circulatory system #3 Flashcards
what is stroke volume?
the amount of blood forced out of the heart with each beat (mL/beat)
what is the average stroke volume?
70mL/beat
what does a larger stroke volume mean?
a stronger heart
what is cardiac output?
the amount of blood pumped by the heart per minute
how do you calculate cardiac output?
heart rate x stroke volume = cardiac output
what is the average cardiac output?
4900mL/min
what does your cardiac output depend on?
- the strength of your heart
- your size
- your age
how does size affect cardiac output?
the smaller you are, the less blood you have, less blood pumped per minute
how does age affect cardiac output?
as you get older, heart rate decreases, therefore cardiac output decreases
how can you change cardiac output?
- exercise - temporary change in HR
- age - due to decrease in HR
what factors affect blood pressure?
- eating
- caffeine
- nicotine
- high altitudes
- stress
- atherosclerosis (plaque on artery walls)
- exercise
what is myocardial infarction?
interruption of blood supply to the heart (clot in an artery)
what is an aneurysm?
abnormal ballooning of an artery
what is a stroke?
loss of blood flow to a part of the brain - brain can’t get enough oxygen
what are congenital heart defects?
defects in the structure of the heart or great vessel, present at birth
what are the two components of blood?
- plasma
- blood cells
how much of blood is made up of plasma?
55%
how much of blood is made up of blood cells?
45%
what are the characteristics of plasma?
- slightly basic
- yellow colour
- 90% water
- organic substances (proteins, carbs, etc)
- CO2 and O2
- hormones and minerals
what % of plasma is water?
90%
what are the 3 types of blood cells?
- erythrocytes (red blood cells)
- leukocytes (white blood cells)
- thrombocytes (platelets)
what are erythrocytes?
red blood cells
what % of blood volume do erythrocytes make up?
44%
where do erythrocytes originate?
bone marrow
what is the main function of erythrocytes?
to carry oxygen throughout the body - 20 secs to circulate
what are the characteristics of erythrocytes?
- lack cell nucleus (enucleated)
- bi-concave structure (increases surface area)
what is the life span of erythrocytes?
100-120 days
what molecule does red blood cell contain?
hemoglobin
what is hemoglobin?
a molecule with iron for carrying oxygen
how many hemoglobin per RBC?
280 million/RBC
what is erythropoiesis?
the process of producing RBCs
what is the process of producing RBCs called?
erythropoiesis
how many RBCs can bone marrow produce per second?
2.2 million/sec
what determines RBC production?
determined by the amount of O2 available
what happens when oxygen levels are low?
kidneys secrete erythropoietin (hormone) which stimulates the bone marrow to produce RBCs
what happens to our oxygen levels after we donate blood or are at a high altitude?
it lowers
what does the spleen do?
- stores extra RBCs for emergencies
- filters blood and destroys worn out RBCs
what % of blood volume do leukocytes make up?
they make up <1% of blood volume
what are leukocytes?
white blood cells
where do leukocytes originate?
the bone marrow and thymus gland
what is the ratio of WBCs to RBCs?
1:700
what are the two categories of leukocytes?
- granulocytes
2. agranulocytes
what are the three types of granulocytes?
- neutrophil
- eosinophil
- basophil
what are the types of agranulocytes?
- lymphocytes
- monocytes
what do lymphocytes and monocytes evolve into?
macrophages
what is the function of lymphocytes?
antibody production
what is the function of macrophages?
phagocytosis
what is the function of neutrophils?
phagocytosis
what do neutrophils look like?
they are multi lobed nucleus
what do lymphocytes look like?
large round nucleus
what do monocytes look like?
C-shaped nucleus
what are thrombocytes?
- platelets
- tiny cell fragments from the bone marrow
- they have no nucleus and they breakdown quickly
what is the main function of a thrombocyte?
blood clotting to prevent blood loss
what attracts platelets when an injury occurs?
collagen fibres attract platelets like a magnet when they are exposed to the bloodstream
what is the blood clotting procedure?
- when platelets arrive at an injury, they rupture and release a protein called thromboplastin
- thromboplastin combines with calcium and activates a protein called prothrombin
- thrombin reacts with fibrinogen to form fibrin
- fibrin then forms a mesh of fibres to clot and close a wound
is fibrin soluble?
no
what Is thermoregulation?
keeping the temperature of the body within a range that allows cells to function normally
what is body temp regulated by?
the brain
what is the average core temp of a human?
~37 degrees celcius
what controls heat loss?
the nervous system, blood vessels near the skin surface can dilate or constrict to control heat loss
how does vasodilation affect body temp?
increases heat loss
how does vasoconstriction affect body temp?
decreases heat loss (conserves heat)
what part of the brain is responsible for monitoring body temp?
the hypothalamus
what happens when your body temp is too high?
