ANATOMY: STRUCTURE AND
MOVEMENT
Chapters 17-23
LEVELS OF ORGANIZATION
• Atoms 
• Molecules 
• Organelles 
• Cells 
• Tissues 
• Organs 
• Organ Systems 
• Organism
THE SKELETAL SYSTEM
• Bone is an organ composed of bone tissue
– Bone tissue is made up of bone cells
• There are 4 types of bone cells
– All begin with “Osteo-” which is Greek for “bone”
• Can be any size
– The femur is the longest bone (about 50 cm)
– The stapes is the smallest (about 3 mm)
• There are 206 bones in the adult body
– Newborn babies have 270
• Several fuse during development
FUNCTIONS OF SKELETAL SYSTEM
• Your bones (organs) compose your skeletal system
(organ system)
• It serves several important functions
1. Gives shape and support to your body
2. Protects internal organs
3. Provide attachment points for muscles (movement)
4. Forms blood cells
5. Stores minerals
STRUCTURE OF BONE
• External Bone
– Bone is covered in a membrane called periosteum
• Veins, arteries and nerves run through the periosteum into the internal bone
• Internal Bone
– Made up of 2 tissues (Compact Bone and Spongy Bone)
• Compact Bone
– Hard, strong layer directly under the periosteum
– Composed of calcium phosphate deposits
•
Protects bone from damage or fracture
• Spongy bone
– Many small, open spaces
•
Keep bone lightweight
– Contain cavities filled with bone marrow
CARTILAGE
• The ends of bones are covered with cartilage
– Smooth, slippery, thick
– Does not contain blood vessels or minerals
– Flexible
• Shock absorber
• Friction reducer
• When cartilage is damaged, movement is painful
– Rheumatoid arthritis
BONE FORMATION
• During embryonic development, your skeleton was
composed of cartilage
– The cartilage was broken down and replaced by bone
• Bone-forming cells are called osteoblasts
– They deposit Calcium and Phosphorus in bones, which causes
the bone to become hardened
• Another type of cell, called Osteoclasts, break down
bone tissue
JOINTS
• Any place where 2 or more bones come together
– Cartilage keeps bones apart
– The bones are held in place by tissues called ligaments
• Muscles move bones by pulling on ligaments
– Ligaments you may know:
•
MCL-Medal Collateral Ligament
•
LCL-Lateral Collateral Ligament
•
ACL-Anterior Cruciate Ligament
– All of these are in the knee, and are common sports injuries
• Joints can be movable or immovable
IMMOVABLE JOINTS
• Allows little or no movement
– Example: Bones of the skull
MOVABLE JOINTS
• Joints that allow the bones to move
• 4 types:
– Hinge Joint
• Allows bones to flex and extend
• Example: Knee and elbow
– Pivot Joint
• Allow for rotation
• Example: Radius and ulna in forearm
– Gliding joint
• Allow bones to slide past one another
• Example: bones in hand
– Ball and Socket Joint
• Provides a large range of motion
• Example: Shoulder (Scapula and humerus)
BONE INJURIES AND DISEASES
• Broken bones
– Called fractures
– Able to repair
• https://www.youtube.com/watch?v=qVougiCEgH8
• Arthritis
– Inflammation, damage, or destruction of cartilage between
bones
• Osteoporosis
– Weakening or brittleness of bones
THE MUSCULAR SYSTEM
• A muscle is an organ that allows for movement of bones
– Make everyday movements possible
• Can contract and relax
– Energy is used to do work (Remember ATP)
• Some are always working without you knowing, and
some require you to move them
MUSCLE CONTROL
• Voluntary Muscles
– Muscles that you do not control yourself
• Heart pumps without you having to control it
• Involuntary Muscles
– Muscles that you control yourself
• Arm, legs, etc.
MUSCLE TISSUE
• Skeletal Muscle: muscles that move bones
– Attached in bands called tendons
– Voluntary muscles
– Always work in pairs (one contracts, other relaxes)
• Cardiac Muscle: muscle found only in the heart
– Involuntary muscle
• Smooth Muscle
– Involuntary muscle
– Found in intestines, bladder, and other organs
THE SKIN
• Your bodies largest organ
• Sensory organ
• Made up of 3 layers of tissue
– Epidermis-Top layer
– Dermis-Middle layer
– Hypodermis-bottom layer
• Cells produce a chemical called melanin
– Melanin protects your skin from UV radiation and gives it color
• More melanin=darker skin
• Ultraviolet rays (sunlight) increases the production of melanin
– This is why you tan
EPIDERMIS
• Outermost layer of skin
• Cells are continually replenished
– You lose and replace thousands of epidermal cells each day
DERMIS
• Middle layer of skin
• Contains blood vessels, oil and sweat glands, and hair
follicles
• Erector pili muscles cause goosebumps
HYPODERMIS (HYPO=BELOW)
• Fatty layer below the dermis
FUNCTIONS OF SKIN
• Protection
• Sensory response
• Formation of Vitamin D, which you need
• Regulation of body temperature
• Ridding the body of wastes
DAMAGE TO SKIN
• Bruises
– Breaking of blood vessels without cutting the skin
• The color is caused by the release of blood into the tissues
• Cuts
– Cut skin and vessels
• Scab to prevent infection
• Heal quickly
• Burns
– Classified based on how many layers of skin are damaged
1ST DEGREE BURN
• Damages only the epidermis
• Usually no blisters
– May cause peeling of skin
• Heal in a few days
2ND DEGREE BURN
• Damages epidermis and dermis
• Blisters common
• Most painful
• Heals in several weeks; may leave scar
3RD DEGREE BURN
• Damages all 3 layers of skin-may reach bone
• May require surgery to repair
• Scarring likely
• May damage nerves-No pain (Graphic image coming)
4TH DEGREE BURNS
• Most severe
• May damage bone and underlying tissue
• Nerves are destroyed-No pain
• Amputation needed in many
• Skin unlikely to recover
• (Graphic image coming)