Skeletal System

How many bones are there in the body?

206

What is the longest bone in the body?

The femur

What is the smallest bone of the body?

The stirrup (stapes)

Which has more bones… a newborn baby or an adult?

A newborn

Which has more vertebrae… a human or a giraffe?

Giraffe vertebrae are just much longer

Long

Bones which are longer than they are wide. Ex: Femur

Short

Bones nearly as wide as they are long. Ex: Carpals

Flat

Thin bones with flat surfaces; these surfaces may be curved. Ex: Mandible

Irregular

Bones that do not fall into any of the above categories. Ex: Calcaneus

What is bones?

They are composed of organs called bones.

In addition to the bones, the skeletal system includes?

Joints, cartilages, and ligaments

What are the two divisions?

Axial Division (80 bones), Appendicular Division (126 bones)

What is axial skeleton?

Bones that form the longitudinal axis of the body. Ex: Skull, hyoid, vertebrae, sternum, and ribs

What is appendicular skeleton?

Bones of the limbs and girdles that are “appended” (attached) to the axial skeleton. Ex: The upper and lower extremities

What is fontanels?

It is a soft spot on the baby’s head.

How many bones does the facial bones have?

15

How many bones does the ear have?

6

How many bones does the vertebral column (spine) have?

30

What attaches to the manubrium of the sternum medially and to the scapula laterally.

The clavicle

What are the 3 borders from the scapula?

Superior, medial, and lateral

What is the glenoid cavity?

The shallow socket that receives the head of the arm bone.

What bone forms the arm?

The humerus

Proximal end has rounded ____ that fits into glenoid cavity of the scapula.

Head

Anterolateral to the head are the

Greater and lesser tubercles

The distal end is the medial _____ and the lateral

Trochlea, capitulum

Above the trochlea anteriorly is a depression, the

Coronoid fossa

Radius has disc-shaped **____** that forms a joint with capitulum of the humerus.

Head

Ulna has anterior __________ and posterior **_______** that grip the trochlea of the humerus.

Coronoid process, olecranon

Articulate proximally and distally at small

Radioulnar joints

**______** are arranged in two rows of four bones each and make up the wrist.

Carpals

**________** make up the palm and are numbered 1-5 from thumb side towards pinky.

Metacarpals

**_________** make up the fingers and are divided into proximal, middle, and distal except in the thumb which only has two (proximal and distal)

Phalanges

The _________ includes the 2 _______ or _________, and the sacrum.

Pelvic girdle, coxal bones, ossa coxae

The **_________** includes the 2 ________ ,sacrum, and coccyx.

bony pelvis, coxal bones

What is the pelvic formed by?

Ilium, ischium, and pubis

Pubic bones fuse anteriorly at the __________

Pubic symphysis

______ end has ball-like head, a neck, and greater and lesser trochanters.

Proximal

______ end are the lateral and medial condyles which articulate with the tibia.

Distal

Anteriorly on distal end is ___________ which forms a joint with the patella (kneecap)

Smooth patellar surface

**_______** is larger and more medial.

Tibia

Proximal end has ____________ that articulate with distal end of the femur.

Medial and laterl condyles

_______ attaches to the tibial tuberosity.

Patella

**_________** forms inner bulge of the ankle.

Medial malleolus

______ is thin and sticklike and lies alongside the tibia; forms joints with it proximally and distally.

Fibula

_________ forms outer part of the ankle.

Lateral malleulus

________ form the posterior half of the foot.

Tarsals

________ form the sole and are numbered 1-5 medially to laterally.

Metatarsals

_________ form the toes and are divided into proximal, middle, and distal except in the great toe which only has two (proximal and distal).

Phalanges

Bones form the internal framework that supports the body and cradles its soft organs.

Support

Bones protect soft body organs.

Protection

Skeletal muscles, attached to bones by tendons, use the bones as levers to move the body and its parts.

Movement

Bone itself serves as a storehouse for minerals like calcium and phosphorus.

Storage

Hematopoiesis, occurs within the red bone marrow of certain bones.

Blood Cell Formation

Bones are organs, so they contain multiple types of tissues:

Osseous (bone), fibrous, cartilage, adipose, and blood

What are the two basic bones?

Compact, Cancellous or Spongy

Dense and looks smooth

Compact

Composed of small needlelike pieces of bone and lots of open space

Cancellous or Spongy

Bone is classified according to *shape* into four groups-

Long, short, flat, and irregular

Typically longer than they are wide

Long Bone

Have a shaft with heads at both ends

Long Bone

Mostly compact bone

Long Bone

Include all the bones of the limbs, except the patella (kneecap) and the wrist and ankle bones. Ex: Femur, and humerus

Long Bone

Generally cube-shaped

Short Bone

Mostly spongy bone

Short Bone

Include bones of the wrist and ankle

Short Bone

Sesamoid bones are a special type of short bone. Ex: Patella, carpals, and tarsals

Short Bone

Thin, flattened, and usually curved

Flat Bone

Have two thin layers of compact bone sandwiching a layer of spongy bone between them

Flat Bone

Include most bones of the skull, the ribs and the sternum (breastbone). Ex: Scapula, sternum

Flat Bone

Bones that do not fit into any of the preceding categories

Irregular Bone

Include the vertebrae, which make up the spinal column. Ex: Facial, vertebral

Irregular Bone

There are two general classes of bone markings:

Projections, and depressions

Groove or depression

Fossa

Hole in the bone

Foramen

Projection or raised area

Process

Large, rough projection

Trochanter

Smaller, rough projection

Tuberosity

Smooth, rounded articular surface

Condyle

What is a long bone?

It is a long bone that makes up your arms and legs

What are examples of long bones?

Femur, humerus, radius, ulna, tibia, etc

What is an epiphysis?

Long bones that have bulbous ends

What is diaphysis?

The shaft or central part of a long bone

What happens at the epiphyseal plates?

Long bones grow bigger and taller during a person’s life.

What is the hollow portion of the inside of the bone called?

The medullary cavity

What is the yellow bone marrow for?

Fat storage

What is red bone marrow for?

Producing blood

What is the difference between cortical bone and trabecular bone?

Cortical bone is dense, while trabecular is spongy.

What is the casing around the medullary cavity called?

Endosteum

What is the casing around the entire bone called?

Periosteum

Why do we have articular cartilage, and where on a long bone is it found?

Articular cartilage is the smooth, white tissue that covers the ends of bones where they come together to form joints.

Main shaft like portion

Diaphysis

Ends of long bone

Epiphysis

Hyaline cartilage covering joint surface

Articular Cartilage

White, fibrous membrane covering bone/partially responsible for growth

Periosteum

Hollow portion filled with marrow (yellow/red)

Medullary Cavity

Membrane lining medullary cavity

Endosteum

Mature bone cells called _______ are found within the matrix of compact bone in cavities called _______.

Osteocytes, lacunae

The lacunae are arranged in concentric circles called ______ around ________.

Lamellae, central (haversian) canals

Each complex consisting of central canal and matrix rings is called an ______.

Osteon

Bone formation

Ossification