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Chapter 5. Anatomy, Physiology and Pathophysiology. National EMS Education Standard Competencies. Anatomy and Physiology Integrates complex knowledge of the anatomy and physiology of the airway, respiratory, and circulatory systems to the practice of EMS Pathophysiology
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Chapter 5 Anatomy, Physiology and Pathophysiology
National EMS Education Standard Competencies Anatomy and Physiology Integrates complex knowledge of the anatomy and physiology of the airway, respiratory, and circulatory systems to the practice of EMS Pathophysiology Applies comprehensive knowledge of the pathophysiology of respiration and perfusion to patient assessment and management
Introduction • Anatomy refers to structure and components of human body • Gross anatomy: visible to naked eye • Microscopic anatomy: visible through microscope • Physiology examines body functions • Pathophysiology studies body functions in an abnormal state
Topographic Anatomy • Planes and Lines • Terms of Direction • Terms of Movement • Positions and Postures
The Integumentary System (Skin): Anatomy • Germinal layer of epidermis produces new skin cells • Dermis contains sweat glands, sebaceous glands, hair follicles, blood vessels, specialized nerve endings • Mucous Membranes
The Integumentary System (Skin): Physiology • Functions • Protect the body in the environment • Regulate body temperature • Transmit information from environment to brain
The Skeletal System: Anatomy • Skeleton gives us our recognizable human form, protects vital internal organs. • Bones • Tendons—connect muscles to bones • Ligaments—connect bone to bone • Cartilage—cushions between bones • Lubricated by joint fluid (synovial fluid)
Overview of Bones(2 of 2) Components of a long bone (humerus)
The Skeletal System: Physiology • Bones protect internal organs. • Together with muscles, bones enable movement. • Bone stores minerals. • Particularly calcium • Bone plays role in forming blood cells and platelets.
The Skeleton • Axial • Appendicular • Joints
The Musculoskeletal System: Anatomy • Three types of muscle: • Cardiac • Found only in the heart • Specially adapted • Skeletal • Smooth • Involuntary • In blood vessels, intestines
The Musculoskeletal System: Physiology • Contraction and relaxation makemovement possible. • A by-product of movement is heat. • Muscles protect structures under them. • For example, intestines are protected by rectus abdominus muscles.
The Respiratory System: Anatomy • Nose • Mouth • Throat • Larynx • Trachea • Bronchi • Bronchioles • Lungs • Diaphragm • Muscles of chest wall • Accessory muscles of breathing
The Respiratory System: Physiology • Respiration • Exchanges gases • Ventilation • Process of moving air in and out of lungs • Breathing control • Medulla • Pons • Chemoreceptors • Carboxic drive • Hypoxic drive
Acid-Base Regulation • pH ranges from 0 (most acidic) to 14 (most basic). • Normal pH of the human body is 7.35 to 7.45. • Buffer systems are defenses against acid-base changes in the body.
Acid-Base Regulation • Hydrogen ions combine with bicarbonate ions to form carbonic acid • Carbonic acid breaks down into carbon dioxide and water • As hydrogen ions are liberated in the body, they combine with bicarbonate ions (action of the buffer system) to resist pH changes in blood • H+ binds to HCO3- to form H2CO3
Acid-Base Regulation • The body attempts to maintain a ratio of HCO3:H2CO3 of 20:1 • As carbonic acid is manufactured by the buffer system it breaks down into carbon dioxide and water • H2CO3 produces CO2 and H2O
Acid-Base Regulation • The respiratory system is responsible for maintaining appropriate levels of carbon dioxide in blood • As Carbon dioxide is generated, chemoreceptors send messages to the control centers of the brain • Control centers respond by elevating the respiratory rate
Acid-Base Regulation • The kidneys are responsible for secreting excess hydrogen ions or excess bicarbonate ions in urine in order to maintain appropriate acid-base balance • If blood is acidic, the kidneys secrete hydrogen ions • If blood is alkaline, the kidneys secrete bicarbonate ions • Urine production is a relatively slow process
Acid-Base Abnormalities • Metabolic • Acidosis occurs when the body liberates more hydrogen ions than the kidneys excrete • Alkalosis occurs when the body absorbs more bicarbonate than is eliminated by the kidneys • Respiratory • Acidosis occurs when the body fails to eliminate carbon dioxide • Alkalosis occurs when the body releases too much carbon dioxide
Interpreting Blood Gases • Acidosis = pH < 7.35 • Respiratory • pCO2 > 45; If compensated, HCO3- > 26 mg/dl • Metabolic • HCO3- is < 22 mg/dl, pCO2 is normal • Alkalosis = pH > 7.45 • Metabolic • pCO2 < 35 and HCO3- is low • Respiratory • HCO3- > 26 mg/dl, pCO2 is normal
Ventilation (1 of 2) • Tidal volume—air moved in a single breath • Inspiratory reserve volume—deepest breath you can take after normal breath • Expiratory reserve volume—maximum amount of air you can forcibly breathe out after normal breath
Ventilation (2 of 2) • Vital capacity—amount of air moved with maximum inspiration and expiration
Characteristics of Normal Breathing • Normal rate and depth (tidal volume) • Regular rhythm (pattern of inhalation and exhalation) • Good audible breath sounds on both sides of chest • Regular rise and fall movement on both sides of chest • Movement of abdomen
Compromised Breathing Patterns in Adults • Labored breathing • Minute alveolar ventilation < 4200 ml • Muscle retractions (clavicles, ribs) • Pale or cyanotic (blue) skin • Cool, damp (clammy) skin • Tripod position
The Circulatory System: Anatomy • Heart • Location • Chambers, valves, accessory structures • Heartwall and Pericardium • Blood vessels • Types • Circulatory pathways • Blood
Heart Sounds • Created by contraction and relaxation of heart and flow of blood • Heard during auscultation with stethoscope • Normal heart sound: “lub-DUB” • S1 and S2 are normal sounds, S3 and S4 are often not • Also abnormal: murmurs, bruits, clicks, snaps
The Electrical Conduction System • Electrical stimulus controls mechanical pumping action. • Conduction system components: • Sinoatrial (SA) node • Atrioventricular (AV) node • Bundle of His • Right and left bundle branches • Purkinje fibers
Regulation of Heart Function • Autonomic nervous system, endocrine hormones, and heart tissue, control: • Rate of contraction (chronotropic state) • Rate of electrical conduction (dromotropic state) • Strength of contraction (inotropic state) • Baroreceptors respond to changes in pressure. • Chemoreceptors sense changes in chemical composition of blood.
