© 2011 National Safety Council 5-1 THE HUMAN BODY LESSON 5

© 2011 National Safety Council 5-2 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

© 2011 National Safety Council 5-3 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

© 2011 National Safety Council 5-4 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

© 2011 National Safety Council 5-5 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

© 2011 National Safety Council 5-6 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

© 2011 National Safety Council 5-7 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

© 2011 National Safety Council 5-8 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

© 2011 National Safety Council 5-9 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

© 2011 National Safety Council 5-10 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

© 2011 National Safety Council 5-11 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

© 2011 National Safety Council 5-12 Respiratory System

© 2011 National Safety Council 5-13 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

© 2011 National Safety Council 5-14 Respiratory System: Primary Organs

© 2011 National Safety Council 5-15 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

© 2011 National Safety Council 5-16 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

© 2011 National Safety Council 5-17 Emergency Conditions Related to 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

© 2011 National Safety Council 5-18 Cardiovascular System

© 2011 National Safety Council 5-19 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

© 2011 National Safety Council 5-20 Cardiovascular System: Primary Organs Heart Blood Blood vessels

© 2011 National Safety Council 5-21 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

© 2011 National Safety Council 5-22 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

© 2011 National Safety Council 5-23 Pulses Pulsing blood pressure changes occur in arteries that can be felt as pulse Commonly measured pulses: -Carotid -Femoral -Radial -Brachial

© 2011 National Safety Council 5-24 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 body’s greater need for oxygen

© 2011 National Safety Council 5-25 Emergency Conditions Related to the 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

© 2011 National Safety Council 5-26 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)

© 2011 National Safety Council 5-27 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)

© 2011 National Safety Council 5-28 Musculoskeletal System

© 2011 National Safety Council 5-29 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

© 2011 National Safety Council 5-30 Musculoskeletal System: Primary Organs Bones Muscles Tendons Ligaments

© 2011 National Safety Council 5-31 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

© 2011 National Safety Council 5-32 Emergency Conditions 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 stretching and tearing of ligaments and other structures in a joint Strain is muscle or tendon tear usually caused by overexerting muscle

© 2011 National Safety Council 5-33 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, 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

© 2011 National Safety Council 5-34 Nervous System

© 2011 National Safety Council 5-35 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

© 2011 National Safety Council 5-36 Nervous System: Primary Organs Brain Spinal cord Sensory receptors Nerves

© 2011 National Safety Council 5-37 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

© 2011 National Safety Council 5-38 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

© 2011 National Safety Council 5-39 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

© 2011 National Safety Council 5-40 Other Body Systems

© 2011 National Safety Council 5-41 Integumentary System: Primary Functions Protect body Help regulate body temperature Help prevent water loss Sensation (e.g., touch, pressure, pain, temperature)

© 2011 National Safety Council 5-42 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

© 2011 National Safety Council 5-43 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)

© 2011 National Safety Council 5-44 Gastrointestinal System Digests food and extracts nutrients Organs easily injured by traumatic forces

© 2011 National Safety Council 5-45 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

© 2011 National Safety Council 5-46 Functions of the Urinary System Removes metabolic wastes from body in urine Helps body maintain fluid and electrolyte balances

© 2011 National Safety Council 5-47 Urinary System: Primary Organs Blood transports wastes to kidneys Kidneys filter wastes and produce urine

© 2011 National Safety Council 5-48 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

© 2011 National Safety Council 5-49 Reproductive System Female -Produces eggs -Supports and nurtures fetus in uterus -Childbirth -Lactation Male -Produces and transports sperm

© 2011 National Safety Council 5-50 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

© 2011 National Safety Council 5-51 Endocrine System Glands that produce hormones Most problems develop slowly and are rarely emergencies Diabetes can cause emergencies

© 2011 National Safety Council 5-52 Lymphatic System Helps defend against disease Part of immune system Problems seldom cause emergencies

© 2011 National Safety Council 5-53 Growth and Development Through 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