4/19 Lecture E1 Flashcards
What is the normal arterial blood pH?
7.35-7.45
What is the normal arterial blood PCO2?
40 mm Hg (37-43)
What is the normal arterial blood PO2?
95 mmHg
What monitors the composition of CSF and blood?
chemoreceptors
What is the most potent stimulus for breathing?
pH
What is the least potent stimulus for breathing?
O2
Where are the central chemoreceptors located?
the medulla
What % of the change in respiration induced by pH shift is produced by central chemoreceptors?
75%
___ does not cross the BBB well.
H+
What crosses the BBB, reacting with water in the CSF to produce carbonic acid?
CO2
What stimulates the chemoreceptors when CO2 crosses the BBB?
H+
What % of the change in respiration induced by pH shift is produced by peripheral chemoreceptors?
25%
What is acidosis?
blood pH lower than 7.35
What is alkalosis?
blood pH higher than 7.45
What is hypocapnia?
PCO2 less than 37 mm Hg
What is the most common cause of alkalosis?
hypocapnia (usually from increased RR)
What is hypercapnia?
PCO2 greater than 43 mm Hg
What is the most common cause of acidosis?
hypercapnia (usually from decreased RR)
What can be a corrective homeostatic response to metabolic acidosis?
hyperventilation: rids the body of CO2 faster than the body can produce it. Reduces H+ (acid!) by reducing carbonic acid
What can be a corrective homeostatic response to metabolic alkalosis?
Hypoventilation: allows CO2 to accumulate in body fluids faster than exhaled, raising the H+ concentration by raising the concentration of carbonic acid
what are some causes of metabolic acidosis?
uncontrolled diabetes; increased intake of alcohol; antifreeze, aspirin, or methanol poisoning; renal failure
What can cause metabolic alkalosis?
increased vomiting, increased use of antacids
What type of cancer accounts for more deaths than any other form of cancer?
Lung cancer
What is the most important cause of lung cancer?
smoking
What is the most common form of lung cancer?
squamous-cell carcinoma
How does lung cancer first start to form?
The transformation of bronchial ciliated pseudostratified columnar epithelium into stratified squamous. The dividing cells invade the bronchial wall, causing bleeding lesions. Keratin replaces functional respiratory tissue
Where does adenocarcinoma originate?
in mucous glands of lamina propia
What is the least common, but most dangerous form of lung cancer?
small-cell (oat cell) carcinoma
Where does small cell carcinoma originate?
In primary bronchi, invades mediastinum, metastasizes quickly to other organs.
Where does most small cell carcinoma originate? (90%)
mucus membranes of large bronchi
What is atelectasis?
collapse or closure of a lung
What is often the first sign of small cell carcinoma cancer?
coughing up blood
Where are the common sites that small cell carcinoma metastasizes to?
pericardium, heart, bones, liver, lymph nodes, brain.
What is the prognosis of small cell carcinoma after diagnosis?
only 7% of patients survive 5 years.
What are three characteristics that distinguish adaptive immunity from innate immunity?
1) systemic effect: effects the entire body
2) specificity: immunity is directed against a particular pathogen
3) memory: when re-exposed to the same pathogen, the body reacts so quickly that there is no noticeable illness
What are two types of adaptive immunity?
1) cellular
2) humoral