Patho Midterm Two Flashcards
How is O2 transported in the body?
O2 binds to Hbg sites (has preferential binding).
Dissolves in blood
What effect will giving more O2 to a person will 99% sats have?
No effect. Site are already at max capacity.
What is the normal PaO2?
80mmHg
What happens to PaO2 as HbO2 drops?
Decreases. O2 will preferentially bind to HgB. If it isn’t binding to HgB then it won’t stay in blood
What factors affect HbO2 binding? How do they affect?
- pH - <7.4 saturation binding decreases
- temp - Increasing temp decreases binding abilities
- Diphosphoglycerate (DPG) increases presence decreases O2 binding
What is a Bohr shift?
Shift to the right of the O2 dissociation curve
How does DPG decrease O2 binding? What causes increased levels of DPG
DPG binds to Hbg instead of O2.
Increase temp, thyroid hormone, testosterone and epinephrine raise DPG
What is Meconium? How does it influence fetal ARDs?
Meconium is fetal feces; if it enters the amniotic fluid it can contaminate it. In late gestation, the baby starts fetal breathing movements (FBM)s which can draw amniotic fluid into the lungs. Contaminated fluid can cause inflammation leading to hyaline inflammatory disease
What is ARDS?
Acute Respiritory Distress syndrome
What is the pathophysiology of ARDS?
Foreign particles / substances enter the alveoli (soot, pollutants) causing injury to type I epithelial cells. Neutrophiles enter and release inflammatory mediators and proteolytic enzymes. Causes hyaline membrane disease (thickening of injured area). Thickened area + fluid in alveoli = decreased diffusion in the area
What is hyaline membrane disease?
Inflammation of the basment membrane where damage to the epithelium was. Causes exposed basement membrane to thicken = decreased diffusion
What are manifestations of ARDS? Clinical consequences?
Manifestations:
- Leaky capillaries which lead to non cardiogenic edema
- Destruction of Type II alveoli cells causing atelectaisis
- Inflammation dt injury which causes fibrosis
Results in increased WOB, shunting (with alveoli collapsed, blood gets shunted elsewhere), hypoxemia
What is noncardiogenic pulmonary edema?
Pulmonary edema dt non CHF reasons (exudate following WBCs into lung)
What is patho cystic fibrosis?
Recessive disorder in individuals lacking the Cystic fibrosis transport regulator (CFTR) which causes a decrease in transport of Cl- watery solution. Without this solution the mucous sticks to the cillia in the bronchials..
The mucous forms a culture medium for bacteria growth causing recurrent infections
What are ways to management of CF?
Gene therapy, lung transplant, patthing person on the back, suctioning
What body parts does CF affect? What are possible S&S?
Respiritory: decreased air conductance
Pancreatic and bilary ducts: digestive problems, flatulence, steatorrhea, weight loss
What micro-organisms can cause respiritory tract infections?
Bacteria, viruses, mycosis, mycoplasma
What is typical pneumonia?
aka alveolae pneumonias. Dt bacteria
Infection attracts PMNs into alveolar lumen which produces exudate. Exudate causes respiritory distress
Cap endothelium breaks causing RBCs to enter alveoli - blood in sputum
Likely to have productive cough
What is atypical pneumonia?
aka interstitial pneumonia dt viruses
Alveoli lumen is clear. WBC enter alveoli walls though blood vessels. Edema builds up in walls
Increased thickness of walls decreases diffusion
Produces non productive cough
Differences between alveolar and interstitial pneumonias?
Alveolar
- fluid is in the alveoli
- RBC + WBCs in alveoli
- Productive bloody cough
- caused by bacteria
Interstitial:
- fluid is in interstitial walls
- alveoli lumen are clear
- non productive cough
- caused by viruses
What is bronchopneumonia? S&S?
Patchy distribution throughout both lungs. Diffuse.
S&S: Chills, fever, increased peripheral resistances, increased resp rate, bronchial breathing (gas exchange in the bronchi), purulent and bloody sputum. Severe chest pain and abdominal distension)
What is lobar pneumonia? what are clinical manifestations?
Pneumonia in one lobe of lung. All the alveoli are infected. Associated with consolidation of lobe.
S&S: Shallow breathing, cyanosis, pleurisy (pleuritis), N&V, rust colored sputum, fever, chills
What is interstitial pnemonia? Clinical manifestiation?
