© 2011 national safety council 5-1 the human body lesson 5

© 2011 National Safety Council 5-1

THE HUMAN BODYLESSON 5


Introduction

• Body is composed of different organs and tissues working together

• Minor injury or illness may damage only a specific body part or function

• Serious injury or sudden illness can threaten vital body functions

• Understanding human body can help you recognize effects of injuries and illnesses


Body Regions and Directions

• Special terms are used by health care providers for body regions

• Directional and positional terms used to describe relationship of body structures


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


Body Regions and Cavities (continued)

• Abdominal cavity includes stomach, intestines, other organs

• Pelvis refers to area below abdomen: pelvic bones between hip and lower spine

• Pelvic cavity contains bladder and other organs

• Spine, or spinal column, refers to bones of neck and back and nerves, or spinal cord, that run through vertebrae


Abdominal Quadrants

Used to describe specific injuries or signs and symptoms

• Upper and lower quadrants divided by line passing through umbilicus

• Quadrants based on anatomical position, with face forward and palms facing forward


Directional Terms

All positional and directional terms are based on anatomical position:

• Right and left refer to patient’s 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


Body Systems

• Organs have one or more specific functions

• The organs that work together for a specific function are called a body system

• Body systems are closely interrelated and work together


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 and 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


Key Body Systems

• Most fundamental for life are the respiratory and cardiovascular systems

• Body cells need a constant supply of oxygen

• Any failure of breathing or blood circulation threatens life within minutes


Pathophysiology

• “Patho” refers to an abnormality

• Understanding what can go wrong in each body system from injury or illness is important for giving emergency care


Respiratory System


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


Respiratory System: Primary Organs


The Breathing Process

Breathing depends on muscular movements under control of nervous system:

• When the diaphragm contracts/moves down, thoracic cavity and lungs expand, pulling air into lungs

• Intercostal muscles assist with ventilation

• In lungs, oxygen enters blood and carbon dioxide leaves blood

• When diaphragm relaxes and moves up, thoracic cavity contracts, and air carrying carbon dioxide flows back out of lungs


Emergency Conditions Related to the Respiratory System

• Respiration can be affected by different injuries and illnesses

• An airway obstruction is blockage of airway preventing air flow

• Inadequate oxygenation due to low oxygen, poison gas, lung infection, etc.

• 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


Emergency Conditions Relatedto the Respiratory System (continued)

• Poisoning or 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 and children, anatomical structures are smaller and airway is more easily obstructed

• Uncorrected respiratory problem is the primary cause of cardiac arrest in infants and children


Cardiovascular System


Functions of the Cardiovascular System

• To transport oxygen and nutrients in the blood to all parts of body

• To remove carbon dioxide and other wastes


Cardiovascular System: Primary Organs

• Heart

• Blood

• Blood vessels


The Blood

• Red blood cells carry oxygen to body cells

• White blood cells are an important part of the immune system

• Plasma is the liquid substance of blood

• Blood also carries glucose to body cells for energy

• Blood clotting factors help control bleeding


Pathway of Blood

Ventricles pump blood through 2 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


Pulses

• Pulsing blood pressure changes occur in arteries that can be felt as pulse

• Commonly measured pulses:

- Carotid

- Femoral

- Radial

- Brachial


Heart Rate

• Heart rate, measured as pulse, is affected by many factors

• Average resting heart rate in adult males is 6472 beats/minute; in females, 7280 beats/minute

• Heart rate of infants and children is higher

• With exercise, fever or emotional excitement, heart rate increases to meet body’s greater need for oxygen


Emergency Conditions Related tothe Cardiovascular System

• Cells begin to die in vital organs such as brain after only a few minutes without oxygen

• Shock is a life-threatening condition that occurs when vital body organs are not receiving enough oxygen

• Oxygen delivery diminished by injury or 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

• Problems affecting blood volume (bleeding, repeated vomiting or diarrhea, or burns) affect circulation

• Blood vessel problems (inability to constrict) cause poor circulation; may occur with spinal cord injuries, infection or anaphylaxis

Emergency Conditions Related to the Cardiovascular System (continued)