The Cardiac Cycle • Process that creates the pumping of the heart • Systole • Diastole • Pulse pressure • Afterload • Stroke volume • Cardiac output = stroke volume × heart rate
Blood Composition • Plasma • Red blood cells • Hemoglobin • Surface Antigens • White blood cells (leukocytes) • Fight infection • Granulocytes (neutrophils, eosinophils, basophils) • Agranulocytes (monocytes, lymphocytes) • Platelets
The Circulatory System: Physiology (1 of 2) • Pulse is created by blood pumping out of left ventricle into major arteries. • Blood pressure is pressure blood exerts against artery walls. • Sphygmomanometer measures high/low points. • Systemic vascular resistance is how dilated or constricted the blood vessels are.
The Circulatory System: Physiology • Average adult has about 5 L of blood • Infants 300 mL, children 2 to 3 L • Central and peripheral pulses • BP = CO X SVR
The Lymphatic System • Absorb fat from digestive tract, maintain fluid balance, and fight infection • Transports lymph • Lymph nodes interspersed along course of lymph vessels • Lymph vessels absorb excess fluid and return it to the central venous circulation
Cellular Transport Mechanisms • Cell membrane is selectively permeable. • Allows differences in concentrations inside and outside cell
Cellular Transport Mechanisms • Diffusion • Movement of solutes from an area of high concentration to an area of low concentration to produce an even distribution of particles in the space available • Depends on: • Permeability of membrane • Concentration gradient
Cellular Transport Mechanisms • Osmosis • Movement of a solvent from an area of low solute concentration to one of high concentration • Osmotic pressure • Facilitated diffusion • Active transport
Body Fluid Balance • Body fluid is divided into: • Intracellular fluid (ICF) • Extracellular fluid • Intravascular fluid (plasma) • Interstitial fluid • Fluid balance maintains homeostasis • Regulated by • Antidiuretic hormone from pituitary gland • Thirst • Fluid imbalance can be life-threatening
The Nervous System: Anatomy and Physiology • Components • Central nervous system • Peripheral nervous system
The Central Nervous System • Brain • Spinal Cord • Meninges
The Peripheral Nervous System • Divisions • Somatic nervous system • Autonomic nervous system has two parts: • Sympathetic nervous system • Parasympathetic nervous system • Sensory and Motor Nerves • Cranial and Spinal Nerves
The Endocrine System: Anatomy and Physiology (1 of 2) • Made up of glands located throughout body • Glands • Remove, concentrate, or alter materials from blood • Secrete them back into body • Glands secrete proteins called hormones. • Regulate mood, growth and development, metabolism, sexual development, much else
The Pituitary Gland and the Hypothalamus • Pituitary gland is called “master gland.” • Its secretions control those of other endocrine glands. • Secretes growth hormone, thyroid-stimulating hormone, adrenocorticotropin hormone, gonadotropic hormones, ADH, oxytocin • Hypothalamus is main link between endocrine system and nervous system.
The Thyroid Gland • Large gland at base of neck • Manufactures and secretes hormones that have role in growth, development, metabolism • Secretes calcitonin • Helps maintain normal calcium levels in blood • Parathyroid glands • Located in thyroid • Secrete parathyroid hormone
The Pancreas • Organ of both the endocrine system and digestive system • Produces insulin and glucagon • Insulin causes uptake and metabolism of sugar, fatty acids, amino acids. • Glucagon stimulates breakdown of glycogen to glucose. • Also stimulates liver and kidneys to produce glucose
The Adrenal Glands • Located on top of each kidney • Secrete: • Sex hormones • Hormones vital in maintaining water and salt balance • Adrenaline (mediates “fight-of-flight” response) • Epinephrine and norepinephrine
The Reproductive Glands and Hormones • Gonads are ovaries in women and testes in men. • Major female hormones • Estrogen • Progesterone • Human chorionic gonadotropin (hCG) • Ovaries produce estrogen and progesterone. • Developing fetus manufactures hCG • Testosterone is produced by testes. • And to smaller extent by adrenal glands and ovaries