Lesson 4

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. Special terms are used by healthcare providers for body regions Directional/positional terms used to describe relationship of body structures Body Regions and Directions

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

5. 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 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

8. Body Systems Organs have one or more specific functions The organs that work together for a specific function are called a body system

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 /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

10. Respiratory

11. 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

12. Respiratory System: Primary Organs <Fig 3-3>

13. 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

14. 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

15. 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

16. Circulatory

17. 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

18. Cardiovascular System: Primary Organs Heart Blood Blood vessels

19. 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

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

21. 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 

22. 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

23. 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 heart’s pumping ability Fibrillation, a serious dysrhythmia, common after heart attack

24. Musculoskeletal System

25. 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

26. Musculoskeletal System: Primary Organs Bones Muscles Ligaments Tendons

27. 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

28. 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

29. Nervous System

30. 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

31. Nervous System: Primary Organs Brain Spinal cord Sensory receptors Nerves

32. 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

33. 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

34. 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

35. Other Body Systems

36. 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)

37. 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

38. 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)

39. Gastrointestinal System Digests food and extracts nutrients Organs easily injured by traumatic forces

40. 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

41. Functions of the Urinary System Removes metabolic wastes from body in urine Helps body maintain fluid and electrolyte balances

42. Urinary System Blood transports wastes to kidneys Kidneys filter wastes and produce urine

43. Urinary System Traumatic injury may damage organs Look for blood in urine Health problems May cause change in urination Dehydration Lack of urination

44. Reproductive System Male Produces and transports sperm Female Produces eggs Supports and nurtures fetus in uterus Childbirth Lactation

45. Emergency Care Related to the Reproductive System Abdominal injuries may damage genitals/reproductive organs such wounds may require special care, including concern for victim’s privacy Complications may develop in pregnancy Childbirth may occur unexpectedly away from a healthcare facility

46. 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