Heme structure & function Flashcards
1
Q
functions of blood
A
- transport of:
- ->metabolic components, nutrients, hormones
- gas exchange
- immune defense
- coagulation
2
Q
WHOLE BLOOD b/d:
-whats in it
A
plasma 55%
- ->proteins–albumins, globulins, fibrinogen, prothrombin
- ->water (91%)
- ->other solutes–ions, nutrients, waste products, gases, regulatory processes
formed elements 45%
- ->platlets
- ->leukocytes–neutrophils, lymphocytes, monocytes, eosinophils, basophils
- ->erythrocytes= >99% of formed elements
3
Q
in a centrifuged sample of blood, what is the layer order
A
plasma on top
buffy coat
formed elements on bottom
4
Q
what is plasma mainly consisted of
A
water
5
Q
serum vs plasma
A
serum=plasma thats been allowed to clot in the lab in order to remove fibrinogen and other clotting factors that can interact with diagnostic testing
6
Q
what contains clotting factors
A
plasma
7
Q
most plasma proteins are produced by ?
-except for?
A
liver
EXCEPT for immunoglobulins aka antibodies-
8
Q
what produces antibodies
A
plasma cells in lymph nodes
9
Q
total blood volume in adult
A
5.5 L
10
Q
plasma contains two major groups of plasma proteins
A
- albumins
2. globulins
11
Q
list the cellular elements of blood
A
RBCS (erythryocytes)
WBCS (leukocytes)
Platelets (thrombocytes)
12
Q
role of erythrocytes
A
tissue oxygenation
13
Q
what is the most abundant cells in blood
A
erythrocytes
14
Q
erythrocyte structure, life span, what removes old rbcs?
A
inside=hemoglobin
- mature rbc lacks nucleus and cytoplasmic organelles
- limited life span=100-120 days
- spleen removes RBCs from circulation
15
Q
role of hemoglobin
A
carries the gases, electrolytes that regulate diffusion thru cell plasma membrane
16
Q
role of leukocytes
-categories?
A
- defend the body against infection
- remove dead or injured host cells
- granulocytes–neutrophils, basophils and eosinophils—all PHAGOCYTES
- agranulocytes
- ->monocytes, macrophages–PHAGOCYTES
- ->lymphocytes—IMMUNOCYTES
17
Q
role of thrombocytes
A
blood coagulation
control bleeding
**technically not true cells—they are irregularly shaped cytoplasmic fragements
18
Q
basic roles of the lymphoid organs
A
provide sites of:
-residence, proliferation, differentiation or function of lymphocytes and mononuclear phagocytes
19
Q
largest lymphoid organ
A
spleen
20
Q
role of spleen (3)
A
- functions as site of fetal hematopoiesis
- filters and cleanses the blood
- acts as a resevoir for lymphoctes and other blood cells
21
Q
list the primary lymphoid organs
A
thymus
bone marrow
22
Q
secondary lymphoid organs
A
spleen
lymph nodes
tonsils
Peyer patches in ileum of small intest
23
Q
lymph nodes role
A
-site of development or activity of large number of lymphoctes, monocytes and macrophages
24
Q
red marrow consists of?
-also called
A
red aka active or hematopoietic marrow
-also called myeloid tissue
25
yellow marrow consits of
inactive marrow
26
where are stem cells found
bone marrow
27
two most common stem cell populations
1. hematopoietic stem cells
| 2. mesenchmal stem cells
28
Hematopoietic stem cells
- what are they
- what do they develop into?
progenitors of all hematologic cells
| -develop into: blood cells (RBC + WBC + Plats) and osteoclasts
29
mesenchymal stem cells are?
- role?
- what can they differentiate into?
stromal cells and have a role in maintaining hematopoietic stem cells
-can differentiate into: osteoblasts, adipocytes, chondrocytes
30
what do osteoblasts and osteoclasts produce?
cytokines
31
what do cytokines do
proliferate and maintain hematopoietic cells
32
Myelopoiesis
| -define
is the development of GRANULOCYTES (BEN) and monocytes from the differentiate of myeloid progenitor cells in bone marrow
33
what are the granuloctes and monocytes generated from
Myeloid progenitor cells
34
lymphocytes are generated from
| -what is this process called
lymphoid progenitor cells-->lymphopoiesis
35
what are platelets derived from and what is the process called
megakaryocytes
| process is called thrombopoiesis
36
what controls thrombopoiesis
thrombopoietin
37
what do megakaryocytes under during thrombopoiesis
mitosis--- but NOT cell division
| -cytoplasm and plasm membrane fragment into the platelets
38
lymphoid progenitor cells differentiate into?
