SKELETAL NOTES


NOTES

CHECKING for UNDERSTANDING REVIEW QUESTIONS

I. Functions

A. Support--acts as the framework of the body, giving support to the soft tissues and providing points of attachment for most of the body muscles

B. Movement--many of the body muscles attach to the skeleton and many of the bones meet at movable joints

C. Protection--vital internal organs are protected from injury by the skeleton

D. Mineral Reservoir--calcium, phosphorus, sodium, potassium and other minerals are stored within the bones

E. Hemopoiesis--following birth, the red marrow within certain bones produces the blood cells that are found within the circulatory system

Name and explain at least 3 functions of the skeletal system.

II. Classification--according to their shape

A. Long bones--longer than they are wide (upper and lower limbs)

B. Short bones--do not have a long axis (wrist and ankle bones)

C. Flat bones--thin bones that form the roof of the cranium, ribs and sternum

D. Irregular bones--do not fit in any of these categories (skull bones, vertebrae, pectoral and pelvic girdles)

Describe how bones are classified.

 

Name one bone for each type of classification.

III. Structure of Bones

A. Gross Anatomy

1. diaphysis--the bone shaft

a. compact bone--tightly packed together tissue that is solid, strong and resistant to bending

b. medullary cavity--also called yellow marrow which serves as a fat storage area and is inactive in blood cell production.

c. endosteum--a thin layer of connective tissue that lines the medullary cavity

2. epiphysis--the two ends of the shaft

a. compact bone--outer surfaces only

b. spongy bone--contains the red marrow that functions in the formation of red blood cells, certain white blood cells and platelets. It is red because of the red, oxygen-carrying pigment called hemoglobin

3. periosteum--a tough, vascular covering of fibrous tissue the encloses the bone except for the articular (hyaline) cartilage

 

 

 

What is the bone shaft called?

 

Name the components of the bone shaft.

 

 

What are the ends of the bone called?

 

Of what are the ends composed?

 

What is the outer covering of a bone called?

 

 

B. Microscopic Anatomy

1. Haversian system--organized system of interconnecting canals

a. Haversian canal--contains at least one blood capillary which is the source for nutrients and a means of waste disposal

b. lacunae--small cavities or spaces that contain a bone cell

c. osteocyte--bone cell

d. canaliculi--the canals that link one lacuna to another

Name several microscopic parts of a bone and give their function.

IV. Fractures--many involve injury to cartilaginous structures, but it is usually defined as a break in a bone

A. Compound--broken bone sticks out of the skin

B. Simple--break that does not come through the skin

C. Types

1. transverse--break occurs at a right angle to the axis

2. oblique--break occurs at any angle other than right

3. spiral--spiral or S-shaped; caused by a twisting action

4. longitudinal--fracture splits the bone lengthwise

5. greenstick--incomplete fracture in the long axis of the bone (more common in children)

6. compression--bones are pressed together

7. depressed--fracture due to denting in a bone

8. impacted--broken ends are jammed together

9. comminuted--produced by severe, direct violence; three or more fragments

How could you tell the difference between a simple and compound break?

Name the following types of breaks.

CLICK HERE FOR ANSWERS.

V. Common Skeletal Structural Terms

A. crest--sharp projection or bony ridge

B. condyle--a rounded projection that articulates with another bone

C. epicondyle--small projection on or above a condyle

D. facet--smooth, nearly flat articular surface

E. fissure--narrow passageway

F. foramen--a hole

G. fossa--a depression, dent

H. fovea--a pit

I. head--generally, the larger end of a long bone

J. meatus--a canal

K. process--any projection on a bone

L. sinus--a cavity or hollow space within a bone

M. spine--a ridge on the top of a bone

N. suture--a line that joins 2 bones

O. trochanter--a large, somewhat blunt process

P. tubercle--a small, rounded process

Q. tuberosity--a medium process

Fill in your Structural Crossword using these terms. (This was given in class.)

 

Make a set of flash cards to help with these terms.

VI. Axial Skeleton

A. Skull

1. Cranial bones--8

a. frontal--forms the anterior portion of the skull above the eyes

b. parietal--2 bones on each side of the skull just posterior to the frontal bone

(1) sagittal suture--line between the parietal bones

(2) coronal suture--line between the parietal and frontal bones

c. occipital--back of the skull and base of the cranium

(1) lambdoidal suture--line between the parietal and occipital bones

d. temporal--two bones on each side of the skull

(1) squamosal suture--line between the parietal and temporal bones

e. sphenoid--anterior to temporal

f. ethmoid--located in front of the sphenoid

2. Middle ear bones--ossicles

a. malleus--2 bones (hammer)

b. stapes--2 bones (stirrup)

c. incus--2 bones (anvil)

3. Facial--13 immovable ones and one immovable lower jawbones

a. maxilla--2 bones of upper jaw

b. palatine--2 bones behind the maxilla; make up posterior portion of the hard palate

c. zygomatic--2 bones that make up the cheeks

d. lacrimal--2 bones in the medial wall of each orbit

e. nasal--2 bones that fuse to form the bridge of the nose

f. vomer--a single bone in the middle of the nasal cavity

g. inferior nasal concha--2 fragile, scroll-shaped bones attached to the nasal cavity

h. mandible--1 lower jawbone

Where would each of the following bones or parts be found?

  • frontal
  • parietal
  • sagittal suture
  • coronal suture
  • occipital
  • lambdoidal suture
  • temporal
  • squamosal suture
  • sphenoid
  • ethmoid

Can you find these are the diagrams? Label or color code.

