exam 4 review Flashcards
what should the ratio of hco3 be to co2?
20:1
acidosis vs alkalosis
if 20:1 ratio goes DOWN you have acidosis
if 20:1 ratio goes UP you have alkalosis
respiratory vs metabolic acidosis and alkalosis
respiratory involves co2 and respiratory dysfunction
metabolic involves metabolic disturbances and HCO3
possible causes of respiratory acidosis and ways our body compensates
causes
* HYPOventilation
* lung disease
* depression of respiratory center by drugs or disease
* nerve or muscle disorders that reduce respiratory muscle activity
* holding breath
compensations
* chemical buffers immediately taking up additional hydrogen ions
* KIDNEYS IMPORTANT FOR COMPENSATING
respiratory alkalosis possible causes and buffers
causes
* hyperventilation
* anxiety
* fever
* aspirin poisoning
* physiologic mechanisms at HIGH ALTITIUDE
compensations
* chemical buffer systems liberate hydrogen ions
* if situation continues kidneys compensate by conserving hydrogen ions and excreting more HCO3
metabolic acidosis causes and compensations
causes
* severe diarrhea
* diabetes mellitus
* strenous exercise
* uremic acidosis
compensations
* buffers take up extra hydrogen
* ventilation increased so extra hydrogen ion producing co2 is removed from system
* kidneys excrete more H+ and conserve more hco3
metabolic alkalosis causes and compensations
causes
* vomiting
* ingestion of alkaline drugs
compensations
* buffer systems immediately liberate H+
* ventilation is REDUCED
* if condition persists for several days, kidneys conserve H+ and excrete HCO3 in the urine
intracellular fluid
- holds fluid WITHIN CELLS
- 2/3 total body fluid
extracellular fluid
- same thing as interstitial fluid pretty much
- FLUID OUTSIDE CELLS
- remaining 1/3 total body fluid
- interstitial fluid, lymph, and transcellular fluid are all ECF’s
interstital fluid
fluid immediately surrounding cells
ECF
lymph
fluid returned from intersitial fluid to plasma
ECF
transcellular fluid
small, specialized cell volumes secreted
by specialized cells into a particular cavity
* CSF
* intraocular fluid
* synovial fluid
* pericardial, intrapleural, and peritoneal fluids
* digestive juices
intracellular vs extracelluar fluid volume
intracellular-55% total body water
extracellular- 45% total body water
type A vs type B intercalated cells
type A= H+ secreting, HCO3-
reabsorbing, K+ reabsorbing cells
type B= HCO3- & K+
secreting H+ reabsorbing cells.
osmolarity
- Measure of the concentration of individual
solute particles dissolved in a fluid. - Na+, Cl- in ECF
- K+, intracellular anions in ICF
hypertonicity
- Cells tend to shrink
- Causes
Insufficient water intake
Excessive water loss
Diabetes insipidus
Deficiency of ADH
Symptoms and effects - Shrinking of brain neurons
- Confusion, irritability, delirium, convulsions, coma
Circulatory disturbances - Reduction in plasma volume, lowering of blood pressure,
circulatory shock
Dry skin, sunken eyeballs, dry tongue
HYPOtonicity
- Cells tend to swell
- Causes
- Patients with renal failure who cannot excrete
a dilute urine become hypotonic when they
consume more water than solutes - Can occur in healthy people when water is
rapidly ingested and kidney’s do not respond
quickly enough - When excess water is retained in body due to
inappropriate secretion of vasopressin - Symptoms and effects
- Swelling of brain cells
- Confusion, irritability, lethargy, headache, dizziness,
vomiting, drowsiness, convulsions, coma, death - Weakness (due to swelling of muscle cells)
- Circulatory disturbances (hypertension and
edema) - Water intoxication: overhydrating,
hypotonicity, and cellular swelling
pH
- Designation used to express the concentration of H+
- pH 7 – neutral
- pH less than 7 → acidic
- pH greater than 7 → basic
- Every unit change in pH represents a 10 fold change in
[H+].
bases
Substance that can combine with free H+ and remove it
from solution.
acids
Group of H+ containing substances that dissociate in
solution to release free H+ and anions.
