Lecture 9: Blood Flashcards
what does your body prioritize when it comes to maintaining warmth
brain and core
the hands and feet get cold because you body is sending blood to core organs; your body will sacrifice your extremities to save brain and core
what are the cellular elements known as, what are they?
formed elements
they include:
- RBC
- WBC
- Platelets (cell fragments; megakyrocyte)
what is the extra cellular matrix within a blood vessel, what is it mostly made up of? what does it do
plasma, water
perpetually suspends the formed elements and ebanables them to circulate throughout the body within the CV system
- evenly distributes and carries cells
what is the composition of blood
55% plasma
45% formed elements
what’s the primary function of blood?
to transport and deliver O2 + CO2 and nutrients to and remove waste from the body cells
- also provides defence/protection;
- regulation/maintenance of homeostasis
where are nutrients from absorbed? how are they transported/delivered
in digestive tract
most travel in bloodstream directly into liver, where they are processed back into the bloodstream for delivery to body cells
how is O2 transported (basically)
diffuses into the blood, which moves from lungs to heart, which then pumps it out to the result of the body
how are waste products removed
CO2 is brought to the lungs for exhalation
various waste products are transported to the kidneys for excretion in the form of urine, or bile from the liver
what is the function of WBC
to protect the body from external threats (like bacteria)
and to seek out and destroy internal threats (mutated DNA/infected cells)
role of platelets
when damage to vessels results in bleeding, blood platelets and certain proteins dissolved in the plasma, interact to block the ruptured areas of the blood vessel involved
how do platelets block ruptured areas? when do they cease?
they create clots which keep building until there is no further blood loss
which fb loop regulates body temp? how is homeostasis of blood maintained?
negative
- blood helps to maintain the chemical balance of the body
- proteins and other compounds in blood act as buffers, which thereby help to regulate the pH of body tissues
- blood also helps to regulate the water content of the body cells (albumins hold water in body by osmotic pressure)
explain the properties of blood
blood rich in O2 in lungs is bright red, and blood that has released O2 in the tissues is a more dusky red
- hb id a pigment that changes colour and varies with O2 saturation levels
sticker and thicker than water - viscosity
how does hb vary with O2 saturation levels
when more O2 is bonded, shape of molecule causing light to refract (results in a bright red colour)
what is viscosity
the measure of a fluid’s thickness or resistance to flow, and is influenced by the presence of the plasma proteins and formed elements within the blood
what is the normal blood hematocrit levels? what is the viscosity of water? what about normal blood? how about plasma?
40-45% is normal
20-65% is still acceptable
>75% blood is too thick to move around (need lots of energy)
- hard to reach this level cuz even if you’re dehydrated, you never get above 55%
water=1
normal blood=5x
plasma=2 (twice as viscose as water)
during exercise, what happens to hematocrit levels?
slight raise in hematocrit cuz of higher pressure, plasma is pushed out into the interstitial space (not that u made more RBC’s)
- decrease in plasma = increase in hematocrit levels
what is the normal blood temp
slightly higher than body - 38°c
how do blood vessels experience friction/resistance? what is this known as?
as blood flows through them, it produces some heat and other effects
shear stress
what is the normal pH range of blood? is it slightly basic/acidic? how does it regulate pH
average about 7.4, but ranges from 7.35-7.45
slightly basic (alkaline)
contains numerous buffers to aid in regulation of pH
blood constitutes about _% of adult body weight. what is the amount of blood in males and females? what happens when we don’t hav enough blood
8%
in males: 5-6 litres
in females: 4-5 litres
start to notice symptoms at around 400-500 ml
(requires blood donation)
1L-can’t even stand up
2-2.5L is fatal
what is the amount of hematocrit for differnt conditions of the body? what about after blood donation
normal - 45%
anemia - 35%
polycythemia - 70%
dehydration - 70%
hematocrit goes down after 24-48hrs
- plasma is replenished quickly (within 24-48hrs), but RBC’s take up to 90 days
what are the components of plasma
91% water, 7% proteins;
- albumin (largest part of plasma)
- globulins (soluble in blood)
- fibrinogen
what is serum?
plasma without the clotting factors
what is the most abundant plasma protein, where is it created? what are its roles/functions?
albumin (takes up 54% of plasma) is produced in the liver
functions as a binding protein for transporting lipid soluble hormones
most significant contributor to the osmotic pressure of blood
- pulls water into the bloodstream (or plasma) from tissues
- this in turn helps to maintain both blood volume and pressure
how do albumin and Na help maintain Colloid osmotic press. (COP)
Na is highly attracted to albumin, which can’t readily move though capillary pores,
it binds to albumin and pulls ware into blood (intravascular space)
what percent of plasma do globulins make up? what kind of group are they? where are they produced?
