Human Body Systems
Introduction
• Understanding the body’s systems
and how they interact and depend
on each other will help you give
appropriate care to an injured or ill
person.
Body Cavities
• A body cavity is a
space in the body
containing organs,
such as the heart,
lungs and liver.
• Five major cavities:
Cranial
Spinal
Thoracic
Abdominal
Pelvic
Body Systems
• The body is made up
of billions of
microscopic cells,
the basic units of all
living tissue.
• Similar cells form
tissues.
• An organ is a
collection of similar
tissues acting
together to perform a
specific body
function.
Body Systems
(continued)
• A body system is a group of organs and other
structures that adapt to perform specific body
functions.
• For the body to work properly, all of the following
body systems must work well together:
Respiratory Integumentary
Endocrine Digestive
Genitourinary Circulatory
Nervous Musculoskeletal
Body Systems
(continued)
Interrelationships Among
Body Systems
• Each body system plays a vital role
in survival.
• Body systems work together.
• The condition that results from the
progressive failure of body systems
is called shock.
Respiratory System
• Function: provides oxygen needed for cellular
respiration and removes excess carbon dioxide
from the body
• Major Organs and their function:
• nose – contains 2 nostrils through which air can
enter and leave the nasal cavity
• pharynx – (throat) – passageway for air traveling
between the nasal cavity and the larynx
• larynx – an enlargement in the airway at the top
of the trachea – conducts air in and out of the
trachea and prevents foreign objects from
entering the trachea (epiglottis) – it also houses
the vocal cords
Respiratory System
• trachea – (windpipe) – flexible tube that extends
down into the thoracic cavity where it splits into
right and left bronchus
• bronchi – (bronchial tree) – the bronchi and their
branches that carry air from the trachea to the
alveoli of the lungs
• bronchioles – small branches of a bronchus
within the lung
• alveoli – the site of gas exchange within the
lungs
• lungs – soft, spongy, cone-shaped organs found
in the thoracic cavity in which air moves into and
out of for breathing
Interesting Facts:
• There are no muscles connected to the
lungs...the force that drives air into the
lungs comes from ordinary air pressure.
Breathing results from the contraction and
expansion of the diaphragm increasing the
volume of the thoracic cavity. Because
the chest cavity is sealed, this creates a
partial vacuum inside the cavity causing
air to rush into the nasal cavity and down
into the lungs.
Common Injuries or Illness:
• emphysema and lung cancer...can be
caused by prolonged exposure to tobacco
smoke and other carcinogens.
• Choking
• Drowning
• Suffocation
• Asphyxiation
Respiratory System
Activity:
• If an airway
obstruction
blockage does not
permit air to reach
the lungs and
prevents oxygen
from being
circulated to the
vital organs, what
can happen?
Nervous System
• Function: coordinates the body’s response to
changes in its internal and external
environments
• Major Organs and their function:
• Brain – main switching area of the central
nervous system (relays messages, processes
information, and analyzes information)
• Spinal cord – the main communications link
between the brain and the rest of the body)
• Peripheral nerves – consists of all nerves and
associated cells that are not a part of the brain
or spinal cord (transmits impulses from sense
organs to the central nervous system and from
the central nervous system to the muscles or
glands)
Injuries and Illness of the Nervous
System
• Parkinson’s disease (results from neurons
near the brain releasing a decreased
amount of dopamine – causing over
activity in the basal nuclei region of the
brain – which inhibits movement)
• Concussion
• Stroke
• Aneurysm
• Subdural Hematoma
Nervous System
• If a significant injury
to the brain occurs,
what can happen?