what does acid base balance refer to
Refers to precise regulation of free H+ concentration in body fluids
pH below 7.35 indicates what?
metabolic acidosis
pH above 7.45 indicates what?
metabolic alkalosis
carbonic acid
- great buffering system
- bicarbonate ion + hydrogen
4 chemical buffer systems in the body
- H2CO3, HCO3 buffer system= primary ECF buffer for noncarbonic acids
- protein buffer system= primary ICF buffer; also buffers ECF
- hemoglobin buffer system= primary buffer against carbonic acid changes
- phosphate buffer system= important urinary buffer; also buffers ICF
insensible vs sensible sweat loss
- Sensible loss – sensory
awareness - Sweating
- Feces
- Urine excretion
- Insensible loss – no sensory
awareness - Lungs
- Non-sweating skin
vasopressin
- Also known as Antidiuretic Hormone (ADH)
- Produced by hypothalamus
- Stored in posterior pituitary gland
- Released on command from hypothalamus
(NOT! Produced in hypo. Released from post. Pit.) - Also location of thirst center
blood flow and thermoregulation
Narrowing the blood vessels (vasoconstriction) means less heat will be lost this way thereby maintaining the core temperature of the body
osomolarity and thirst
homeostasis
-Osmolarity increase → vasopressin secretion
and thirst stimulated.
- Osmolarity decrease → vasopressin secretion decreased and thirst suppressed
left atrial receptors
vasopressin
- Monitor pressure of blood flowing through
(reflects ECF volume) - Upon detection of significant reduction in
arterial pressure, receptors stimulate
vasopressin secretion and thirst - Upon detection of elevated arterial pressure,
vasopressin and thirst are both inhibited
angiotenson II
vasopressin; water regulation
- In addition to stimulating aldosterone
secretion….. - Stimulates vasopressin secretion and thirst
when RAAS mechanism is activated to conserve
Na+
diabetes insipidus
Caused by an inability of the pituitary to
secrete ADH (type1) or an inability of the
collecting ducts to respond to ADH (TypeII)
all compounds we absorb will have to pass through….
lymphatic tissue (GALT)
lamina propria
digestive
- Houses Gut-Associated Lymphoid Tissue (GALT)
- Important in defense against disease-causing intestinal bacteria
how is food digested mechanically in the small intestine?
mixing
how does chemical digesting of food occur?
pancreatic enzymes
submucosa
digestive system
- Thick layer of connective tissue
- Provides digestive tract with
distensibility and elasticity - Contains larger blood and lymph
vessels - Contains nerve network known as
submucosal (Meissner’s) plexus.
what do brush border enzymes ingest?
secreted by small intestine
responsible for the degradation of di- and oligosaccharides into monosaccharides, and are thus crucial for the energy-intake of humans and other mammals. AKA STARCH BREAKDOWN
pancreatic enzymes and their functions
secreted by acinar cells
- pancreatic amylase=breaks down carbs
- pancreatic lipase=breaks down fat molecules
- proteolytic enzymes= protein digestion
two distinct areas of gastric mucosa that secrete gastric fluid
oxyntic mucosa and pyloric gland area (PGA)
chief cells
gastric exocrine secretory cell
- Secrete enzyme precursor, pepsinogen
- When activated by HCl, begin protein digestion VIA PEPSIN
- Pepsinogen stored in Zymogen granules
- Pepsin self activates pepsinogen as well, called “autocatalytic process”.
parietal (oxyntic) cells
gastric exocrine secretory cell
- Secrete HCl and intrinsic factor
- Activates pepsinogen, breaks down connective tissue, denatures
proteins, kills microorganisms, facilitates absorption of B12
mucous cells *goblet cells
gastric exocrine secretory cell
- Secrete mucin > forms mucous
- Protects mucosa against mechanical, pepsin, and acid injury
Also three types of Endocrine/Paracrine secretory
cells
stomach mucosa and the gastric glands
- Enterochromaffin Like (ECL) Cells: Secretes Histamine, stimulates Parietal Cells
- G-Cells: Secretes gastrin, stimulates parietal, chief, and ECL cells
- D-Cells – Secretes somatostatin, inhibits Parietal, G, and ECL cells.
primary contribution to digestion is through the delivery of…
bile salts