The Skeletal System
Unit-Anatomy and Physiology Part I
What you will Learn!
•
The functions of the skeleton
•
Describe the general structure of a bone and list the
functions of its parts
•
List and define the major kinds of bones in the human
skeleton
•
Name and describe the general types of fractures
•
Distinguish between the axial and appendicular skeletons
and name the major parts of each
•
Locate and identify the bones and the major features of
the bones that comprise the skull, arms, legs, pectoral
and pelvic girdles
What Does Your Skeleton Do?
Five Functions:
•
Protects your internal organs
•
Supports-provides a framework so that we can
stand up and move
•
Movement-many of the body muscles attach to the
skeleton and joints and produce movement
•
Stores minerals such as calcium, potassium,
phosphorus, and sodium so that our body can
function properly
•
Produces blood cells
The Skeletal System
• The
Skeletal System is made up of
206 different bones.
• There
are 4 basic shapes of bones.
4 Basic Shapes
1. Long bonesAre longer than
they are wide and
are found in the
upper limbs such as
the humerus (arm)
and lower limbs
such as the femur
(thigh).
4 Basic Shapes
2. Short bonesSuch as those
found in the wrist
and ankle bones.
4 Basic Shapes
3. Flat bonesSuch as the
scapula, ribs and
sternum, and the
thin bones that
form the roof of
the skull.
4 Basic Shapes
4. Irregular
bones- Such as
the vertebrae,
pelvic girdle (hip
bones), and parts
of the skull bones
such as your ear
bones.
2 Types of Bone Tissue
Compact Bone-
Cancellous Bone-
•
Dense
•
Spongy
•
Smooth
•
Lightweight
•
Strong
•
Both Compact and
Cancellous bone
tissue contain living
cells which help
make repairs if a
bone is injured or
broken.
Structure of the Bone
1.Diaphysis-the bone shaft
•
Composed of compact bone
tissue-tightly packed together
tissue that is solid, strong and will
not bend.
•
Inside the bone shaft is a cavity
called the Medullary Cavity (also
called yellow marrow) that stores
fat, produces blood cells and
plays an important part in our
immune system.
Structure of the Bone
2. Epiphysis-the two ends of the
shaft
•
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 that
covers the bone.
The Skeletal System
Part II
The Axial and Appendicular Skeleton
Unit-Anatomy and Physiology Part II
2 Divisions of the Skeletal System
Appendicular
Skeleton
Axial
Skeleton
The Appendicular Skeleton
Appendicular
Skeleton
•
Has 126 bones
•
Contains upper
extremities
•
Shoulders
•
Lower
extremities
•
Hips (Pelvic
Girdle)
Upper Extremities and Shoulder
Upper Extremities (Arms):
•
humerus-the bone that
extends from the scapula
to the elbow
•
radius—the bone that
extends from the elbow
to the wrist
•
ulna-the bone that
overlaps the end of the
humerus posteriorly
Shoulder girdle:
•
Scapula-shoulder blade
•
Clavicles-collar bone
The Hands
•
27 bones
•
carpal bones-8 on each arm
make up the wrist
•
metacarpal bones-5 on each
hand make of the palm
•
phalanges-3 in each finger,
2 in the thumb, a total of
14 in each hand
Lower Extremities and Hips
Lower Extremities-(Legs)
•
femur- thigh bone
•
patella- kneecap
•
tibia-shinbone
•
fibula-lateral side of the tibia
Hips (Pelvic Girdle)-protect
the bladder, the reproductive
organs, lower colon and
rectum.
•
os coxa--2 bones that make
up the hip
•
ilium--largest and uppermost
portion
•
ischium-lowest portion and is
L-shaped; supports ones
weight when seated
•
pubis--the anterior portion
The Foot
• 26
bones and 33 joints
• tarsals--7
bones in each foot; make up
the ankle that includes the calcaneus
(heel bone) which is the largest of the
ankle bones
• metatarsals--5
• phalanges—3
bones on each foot
bones in each toe,
except the big toe which has only 2
• 7+5+12+2=26
The Axial Skeleton
• Has
80 bones
Consist of:
• Bones
of the Skull
• Hyoid
Bone (neck bone)
• The
vertebral column
• The
thorax (cage)
Bones of the Skull-Cranial Bones
Cranial Bones:
A. Frontal Bone--forms the
anterior portion of the skull
above the eyes
B. Parietal Bone--2 bones on each
side of the skull just posterior to
the frontal bone
C. Occipital Bone--back of the
skull and base of the cranium
D. Temporal Bone—2 bones on
each side of the skull
E. Sphenoid Bone--anterior to
temporal
F. Ethmoid Bone--located in front
of the sphenoid
Cranial Sutures-lines that join
two bones
Skull-Ear Bones
•3
Middle ear bonesossicles
• malleus-hammer
• stapes-stirrup
(smallest bone in the
body)
• incus-anvil
Skull –Facial Bones
13 immovable ones and 1 immovable lower jawbones
•
maxilla--2 bones of upper jaw
•
palatine--2 bones behind the maxilla; make up posterior portion of the hard
palate
•
zygomatic--2 bones that make up the cheeks
•
lacrimal--2 bones in the medial wall of each orbit
•
nasal--2 bones that fuse to form the bridge of the nose
•
vomer--a single bone in the middle of the nasal cavity
•
inferior nasal concha--2 fragile, scroll-shaped bones attached to the nasal
cavity
•
mandible--1 lower jawbone (only part that moves when you eat and talk)
Hyoid Bone
• Hyoid
bone--located in the neck between
the lower jaw and the larynx
• serves
as an attachment for muscles that
help move the tongue and for swallowing
The Vertebral Column
• Supports the body's frame, keeping it
standing upright.
• It connects the head to the rest of the
body
• Serves as protection for the spinal cord
Bones:
• cervical--7 bones
• thoracic--12 bones
• lumbar--5 bones
• sacrum--1 bone; composed of 5 fused
bones
• coccyx--1 bone; tailbone
composed of 4 fused vertebrae
The Thorax
Thoracic Cage-protects the heart and
lungs
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
The End!