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195 Cards in this Set
- Front
- Back
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function of respiratory system
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supply tissues with oxygen and remove CO2
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collective processes of respiratory system (4)
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1. pulmonary ventilation
2. external respiration 3. gas transport 4. internal respiration |
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pulmonary ventilation
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movement of air in and out of lungs (breathing)
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external respiration
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movement of oxygen from lungs to blood and CO2 from blood to lungs
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gas transport
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movement of oxygen (in blood) from lungs to tissues and CO2 from tissues to lungs
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internal respiration
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movement of oxygen from blood to tissue cells and CO2 from tissue cells to blood
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functions of nose (5)
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1. airway for respiration
2. moistens/warms entering air 3. filters/cleans air 4. resonating chamber for speech 5. houses olfactory (smell) receptors |
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vibrissae
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nose hairs of outer nasal region (trap inhaled particles)
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boundaries of nasal cavity
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roof = sphenoid and ethmoid bones
floor = maxilla, palatine, soft palate |
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conchae of nasal cavity (3)
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1. superior nasal concha (SNC)
2. middle nasal concha (MNC) 3. inferior nasal concha (INC) **increase surface area of nasal cavity |
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mucosal linings of nasal cavity (2)
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1. olfactory mucosa
2. respiratory mucosa |
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olfactory mucosa
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in superior nasal concha (SNC)
contains olfactory receptors |
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respiratory mucosa
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in middle and inferior nasal conchae (MNC and INC)
contains defensins (natural antibiotics) and lysozymes (destroy bacteria) irritation --> sneezing |
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functions of nasal conchae and mucosa (during inhalation and exhalation)
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inhalation = warm, moisten, and filter air
exhalation = conserve heat and moisture |
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components of respiratory system (8)
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1. nose
2. nasal cavity 3. pharynx 4. larynx 5. trachea 6. bronchi 7. alveoli 8. lungs |
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paranasal sinuses
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mucus-lined, air filled cavities in cranial bones surrounding nasal cavity
functions: 1. warm/moisten air 2. lighten skull |
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bones of paranasal sinuses (4)
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1. frontal
2. ethmoid 3. sphenoid 4. maxilla |
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sinus headaches
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blocked drainage of nasal cavity --> air absorbed into bones of paranasal sinuses
creates vacuum |
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pharynx
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"throat"
connects: nasal cavity --> larynx oral cavity --> pharynx 1. nasopharynx (air) 2. oropharynx (air and food) 3. laryngopharynx (air and food) |
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nasopharynx
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superior part of pharynx
ingests air only tissue = pseudostratified columnar closed by uvula/soft palate when swallowing |
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oropharynx
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middle section of pharynx
ingests food/fluid and air tissue = stratified squamous location of palatine and lingual tonsils |
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laryngopharynx
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inferior section of pharynx
ingests food/fluid (goes to esophagus) and air (goes to larynx) tissue = stratified squamous |
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larynx
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"voicebox"
connects laryngopharynx --> trachea functions: 1. maintain open pathway 2. switching mechanism (food vs. air) 3. role in voice production contains vocal cords (TVC and FVC) |
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construction of larynx (6)
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**all hyaline cartilage (except epiglottis)
1. thyroid cartilage 2. cricoid cartilage 3. arytenoid cartilage 4. cuniform cartilage 5. corniculate cartilage 6. epiglottis (elastic cartilage) |
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glottis
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space between false vocal cords (FVC) and true vocal cords (TVC)
closure prevents passage (when sneezing/coughing) |
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valsava maneuver
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closure of glottis
prevents air passage when sneezing/coughing allows for increased abdominal pressure (i.e. pooping, lifting heavy objects) |
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false vocal cords vs. true vocal cords
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false = close glottis
true = sound production |
