marrow, heads of femur and humerus

Function of bones - triglyceride (fat) storage:

• yellow bone marrow store triglycerides = potential energy reserve

• stored in bone cavities

Function of bones - hormone production:

• produce osteocalcin

• helps regulate bone formation

• protects against obesity, glucose intolerance