Download YR 10 Anatomy - Western Springs College

THE
SKELETON
THE
MUSCLES
The muscles play a major role in supporting the
human skeleton and allowing it to move.
Muscles hold together the bones and joints of
the skeleton. They are the skeleton’s support
system.
They are placed over the joints of the body to
allow them to function.
The key point to remember is that muscles don’t
push they only pull.
MOVEMENT OF THE JOINTS:
FLEXION: The movement at the joint which makes
the angle at the joint smaller. In order for the
movement to happen at the knee, the hamstring
flexes and PULLS the tibia and fibula towards the
femur.
EXTENSION: The movement at the joint which
makes the angle at the joint larger. In order for the
movement to happen, the quadriceps flexes and
PULLS the tibia and fibula away from the femur.
When you bend at the knee, the hamstrings are the
working muscles which are pulling the lower leg towards
the upper leg. Therefore, the hamstring is called the
AGONIST MUSCLE. At this time, the quadriceps are
relaxing, allowing the movement to happen. They are
called the ANTAGONIST MUSCLE.
Therefore…
When you straighten the knee, the quadriceps are the
working muscles which are pulling the lower leg away
from the upper leg. Therefore, the quadriceps are called
the AGONIST MUSCLE. At this time, the hamstrings are
relaxing, allowing the movement to happen. They are
called the ANTAGONIST MUSCLE.
MOVEMENT:
KNEE FLEXION
MOVEMENT:
KNEE EXTENSION
AGONIST:
HAMSTRING
AGONIST:
QUADRICEP
ANTAGONIST:
QUADRICEP
ANTAGONIST:
HAMSTRING
When we bend our arm, the angle at the joint is
getting smaller. Therefore the movement is
_______________. The ___________ is pulling the
radius and ulna towards the humerus.
When we straighten our arm, the angle at the joint is
getting bigger. Therefore the movement is
_______________. The ____________ is pulling the
radius and ulna away from the humerus.
EXTENSION OF
THE ELBOW:
FLEXION OF THE
ELBOW:
AGONIST:
______________
AGONIST:
______________
ANTAGONIST
MUSCLE:
______________
ANTAGONIST
MUSCLE:
______________