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composition of vocal cords (tissue type)
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elastic connective tissue
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front/back attachments of vocal cords
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front = thyroid cartilage
back = arytenoid cartilage |
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sound production in larynx
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vibration of true vocal cords due to air movement through larynx
1. pitch = length/tension of cords 2. volume = force of air through glottis 3. pharynx = resonating chamber 3. tongue/lips/pharynx/palate = language production |
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layers of trachea (windpipe)
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1. mucosa
2. submucosa 3. adventitia |
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mucosa layer of trachea
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innermost layer (lines lumen of trachea)
tissue = pseudostratified epithelium contaings cilia and goblet cells |
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submucosa layer of trachea
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middle layer of trachea
contains seromucous glands |
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adventitia layer of trachea
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outermost layer
includes trachea cartilage fxn = keeps airway open |
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trachealis
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muscle of trachea between trachea and esophagus
contraction --> constriction of trachea increases force during coughing, projects substances out |
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tracheotomy
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surgical procedure that opens up trachea (windpipe) upon blockage of larynx
allows for passage of air when larynx is blocked |
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carina
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point where trachea splits into bronchi
highly sensitive mucosa due to high number or neurons |
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order of bronchi/bronchioles
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carina --> primary (main) bronchi --> secondary (lobar) bronchi --> tertiary (segmental) bronchi -->-->--> bronchioles --> terminal bronchioles (smallest)
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respiratory zone
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defined by presence of alveoli
order of flow: 1. terminal bronchioles 2. respiratory bronchioles 3. alveolar ducts 4. alveolar sacs 5. alveoli surface area = 300 mill alveoli (incr. surface area for gas exchange) |
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pleural cavity
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1. parietal pleura (outer lining of lungs covering inside of thoracic wall)
2. pleural space (filled with pleural fluid - decr friction) 3. visceral pleura (covers external surface of lungs) |
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pleurisy
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inflammation of pleura (lining of pleural cavity)
inflammed layers rub against each other, causes pain during breathing |
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pulmonary ventilation
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"breathing"
mechanical process depends on volume changes, which lead to pressure changes, which lead to gas movement in/out of lungs |
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intrapulmonary pressure (Ppul)
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pressure in alveoli
fluctuates with breating always eventually equalizes with Patm Ppul > Pip decreases as lung volume increases (inspiration) |
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intrapleural pressure (Pip)
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pressure in pleural cavity
fluctuates with breathing Pip < Ppul becomes more negative as chest wall expands (inspiration) |
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forces promoting lung collapse (2)
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1. elasticity of lungs
2. suface tension of alveolar surfactant (prevent alveoli from clumping together) |
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forces promoting lung expansion (2)
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1. elasticity of chest wall
2. low intrapleural pressure (Pip) |
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pneumothorax
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"collapsed lung"
collection of ait in intrapleural space (b/w lungs and chest wall) |
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greatest resistant to airflow in lungs
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medium-sized bronchi (account for biggest drop in diameter)
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asthma attack - reactions, triggers, Tx
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1. constricted bronchioles
2. inflammed airway 3. excess mucus production triggers = exercise, allergies, etc Tx = bronchodilators, anti-inflammatory (steroids) **epinephrine --> natural bronchodilator (opens airways) |
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lung compliance
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distensibility (stretchiness) of lungs
the higher the lung compliance, the easier it is to expand lungs at any transpulmonary pressure |
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homeostatic imbalances that reduce compliance (3)
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1. deformities of thorax
2. ossification of costal cartilage (turn into bones) 3. paralysis of |
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transpulmonary pressure
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Ppul - Pip
keeps lungs from collapsing incr TP pressure = incr size of lungs |
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dalton's law
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total pressure = sum of pressures exerted by each gas
