The Human Body

1
Lesson 4

• The Human Body

2
Introduction

• Body is composed of different organs/tissues
  working together
• Minor injury/illness may damage only a specific
  body part/function
• Serious injury or sudden illness can threaten
  vital body functions
• Understanding human body can help you recognize
  effects of injuries/illnesses

3
Body Regions and Directions

• Special terms are used by healthcare providers
  for body regions
• Directional/positional terms used to describe
  relationship of body structures

4
Body Regions and Cavities

• Extremities refers to both arms and legs
• Thorax refers to chest area enclosed by the ribs
• Thoracic cavity is area inside chest
• Abdomen refers to area immediately below thoracic
  cavity

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Body Regions and Cavities continued

• Abdominal cavity includes stomach, intestines,
  other organs
• Pelvis refers to area below abdomen-- pelvic
  bones between hip/lower spine
• Pelvic cavity contains bladder and other organs
• Spine, or spinal column, refers to bones of
  neck/back and nerves, or spinal cord, that run
  through vertebrae

6
Abdominal Quadrants

• Used to describe specific injuries or
  signs/symptoms
• Upper and lower quadrants are divided by a line
  passing through umbilicus
• Quadrants are based on anatomical position, with
  face forward and palms facing forward

7
Directional Terms

• All positional and directional terms are based on
  anatomical position
• Right and left refer to the patients right and
  left, divided by midline down center of body
• Lateral and medial
• Anterior and posterior
• Proximal and distal
• Superior and inferior
• Prone and supine

8
Body Systems

• Organs have one or more specific functions
• The organs that work together for a specific
  function are called a body system

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Examples of Interrelated Body Systems

• Blood carries oxygen from lungs to body cells
• Nerve sensors detect amount of oxygen and carbon
  dioxide in the blood and speed up or slow down
  heart beat /breathing to change oxygen level
• If body temperature drops, muscles in extremities
  start shivering to produce heat, which is carried
  by blood to vital organs

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Respiratory
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Functions of Respiratory System

• To bring air into lungs
• To allow oxygen from air to enter blood
• To remove carbon dioxide from blood into air
  breathed out (exhaled)
• This process is called respiration

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Respiratory System Primary Organs

• ltFig 3-3gt

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The Breathing Process

• Breathing depends on muscular movements under
  control of nervous system
• When the diaphragm contracts/moves down, thoracic
  cavity/lungs expand, pulling air into lungs
• In lungs, oxygen enters blood and carbon dioxide
  leaves blood
• When diaphragm relaxes/moves up, thoracic cavity
  contracts, and air carrying carbon dioxide flows
  back out of lungs

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Emergency Care Related to the Respiratory System

• Respiration can be affected by different
  injuries/illnesses
• An airway obstruction is blockage of airway
  preventing air flow
• A broken rib may puncture a lung, making
  breathing ineffective
• A penetrating injury into lungs may alter lung
  pressures keeping lungs from filling with air

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Emergency Care Related to the Respiratory System
continued

• Poisoning/drug overdose may depress nervous
  system functions, slowing or stopping breathing
• Asthma is a common illness in which airway
  tissues swell making it hard to breathe
• In infants/children, anatomical structures are
  smaller and airway is more easily obstructed
• Uncorrected respiratory problem is the primary
  cause of cardiac arrest in infants/children

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Circulatory
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Functions of the Circulatory System

• To transport oxygen and nutrients in the blood to
  all parts of body
• To remove carbon dioxide and other wastes

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Cardiovascular System Primary Organs

• Heart
• Blood
• Blood vessels

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Pathway of Blood

• Ventricles pump blood through two loops or cycles
  in body
• Right ventricle pumps blood to lungs picking up
  oxygen and releasing carbon dioxide
• Blood returns to left atrium, from which it moves
  to left ventricle
• Left ventricle pumps oxygenated blood into body
  to release oxygen and pick up carbon dioxide for
  removal
• Blood returns to right atrium, moving to right
  ventricle to be pumped again to lungs

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Pulses

• Pulsing blood pressure changes occur in arteries
  that can be felt as pulse
• Commonly measured pulses
• Carotid
• Femoral
• Radial
• Brachial

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Heart Rate

• Heart rate, measured as pulse, is affected by
  many factors
• Average resting heart rate in adult males is 64-
  72 beats/ minute in females, 72 - 80 beats/
  minute
• Heart rate of infants and children is higher
• With exercise, fever, or emotional excitement,
  heart rate increases to meet bodys greater need
  for oxygen

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Emergency Care Related to the Cardiovascular
System

• Cells begin to die in vital organs such as brain
  after only a few minutes without oxygen
• Oxygen delivery diminished by injury/illness
  affecting heart, blood, or blood vessels
• Severe bleeding leaves not enough blood in
  circulation to provide body with oxygen
• Arterial bleeding is most severe - blood may
  spurt out under pressure, leading to
  life-threatening shock
• Bleeding from veins generally slower but can
  still be serious or life-threatening if it
  continues
• Capillary bleeding usually minor and stops by
  itself as blood clots

