Lecture 13 Composition and general function Flashcards
3 general functions of blood
Transport
Immune response
Coagulation
Blood Transport
O2, water, nutrients (cell metabolism)
CO2, waste products
Ions (Ca2+) to maintain pH and homeostasis
Heat (burn ATP through oxidative metabolism, makes energy, Raises core temp)
Hormones - coordinate the activities of organs of the body
Immune cells and coagulation factors
Immune
For fighting infection and production of the immune response.
Recognise threats, attack, engulf, digest to get them out
Via phagocytes, antibodies, and other WBCs
Coagulation
Prevent bleeding
Via platelets and coagulation factors in plasma
Clot to seal injury and won’t continue to lose blood and invite dangerous particles into body
Composition of blood
Plasma (solution the cells sit within)
Formed elements (cells in blood)
70 kg Person has
5.5 liters of blood
60 - 80 ml per kg body mass
Blood volume is typically in proportion to
lean body mass
Person heavier due to muscular tissue means
More blood in system
Person heavier due to adipose tissue means
Less blood in system
Plasma 55% composed of
Plasma proteins 7%
Other solutes 1%
Water 92%
Water 92% is a
Main component of plasma
Capable of dissolving proteins and ions
Hold a lot of heat (and release heat)
Formed elements composed of
RBC 99.9%
WBC (<0.1%)
Platelets (<0.1%)
RBC 99.9%
Most common cell in blood
Highly specialised for transporting oxygen
WBC (<0.1%)
Immune cells
Immune and response and defense mechanisms
Seek and destroy invading pathogens
Recognise threats engulf digest eliminate from system
Platelets (<0.1%)
Cell fragments that participate in clotting to stop bleeding
Hematopoiesis
formation of blood cells
Hemocytoblasts
what it is, where, how
progenitors for all blood cells
In red bone marrow
Become any type of blood cell
When Hemocytoblasts stimulated
Divide into different paths to make all the different types of blood cells
In the process of hematopoiesis always start with
hemocytoblasts
Erythropoietin is a process that stimulates
RBC
Erythropoietin
Substance that helps to move hemocytoblasts down the pathway to make RBC
RBC (erythrocytes)
shape, surface area, movement, nucleus, from what cells
Highly specialized
Biconcave Disc shape
large surface area:volume ratio (allows for efficient diffusion of gases O and CO2)
flexibility for movement through narrow capillaries
No nucleus, don’t need to divide,
From progenitor cells
RBC (erythrocytes) contain
Large amounts of haemoglobin
⅓ weight of RBC
4 heme units where each has iron (binds 4 oxygen)
Iron binds oxygen
PCV
packed cell volume
hematocrit
Centrifuge (spin quickly)
what it does, components order - bottom, middle, top
Blood separate into it main components by how much they weigh
RBC weighs most (at bottom)
WBC and platelets (small layer - middle. Buffy coat)
Plasma (at top)
Hematocrit
Percentage (fraction) of blood that is RBC by volume
Fraction of blood occupied by RBC
More hematocrit means
More RBC
More oxygen capacity to move oxygen around system
Do Men have higher Hematocrit than women?
why, stats
Yes
RBC triggered by testosterone
More testosterone more RBC
Men - 0.40 - 0.54
Women - 0.37 - 0.47
Hematocrit varies
Normal
Anemic
Polycythemic
Normal
35% - 55%
Anemic
hematocrit, oxygen capacity, iron
Low hematocrit, Can’t make RBC
Low oxygen capacity to move oxygen around system
Iron deficient (low iron)
Polycythemic
hematocrit, oxygen capacity, plasma, blood, pressure, blood movement, problems
High hematocrit (lots RBC)
High oxygen capacity
Less plasma
Blood thicker
Increase blood pressure
Have problems moving blood through capillaries, small vessels
Life threatening problems
Erythropoiesis
Generation of RBC
All blood cells derived from common progenitor cell
Erythropoietin
Stimulates production of RBC
Requires iron to make hemoglobin
Why do athletes train at high altitude?
(oxygen, what stimulate prosuction of EPO, EPO absorbed by, makes more, hematocrit, oxygen carrying capacity, performance)
Less oxygen
Kidneys stimulate the production of more EPO
EPO is absorbed by bone marrow and sends signal to make more RBC
Higher hematocrit
More RBC produced
Have higher oxygen carrying capacity
Perform better
Make more RBC
why and how
Increase oxygen carrying capacity
Perform better
Produce more erythropoietin (augmented by testosterone)
Where is EPO made?
in kidneys (sensors for amount of oxygen capacity that you have)
What happens if less oxygen is in system?
Kidneys sends signal by producing more erythropoietin to red bone marrow cells to generate more RBC
what happens if oxygen is high in system?
Kidneys reduce production of erythropoietin
Reduces RBC
Drug doping athletes
what, how, why
EPO and testosterone
Take small amounts of tesosterone to stimulate the production of more RBC
Take EPO which sends signal to red bone marrow to make more RBC and push hematocrit higher
Increase oxygen capacity
Increase performance
