Download Muscular System PowerPoint

Muscular System
Types of Muscles
 Skeletal
 Control voluntary movements of the skeleton and body
 Striated
 Smooth
 Control the involuntary movements of the digestive and
vascular system
 Not striated
 Cardiac
 Control the involuntary muscles of your heart
 Striated
Types of Muscles
Skeletal
Cardiac
Smooth
Skeletal Muscles
Skeletal Muscles
 Skeletal muscles are made up of many muscle fibers
 Those fibers are made up of many myofibrils
 Those myofibrils are made up of actin and myosin, which
work together to contract and relax the muscle
Relaxed Muscle
Actin and
Myosin
 During muscle
contraction the little
sticky heads on
myosin filaments bind
to the actin.
 When ATP (energy
from cellular
respiration) is added
the myosin changes
shape bending towards the middle and pulling the actin fibers with it.
 This makes the muscle fiber shorten or contract.
Actin and Myosin
Tendons and Ligaments
 The reason we move when our muscle contract
is because they are attached to bones by
tendons
 This typically happens at joints.
 Joints are where one bone meets another and
movement can occur.
 Ligaments attach bone to bone,
to restrict and help control our
movements
Joints
 Joints are where one bone attaches to another bone
 Most joints have cartilage between them to prevent bone to
bone contact and damage.
 There are five different types of joints, four of which allow
movement
 The different joints are classified by the type of movement
they allow
Immovable Joint
 These are also referred to as fixed
joints because they allow no
movement
 These can be found in your skull
and pelvis where the different bones
fuse together.
Ball-and-Socket Joint
 Joint formed by a ball at the end of one bone that fits into a
cavity in the end of another bone.
 This allows free movement in almost every direction
 Examples of these would be your shoulders and hips.
Hinge Joint
 Hinge joints allow back and forth movement in one direction, and a
little movement in the other direction
 The bones are held in place by tough ligaments that allow more
limited movement than the
ball-and socket joint.
 Examples can be found in the
elbow, knee, and knuckles of
the fingers.
Pivot Joint
 Pivot joints allow rotation around one
point.
 The bone can twist back and forth allowing
a twisting or rotating movement
 Examples can be found in the radius in the
forearm and in the neck, which allows us
to turn our heads from side to side.
Saddle Joint
 A saddle joint is formed when the end of
one bone is the mirror image of its
adjoining bone creating a saddle shape.
 The two bones meet to form an X, the
saddles cradle each other.
 This allows a wide range of movement, or
rocking movement in either direction
 An example would be your thumbs.
Functions of the Skeletal System
 Protect our soft internal organs
 Provide the body with support and
structure
 Stores important minerals that the
body needs
 Works with the muscular system to
allow movement
 Make most of the blood cells for our
circulatory system
Protection
 There are 206 bones in the human bodies (at least for most of us)
 Skull (29 bones) – protects the brain and sensory organs (eyes, ears,
tongue, nose)
 Spinal Column (26 bones) – protects the spinal cord
 Rib Cage (25 bones) – protects the heart and lungs, and allows us to
breath by supporting the diaphragm
 Shoulders, Arms, and Hands (64 bones) – allow movement for survival
 Pelvis, Legs, and Feet (62 bones) – allow movement for survival, so we
can escape predators and find food
Bones
 There are four layers to your bones:
 Pariosteum – the outer layer that is thin and dense. It contains the blood
vessels and nerves.
 Compact Bone – the next layer that is very smooth and hard. It is made
up of round bone cells that have blood vessels running through the
center of them.
 Cancellous – the next layer down looks spongy, but is still very strong. It
protects the bone marrow.
 Bone Marrow – the inner most layer
that is like a very thick jelly and makes
the blood cells
Mineral Storage
 Bones are made up of . . .
 30% living tissue
 45% mineral deposits
 25% water
 Bones store calcium and phosphorus. As the blood needs more of
these minerals they are released from the bones, but the bones
need them as well to stay hard and strong.
Bone Marrow
 There are two types of marrow:
 Red – this is the site for blood cell production. It makes red blood
cells, white blood cells, and platelets.
 Yellow – contains fatty connective tissues that can be broken down
and used as energy during starvation
Cartilage
 Cartilage is the elastic, fibrous tissue that is flexible.
 It can be found in joints to cushion and allow smooth movements
 Some types of cartilage are used to allow flexibility, like in your
ears, nose, and trachea.
 Some cartilage is meant to bear weight and squish, so the bones
do not crack.
 Cartilage has no blood vessels running through it, but is still
living tissue.
 As a fetus most of your skeleton is made of cartilage.
Breaking Bones
 There are several different types of breaks or
fractures depending on their severity.
 The pain is different for everyone, but usually
it is a deep ache and you may feel nausea
 The best thing is to not move the area that your
think might be broken. Immobilize the area
and get to a doctor.
 Your osteocytes will start producing more
bone cells and eventually your break will heal
Fun Facts
 Bones fuse with age, so when you were a baby you had about 300




bones
Bones in the hand and feet vary, so not every one has exactly the
same number of bone. It usually ranges between 206 and 216
bones
Half the bones in your body are in your hands and feet
Your femur (thigh bone) is stronger than steel rod of the same
size and shape
Standing and sitting squeezes the cartilage between the discs in
your spine, so you are about ½ inch shorter at the end of the day
Human
Skeleton