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RESPIRATORY
SYSTEM
Respiratory System Functions
 Warm, filter and humidify air
 Specific functions
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1. Provide area for gas exchange
2. Move air to and from exchange
surfaces
3. Protect respiratory surfaces
4. Defend respiratory surfaces from
pathogens
5. Permits sound which allows
communication
6. Helps regulate blood volume, blood
pressure and pH of body fluids
Respiratory Tract
 Passageways taking air to and from
alveoli (place where gas exchange
occurs)
 Upper respiratory tract = passageways
to lungs
 Lower respiratory
tract = lungs
Nares
Pharynx
Larynx
Trachea
Main Stem Bronchus
Bronchioles
Alveoli
Nose
 Nares = nostrils
 Function: warm, filter and humidify incoming air
 Hairs are protective. They keep debris out of nasal
cavity and consequently, the lungs
 Nasal septum- divides the nasal cavity
 Hard palate- is in the front
 Soft palate- is in the back
 Nasopharynx – the section of the pharynx posterior to
the nares
Mucous Membrane
 Lines respiratory system
 Helps remove or trap debris
 Very vascular
 Unpleasant stimuli (pathogen, allergens, dust, dangerous fumes)
increase mucous production
 Helps warm and humidify air
 Mouth breathing gets rid of most filtration, heating and humidifying
 Nosebleeds = epistaxis,
 Caused by trauma, drying, infections, allergies, clotting disorders,
hypertension. Treatment: pinch nose, pack with gauze
Pharynx
 Nasopharynx-behind the nose
 Oropharynx- behind the oral cavity
 Laryngopharynx- in area of larynx
Larynx
 Larynx = voicebox
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9 cartiliages
Sits on the cricoid cartilage
 Epiglottis-above the glottis (opening)
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Folds down to cover glottis during
swallowing
Thyroid cartilage is on the anterior of
larynx- ridge on front of thyroid cartilage is
the Adam’s apple
Larynx
 Vocal Folds= vocal cords- ligaments involved in sound production
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Positioned over the glottis so air going through the glottis vibrates
the vocal cords
Frequency or pitch depends on the length and diameter of the vocal
cords.
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Short, thin cords= high pitched
Long, thick cords= lower pitch
Tension on vocal cords also determines pitch- voluntary muscles
control tension
Sounds are modified by pharynx, oral and nasal cavities and
sinuses
Larynx
 Cough- glottis closed forcibly while
lungs are full. Abdominal and
intercostal muscles contract
causing high pressures that create
a blast of air when the glottis
opens again
Trachea
 Trachea = windpipe
 Tracheal blockage- person can’t
breathe or speak.
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Treatment: Abdominal thrusts
Heimlich maneuver
Tracheostomy/ tracheotomy
Bronchi
 Bronchus- singular
 Primary or main stem bronchi branch
into smaller bronchi. They have cartilage
bands
 Bronchioles are smaller than 1mm in
diameter and have no cartilage
 Alveoli- area where gas exchange with
capillaries occurs. Small round grapelike sacs. 150 million in each lung
Lungs
 Lobes
 Right lung has three lobes (
superior [upper], middle, inferior
[lower])
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Left lung has two lobes (superior,
inferior)
Lobes are divided into small
partitions
Lobules are bunches of alveoli
Lungs are light and spongy
Lungs
 Pulmonary Circuit brings blood to and from the lungs
 Alveoli are lined with respiratory membrane that is coated
with surfactant.
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Surfactant reduces evaporation of water on the wet surfaces of
the lungs. Surfactant also prevents the lungs from collapsing
during breathing- so they stay ‘inflated’
 Pleura-serous membrane surrounding each pleural cavity
 Parietal pleura -outer layer
 Visceral pleura- around the lungs
 small amount of fluid separates the 2 layers ( prevents friction)
Lungs
 Bronchoscopy- bronchoscope with fiber
optic bundle that is inserted into trachea
and bronchi to visualize structures
 Thoracentisis- use of a long needle to
extract pleural fluid to check for blood,
WBCs or bacteria
Lung Diseases and
Disorders
 Tuberculosis (TB)- bacterial infection of the lungs.
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Symptoms are variable:
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Coughing, chest pain, fever, night sweats, fatigue and night sweats
Abscess forms at the infection site and then bacteria move into
surrounding tissues and abscess again.
Abscesses decrease the amount of air that can move in and
out of the lungs and the area for gas exchange gets smaller
Bacteria can spread to other tissues and can become resistant
to antibiotics
Treatment: several drugs used in combination for 9 months or
more.