2. incr percentage of gas in mixture = incr partial pressure |
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henry's law
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when gas mixtures come in contact with liquid, each gas dissolves in liquid in proportion to its partial pressure
amt of gas that dissolves in liquid also depends on solubility N = almost insoluble in plasmma O = slightly soluble CO2 = most soluble |
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influences of external respiration (3)
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1. partial pressure gradients of O2 and CO2
2. ventilation-perfusion coupline 3. thickness/permeability of respiratory membrane |
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ventilation
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amount of gas reaching alveoli
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transpulmonary pressure
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Ppul - Pip
keeps lungs from collapsing incr TP pressure = incr size of lungs |
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perfusion
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blood flow in pulmonary capillaries
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dalton's law
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total pressure = sum of pressures exerted by each gas
2. incr percentage of gas in mixture = incr partial pressure |
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ventilation-perfusion coupling
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synchronizing of alveolar ventilation (gas in alveoli) and pulmonary perfusion (blood flow in pulmonary capillaries)
decr in ventilation/incr in perfusion --> incr CO2/decr O2 --> arterioles constrict --> low vent/perf incr vent/decr perf --> decr CO2/incr O2 --> arterioles dilate --> high vent/perf |
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ways of oxygen transport through body (2)
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1. bound to Hb in blood (98.5%)
2. dissolved in plasma (1.5%... O not very soluble) |
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henry's law
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when gas mixtures come in contact with liquid, each gas dissolves in liquid in proportion to its partial pressure
amt of gas that dissolves in liquid also depends on solubility N = almost insoluble in plasmma O = slightly soluble CO2 = most soluble |
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factors affecting Hb's affinity for oxygen (6)
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1. Po (incr Po = incr affinity)
2. temp (incr temp = decr affinity) 3. blood pH (incr pH = decr affinity) 4. P-CO2 (incr P-CO2 = decr affinity) 5. amount of 2,3-BPG in blood (incr BPG = decr affinity) 6. smoking (incr CO = decr affinity)... blocks binding site for O2 |
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influences of external respiration (3)
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1. partial pressure gradients of O2 and CO2
2. ventilation-perfusion coupline 3. thickness/permeability of respiratory membrane |
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ways of carbon dioxide transport through body (3)
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1. as bicarbonate ion (HCO3-) in plasma - 70%
2. bound to Hb - 20% 3. dissolved in plasma - 10% |
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ventilation
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amount of gas reaching alveoli
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perfusion
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blood flow in pulmonary capillaries
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ventilation-perfusion coupling
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synchronizing of alveolar ventilation (gas in alveoli) and pulmonary perfusion (blood flow in pulmonary capillaries)
decr in ventilation/incr in perfusion --> incr CO2/decr O2 --> arterioles constrict --> low vent/perf incr vent/decr perf --> decr CO2/incr O2 --> arterioles dilate --> high vent/perf |
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ways of oxygen transport through body (2)
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1. bound to Hb in blood (98.5%)
2. dissolved in plasma (1.5%... O not very soluble) |
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factors affecting Hb's affinity for oxygen (6)
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1. Po (incr Po = incr affinity)
2. temp (incr temp = decr affinity) 3. blood pH (incr pH = decr affinity) 4. P-CO2 (incr P-CO2 = decr affinity) 5. amount of 2,3-BPG in blood (incr BPG = decr affinity) 6. smoking (incr CO = decr affinity)... blocks binding site for O2 |
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ways of carbon dioxide transport through body (3)
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1. as bicarbonate ion (HCO3-) in plasma - 70%
2. bound to Hb - 20% 3. dissolved in plasma - 10% |
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formation of bicarbonate ion from CO2
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CO2 + H2O <--> H2CO3 <--> H + HCO3-
means of CO2 transport from blood |
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steps of CO2 transport from blood to lungs (3)
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1. bicarbonate ions go into RBC and bind to H --> cabonic acid (H2CO3)
2. H2CO3 --(carbanhydrase)--> CO2 + H20 3. CO2 diffuses to alveoli |
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control centers of respiration (2)
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neurons in reticular formation of medulla and pons
1.medullary respiratory centers: -dorsal respiratory group -ventral respiratory group 2. pontine respiratory centers |
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dorsal respiratory group (DRG)
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in reticular formation of medulla
fxn = integrates input from peripheral stretch receptors and chemoreceptors and sends info to VRG |
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ventral respiratory group (VRG)
