Circulation and Respiration II Flashcards
Types of blood vessels:
-Arteries/ arterioles (smaller
carry blood away from the heart
-Veins/venules (smaller)
-Capillaries: are specialized for exchange(substances enter and exit the blood here)
High bp (Hypertension)
-affects ~1/3 of all American adults
-can cause MI, stroke, kidney failure, blood vessel rupture, and other hx problems
Risk factors of HTN:
sedentary lifestyle, being overweight, and (in some cases) a high- Na diet
Low bp (hypotension)
-blood in veins from the lower part of the body flows “uphill” against gravity to the R atrium
-this can impair blood flow to the brain and can cause dizziness or fainting
-Hypotension can also be caused by shock: severe circulatory failure that can result from loss of blood (hypovolemic shock), immune reactions (anaphylactic shock), bacterial infections (septic shock)
How is shock tx?
By giving O2, fluids, and norepinephrine to stimulate vasoconstriction
When is bp highest and when is it lowest?
When its in arteries in in it’s highest and lowest in veins
Systolic pressure:
bp during ventricular systole
Diastolic pressure:
bp during ventricular diastole
What is used to measure bp?
sphygmomanometry
What do Valves (in all veins) help prevent ?
Valves (in all veins) prevent blood from flowing backward
Skeletal muscles run parallel to help with what?
Skeletal muscles run parallel to major veins; contraction helps keep blood moving
What is the main factor in determining whether fluid will flow IN or OUT of a capillary?
Blood pressure is the main factor determining whether fluid will flow IN or OUT of a capillary
Blood pressure _________ as it flows through a capillary bed.
decreases
Osmotic pressure:
(always higher in blood and mainly dependent on blood protein content) also contributes
Edema is what?
accumulation of excess interstitial fluid in tissues (a.k.a. swelling)
What happens if the BP is too high?
If BP is too high, more fluid is pushed into the interstitial fluid
Inflammation:
Inflammation can cause increased interstitial osmotic pressure
What can cause decreased capillary osmotic pressure?
A low-protein diet (starvation) and by blocked lymphatic vessels
Describe the Lymphatic System:
-Lymphatic vessels absorb interstitial fluid and return it to the cardiovascular system
-The lymphatic system also plays a major role in our immunity!
Cardiovascular diseases:
affect the heart and blood vessels; usually caused by inappropriate blood clots
Risk Factors:
-Age
-Genetics
-Smoking
-Untreated hypertension
-Sedentary lifestyle
Hypercholesterolemia & hypertriglyceridemia:
-Elevated blood cholesterol and triglycerides
o Leads to atherosclerosis: accumulation of lipids
in artery walls
o HDL and LDL are transporter proteins for
cholesterol
o HDL-C is “healthy” cholesterol: high levels are
associated with a lower risk of heart attack
it removes cholesterol from the blood and stores
it in the liver
o LDL-C is “lethal” cholesterol; causes more
cholesterol to be in the blood
Aneurysm
is a weak spot in a blood vessel wall
Myocardial Infarction (MI) also known as a heart attack:
is usually caused by blood clots stuck in narrow arteries
-blocks blood flow to the heart, causing heart tissue to die (the amt that dies determine’s the pt’s ability to recover)
-
What can be followed with a MI
may be preceded by angina, or chest pain resulting from lack of oxygen flow to the heart; nitroglycerin (metabolized to nitric oxide, a vasodilator) is most often used to treat
Coronary Bypass Surgery
- Can make artificial coronary arteries (blood vessels going to the heart) to bypass clogged ones
- Use veins transplanted from the legs
Heart Failure is when
Failure to adequately perfuse the body with blood
Sx of Heart Failure:
-SOB
swelling of the ankles and feet (edema)
-coughing (due to fluid in lungs)
Heart Failure can be caused by what?
-MI
-Smoking
-HTN
-Congenital heart defects
Congenital heart defects
-Leading cause of childhood death
-Prevalence of around 1% of live births
-Septal defects are among the most common
Heart Transplant
-Donor hearts are in short supply
-Artificial heart was first tried in 1982
-Berlin heart is the latest version
-Someday, stem cells may allow us to repair heart tissue or grow artificial human hearts
What cells make all types of blood cells?
Stem cells in bone marrow
a hormone made by kidneys, increases erythrocyte production, and has been used to (illegally) enhance athletic performance:
Erythropoietin
4 components of respiration:
- Ventilation: exchange of air between lungs & atmosphere
- Exchange of O2 and CO2 between lungs & blood
- Transport of O2 and CO2 by blood
- Exchange of O2 and CO2 between blood & cells
______ results from changes in pressure in the chest cavity
Breathing
The diaphragm:
(and some other muscles) adjust the size of the chest cavity
-For gases, pressure and volume are inversely correlated
P1V1 = P2V2
-Increasing chest volume decreases pressure, causing air to enter the lungs
How is breathing controlled by the brain?
homeostatically
Equation for resiration:
CO2 + H2O -> H2CO3
Sensors in the carotid arteries (brain) and aorta (body) sense what?
Blood pH
What is the main stimulus for breathing?
decreased pH
_______ decreases the work of breathing
surfactant
why does surfactant decrease the work of breathing?
This is because surfactant fluid decreases surface tension on the inside of alveoli which could cause them to collapse.
Surfactant production by_______________normally begins around 25 weeks gestation and is complete by 34 weeks
type II alveolar cells
what is infant respiratory distress syndrome?
Infant respiratory distress syndrome: lack of surfactant leads to tendency of alveoli to collapse easily; often fatal
Gases flow from ___ to ___.
High to low
O2 binding to _______ is influenced by pH.
Hemoglobin
