blood Flashcards
Components of blood
-also , what kind of tissue is blood
–blood is CT
Plasma = extracellular matrix
Formed elements = living cells
- Erythrocytes
- Leukocytes
- Platelets
how does oxygen affect blood color?
low O2 = dark red
high O2 = scarlet
Blood in centrifuge
Plasma on top 55%
Buffy layer = WBC and platelets <1%
Hematocrit = RBCs 45%
- 47% for men; 42% for femals
3 Func of blood
distributing substances
-O2, waste to lings and kidneys, hormones
regulating blood levels
-temp, pH (bicarbonate ion buffers), fluid volume
protection
- no blood loss (clots)
- no infection: antibodies, complement proteins, WBCs
Components of blood plasma
- 90% water
- a ton of dissolved solutes
- most solutes are plasma proteins which are made by the liver and stay in the blood
- 60% albumin; 36% globulins; 4% fibrinogen
Albumin
- main contributor to osmotic pressure
- substance carrier and blood buffer
- made by liver
Where do most blood cells originate?
How long do they last in the blood?
Do they divide?
- bone marrow
- a few days
- nah
What is the formation of blood cells called and how is it regulated?
hemopoiesis or hematopoiesis
regulated by negative feedback for RBC and as needed for WBCs
First two steps of hematopoiesis
!. Pluripotent stem cell
2. Myeloid cell or Lymphoid ell
-what helps push hematopoiesis in one way or another?
-can cells go backward in the process
-where do new blood cells enter the blood stream?
What is the exception to the no dividing rule?
- hormones and growth factors
- no
- blood sinusoids
- lymphocytes
Erythrocyte structure
- biconcave disk
- basically just a Hb filled sack
- has plasma membrane protein Spectrin so that it’s flecible enough to fit through small capillaries
How do Erythrocyte’s structural features compliment their functional tasks?
- biconcave shape = greater surface area for gas exchange
- no mitochondria = anaerobic atp production = no use of the O2 they’re carrying
Hemoglobin components and structure
how much hb per rbc?
- Globin = 4 polypep chains : 2 alpha and 2 beta
- Heme = red pigment bonded to each globin chain
- Heme’s central iron atom binds one O2
250 mil
How do changes in gas content affect Hb?
- O2 loading in lungs = oxyhemoglobin (ruby red)
- O2 unloading in tissues = deoxyhemoglobin (dark red) (reduced)
- CO2 loading in tissues = carbaminohemoglobin = 20% of CO2 in blood binds to Hb
Process of RBC production
-pluripotent stem cell –> myeloid stem cell ——–> reticulocytes enter blood stream –> 2 days later they’re RBCs
reticulocytes don’t have nuclei
Balance of Erythropoiesis
- too few = hypoxia
- too mmany = blood viscosity
- balance depends on hormonal regulation and adequate supplies of iron, AAs and B vits