Anatomy, Physiology and Pathophysiology

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Chapter 5

• Anatomy, Physiology and Pathophysiology

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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

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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

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Topographic Anatomy

• Planes and Lines
• Terms of Direction
• Terms of Movement
• Positions and Postures

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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

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The Integumentary System (Skin) Physiology

• Functions
• Protect the body in the environment
• Regulate body temperature
• Transmit information from environment to brain

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The Skeletal System Anatomy

• Skeleton gives us our recognizable human form,
  protects vital internal organs.
• Bones
• Tendonsconnect muscles to bones
• Ligamentsconnect bone to bone
• Cartilagecushions between bones
• Lubricated by joint fluid (synovial fluid)

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Overview of Bones (2 of 2)

• Components of a long bone (humerus)

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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.

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The Skeleton

• Axial
• Appendicular
• Joints

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The Musculoskeletal System Anatomy

• Three types of muscle
• Cardiac
• Found only in the heart
• Specially adapted
• Skeletal
• Smooth
• Involuntary
• In blood vessels, intestines

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The Musculoskeletal System Physiology

• Contraction and relaxation make movement
  possible.
• A by-product of movement is heat.
• Muscles protect structures under them.
• For example, intestines are protected by rectus
  abdominus muscles.

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The Musculoskeletal System Anatomy (4 of 4)
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The Respiratory System Anatomy

• Nose
• Mouth
• Throat
• Larynx
• Trachea
• Bronchi
• Bronchioles
• Lungs
• Diaphragm
• Muscles of chest wall
• Accessory muscles of breathing

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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

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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.

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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

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Acid-Base Regulation

• The body attempts to maintain a ratio of
  HCO3H2CO3 of 201
• As carbonic acid is manufactured by the buffer
  system it breaks down into carbon dioxide and
  water
• H2CO3 produces CO2 and H2O

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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

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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

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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

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Interpreting Blood Gases

• Acidosis pH lt 7.35
• Respiratory
• pCO2 gt 45 If compensated, HCO3- gt 26 mg/dl
• Metabolic
• HCO3- is lt 22 mg/dl, pCO2 is normal
• Alkalosis pH gt 7.45
• Metabolic
• pCO2 lt 35 and HCO3- is low
• Respiratory
• HCO3- gt 26 mg/dl, pCO2 is normal

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Ventilation (1 of 2)

• Tidal volumeair moved in a single breath
• Inspiratory reserve volumedeepest breath you can
  take after normal breath
• Expiratory reserve volumemaximum amount of air
  you can forcibly breathe out after normal breath

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Ventilation (2 of 2)

• Vital capacityamount of air moved with maximum
  inspiration and expiration

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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

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Compromised Breathing Patterns in Adults

• Labored breathing
• Minute alveolar ventilation lt 4200 ml
• Muscle retractions (clavicles, ribs)
• Pale or cyanotic (blue) skin
• Cool, damp (clammy) skin
• Tripod position

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The Circulatory System Anatomy

• Heart
• Location
• Chambers, valves, accessory structures
• Heartwall and Pericardium
• Blood vessels
• Types
• Circulatory pathways
• Blood

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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

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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

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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.

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The Cardiac Cycle

• Process that creates the pumping of the heart
• Systole
• Diastole
• Pulse pressure
• Afterload
• Stroke volume
• Cardiac output stroke volume heart rate

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Blood Composition

• Plasma
• Red blood cells
• Hemoglobin
• Surface Antigens
• White blood cells (leukocytes)
• Fight infection
• Granulocytes (neutrophils, eosinophils,
  basophils)
• Agranulocytes (monocytes, lymphocytes)
• Platelets

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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.

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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

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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

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Cellular Transport Mechanisms

• Cell membrane is selectively permeable.
• Allows differences in concentrations inside and
  outside cell

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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

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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

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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

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The Nervous System Anatomy and Physiology

• Components
• Central nervous system
• Peripheral nervous system

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The Central Nervous System

• Brain
• Spinal Cord
• Meninges

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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

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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

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The Endocrine System Anatomy and Physiology (2
of 2)
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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.

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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

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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

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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

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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

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The Digestive System Anatomy
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The Digestive System Physiology (1 of 2)

• In succession, different secretions (primarily
  enzymes) are added to food by
• Salivary glands
• Stomach
• Liver
• Pancreas
• Small intestine

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The Digestive System Physiology

• Converts food into basic sugars, fatty acids,
  amino acids
• These products cross wall of intestine and travel
  through portal vein to liver
• Liver further processes and stores or transports
  to heart
• Circulatory system then nourishes all cells

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The Urinary System Anatomy and Physiology (1 of
2)

• Controls discharge of waste filtered from blood
  by kidneys
• Functions
• Controls fluid balance in body
• Filters and eliminates wastes
• Controls pH balance

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The Urinary System Anatomy and Physiology (2 of
2)

• Components
• Kidneys
• Ureters
• Urinary bladder
• Urethra
• This example shows the male urinary system.

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The Genital System Anatomy and Physiology

• Controls reproductive processes by which life is
  created
• Male genitalia lie outside pelvic cavity.
• Except for prostate gland and seminal vesicles
• Female genitalia lie inside pelvic cavity.
• Except for clitoris and labia

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The Male Reproductive System and Organs

• Testicles, epididymis, vasa deferentia, penis
• Functions
• Reproduction
• Production of sex hormones
• Penis is also part of urinary system

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The Female Reproductive System and Organs

• Ovaries, fallopian tubes, uterus, cervix, vagina
• Functions
• Reproduction
• Production of sex hormones

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Life Support Chain (1 of 2)

• Bodys cells require
• Oxygen
• Brought by respiratory and circulatory systems
• Nutrients
• Food broken down by digestive system into glucose
• Brought by circulatory system
• Removal of wastes
• Removed by circulatory system

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Life Support Chain (2 of 2)

• Aerobic metabolism uses oxygen.
• Only possibility for some cells (eg, heart,
  brain)
• Anaerobic metabolism does not use oxygen.
• Most cells can operate without oxygen for 1 to 3
  minutes.
• Lactic acid is a by-product.
• Converted back to useful energy source once
  oxygen becomes available

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Pathophysiology (1 of 4)

• Study of functional changes that occur when body
  reacts to disease
• Airway patency
• Can be impaired by blocked airway
• Muscles of breathing can be impaired.
• Decreased level of consciousness can impair
  ventilation.

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Pathophysiology (2 of 4)

• Respiratory compromise
• Can be caused by decrease of oxygen in air
• Fluid in alveoli can prevent gas exchange.
• Cells will move to anaerobic metabolism.
• Body can adapt to mild, gradual compromise.
• Severe or prolonged compromise can cause death.

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Pathophysiology (3 of 4)

• Shock
• Condition in which perfusion is inadequate to
  organs and tissue
• Hypovolemic shock results from lack of blood
  volume (as from trauma).
• Cardiogenic shock results from heart
  inefficiencies.
• Distributive shock results from issues regarding
  dilation and constriction of blood vessels.

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Pathophysiology (4 of 4)

• Alteration of cellular metabolism
• In strenuous exercise, demand for glucose exceeds
  supply.
• Body burns fats and turns them into glucose.
• This process is inefficient, but body can sustain
  for a while.
• If there are breathing or perfusion problems,
  however, process can cause damage or death.