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in reticular formation of medulla
fxn = generates basic respiratory rhythm (on/off neurons) inspiration --> impulses down phrenic/intercostal nerves --> diaphragm/external intercostals **sets eupnea (normal breathing pattern) |
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eupnea
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normal respiratory rate (set by VRG of medulla)
12-15 breaths per minute inspiratory phases = 2 sec expiratory phases = 3 sec |
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pontine respiratory group
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in reticular formation of pons
fxn = sends input to VRG of medulla to modify/fine-tune breathing rhythms (during vocalization, sleep, exercise) |
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theories for genesis of respiratory rhythm (3)
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1. inhale neurons as pacemakers for breathing
2. **reciprocal inhibition of on/off neurons 3. stretch receptors in lungs establish rhythm |
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negative feedback mechanism in regulation of ventilation (gas flow)
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incr arterial P-CO2 --> incr acidity in brain ECF --> chemoreceptors --(afferent impulses)--> medullary respiratory centers --(efferent impulses)--> respiratory muscle --> incr ventilation (more CO2 exhaled)
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influences on brain stem respiratory centers (6)
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1. peripheral chemoreceptors (incr O2, decr CO2/ H+)
2. central chemoreceptors (incr CO2/H+) 3. receptors in muscles/joints 4. irritant receptors in lungs 5. stretch receptors in lungs 6. receptors/emotional stimuli in hypothalamus |
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hyperventilation
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incr in rate/depth of breathing; clears CO2 from body
dizziness fainting from anxiety attack: hypocapnia (low blood CO2) = BVs in brain to constrict = decr brain perfusion = cerebral ischemia |
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hypoventilation
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arterial P-CO2 abnormally low
respiration is inhibited (becomes slow/shallow) can cause apnea |
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apnea
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breathing cessations caused by low arterial P-CO2
can occur in sleep |
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"the bends" - gas imbalance
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ex --> divers
nitrogen is insoluble at PM at normal pressure but becomes soluble deep in water; nitrogen bubbles come back out of solution when diver rises to top symptoms = dizziness, "on fire", bubbling sensation Tx = decompression chamber (showly brings N back out) |
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carbon monoxide toxicity
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from exhaust or petroleum-based furnace
CO2 binds to Hb stronger than O2 Tx = O2 or hyperbaric chamber |
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oxygen toxicity
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high O2 levels --> free radicals --> destruction of tissues (especially vascular ones)
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chronic obstructive pulmonary disease (COPD)
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irreversible decr in ability to force air out of lungs
exemplified by: 1. chronic bronchitis (long term mucus cough) 2. emphysema (airflow obstruction) -80% caused by smoking -dsypnea (labored breathing) -coughing/pulmonary infections -respiratory failure (hypoventilation, respiratory acidosis, hypoxemia) |
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chronic bronchitis
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cause = continual bronchial irritation/inflammation (from smoking/pollution)
symptoms = bronchial edema, chronic cough, bronchiospasm results in... airway obstruction, dyspnea, freq. infections complications = abnormal ventilation/perfusion ratio, hypoxemia, hypoventilation |
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emphysema
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cause = breakdown of elastin in CT of lungs (from smoking)
condition = destruction of alveolar walls, loss of elasticity, air trapping leads to... airway obstruction, dsypnea,frequent infections complications = abnormal ventillation/perfusion ratio, hypoxemia, hypoventillation |
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primary mechanism of destruction in lung cancer
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accounts for 1/3 of all cancer deaths
90% due to smoking destructive mechanism: smoking paralyzes cilia --> accumulation of pathogens/irritants --> free radicals |
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common forms of lung cancer (3)
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1. squamous cell carcinoma (bronchial epithelium)
2. adenocarcinoma (peripheral lung) 3. small cell carcinoma (primary/main bronchi) **all 3 can metastasis (spread to other tissues) |
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alimentary/GI tract organs (6)
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1. mouth
2. pharynx 3. larynx 4. stomach 5. small intestine 6. large intestine |
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accessory organs of digestive system (6)
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1. teeth
2. tongue 3. salivary glands 4. pancreas 5. liver 6. gallbladder |
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digestive processes (6)
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1. ingestion
2. propulsion (swallowing, peristalsis) 3. mechanical digestion (chewing, churning, segmentation) 4. chemical digestion 5. absorption 6. defacation |
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mechanical/chemical stimuli of digestion
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external = sight, smell, taste, thought of food
internal = stretching of organ, osmolarity/pH of contents, presence of substrates |