38%, heterogenous
alpha and beta globulins are produced in liver
- transport iron, lipids, and fat-soluble vitamins
- aid albumin in contributing to osmotic pressure
explain the role of fibrinogen
produced in the liver
is the least abundant and makes up 7% of the plasma proteins
an essential component of the blood clotting process
where are blood cells produced? what is their lifespan? compared to other cells? what type of cell is the exception, why?
formed in bone marrow, broken down in liver
RBC typically live for 120 days (no nucleus), while most wbc and platelets normally life a few hours to a few weeks
- lymphocytes (memory cells) can live for months to years, otherwise long lasting immunity would be hard
why do RBC’s lack a nucleus
RBCs lack a nucleus to maximize space for hemoglobin and oxygen transport. However, this means they can’t repair themselves or produce new proteins, making them vulnerable to metabolic stress like oxidative damage.
explain hemopoiesis. what does it mean literally
body must form new blood cells and platelets quickly and continuously
- haima– = “blood”
- —poiesis = “production”
what is Erythropoietin (EPO)? what does it promote?
glycoprotein hormone secreted by the interstitial fibroblast cells of the kidneys and liver and in response to low o2 levels
- prompts the production of erythrocytes in red bone marrow
what is blood doping
aka synthetic EPO as a performance enhancing drug to increase RBC counts and subsequently increasing O2 delivery to tissues thought the body
what did Lance admit to doing in The Interview. Could this have been detected easily?
- to using EPO
- used hGh (for healing tissue damage)
- no… that’s how he got away (not easy cuz RBC’s are smth everybody has
a single drop of blood contains millions of ___, and just thousands of ____
erythrocytes, leukocytes
what percent of the total cells in the body do RBC make up
~25%
explain the control of erythropoiesis
- kidneys detect low O2 in the blood
- secrete erythropoietin
- the hormone stimulates the production of erythrocytes in the bone marrow
- additional circulating erythrocytes increase O2 carrying capacity of the blood
- this relates the initial stimulus
explain the live high train low strategy
Many endurance athletes live at high altitudes (~2600m) but train at lower elevations (~1000m).
Why? Living high boosts RBC production, while training low allows for more intense workouts (since oxygen is more available).
explain the hypoxia tents
Athletes sleep in low-oxygen tents to mimic high-altitude conditions and stimulate EPO production.
This is a legal way to increase RBC count without traveling to high altitudes.
explain the hyperbaric chambers
These increase oxygen availability, sometimes used for injury recovery.
Their effectiveness for endurance training is questionable.
what is blood flow restriction training
Training with restricted blood flow simulates oxygen deprivation, potentially triggering EPO production and muscle adaptations.
what’s the primary function of RBC’s
to transport O2 from lungs to tissues
and return CO2 and waste from tissues to lungs for exhalation
t/f at sea level, there’s not enough O2 for the lungs to uptake
f it’s because all the hb is occupied, so if we inc hb we are able to get more o2, additionally lungs are able to bring in more o2
what doe each hb molecule contain? what does this allow hb to do
an iron ion which allows hb to bind four O2 molecules
what does it mean when hb can reversible bind to O2
O2 can attach to hb when needed (like in the lungs, where oxygen is abundant) and detach from hemoglobin when it needs to be delivered to tissues
what does the biconcave shape of the hb allow for
more SA for better O2 transport
how many hb molecules per RBC? what is the amount of hb in males and females
2000-300 million
4 heme groups + globin\
males - 13.5-17.5
females - 11.5-15.5 g/L
how are hb levels different between men and women
the difference is independent of iron status
- premenopausal women’s hb levels are 12% lower than age and race matched men
mean circulating erythropoietin levels do not differ between men and women, or between pre and post menopausal women
which hormones acts differently in males and females in the regulation of RBC
gonadotropin hormones up and down regulate RBC production differently
- test. increase the EPO in males
- est. decreases the EPO in females
the biconcave shape of a RBC leads to a __% increase in surface area
30%
the large surface area allows for what?
oxygen is close to the surface so its readily available to tissues
explain osmotic pressure sensitivity of RBC
hypotonic plasma (low solutes) - sphere
isotonic plasma - biconcave
hypertonic plasma (more solutes) - spikes