- blood vessels near skin surface dilate
- sweating begins to cool the body
what happens when your body temperature is too cold?
- vessels constrict to limit blood flow to extremities
- hairs on arm raise to trap warm air (goosebumps)
- shivering begins (quick contractions of skeletal muscles)
what are antigens?
- the markers that classify a person’s blood type
- they are a cell’s ID
- they are inherited
what are antibodies?
- Y-shaped proteins created by your body that bind to specific antigens
- they bind to foreign antigens to disable them
- specifically designed to target forge in invaders
where are antibodies found?
in the plasma
what are the two antigen systems?
- ABO system
2. Rh system
what are the two inherited antigens?
A and B
what do RBC antigens form?
naturally occurring complimentary antibodies
what is agglutination?
- aka. clumping
- occurs if blood types are not compatible - can be deadly
what are blood donations?
donating whole blood, but it is then separated into its parts (WBCs, RBCs, and plasma)
what are blood transfusions?
the transfer of only the blood cells, not the plasma, from one person to another
what is a universal donor?
blood type -O is the universal donor because it doesn’t contain any antigens
can antibodies be transfused?
no
what is a universal recipient?
blood type AB+ is the universal recipient because it’s plasma doesn’t contain any antibodies
what happens if the wrong blood type is transfused?
agglutination (clumping) will occur because the body will reject the antigens and form antibodies against them
what is the Rh system?
a system separate from the ABO system, it is another set of antigens found on most blood cells
what is hemolytic disease of newborns?
this is when a mother is Rh- and has one Rh+ baby, during birth she develops anti-Rh antibodies, so if she has another Rh+ baby, her antibodies will attack the baby’s red blood cells, possibly killing it
what is anemia?
reduced red blood cells
what is hemophilia?
insufficient clotting protein inherited
what is leukaemia?
cancer of the white blood cell
what is the lymphatic system?
a network of ducts and nodes containing lymph that runs parallel too to blood vessels
what is lymph?
pale yellow - colourless fluid
what are lymph nodes?
nodes located around the body that store lymphocytes (filter lymph)
what happens when lymph nodes are working extra hard?
they swell
what is the function of the lymphatic system?
- to collect lymph
- to maintain fluid balance through subclavian ducts
- fat transportation through intestinal villi
- to aid in immunity
how does the lymphatic system aid with immunity?
- WBC mature in lymph nodes
- lymph vessels also contain macrophages
what are the lymphatic organs?
- thymus gland, spleen, lymph nodes, bone marrow
- they all help to create leukocytes
which lines of defence in the immune system are specific/nonspecific?
- 1st and 2nd are non specific
- 3rd is specific
what is the first defence?
barriers
what are the barriers of the first defence?
- skin (keratinized and acidic)
- mucus (traps particles)
- cilia (catch particles)
- saliva + tears (contain enzymes)
- acidic stomach (destroys foreign substances)
what is the second defence?
inflammatory response (cell mediated immunity)
what happens during the second defence?
- macrophages and neutrophils (phagocytes) are activated
- damaged tissues release histamine
- histamine causes capillaries to swell and leak - releasing phagocytes
- phagocytes then “eat” any bacteria and dead debris in infected tissue
what is the third defence?
7-step immune response (antibody mediated immunity)
what are the two main types of lymphocytes?
T-lymphocytes and B-lymphocytes
where do B-cells mature?
in the Bone marrow
where do T-cells mature?
in the Thymus
what are the two types of B-cells?
Plasma B and Memory B
what are the four types of T-cells?
Helper T, Killer T, Suppressor T and Memory T
what are plasma B-cells?
- they make antibodies that match the foreign invaders
- binding of the antibody to the antigen results in disabling of the antigen
what are memory B-cells?
remember the invaders for next time so that antibodies are made sooner in response
what are helper T-cells?
recognize antigens and give off chemical signals that stimulate macrophages, B-cells and other T-cells
what are killer T-cells?
attaches itself to damaged cells, releases toxins to split the cell thereby killing the invader and itself
what are suppressor T-cells?
slow/turn off immune response to protect healthy tissues after invader is killed off
what are memory T-cells?
remain in the bloodstream after immune response is shut down, if antigen is encountered again it will start immune response quickly (like memory B)
what is the process of the 3rd defence?
1: monocytes identify foreign cells
2: monocyte changes into macrophage, adheres to organism and slowly eats it
3: macrophage places intruders antigens on its outer membrane - this alarms other cells
4: helper T-cells make copy of antigen, activate plasma B cells and killer T cells
5: plasma B cells divide rapidly and also make antibodies that correspond to antigen
6: antibodies attach to antigen (antigen-antibody complex), dump together, easier for the macrophages to find and destroy cells
7: when invasion is under control, suppressor T cells shut off the immune response
what is the antigen- antibody complex?
what is is called when antibodies attach to antigen