Cardiovascular Illnesses

• 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 heart’s pumping ability

• Fibrillation, a serious dysrhythmia, common after heart attack

• Any problem affecting the heart rate or strength of contractions can cause poor circulation and shock (poisoning, heart disease)


Musculoskeletal System


Functions of the Musculoskeletal System

• Skeletal system provides shape and 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


Musculoskeletal System: Primary Organs

• Bones

• Muscles

• Tendons

• Ligaments


Types of Muscles

• Skeletal muscles create body movements and also produce heat usually under voluntary control

• Smooth muscles such as in the esophagus and blood vessels are usually under involuntary control

• Cardiac muscle is also involuntary but is unique in that the heart produces its own stimuli to contract


Emergency Conditions Related tothe Musculoskeletal System

• Most fractures are not life-threatening

• In a dislocation, one or more bones move out of position in joint

• Sprain is stretching and tearing of ligaments and other structures in a joint

• Strain is muscle or tendon tear usually caused by overexerting muscle


Musculoskeletal InjuriesAssociated with Other Injuries

• Vertebral fractures likely to injure spinal cord and cause nervous system damage

• Fractures of femur often cause much soft-tissue damage, bleeding and femoral artery damage

• Pelvis fracture may damage bladder/other organs in pelvic cavity or femoral arteries

• A skull fracture may cause brain damage


Nervous System


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


Nervous System: Primary Organs

• Brain

• Spinal cord

• Sensory receptors

• Nerves


Emergency Conditions Related to the Nervous System

• Head and spinal injuries

- Serious or 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 or paralysis


Emergency Conditions Related to the Nervous System

(continued)

• Altered mental status from:

- Head injuries

- Any injury causing decreased oxygenation

- Sudden illness (e.g., stroke, seizure, diabetes)

- Severe infection or fever

- Poisoning or drug overdose


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


Other Body Systems


Integumentary System: Primary Functions

• Protect body

• Help regulate body temperature

• Help prevent water loss

• Sensation (e.g., touch, pressure, pain, temperature)


Emergency Conditions Related to the Integumentary System

• Cuts and scrapes

- Bleeding

• Openings in skin

- Allow pathogens into body

• Heat and chemical burns

- Loss of body heat

- Loss of body fluid


Importance of Skin Condition

• Skin often reveals important information about body condition

• Skin of hypothermia patient

• Skin of heatstroke patient

• Skin of patient with low blood oxygen levels

• Skin of patient in shock

• Many sudden illnesses cause sweating and skin color changes (flushed or pale)


Gastrointestinal System

• Digests food and extracts nutrients

• Organs easily injured by traumatic forces


Emergency Conditions Related to the Gastrointestinal System

• Abdominal cavity not protected by bones, gastrointestinal organs may be easily injured by traumatic forces

• In closed injury, pain or 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


Functions of the Urinary System

• Removes metabolic wastes from body in urine

• Helps body maintain fluid and electrolyte balances


Urinary System: Primary Organs

• Blood transports wastes to kidneys

• Kidneys filter wastes and produce urine


Emergency Conditions Related to the Urinary System

• Traumatic injury may damage organs

- Look for blood in urine

• Health problems

- May cause change in urination

• Dehydration

- Lack of urination


Reproductive System

• Female

- Produces eggs

- Supports and nurtures fetus in uterus

- Childbirth

- Lactation

• Male

- Produces and transports sperm


Emergency Conditions Related to the Reproductive System

• Abdominal injuries may damage genitals or reproductive organs – such wounds may require special care, including concern for patient’s privacy

• Complications may develop in pregnancy

• Childbirth may occur unexpectedly away from a health care facility


Endocrine System

• Glands that produce hormones

• Most problems develop slowly and are rarely emergencies

• Diabetes can cause emergencies


Lymphatic System

• Helps defend against disease

• Part of immune system

• Problems seldom cause emergencies


Growth and DevelopmentThrough the Life Span

• Basic body functions are similar in people at all ages

• Many significant changes occur in the body throughout the lifespan

• Be aware of such differences when assessing and caring for patients

© 2011 national safety council 5-1 the human body lesson 5

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