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local eneteric nerve plexus
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"gut brain"
recieves impulses from receptors in GI tract (short reflex) stimulates smooth muscle/glands --> change in contractile/secretory activity |
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peritoneum
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lines the abdominopelvic cavity
components: 1. visceral peritoneum (around GI tract) 2. peritoneal cavity (filled with lubricating serous fluid) 3. parietal peritoneum (lines body wall) 4. mesentery (in peritoneal organs) |
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mesentery
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double layer of peritoneum that provides routs for BVs, lymph, and nerves, holds organ in place, and stores fat)
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retroperitoneal organs
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most of pancreas and parts of LI
organs that lose their mesentery and adhere to dorsal abdominal wall |
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layers of GI tract (4)
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1. muscularis externa (2 layers)
2. submucosa 3. mucosa (3 layers) 4. serosa (2 layers) |
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muscularis externa
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layer of GI tract, external to mucosa and submucosa
fxn = segmentation and peristalsis layers: 1. outer longitudinal muscle 2. inner circular muscle (forms sphincters) |
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mucosa
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innermost layer of GI tract
functions: 1. secrete mucus/ enzymes/ hormones 2. absorption 3. protection sublayers: 1. inner epithelium 2. lamina propria 3. muscularis mucosae |
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submucosa
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second most internal GI tract (outside of mucosa)
contains supply of blood, lymph, and nerves |
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muscularis externa
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layer of GI tract external to mucosa and submucosa
fxn = peristalsis and segmentation sublayers: 1. inner circular layer (form sphincters) 2. outer longitudinal layer |
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serosa
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protective outermost layer of peritoneal organs'
replaced by adventitia in esophagus retroperitoneal organs have BOTH serosa and adventitia |
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mouth (oral/buccal cavity)
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boundaries = lips (ant opening), cheeks, palate, tongue, oropharynx (post. opening)
epithelium = stratified squamous; keratinized (gums, hard palate, back of tongue) responds to injury by producing defensins |
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lips and cheeks - components (4)
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1. skeletal muscle (orbicularis oris [lips] and buccinators [cheeks])
2. vestibule (outside teeth, inside lips) 3. oral cavity proper (inside teeth and gums) 4. labial frenulum (fold joining inside of lip to gum) |
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components of palate
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1. hard palate (palatine bone, palatine process of maxilla) --> assists in chewing
2. soft palate (sk muscle, uvula closes off masopharynx during swallowing) |
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functions of tongue (4)
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functions:
1. grip/position food when swallowing 2. mix food w/ saliva 3. swallowing/speech 4. tasting |
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components of tongue (4)
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1. intrinsic muscles (shape)
2. extrinsic muscles (positioning) 3. lingual frenulum (holds tongue to floor of mouth) 4. papillae |
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papillae
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on bottom of tongue
act as grippers location of tastebuds |
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salivary glands (4)
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intrinsic:
1. buccal glands (keep mouth moist) extrinsic: 2. parotid gland 3. submandibular gland 4. sublingual gland |
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functions of saliva (4)
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1. moisten/dissolve food
2. break down food (enzymes) 3. cleanse mouth 4. help form bolus |
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regulation of saliva production
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stimulation = food --> P-ANS (facial and glossopharyngeal nerves); sight/smell of food
inhibition = S-ANS and dehydration |
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pharynx - in digestion
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oropharynx and laryngopharynx passageway for food (oral cavity --> esophagus)
epithelium = stratified squamous w/ mucus glands skeletal muscle layers |
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esophagus
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connect LP to stomach
layers = **adventitia, muscularis, submucosa, mucosa epithelium = stratified squamous |
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deglutition (5 steps)
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"swallowing"
1.buccal phase (voluntary) 2. uvula/epiglottis block resp pathways; UES relaxes 3. constricter muscles of pharynx contract 4. peristalsis moves food to stomach 5. LES opens and food enters stomach |
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regions of stomach (4)
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1. cardiac
2. fundus 3. body 4. pylorus |
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modified layers of stomach (2)
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1. muscularis externa - longitudinal, circular, and OBLIQUE muscle layer
2. mucosa - simple columnar, goblet cells, gastric pits (gastric juice from fundus and body) |
