13.2 Human Body Systems
11 Body Systems ( We won’t cover all
of them)
• Although the body can be divided into 11
different organ systems, all of the systems are
interconnected with each other
• 11 Systems: Integumentary, Skeletal,
Muscular, Nervous, Circulatory, Respiratory,
Excretory, Digestive, Endocrine, Reproductive,
Immune
Integumentary system ( skin)
• 2 layers: epidermis and dermis
• Functions: temperature regulation, vitamin
production, protection, senses
• Hair- keratin, sebaceous glands to lubricate/
protect
Skeletal system
• Functions- support, protection, blood cell
formation, reservoir for minerals, movement
• Axial system- skull, vertebrate, ribs, sternum
• Appendicular- shoulders, arms, hips, legs
• Compact bone- dense, tough, strong
• Spongy bone- lightweight
• Osteocyte- living bone cells
Muscular system
• 3 types of muscle tissue:
– smooth: no striations, one nucleus per cell
– skeletal: many nuclei, striations
– cardiac: one nucleus per cell, striations
Nervous system
• Neuron- nerve cell consisting of 3 parts:
dendrite, cell body, axon
• Neurotransmitter- chemical that transfers
electrical impulse from one cell to another
• Synapse- gap between neurons and other cells
Circulatory system
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Functions: transport, temperature control
4 chambered heart: 2 atria, 2 ventricles
Closed circuit, double loop
Red blood cell- carries oxygen
White blood cell- fights infection
Artery- carries blood away from heart
Vein – Carries blood towards heart
Capillary- smallest blood vessel where exchange
of gases and nutrients, into cells, occur
Respiratory System
• Air enters through mouth, past larynx ( voice
box/ adam’s apple), trachea, L and R Bronchi,
then to alveoli
• Alveoli are the site of gas exchange ( oxygen
and carbon dioxide)
• Diaphragm- special muscle in mammals that,
along with rib muscles, cause movement of air
in and out of lungs
Excretory System
• Kidneys filter waste from blood
• Waste then moves to bladder and awaits
signal to empty
Digestive System
• Mechanical digestion- chewing
• Chemical digestion- chemicals ( enzymes) are
added to speed up chemical breakdown of
food
• Peristalsis- muscular movement of food
through digestive system
• Path: esophagus, stomach, small intestine,
large intestine
We didn’t cover all of them!