Download The Skeletal System

The Skeletal System
Stephen Pou & Rahul Rai
Human Biology
6-Wolsko
Skeletal System Overview
Consists of 206
bones divided into
two main categories:
– Axial Skeleton
– Appendicular Skeleton
Has major functions
Made of different
types of bones
Bones are about 13%
of total body weight
Functions
Support keeps the
body up and gives it
shape and form
Protection protects
organs from damage
Movement gives
the body the ability to
move
Functions
Storage stores
minerals such as
calcium and iron
Blood Cell
Production makes
the red blood cells
Endocrine
Regulation
regulates fat and
blood sugar
deposition
Axial Skeleton
Made up of the
vertebral column,
thoracic cage, and
skull
Has 80 bones in total
Transmits weight of
upper body to lower
body.
Appendicular Skeleton
Has a total of 126
bones
Consists of the upper
and lower extremities
and the pelvic and
pectoral girdles
Distributes weight
from head and torso
evenly throughout
body
Types of Bones
Long:
– Used to support body weight
– Composed of mostly compact
bone with little marrow
– Found in the legs and arms
Short:
– Thin layer of compact bone
with mostly marrow
– Found in wrists and ankles
Flat:
– Two thin layers of compacts
bone with marrow in the
middle
– Found in skull and sternum
Types of Bones
Irregular:
– Don’t have a specific shape
– Usually have even amount
of marrow and compact
bone
– Found in hips and spine
Sesamoid:
– The bones embedded in
tendons
– Increases leverage of
muscle
– Found in wrists and ankles
Bone Composition
Made up of two types of
material:
– Compact/dense bone
Forms the outside of bone
Very strong
Formed by stacked layers
of tissue
– Spongy bone
Inside of bone known as
the marrow
Light and porous
Absorb stress from
compact bone
Bone Cartilage
Cartilage is the
connective tissue
between bones
There are 3 different
types:
– Firbro strongest type of
cartilage found in high
stress areas
– Hyaline strong but
flexible cartilage that
reduces friction and eases
bone movement
– Elastic not very strong
but really flexible; provide
flexibility in low stress
areas
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Tendons, Ligaments & Joints
All three are
connections of bones
and are made of
hyaline cartilage
Keep bones together
and provide
movement and
flexibility
Tendons, Ligaments & Joints
Tendons
– Connects bone to muscle
– Provides the expand and contract that the muscle
does in order to move
Ligaments
– Connects bone to bone
– controls range of motion and stabilization in the joints
Joints
– Formally known as an articulation
– With the help of ligaments, give bone connections
movements and range of motion
Tendons, Ligaments & Joints
There are different types
of joints that are used for
different purposes and
classified by their type of
movement:
– Ball and socket
– Hinge
– Condyloid- a joint that
provides angular motion
– Pivot
– Gliding (Plane)
– Saddle
Ossification
Ossification- the process in which bones are
made
– This is done by connective tissue turning into bone or
bone-like material
– Done by two different processes:
Endochondral Ossification
Intramembranous Ossification
– The difference between these two processes are that
endochondral is when your body matures and
intramembranous is when a human is being formed
inside of a whom.
Ossification
Endochondral Ossification gradual
transformation of cartilage into bone
– Happens as osteoblasts turn into osteocytes which
are a hardened, mature form of osteoblasts
Ossification
Intramembranous
Ossification the
development of
embryonic cells into
bone
– The embryonic cells
involved develop into
connective tissue then
blood and bones
Osteoporosis
When, for a variety of reasons, a person’s Bone
Mineral Density (BMD) decreases and is below the
normal amount
Reasons for Osteoporosis
– Age
– Lack of calcium
– Low estrogen levels
Some symptoms include severe back pain, height loss,
frequent bone fracture
Cures include:
– Calcium pills
– Menopausal hormone therapy
– Prescribed medication
Osteoarthritis
The breakdown of cartilage in joints causing
inflammation
Causes include:
–
–
–
–
Heredity
Obesity
Injury to a joint
Overuse of a joint
Symptoms are soreness and aching, inflammation, bony
enlargements on joint
To cure Osteoarthritis:
–
–
–
–
Exercise
Avoid use of joint (crutches, wheelchair, bandage)
Temperature treatments
Prescribed medication
Rheumatoid Arthritis
Chronic arthritis usually affecting both sides of
the body (ex. Both wrists or both ankles)
A person could get RA genetically, by being
obese, suffering an injury, or overuse of a joint
Symptoms include:
– Joint pain
– Swelling
– Fatigue
Methods to totally cure RA do not exist but one
could take could take Disease-Modifying AntiRheumatic Drugs (DMARDs) to slow down the
progression of RA