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protective barrier of stomach mucosa (3)
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1. thick mucus barrier that traps bicarbonate
2. tight junctions b/w epithelial cells (prevents leakage of gastric juice) 3. continuous renewal of mucosal cells (every 3-6 days) |
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gastric secretory cells
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1. neck cells (thin, acidic mucus)
2. parietal cells (HCl, intrinsic factor - vit B12 uptake) 3. chief cells (pepsinogen, lipases) 4. enteroendocrine cells (histamine, somatostatin, gastrin) |
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intrinsic factor
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secretion of parietal cells in stomach
required for absorption of vitamin B12 in SI |
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enteroendocrine cells
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secretory cells in gastric glands of stomach
secrete gastrin, histamine, somatostatin |
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neck cells
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secretory cells in gastric pits of stomach
secrete thin, acidic mucus |
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parietal cells
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secretory cells in gastric pits of stomach
secrete HCl (pepsinogen activation) and intrinsic factor (vit B12 uptake) |
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stimulation of HCl secretion
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stimulated by: ACh (P-ANS), gastrin (G cells), and histamine (ECI cells)
ACh and gastrin increase intracellular Ca levels histamine produces cAMP the more ligands bound to parietal cells, the higher the production of HCl |
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stimulatory events of gastric juice - cephalic, gastric, intestinal phases
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cephalic:
1. sight/thought of food 2. taste/smell receptors when eating food gastric: 1. distension (stretch receptors) 2. food chemicals and rising pH (chemoreceptors) intestinal: 1. presence of low pH, fats, hypertonic solution in duodenum when stomach begins to empty |
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inhibitory events of gastric juice - cephalic, gastric, and intestinal phases
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cephalic:
1. loss of appetite/depression gastric: 1. excessive acidity in stomach 2. emotional upset intestinal: 1. distension; presence of fatty, acidic, part digested food in duodenum |
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sufrace area modifications of SI (3)
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1. plicae circularis (circular folds, slow movement of chyme for better absorption)
2. villi 3. microvilli |
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intestinal juice
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produced in intestinal crypts of SI
alkaline, mostly water, enzyme-poor buffers pH of stomach juice remaining in GI tract |
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submucosal modifications of SI (2)
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1. brunner's glands (secrete alkaline mucus into duodenum)
2. peyer's patches (lymphoid cells - immune system) |
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cholecystokinin (CCK)
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produced in duodedal mucosa
produced upon presence of fats/proteins in SI 1. increases pancreatic juice production 2. stimulates gallbladder contraction 3. relaxes hepatopancreatic sphincter |
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gastric inhibitory peptide (GIP)
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produced in dudeonal mucosa
stimulated by presence of glucose, FAs, AAs in SI 1. stimulates insulin release (pancreas) 2. inhibits HCl production |
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gastrin
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produced by G cells in stomach mucosa
stimulated by food in stomach and ACh 1. increases HCl secretion 2. stimulates intestinal muscle contraction 3. relaxes iliocecal valve |
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histamine
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produced in stomach mucosa
stimulated by food in stomach activates parietal cells to release HCl |
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intestinal gastrin
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produced in duodenal mucosa
stimulated by acid/PD food in stomach stimulates gastric glands and motility |
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secretin
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produced in duodenal mucosa
stimulated by acidic chyme 1. inhibits gastric gland secretion/gastric motility 2. increases output of pancreatic juice (bicarbonate rich) 3. increases bile output (liver) |
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serotonin
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produced in stomach mucosa
stimulated by food in stomach causes contraction of stomach muscle |
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somatostatin
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produced in stomach mucosa/duodenal mucosa
stim by food in stomach and S-ANS 1. inhibits gastric secretion 2. inhibits pancreatic secretion 3. inhibits GI blood flow (thus SI absorption) 4. inhibits gallbladder contraction |
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vasoactive intestinal peptide (VIP)
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produced in enteric neurons
stimulated by chyme containing PD foods 1. stimulates buffer secretion 2. relaxes intestinal sm muscle 3. increases pancreatic secretion 4. inhibits gastric acid secretion |
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functions of liver (4)
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1. produce bile
2. process bloodborne nutrients 3. store fat-soluble vitamins 4. detoxification |
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composition of bile (5)