1. B cells
2. T cells
3. NK cells
39
megakaryocytes differentiate into?
thrombocytes
40
reticulocytes differentiate into?
erythryocytes
41
myeloblasts differentiate into?
basophils eosinophils neutrophils (granuloytes)
| monocytes----which then differenatie into dendritic cells and macrophages
42
colony stimulating factors
- specific hematopoietic growth factors
| - needed for prod of myeloid, erythroid, lymphoid and megakaryocytic lineages
43
where does hematopoiesis occur
- fetus
- after birth
liver
spleen
of the fetus
bone marrow after birth
44
regulation of erythropoiesis mediated by
erythropoietin
45
where is erythropoietin secreted and in resp to what
kidneys and in response to tissue hypoxia
46
erythropoietin (EPO) causes?
compensatory increase in erythryocyte production if oxygen content of blood decreases (anemia, high altitude, pulm dz, etc)
47
erythropoesis define
development of RBC
48
erythropoiesis depends on?
vitamin B12 *******
folate ********
B6
riboflavin
niacin
49
iron binds to ____ in the blood
transferrin
50
iron is transported to ____ after binding to transferring
macrophages
51
where is iron stored and as what
stored in cytoplasm as ferritin
52
describe the steps of iron cycle
* ***reutilizes iron released from old or damaged erythrocytes***
1. iron binds to transferrin in blod
2. transported to macrophages
3. stored in cytoplasm as ferritin
53
iron homeostasis is controlled by
hepcidin
54
what is hepcidin and its role
| -where is it produced
small hormone---regulates ferroportin--principal transport for iron from stores in hepatocytes + macrophages (in spleen + intestines)
its prod by hepatocytes
55
ferroportin role
transmembrane protein--- transports the stored iron from hepatocytes, macrophages in spleen/intestines
56
hemostasis define
arrest of bleeding
57
two pathways involved w/ hemostasis
PRIMARY HEMOSTASIS
1. vasoconstriction
2. formation of platelet plug
SECONDARY HEMOSTASIS
3. activation of the clotting/coag cascade
4. formation of a fibrin bloood clot
58
basic steps/process for hemostasis
1. injury/rupture of BV
2. BV around wound constricts----this reduces blood flow to the damaged area
3. activated platelets stick to injury site
4. plats become sticky and clump together to form platelet plug
5. plats and damaged tissue release clotting factors
6. blood clotting mechanism to form Fibrin-----acts like a mesh to stop bleeding
59
what factors involved with intrinsic pathway
| -blood test?
```
XII
XI
X
IX
VIII
TEST=aPTT---activated partial thromboplastin time
```
60
factors involved for extrinsic pathway
| -blood test?
VII
X
TEST=prothrombin time PT
61
common pathway steps
Prothrombin II + thrombin-->fibrinogen I-->fibrin clot
62
Fibrinolysis define
| ex
enzymatic b/d of the fibrin in blood clots
-process tht prevents blood clots from growing and become problematic
**clot retraction + clot dissolution
EX: TPA
63
what enzyme is responsible for fibrinolysis
plasmin---splits fibrin and fibrinogen into fibring degradation products that dissolve the clots
64
life span of RBC
120 days
65
structure of RBC
| -what can affect their strucutre
- disc shape, uniform in size and shape
- inside=hemoglobin
* **B12 deficiency, folate deficiency and iron deficiency can affect their appereance
66
what is hemoglobin
protein that transport oxygen
67
infections stimulate _____ to produce a higher number of _____
bone marrow to produce neutrophils
68
what WBC is incr with allergies
eosinohpils
69
thrombocytopenia
low platelets
70
excessive bleeding and bruising
thrombocytopenia
71
thrombocytosis
too many platelets
72
what is evaluated in CBC lab test
all the cells that circulate in the blood:
- RBCs
- WBCs
- Plats
73
anemia
low RBC count
74
RBC count?
actual number of RBCs in blood sample
75
hemoglobin lab test
total amount of oxygen-carrying protein in the blood---generally reflects number of RBCs in blood
76
Hematocrit
measure percentage of total blood volume that consists of RBCs
77
RBC indicies?
provide information on the physical features of the RBCs
78
Mean Corpuscular Volume (MCV)
measurement of the avg size of RBCs
79
Mean corpuscular hemoglobin (MCH)
calculated measurement of the avg AMOUNT of hemoglobin inside your RBCs
80
mean corpuscular hemoglobin concentration (MCHC)
calculated measurement of the avg CONCENTRATION of hgb inside RBCs
81
Red Cell distribution width (RDW)
measurement of the variation in size of RBCs
82
Reticulocyte count
measurement of the absolute count or pervent of newly released young RBCs
83
WBC differential
can be added if WBC count is too low or high
| -differential IDs and counts number of the five types of WBCs present
84
Mean platelet volume
can be indicated in a CBC or not
| -measurement of avg size of plats
85
platelet distribution width (PDW)
can be included in a CBC or not
| -reflects how uniform plats are in size
86
immature granulocytes
- what is it
- what does it indicate
WBCs that havent fully developed b4 being releasd from bone marrow into cirulation
- only present in bone marrow (NOT in circulating blood)
* can indicate an infection or blood CA
87
Reticulocyte Hemoglobin
measures hgb present inside of reticulocytes
| -often reported as a Mean reticulocyte hemoglobin content or a reticulocyte hemoglobin equivalnt
88
blood smear
- done when
- wht does it do
as a follow up to abnormal results on an automated CBC
compares WBC size, shape and general apperance to normal WBCs
RBC morphology=evals size, shape and color----indicator of hgb content
