The Human BodySkeletal, Muscular &
Integumentary Systems
Textbook Chapter 13Review Book Topic 1
Structure of the Skeletal System
• 206 bones in the human body
• Two divisions:– Axial ~ skull, vertebral column, ribs
and sternum
– Appendicular ~ bones of shoulders, arms, hands, hips, legs and feet
Types of Bones
• Connective tissue classified as short, long, flat or irregular
• Compact ~ dense/strong for strength and protection
• Spongy ~ contains cavities that contains bone marrow in the center of short or flat bones
• Bone marrow– Red ~ produces red and white blood
cells
• Arm, leg, rib, vertebrata, and pelvis bones
• Children’s bones have more than adult bones (only 21% left by age 21)
– Yellow ~ stores fat
Bone Function
• Support
• Protection
• Movement
• Storage
• Blood cell formation
Bone Formation
• Composed of cartilage in embryos
• During fetal development they form into osteoblasts (bone forming cells)
• Ossification leads to the formation, growth and repair of bones
– Does not occur in the tip of your nose, between vertebrate discs, and lining of joints
Bone Repair
• Simple fracture – doesn’t breakthrough skin
• Compound fracture – breaksthrough skin
• Stress fracture – thin crack in bone
• When a bone is fractured, repair happens immediately
– Endorphins (chemicals which act as natural pain killers) flood the area of injury temporarily
– Area becomes swollen which lasts for 2-3 weeks
– Blood clots form within 8 hours
– New bone begins to form as cartilage (weak)
– Three weeks later, spongy bones surrounds break
– Stronger, compact bone forms
– Splints/casts help hold bones in place while healing
– Age, nutrition, location and severity of break influence healing
• 4/6 weeks to 6 months
Joints
• Occur where two or more bones meet
• Can be classified based on movement and shape (except bones of skull)
• Not all joints are moveable
• Ligaments – bands of connective tissue which attach two bones together
• Types:– Ball-and-Socket
• Widest range of movement• Ex. hips/shoulders
– Pivot• Rotation• Ex. neck/head
– Hinge• Back-and-forth movement
(door hinge)• Ex. knee/elbow
– Gliding•Side-to-side movement•Back-and-forth movement•Ex. wrists, ankles, vertebra
– Sutures•Non-moveable•Skull joints (22 bones)
Muscular System
• Consists of groups of fibers or muscle cells bound together
• Classified according to their structure and function
• Tendons – attach muscle to bone
Types of Muscle
• Smooth– Involuntary muscles which cannot be
controlled consciously
– Ex. organ muscles: stomach, bladder, intestines, uterus
• Cardiac– Involuntary muscle of the heart
– Arranged in a web to allow for muscle contraction
– Striated with light and dark bands with many nuclei
• Skeletal– Majority of muscles in the body
– Muscles attached to bones
– Voluntary movement which is consciously controlled
– Striated
Integumentary System
• Organ system that covers and protects the body
• Main organ: skin
• Tissue types: – Epithelial tissue– Connective tissue– Muscle tissue– Nerve tissue
• Epithelial tissue covers the body surfaces
• Connective tissue provides support and protection
• Muscle tissue is involved with movement
• Nerve tissue forms the body’s communication network
Functions of Integumentary System
• Temperature Regulation
• Vitamin Production
• Protection
• Senses
Structure of the Skin
• Epidermis– Outer layer of skin
– 10-30 cells thick
– Outer cells contain keratin• Waterproof, protective protein layer on
top of skin
– Melanin• Pigment that absorbs light energy• Amount produced influences skin color
• Dermis– Layer below epidermis
– 10-40 times thicker than epidermis
– Consists of connective tissue to prevent skin from tearing and gives it elasticity
– Contains nerve cells, muscle fibers, sweat glands, oil glands, and hair follicles
– Deeper layer stores fat to help retain body heat
• Hair and Nails– Contain keratin
– Develop from epithelial cells
– Hair grows out of hair follicles
– Nails grow 0.5 to 1.2 mm per day
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