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1. bile salts*
2. phospholipids* 3. bile pigments 4. neutral fats (TGs) 5. electrolytes |
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bile salts
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synthesized from cholesterol
chief pigment = bilirubin |
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functions of bile (3)
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1. emulsify fat
2. solubilize fat/chol 3. aid in fat/chol absorption |
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stimulation of bile secretion (3)
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1. bile salts
2. fatty meals 3. secretin |
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stimulation of gallbladder contraction (3)
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1. CCK (fats/proteins)
2. secretin (HCl) 3. P-ANS (vagus nerve) |
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segmentation
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most common motion of SI
initiated by intrinsic pacemaker cells |
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regulation of SI motility by local enteric neurons (3)
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coordinate activity/motility
cholinergenic neurons: 1. contraction of longitudinal muscle layer 2. contaction of circular muscle layer 3. distention of intestine |
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regulation of SI motility by gastroileal reflex and gastrin (2)
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1. iliocecal sphincter opens
2. chyme moves into large intestine |
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gastroileal reflex
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long reflex that enhances force of segmentation in ileum
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3 unique features of LI
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1. tenia coli (bands of long. muscle)
2. haustra (outpocketing) 3. epiploic appendages (fat-filled pouches of visceral peritoneum) |
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teniae coli
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bands of longitudinal muscle in large intestine
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haustra
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outpocketing in LI formed by tone of teniae coli (long muscle)
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epiploic appendages
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fat-filled pouches of visceral peritoneum in large intestine
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5 subdivisions of LI
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1. cecum
2. appendix 3. colon (6 parts) 4. rectum 5. anal canal |
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6 subdivisions of colon
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ascending colon (AC)
hepatic flexure (HF) transverse colon (TC) splenic flexure (SF) descending colon (DC) sigmoidal colon (SC) |
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components of anal canal (3)
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1. rectal valve (allows gas excretion w/o feces excretion)
2. external anal sphincter (sk muscle, voluntary) 3. internal anal sphincter (sm muscle, involuntary) |
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LI mucosa - epithelium and crypts
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epithelium = simple columnar
crypts = goblet cells |
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anal canal mucosa - epithelium, function of sinuses
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epithelium = stratified squamous
sinuses = exute mucus, compress fecal matter |
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hemorrhoids
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caused by damage/variscosities to superficial venous plexi of anal canal
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actions of bacterial flora in LI (4)
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1. colonize colon
2. ferment indigestible carbs 3. release irritating acids and gases 4. synthesize vitamin K and B complex |
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functions of large intestine (3)
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1. digest enteric bacteria
2. reabsorb water, electrolytes, vitamins 3. propel fluid matter to anus |
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haustral contractions
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slow, segmenting movements by LI
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mass movements (mass peristalsis)
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long, slow-moving, powerful contractile waves over large areas of colon
occur 3-4 times/day activates gastroileal reflex in SI and gastrocolic reflex in colon |
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steps of initiating defecation (5)
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1. rectal walls distended by feces
2. contraction of rectal wall stimulated (P-ANS) 3. internal anal sphincter relaxed (P-ANS) 4. person voluntarity stimulations relaxation of external anal sphincter 5. defecation occurs |
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colon cancer
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forms from benign mucosal tumors called POLYPS
polyp formation increases with age |
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causes of malabsorption (2)
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1. anything interfering with delivery of bile/pancreatic juice
2. damaged intestinal mucosa (i.e. bacterial infection) |
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functions of immune system (3)
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1. protect body against invaders
2. repel pathogens 3. respond immediately |
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innate defenses of immune system
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non-specific
1. surface barriers (1st line of defense) 2. internal defenses (2nd line of defense) |
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surface barrier of innate immune defense - skin