Lung Diseases and Disorders
 Pulmonary embolism- all blood goes through the
pulmonary circuit. Vessels can be blocked by a
clot, fat mass or air bubble. This will stop all
blood flow to the alveoli served by the vessel
and can lead to permanent collapse of the
alveoli. Congestive heart failure can result
Lungs Diseases and Disorders
 Cystic Fibrosis- genetic disease. Usually fatal before age
30. Death is generally caused by bacterial infection of the
lungs that leads to heart failure. Disease causes the
secretion of thick, sticky mucus that blocks respiratory
passages
 Pneumonia- pathogenic infection of lobules. Fluid leaks
into alveoli causing respiratory function to decrease. Can
lead to swelling or constriction of bronchioles. Can be
caused by a wide variety of pathogens
Respiratory Changes at Birth
 Respiratory system in fetus- pulmonary vessels are
collapsed; rib cage is compressed; lungs and
passageways have small amount of fluid, but no air.
Respiratory Changes at Birth
 At birth- the first breath is caused by contraction of
the diaphragmatic and intercostal muscles. Air
coming in pushes fluids out of the way and inflates
the bronchi, bronchioles and most of the alveoli.
The pressure change in the respiratory system
takes blood into the pulmonary circulation, the
foramen ovale (between the atria of the heart)
closes, so does the ductus arteriosus ( between the
pulmonary trunk and aorta)
Respiratory Changes at Birth
 Neonatal Respiratory Distress Syndrome (RDS) – happens
when there is not enough surfactant in lungs for normal
function (usually in premies). Too little surfactant causes
alveoli to collapse with exhalation. Baby then needs to use
extra force with each inhalation to reopen alveoli.
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This leads to exhaustion. (surfactant production begins at the
end of 6th month development. By 8th month there is usually
enough surfactant for normal respiratory function
Treatment: administer air under pressure until surfactant
production increases. Surfactant is administered via a fine mist
Respiratory Physiology
 Pulmonary ventilation- breathing- air
movement in and out of lungs.
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Purpose: to keep adequate air movement in and
out of alveoli. Makes sure enough oxygen is
coming in to supply the bloodstream
Respiratory Physiology
 Inspiration-inhalation- volume of air
increases which causes pressure in
lungs to decrease which lets air in lungs
 Expiration-exhalation- volume of air
decreases which causes pressure in
lungs to increase which lets air out of
lungs
Respiratory Physiology
 Respiratory muscles expand and contract chest
with inspiration and expiration
 Eupnea- good breathing. Normal, quiet
breathing
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Types of eupnea:
 Diaphragmatic
breathing (deep breathing) involves
contraction of diaphragm
 Costal breathing (shallow breathing) rib cage expands
Respiratory
Physiology
 Hypoxia- decreased oxygen in tissues
 Anoxia- no oxygen- leads to death
 Pneumothorax- damage to lungs that allows air to
escape into the pleural cavity leading to atelectasis
(imperfect expansion)- collapsed lung.
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Treatment: remove air, seal opening- reinflates lung
Respiratory Rate
 Respiratory rate = number of breaths per
minute
 Normal adult 12-20 breaths per minute
 Normal child 18-22 breaths per minute
Disorders
 Asthma-constriction of small muscles in bronchial
tree, edema and swelling in walls of respiratory
passages, increased production of mucus
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Person can’t exhale all air, mucus and fluids build up in
passageways leading to coughing and wheezing
Can lead to oxygen starvation of peripheral tissues and
death
Treatment: bronchodilators and inhaled steroids
Disorders
 Bronchitis- inflammation of the bronchial
lining leading to overproduction of
mucus. Causes cough. 20% of adult
males that have chronic bronchitis
usually get it from cigarette smoking.
Bronchitis can block the small airways
and reduce respiratory efficiency
Disorders
 Emphysema- chronic, progressive disease.
Causes shortness of breath. The alveoli expand
and the alveoli walls become thickened with
fibrous tissue. The capillaries deteriorate leading
to no gas exchange
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Cause: cigarette smoking
66% of adult males and 25% females have some
emphysema in their lungs
Damage has to be severe before symptoms are seen
Disorders
 COPD-chronic obstructive pulmonary disease (term covers
chronic bronchitis and emphysema
 2 patterns
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Pink puffers- thin, high respiratory rate, normal oxygenation of
blood leads to pink skin
Blue bloaters- emphysema and chronic bronchitis together.
Leads to heart failure, blood not oxygenated ( blue skin)
 Loss of alveoli and bronchioles is permanent
 Prevent progression by stopping smoking
 Only treatment: oxygen administration, sometime broncho-
dilators
White area is cancer
Disorders
Black area is
Smoker’s lung
 Lung Cancer-starts in bronchial passages or
alveoli. Tumor masses decrease air flow
 Symptoms- chest pain, shortness of breath, cough
weight loss.