Widespread disttribution. Diffuse inflammation dt viral infeciton. Walls are inflitrated with WBCs which increase septum width
S&S: cyanosis, fever, chills, alveolar wall fibrosis, non productive cough, finger clubbing (severe)
Why is the right lower lobe most often implicated with lobar pneumonia?
Rt bronchus is more vertical dt the position of the heart than the lt bronchus. Makes Pathogens more likely to enter and settle
What is the pathogenesis of clubbing fingers?
May be an immune response dt the lack of O2 supply
What is prostration?
extreme weakness and fatigue
Why is the sputum rusty colored in lobar pneumonia?
Caused by inflammation and destruction of tissue
What are complications of pneumonia?
- Pleural fibrosis dt chronic inflammation in lungs
- Empyema - decreases ventilation bc of increase of resistance
- abcess - mass loss of tissue in lung - decreases lung capacity
- Bronchiectasis - bronchi are permanently enlarged. Increases air deaad space which means less air to the alveoli
- Intersitial fibrosis
- Cysts - fluid filled sacs which destroy alveoli
What is TB? Where is it most proliferative?
Infectoius agent that causes the most deaths
Mostly in developing countries
What are characteristics of Mycobacterium tuberculosis hominis?
T bacteria -
Aerobic, has a protective waxy capsule which allows it to say alive in “suspended animation for years.
Usually affect superior lobes
How long does it take after initial infection for the TB test to read positive?
3-6 weeks
What is the Ghon complex?
Encapsulated nodes in the lung lobes which encloses TB to prevent further spread
Contains Macrophages, T cells and inactive TB bacteria
Visible on xrays, partially dt dystrophic calcification of necrotic areas
What is the immune mediated response of initial TB infection?
Bacteria is inhaled.
Macrophages ingest bacteria and present the infectious agents on outside.
T cells are activated to kill macrophages with bacteria inside and also activate macrophages to target TB more efficiently
What is primary TB?
If the immune response is adequate, TB trapped in Ghon foci. Bacteria are rendered inactive and non contagious
If the immune system is weak (Elderly, AIDs) the bacteria multiply in lungs. aka progressively primary TB. These individuals are contagious.
What is Milary TB?
Second phase of TB after Progressive primary TB.
Pt exhibits signs of pneumonia (dt WBC activation), bacteria in sputum and exhaled droplets. TB bacteria can spread to the rest of the body - brain, bone, gonads, urinary tract, GI, heart and adrenal glands
What is secondary TB?
When a person is reinfected with TB which causes reactivation of previously healed lesion
Body can respond quicker
What is consumption?
Creation of cavities in lungs dt untreated TB
Can be fatal
What is potential space?
Free space in the abdomen to allow for movement and expansion of the organs
Different between parietal and visceral peritoneum
Parietal lines abdominal cavity, visceral lines organs
What separates the mucosa and submucosa>
muscalaris mucosa
What are the functions of saliva?
Improves taste of food by dissolving foods
Starts the digestion process
Protects the mouth from infectious agents
What are the different salivary glands?
Parotid: Produces most of the salivary fluid. Serous, watery fluid
Sublingual: Smallest, secretes mucous
Submandibular - secretes serous and mucous
What muscles are found in the esophagus?
Upper 1/3 - skeletal. Gag reflex present
Lower 2/3 - smooth muscles - peristalsis
Why does heart burn occur?
Weakness in diaphragm muscles (around cardiac sphincter) are weak.
When the stomach moves around, acid splashed back and enters the esophagus
What are the stagse of swallowing?
Buccal Phase: Food is turned into a bolus. Tongue moves bolus to the back of the throat towards the esophaugs
Epiglotis covers trachea.
Pharyngeal - esophageal phase: Upper 1/3, pt can regurgitate
Lower 2/3 peristalsis. Moves towards cardiac sphincer
Why does the stomach have three layers of smooth muscle?
To chop food and mix digestive juices
Label the following:
- Fundus
- Cardiac region
- Body
- Longitudinal muscle
- Circular muscle layer
- Oblique muscle
- Gastric rugae
- Antrum
- Pyloric canal
- Pylorus
- Pyloric sphincter
What is the stomach Ph?
1-2
What are the major secretory cells of the stomach? What do they produce?
