PED101: 2011
Anatomical
Directions
The anatomical position
In order to explain the positioning of bones, organs, muscles and the like
on the human body, anatomists have agreed on a standardised position
for the human body in all cases. This is known as the anatomical
position.
Important things to
note:
1. Standing
2. Feet together
3. Arms to side
4. Head, eyes and
palms facing
Lateral vs Medial
Lateral
Lateral
Medial
Medial
Lateral: Further
away from the midline
of the body. E.g.
Little toe is on the
lateral aspect of the
foot.
Medial: Nearer the
midline of the body.
E.g. The big toes is
on the medial aspect
of the foot.
Superior vs Inferior
Superior
Inferior
Superior: Above or on
top of. Towards the top
of the body (head). E.g.
The cervical vertebrae
are superior to the
thoracic vertebrae.
Inferior: Below or
beneath. Towards the
bottom of the body (feet).
E.g. Thoracic vertebrae
are inferior to the cervical
vertebrae.
Proximal vs Distal
Proximal
Distal
Distal: Further away
from the body – usually
refers to limbs. Towards
the end of the limb. E.g.
Wrist is distal to the
elbow.
Proximal: Nearer the
body – usually refers to
limbs. Closer to the top of
the limb. E.g. Elbow is
proximal to the wrist joint.
Anterior
Anterior: On the
front of the body or
limb. E.g. The
chest is on the
anterior of the body.
Posterior
Posterior: On the
back of the body
or limb. E.g. The
buttocks are on
the posterior of the
body.
The skeleton is divided into
two sections:
• Axial skeleton – consists of
the central core of the body
(head, ribs, spine & sternum)
• Appendicular skeleton –
encompasses all of the
bones in the limbs
(arms/legs, hands/feet,
pelvis, scapula & clavicle)
• There are 206 bones in the human adult
body
• At birth, a human has over 300 bones but
they fuse together as they develop
through a process called ossification.
• Adult human bones account for 14% of
the body's total weight.
• Your thigh bone (femur) is stronger than
concrete.
Cranium
Scapula
Humerus
Mandible
Clavicle
Sternum
Ribs
Vertebrae
Radius
Pelvis
Carpals
Ulna
Metacarpals
Phalanges
Femur
Patella
Fibula
Metatarsals
Phalanges
Tibia
Tarsals
The Joints
Flexion
Bending or decreasing the
angle between two joints.
E.g. Arm bending at the
elbow.
Flexion - Sequence of events
Extension
• Straightening or
increasing the angle
between two joints.
E.g. Hip – moving the
leg backward. Knee
– straightening the
knee.
Inversion vs Eversion
Inversion: Movement
of the sole of the foot
inward.
Eversion: Movement
of the sole of the foot
outward.
Dorsiflexion vs Plantarflexion
Dorsiflexion:
Movement of the top
of the foot upward,
closer to the shin.
Plantarflexion:
Movement of the sole
of the foot downward.
Abduction vs Adduction
Abduction: Moving a limb or part
of a limb away from the
midline of the body. E.g.
Moving limbs outwards on a
star jump.
Remember: Aliens abduct people
by taking them away.
Adduction: Moving a limb or part
of a limb towards the midline
of the body. E.g. bring limbs
back together in a star jump.
Remember: ‘Add’ to the midline
Circumduction
A combination of
flexion, extension,
abduction and
adduction. E.g the
armstroke in butterfly.
Rotation
Twisting of a limb about
its long axis.
Pronation vs Supination
Pronation: Movement
of the hand into a
palm down position.
E.g. Turning a card
face down.
Supination: Movement
of the hand into a
palm-up position.
E.g. Turning a card
over in cards.
Medial and Lateral Rotation
Movements
Joint
Ligaments
Types of Joints
Types of Joints
Types of Joints
Anatomy of the Knee
Knee Joint
http://www.arthroscopy.com/sp05001.htm
Knee Joint
http://www.arthroscopy.com/sp05001.htm
Cross-Sectional View of Right
Knee
http://www.arthroscopy.com/sp05001.htm
Anatomy of the Shoulder
Hip Joint
Muscles
Muscle types
There are three main types of muscles
in the body. They are:
1. Skeletal (striated)
2. Smooth
3. Cardiac
Skeletal Muscle
Seen from under
the microscope,
skeletal muscle
fibers show a
pattern of cross
banding, which
gives rise to the
other name:
striated muscle.
Skeletal (striated) muscles move
your bones. These are the
muscles that we can see and
feel. Skeletal muscles attach to
the bones through tendons.
They come in pairs -- one
muscle to move the bone in
one direction and another to
move it back the other way.
Skeletal muscles are voluntary
muscles. Meaning, that you
think about contracting them
and your nervous system tells
them to do so. Skeletal
muscles can perform two types
of contractions: short single
contractions (twitch) and long,
sustained contraction (tetanus).
Smooth Muscle
Smooth muscles are found in the
internal organs (digestive
system, blood vessels,
bladder, airways and, the
uterus). Smooth muscle has
the ability to stretch and
maintain tension for long
periods of time. Smooth
muscles move involuntarily.
You do not have to think
about movement for
movement to occur.
Cardiac Muscle
Cardiac muscle is found
only in your heart.
Cardiac muscle is also
an involuntary
muscle. It can stretch
in a limited way, like
smooth muscle, and
contract with the force
of a skeletal muscle.
Cardiac muscle is a
twitch muscle.
Skeletal, Smooth & Cardiac
Muscles
Skeletal
Smooth
Cardiac
Our muscles
Trapezius
Deltoid
Pectoralis Major
Triceps
Biceps
Latissimus Dorsi
Gluteus Maximus
Abdominals
Hamstrings
Iliopsoas
Quadriceps
Gastrocnemius
Tibialis anterior
Soleus
How muscles work
Muscle create
movement by pulling
on bones. They are
attached to bones via
tough cords called
tendons and most
muscles reach from
one bone to another
across a joint.
But..
Muscles can only pull, and not push so they need
to work in pairs. While one muscle works (pulls)
the other relaxes to allow the movement. When
it’s time to move in the other direction, they
switch jobs. The muscle that is pulling is called
the agonist, and the muscle that is relaxing is
called the antagonist.
(Relaxing)
(Pulling)