  • ossicles
  • malleus
  • stapes
  • incus

 

  • maxilla
  • palatine
  • zygomatic
  • lacrimal
  • nasal
  • vomer
  • inferior nasal concha
  • mandible

 

B. Hyoid bone--located in the neck between the lower jaw and the larynx; serves as an attachment for muscles that help move the tongue; also function in swallowing

  • hyoid

C. Vertebral Column

1. cervical--7 bones

a. atlas--first cervical vertebrae; supports and balances the head (the YES movement)

b. axis--second cervical vertebrae; pivots the head (the NO movement)

2. thoracic--12 bones

3. lumbar--5 bones

4. sacrum--1 bone; composed of 5 fused bones

5. coccyx--1 bone; tailbone composed of 4 fused vertebrae

D. Thoracic Cage

1. ribs--12 pair (24 ribs)

a. true ribs--first 7 pair; directly join the sternum

b. false ribs--remaining 5 pair because their cartilage does not reach the sternum directly

c. floating ribs--last 2 pair of the 5 pair of false ribs; called floating because they have no attachments

2. sternum--1 breastbone

  • cervical
  • atlas
  • axis
  • thoracic
  • lumbar
  • sacrum
  • coccyx

  • true ribs
  • false ribs
  • floating ribs
  • sternum

VII. Appendicular Skeleton

A. Pectoral Girdle

1. clavicles--2 collarbones

2. scapula--2 shoulder blades

B. Upper Limb

1. humerus--2 bones that extend from the scapula to the elbow

2. radius--2 bones that extend from the elbow to the wrist

3. ulna--2 bones that overlap the end of the humerus posteriorly

4. hand

a. carpal bones--8 on each arm make up the wrist

b. metacarpal bones--5 on each hand make of the palm

c. phalanges--3 in each finger, 2 in the thumb, a total of 14 in each hand

C. Pelvic Girdle

1. os coxa--2 bones that make up the hip

a. ilium--largest and uppermost portion

b. ischium--lowest portion and is L-shaped; supports ones weight when seated

c. pubis--the anterior portion

D. Lower Limb

1. femur--2; thigh bone

2. patella--2 kneecap

3. tibia--2; shinbone

4. fibula--2; lateral side of the tibia

5. foot

a. tarsals--7 bones in each foot; make up the ankle

(1) calcaneus--heel bone; largest of the ankle bones

b. metatarsals--5 bones on each foot

c. phalanges--3 in each toe, except the big toe which has only 2

 

  • clavicle
  • scapula

 

  • humerus
  • radius
  • ulna
  • carpals
  • metacarpals
  • phalanges

 

 

 

  • os coxa
  • ilium
  • ischium
  • pubis

 

  • femur
  • patella
  • tibia
  • fibula
  • tarsals
  • calcaneus
  • metatarsals
  • phalanges

Now go back through the list and tell me how many of each of these you have.

VIII. Articulations--the connections of bones

A. Synarthroses--fibrous joints or nonmovable joints; examples-sutures of the cranium

B. Amphiarthroses--slightly movable joints connected by disks of cartilage or by ligaments; example-vertebrae

C. Diarthroses--freely movable joints

1. Characteristics

a. smooth articular surfaces are covered with hyaline cartilage called articular cartilage

b. joint lined with a thin synovial membrane

c. synovial membrane secretes synovial fluid

d. some joints have bursae associated with them; filled with synovial fluid, they act as cushions

2. Types

a. Ball and socket joints

(1) characteristics--one with a ball-shaped head that articulates with the cup-shaped socket of another bone

(2) example--hip and shoulder

b. Condyloid joints

(1) characteristics--oval-shaped condyle of one bone fits into an elliptical cavity of another

(2) examples--radius and carpals; occipital condyles of skull and first cervical vertebra

c. Gliding joints

(1) characteristics--articulating surface of gliding joints are nearly flat or only slightly curved

(2) examples--wrist and ankle

d. Hinge joints

(1) characteristics--convex surface of one bone fits into the concave surface of another

(2) examples--elbow, knee, and phalanges

e. Pivot joints

(1) characteristics--a cylindrical surface of one bone rotates within a ring formed of bone and fibrous tissue

(2) examples--atlas/axis joint

f. Saddle joints

(1) formed between bone whose articulating surfaces have both concave and convex regions

(2) examples-- carpal and metacarpal of thumb

 

 

Use your chart and diagrams to match the correct terminology.

3. Body Movements

a. flexion--two end portions of an extremity are being brought closer together

(1) dorsiflexion-raising the toe toward the shin

b. extension--moving the two ends of an extremity apart

(1) plantar flexion-pointing the toe

c. rotation--partial revolving of a body part on the part's axis

(1) supination--rotation that makes the palm of hand face forward

(2) pronation--rotation that makes the palm face backward

d. inversion--feet have been turned inward so that the soles face each other

e. eversion--soles of feet face laterally or outward

f. abduction--movement of an extremity laterally, away from the median plane of the body

g. adduction--an extremity is moved toward the medial plane

h. circumduction--(hip and shoulder joints); follows a cone shaped path

i. protraction--mandible, tongue, and/or head are protruded or pushed forward

j. retraction--jaw, tongue, or head is drawn backward

k. elevation--mandible is closed or scapula is raised (shrug shoulders)

l. depression--opening of the mouth (jaw) or lowering of the shoulders

 

 

Use your chart and diagrams to match the correct terminology.

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