Quiz 6 Flashcards
What are some functions of fibroblasts?
-secretion of molecules for ECM
-secretion of cytokines
What are cytokines?
signaling molecules that coordinate the activity of immune cells, to include differentiation and division
What kind of tissue is blood?
connective tissue
What is blood made of, liquid or solid matrix?
liquid
What is differentiation?
a change in the gene transcription pattern of a cell
What kind of changes (3) does differentiation often result in?
changes in:
-appearance
-capacities
-behavior
Other than rare exceptions, does every human cell possess every human gene?
yes, just genes are not always expressed
What is erythropoiesis?
the production of RBC
How doe genes contribute to erythropoiesis?
erythrocytes come from stem cells:
-> stem cell divides -> 1 daughter cell (stem cell) & 1 daughter cell (differentiated)
HSCP -> HSC -> MCP-> erythrocytes!
What is the biological source of erythrocytes?
lots of cell division: daughter cells keep differentiating & dividing until ultimately becoming polychromatic erythroblasts -> then just differentiation -> terminally differentiated cell until orthochromatic erythroblast
What are some properties of erythrocytes?
-have no nucleus (more room for hemoglobin)
-translation can still occur due to RNA still present in cell
- ~270 mil tetromers per blood cell
What is hypoxia?
(memorize verbatim)
condition in which cells do not receive sufficient O2 to function normally or to survive
At which altitude would the effects of hypoxia begin to occur?
around 2,500 m
-lowest pO2 human can function is 109 mmHg
-pO2 of air in alveoli around 3,000m is 102.5 mmHg
What major cells/tissues/organs (4) that contribute to our response to hypoxia?
-lungs
-erythrocytes
-kidneys
-bones
What is the lungs’ response to hypoxia?
O2 diffuses from atmosphere into bloodstream
What is erythrocytes’ response to hypoxia?
majority of O2 cargo is carried by intracellular hemoglobin
What is the kidneys’ response to hypoxia?
fibroblasts can detect O2 concentration
(remember loop of henle?)
What are our bones’ response to hypoxia?
erythroblasts proliferate, generating more erythrocytes
How is erythrocyte production controlled?
-process begins in the kidneys: fibroblasts
-process ends in bone marrow: erythrocytes
How do our bodies generate erythrocytes?
erythropoietin
-cells in kidney can be brought to cells in bone marrow
What should we know about the structure of the kidney?
-outer layer = cortex
-nephron = filter out blood
Is the [O2] uniform throughout the kidney?
they are normoxic condition numbers
What are agents of [O2] detection in kidney?
kidney fibroblasts
What do the kidney fibroblasts do when detecting [O2] in kidneys?
-fibroblasts in normoxic conditions are around the medulla
-fibroblasts move to higher [O2] and make more erythropoietin at hypoxia