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thick stratified squamous epithelium (physical barrier)
karatin (resistant to weak acids/bases) secretions = sebum and sweat (pH 3-5) inhibit bacterial growth |
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surface barrier of innate immune defense - mucous membrane
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lining digestive, respiratory, urinary, reproductive organs
mucus traps particles |
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secretions of surface barriers - innate defenses
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1. HCl (stomach)
2. mucus (digestive, resp, urinary, reprod organs) 3. sweat/sebum (skin) 4. saliva 5. tears (contains lysozyme) |
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internal defenses of innate immune system (5)
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1. phagocytes
2. NK cells 3. inflammation 4. fever 5. antimicrobial agents |
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phagocytes of internal defense system (4)
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1. macrophages
2. neutrophils 3. eosinophils 4. mast cells |
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macrophages
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phagocyte of internal defense system
derived from monocytes 1. free - wander throughout tissue searching for foreign invaders 2. fixed - liver/microglia of brain |
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neutrophils
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phagocyte of internal defense system
most abundant phagocyte; first responsders to inflammation sites destroy themselves in process of phagocytosis |
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eosinophils
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phagocyte of internal defense system
weakly phagocytic; important against parasites |
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mast cells
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internal defense system
release histamine in presence of foreign substances - key in inflammatory response **allergies |
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natural killer cells
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lyse and kill cancer and virus-infected cells; cause cells to undergo apoptosis
type: large granular lymphocytes |
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mechanism of action of NK cells (4)
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1. non-specific - kill self cells if infected
2. doesn't require adaptive immune response 3. release perofrins (lyse offending cells) 4. enhance inflammatory response |
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inflammation
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internal mechanism of innate defense system
triggered by any tissue damage (pH, temp, chem, infection, cuts) 4 cardinal signals = swelling, redness, pain, heat |
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benefits of inflammatory response (3)
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1. prevent spread of injuring agents
2. dispose of pathogens/dead cell tissues 3. promote tissue repair |
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pro-inflammatory chemicals (6)
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1. cytokines
2. histamines 3. kinins 4. prostaglandins 5. leukotrienes 6. complement |
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steps of phagocyte mobilization (4)
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1. leukocytosis (incr WBCs)
2. margination (cell adhesion molecules indicate to neutrophils location of injured tissue) 3. diapedesis (neutrophils squeeze out of cap walls) 4. chemotaxis (WBCs migrate to injury site) |
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interferons
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antimicrobial proteins of internal defense system
proteins released from virus-infected cells that protect uninfected cells from viral attack; also inhibit some cancers |
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complement
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antimicrobial proteins of internal defense system
when activated, these proteins enhance inflammatory and immune response and may lead to cell lysis |
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key features of adaptive immune defenses (3)
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1. specific
2. systemic (body wide) 3. memory |
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functions of adaptive immune defenses (3)
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1. immobilize, neutralize, destroy foreign substances
2. amplify inflammatory response 3. activate complement |
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complete antigens
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antigens that are:
1. immunogenic - can cause proliferation of lymphocytes 2. reactive - ability to react to products of activated lymphocytes |
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haptens
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"incomplete antigens"
reactive antigens, only immunogenic when bound to bodily protein (ex - poison ivy) |
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antigenic determinants
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binding sites on Ags for lymphocytes or other Ags
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cells of adaptive defense system (3)
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1. B lymphocytes (humoral)
2. T lymphocytes (cell-mediated) 3. antigen presenting cells (APCs) |
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B lymphocytes
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cells of adaptive immune system
produced/mature in RBM oversee humoral (Ab) immune response |
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T lymphocytes
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cells of adaptive immune system
produced in RBM; mature in thymus oversee cell-mediated (cell-on-cell) immune response **fine-tuned selection process to identify "self" cells from "non-self" cells |