Parietal cells - produce HCl & Intrinsic factor
Chief cells - granules secrete digestive enzymes (pepsinogen)
Enteroendocrine - secrete hormones into the blood
Surface epithelia - HCO2 & mucous
How is hCl formed?
CO2 in blood is converted to carbonic anahydrase in the parietal cells. It is broken up into HCO3 (which re-enters the blood) and H+ ions, which are secreted into the stomach lumen
Chloride is pumped from the blood stream
What medications stop the hydrogen ion pump?
Pantoloc - inhibits H+K+ATPase. Prevents the release of H ions
What are the phases of HCL secretion?
- Cephalic: Thought of food stimulates the vagus nerve which causes the release of HCl
- Gastric: distension of the stomach causes the release of histamine and gastrin. This causes HCL release
- Intestinal: When food leaves the stomac, hCL is inhibied due to secretin, CCK and GIP
What does secretin do?
Releases HCO3 to neutralize HCL
How do you control gastric secretions?
- Block Muscarinic receptor - block AcH, but not usually done because it can cause other problems
- Block H2 receptors by blocking histamines - treated with Zantac
- Block gastric receptors
What are the functions of HCL?
- Actuvates enzymes such as pepsin
- Breaks up connectoive tissue and plant walls liquifying into chyme
- Converts Ferrie ions +3 to ferrous ions +2 which can be absorbed and utilized for Hbg
- Destroys bacteria and pathogens
How is pepsinogen converted?
HCl cleaves pepsinogen into two particles which creates pepsin
What fluids are secreted in the small intestines? From where? Where to?
Pancrease into duodenum: HCO3, proteases, lipases amylases
Gallbladder to duodenum: Bile acids, pigments, phospholipids
Secretions from intestinal epithelia: brush border enzymes help digest carbs and proteins
What is zymogens?
inactivated proteins
What enzymes do are activated by brush border epithelium?
Trypsinogen to tripsin
When is CCK released? WHat does it cause? What happens if it is missing?
CCK = cholecystokinin
Released from duodenum when stomach acid and fat enter duodenum
Causes the contraction of the gallbladder, secretion of pancreatic enzymes and relaxation of hepatopancreatic sphincter
If lacking, bile not released, fats not emulsified = fatty stool (steatorrhea). Can be a temporary condition
What causes secretin to be released? WHere does this happen? What happens when secretin is released.
Released when chyme released in duodenum, Stimulates all ducts to release bicarbonate
What happens when an enzyme for digestion is missing?
Inaqequate digestion leads to inadequate absorption which leads to malabsorption syndrome
Where does most of the disgestion occur?
In the duodenum - where most of the catalyzing enzymes are put
When a patient is dehydrated, why are they given solutions of glucose + electrolytes(pedialite)?
In the small intesting, Glucose and Na+ are transported together from the blood to the intestine. If one is missing, the transport won’t occur.
If just electrolytes are given orally, gut can become hypertonic, drawing fluid from the blood stream, exacerbating the dehydration
What is the process of fat digestion?
Large fat globules are broken down by Lethcin and bile acids (decreased SA = easier digestion)
Broken into free fatty acids x2, mono glyceride
What’s the role of the illeocecal valve?
Regulates the entrance of chyme into large intestine
WHere does H2O absorption occur in GI tract?
Sm Intesting - absorbs 90% H2O
Lrg intestine - absorbs some
Histiological diffferences between small and large intestine?
- Small intestine
: microvilli & circular folds for increased absoprtion abilities
produce some digestive enzymes
2: Large intestine:
Simple columnar epithelium, intestinal crypts to produce mucous, haustra to compact feces
What are the function of the cells found in the large intestine?
- Peyes patches: clean up infections
- Goblet cells produce mucous to facilitate fecal movement
Haustra: compact feces by removing H2O
What are the functions of smooth muscle movements in the GI tracy (Gastric motility)
- Mixed chyme with intestinal, bile and pancreatic secretions
- Churns chyme to increase contact with mucosa for absoprtion
- Moves residue towards large intestine
What is the difference between segmentation and peristalsis?
Segmentation: Random ringlike constrictions which mixes and churns contents. Occurs ~12/min in duod
Peristalsis: Wave like contractions that pushes food down. Controlled by migrating motor complex