 Beta carotene and other vegetable components
decrease risk
 High cholesterol, high fat diet increase risk
Aging and the Respiratory
System
 Changes:
 1. Decrease in vital capacity (total amount of air
able to move in and out of lungs)
 2. Chest cannot expand and contract as well
 3. Some emphysema- especially if exposed to
cigarette smoke over a lifetime. With smoking,
respiratory disability is inevitable
Urinary System
Urinary System Components
 2 kidneys
 2 ureters
 1 urinary bladder
 1 urethra
Kidney
Ureter
Urinary Bladder
Urethra
Urinary System Functions
 1. Regulates electrolytes
 2. Regulates blood pressure and blood
volume
 3. Stabilizes pH of blood
 4. Prevents loss of nutrients in urine
 5. Eliminates organic wastes
 6. Helps liver detoxify poisons
Kidneys
 Functions:
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Filtration
Reabsorption
Secretion
Basically: make urine
 Location: retroperitoneal- behind the peritoneum
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Right kidney usually a little lower than the left
 Kidneys connected and kept in place by 3 layers
of connective tissue
Kidneys (cont.)
 Size: 10cm X 5.5cm, 3cm
thick
 Weight: 15 g
 Cortex- (outer layer)
 Medulla- (inner layer)
 Renal Pelvis- chamber that connects the ureter. Helps
drain urine from kidneys. The pelvis divides into
calyces. (calyx- sing.) Each calyx connects to a lobe
or pyramid to drain urine
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About ¼ of the body’s blood pumped every minute goes
through the kidneys. More than 90% of blood entering the
kidney goes through the cortex which contains nephrons
Kidneys (continued)
 Nephron- basic functional unit of the kidney
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Made of a renal tubule
The Nephron starts with a glomerulus (Bowman’s
capsule) which is a knot of about 50 capillaries. Urine
formation begins in the glomerulus with the production
of filtrate
Glomerulonephritis- inflammation of the renal cortex.
The filtration mechanism gets clogged up- so urine
production is interupted
Through the remainder of the tubule, water, ion and
nutrients are reabsorbed. The final result is urine
Urine
 Normal Urine:
 pH = 6.0 (4.5-8)
 93-97% water
 1200 ml/day
 Clear yellow
 Sterile
Urine
 Hematuria= blood in the urine
 Proteinuria= protein in urine ( result of kidney
damage)
 Polyuria= excessive urine production (>2 liters/day)
 Oliguria= inadequate urine production
(<500ml/day)
 Anuria= no urine production (kidney failure)
Kidney Disorders
 Nephritis- inflammation of the kidneys.
Causes swelling, but because of the renal
capsule the kidney can’t get bigger ->
pressure builds up -> decreases filtration
 Danger of diuretics ‘water pills’. Drugs to
promote water loss in urine. Purpose:
decreases blood volume
Kidney Disorders
 Renal Failure= kidney failure
 Kidneys can’t perform normal function
 Urine production decreases leading to retention of water, ions
and wastes
 Causes uremia- a change in blood composition indicative
abnormal kidney function
 Upsets fluid balance, pH, muscle contraction, metabolism and
digestive functioning
 Causes hypertension, anemia, CNS disturbances-> seizures
and coma
 Chronic or progressive
Kidney Disorders
 Hemodialysis- blood is passed through an
artificial membrane to replace glomerular
filtration.
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Problems: time, hypotension, anemia, shunt
infections, uremia between treatments
Peritoneal dialysis- peritoneal lining becomes
dialysis membrane. Dialysis fluid put into
abdomen and then removed.
Renal transplant; common, donor may be
living or cadaver, 85-95% 1 year success
rate
Other Urinary Structures
 Ureters- takes urine from kidneys
to bladder
 Urinary bladder-temporary urine
storage
 Urethra-takes urine from bladder to
outside of body
 Micturition = urination
 Void = urination
Disorders of Urinary Structures
 Urinary Tract Infections (UTI)- happens when
bacteria or fungi colonize the urinary tract
 Cystitis- inflammation of the bladder lining
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Dysuria-painful urination
Urge to urinate
 Treatment-
antibiotics
 Incontinence- lack of control over urination
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Causes- muscle weakness or CNS damage
Development and Aging
 Development- kidneys begin producing filtrate by 3rd
month of development
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There is no waste in the urine because waste is removed
by the placenta
 Aging usually brings an increase in kidney problems
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Decreased number of functional nephrons
Decreased glomerular filtration
Decreased sensitivity to ADH
Problems with micturition reflex
Urinary retention (males)