5 - Hemodynamics & Blood Flashcards
Blood pressure vs vessels
goodnotes
- pressure falls steadily with distance from L ventricle
- bottom of wave is diastolic pressure, top is systolic
Systolic & Diastolic pressure
(label on graph + BP measurement)
systolic: Ventricular contraction (peak of curve)
- first sound heard when measuring
diastolic: V. relaxation, start of aortic pressure jump
- once sound goes silent when measuring
BP is S/D average is 120/80mmHg
Pulse pressure
(label on graph + average value)
= diastolic P - systolic P
average is 40mmHg
Mean arterial blood pressure
(label on graph + definition)
average pressure during entire cardiac cycle
= diastolic P + 1/3 pulse P
= cardiac output x total peripheral resistance
= HR x SV x TPR
Pulse points
(name + location)
- common carotid (neck)
- brachial (upper arm)
- radial (lower arm)
- femoral (thigh)
- popliteal (knee)
- !dorsalis pedis (feetsies)
!may indicate poor bloodflow to lower extremities
Factors that increase BP
goodnotes flowchart
Increased cardiac output
- increased heart rate
- down parasympathetic
- UP sympathetic
- increased stroke volume
- UP sympathetic
- UP venous return
- UP BV, muscle pump, resp pump, venoconstriction
Increased systemic vascular resistance
- increased blood viscocity
- UP # of cells (polycythemia)
- increased total blood vessel length
- UP body size (eg: obesity)
- decreased vessel radius (vasoconstriction)
Vascular resistance
friction between blood and vessel walls
Increased by:
- small vessel radius
- higher blood viscocity
- longer vessel
arterioles control BP by changing diameter via precapillary sphincters
Regulating BP
Neural:
- baroreceptor reflexes
- chemoreceptor reflexes
Hormonal:
- epi & norepi (short term)
- RAA system, ADH, ANP (long term)
ReninAngiotensisAldosterone, AntiDiureticH., AtrialNatrureticPeptide
Receptor reflexes
- baro (pressure) & chemo (chemical) receptors
- CN IX & X
- medulla oblongata
- alter sympathetic and parasymp. output
Name for what happens when you stand up too fast and faint
orthostatic hypotension
Hormonal regulation
(mechanisms)
increased E & NE
- UP HR
- vasoconstrict in skin, GI…
- vasodilate cardiac & skeletal muscle
RAA (see goodnotes)
- angiotensin II: UP vasoconstriction
- aldosterone: UP blood volume
ADH
- UP blood volume & systemic vasocontriction
ANP
- DOWN blood volume & systemic vasodilation
Heart failure
Left Sided (input to LA hindered)
- leads to pulmonary edema
Right sided (input to RA hindered)
- leads to pitting edema (around feet and ankles)
Functions of blood
- Transportation (chemicals)
- Regulation (pH, temp., water content of cells)
- Protection (clotting, immune)
Components of blood
45% erythrocytes (RBC) hematocrit
< 1% leukocytes (WBC) & platelets buffy coat
55% plasma (liquid ext. cell. matrix)
- water, proteins, hormones, chemicals…
RBC & WBC are the formed elements of blood
types of blood tests
Complete blood cell count (CBC)
- count types of cells (% and #)
- shapes of cells
Methods to obtain blood sample
kill me
- venipuncture (eg. median cubital v.)
- finger or heel stick
- arterial stick (eg. brachial a.)
Erythrocytes
- about 7.5 µm
- biconcave disc
- greatest surface area to volume shape
- no nucleus (no DNA)
- anaerobic (no mitochondria)
- contain hemoglobin
Hemoglobin
- 4 polypeptide chains (2 alpha, 2 beta)
- each have 1 heme group w/ 1 Fe
- O2 saturation of blood: 97% in lungs, 75% in tissues
- reserves O2 for when needed
O2-Hb Dissociation curve
goodnotes
shifts up/left (less oxygen offload)
- triggered by decrease temp, CO2 or increased pH
shifts down/right (more oxygen offload)
- triggered by increase temp, CO2 or decreased pH
Erythropoesis
- pluripotent stem cell
- myeloid stem cell
- proerythroblast
- eject nucleus
- reticulocyte
- leave bone marrow & mature in 1-2 days
- erythrocyte
stimulated by erythropoetin (hormone)
Life of an RBC
the next pixar movie
~120 day lifespan
- red bone marrow (erythropoesis)
- circulation (damage, can’t repair)
- die
- breakdown (phagocytosis)
Factors affecting EBC production
increased by
- hypoxia (low O2 levels)
- !stenosis in artieries to kidneys
- erythropoetin released by kidneys
!causes kidney to ‘think’ hypoxia is occuring
Blood typing (ABO portion)
named by presence of antigens, changed by antibody presence
- type A (A antigens, anti-B antibodies)
- type B (B antigens, anti-A antibodies)
- type AB (neither antibody)
- type O (both antibodies)
can’t have X antigen and anti-X antibody in same bloodstream
Testing blood type
treat blood with anti-A or anti-B serum
- agglutination reaction indicates presence of respective antigen
(agg. with anti-A only –> type A blood)