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Cardiovascular Illness

• Stroke is problem involving arteries in brain
  reduced circulation may cause mental and physical
  impairments
• If heart muscle does not receive enough
  oxygenated blood because of blocked cardiac
  arteries, cardiac muscle tissue may die
• The heart may stop (cardiac arrest)
• Dysrhythmia (or arrhythmia), an irregular
  heartbeat, may reduce hearts pumping ability
• Fibrillation, a serious dysrhythmia, common after
  heart attack

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Musculoskeletal System
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Functions of the Musculoskeletal System

• Skeletal system provides shape/support for body
  as a whole
• Muscles act on bones, allowing for movement
• Groups of bones protect vital internal organs
• Ribs protect heart and lungs
• Skull protects brain
• Vertebrae protect spinal cord
• Pelvic bones protect bladder and other organs

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Musculoskeletal System Primary Organs

• Bones
• Muscles
• Ligaments
• Tendons

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Emergency Care Related to the Musculoskeletal
System

• Most fractures are not life-threatening
• In a dislocation, one or more bones move out of
  position in joint
• Sprain is damage to ligaments and other
  structures in a joint
• Strain is muscle/tendon tear usually caused by
  overexerting muscle

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Musculoskeletal Injuries Associated with Other
Injuries

• Vertebral fractures likely to injure spinal cord
  and cause nervous system damage
• Fractures of femur often cause much soft-tissue
  damage and bleeding
• Pelvis fracture may damage bladder/other organs
  in pelvic cavity
• A skull fracture may cause brain damage

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Nervous System
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Nervous System Primary Functions

• Sensory receptors gather information about
  environment and send to brain
• Brain integrates and analyzes information
• Nerve signals from brain lead to actions
  throughout body to accomplish tasks or maintain
  homeostasis

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Nervous System Primary Organs

• Brain
• Spinal cord
• Sensory receptors
• Nerves

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Nervous System Emergencies

• Head and spinal injuries
• Serious/life-threatening
• Injury to part of brain or stroke
• May destroy or impair one or more functions
• Damage to spinal cord
• Complete loss of function to body area/paralysis

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Nervous System Emergencies continued

• Altered mental status from
• Head injuries
• Any injury causing decreased oxygenation
• Sudden illness (i.e., stroke, seizure, diabetes)
• Severe infection/fever
• Poisoning/drug overdose

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Nervous System Effects Associated with Other
Injuries

• Injuries and some illnesses also affect nervous
  system
• Pain results from damage to nerve fibers in many
  areas of body
• Crushing pain in chest may be caused by heart
  attack
• Abdominal pain that begins in umbilicus and
  settles into lower abdomen on right side may be
  a sign of appendicitis
• Pain should always be taken seriously

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Other Body Systems
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Integumentary System Primary Functions

• Protect body
• Help regulate body temperature
• Help prevent water loss
• Remove some body wastes
• Produce Vitamin D
• Sensation (i.e. touch, pressure, pain,
  temperature)

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Integumentary System Emergencies

• Cuts and scrapes
• Bleeding
• Openings in skin
• Allow pathogens into body
• Heat and chemical burns
• Loss of body heat
• Loss of body fluid

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Importance of Skin Condition

• Skin often reveals important information about
  body condition
• Skin of hypothermia victim
• Skin of heatstroke victim
• Skin of victim with low blood oxygen levels
• Skin of victim in shock
• Sweating/pale skin
• Many sudden illnesses cause sweating and skin
  color changes (flushed or pale)

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Gastrointestinal System

• Digests food and extracts nutrients
• Organs easily injured by traumatic forces

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Emergency Care Related to the Gastrointestinal
System

• Abdominal cavity not protected by bones,
  gastrointestinal organs may be easily injured by
  traumatic forces
• In closed injury, pain/tenderness along with
  swollen/rigid abdomen may suggest internal injury
• In an open wound, internal organs may be exposed,
  raising risk of infection
• Ingested poison is absorbed in the same manner as
  nutrients from food and enters the bloodstream to
  affect body
• Various illnesses may cause vomiting or diarrhea,
  which can lead to dehydration especially in
  infants
• Vomiting blood is likely sign of a serious
  internal injury

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Functions of the Urinary System

• Removes metabolic wastes from body in urine
• Helps body maintain fluid and electrolyte
  balances

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Urinary System

• Blood transports wastes to kidneys
• Kidneys filter wastes and produce urine

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Urinary System

• Traumatic injury may damage organs
• Look for blood in urine
• Health problems
• May cause change in urination
• Dehydration
• Lack of urination

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Reproductive System

• Female
• Produces eggs
• Supports and nurtures fetus in uterus
• Childbirth
• Lactation

• Male
• Produces and transports sperm

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Emergency Care Related to the Reproductive System

• Abdominal injuries may damage genitals/reproductiv
  e organs
• such wounds may require special care, including
  concern for victims privacy
• Complications may develop in pregnancy
• Childbirth may occur unexpectedly away from a
  healthcare facility

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Endocrine System

• Glands that produce hormones
• Most problems develop slowly and are rarely
  emergencies

47
Lymphatic System

• Helps defend against disease
• Part of immune system
• Problems seldom cause emergencies