Erthrocyte Physiology Flashcards Preview

MCM-COM 2018 > Erthrocyte Physiology > Flashcards

Flashcards in Erthrocyte Physiology Deck (38)
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1
Q

Functions of blood

A
  1. Deliver nutrients and O2
  2. Remove waste
  3. Maintain homeostasis
  4. Circulation
  5. Thermoregulation
  6. Immune response
2
Q

What is the hematocrit formula

A

Height of RBC’s/ total height

3
Q

Normal hematocrit range

A

40%-45% adult

55% for newborn

4
Q

RBC function

A
  1. Carry O2 to body
  2. Carry CO2 to lungs
  3. Acid/base buffering
5
Q

Globulins are not made in

A

The liver

6
Q

What is cyanosis

A

Blue color in lips and skin

-from decreased oxygen in hb

7
Q

Hematocrit is

A

% of blood that is cells

8
Q

Where does erythropoiesis occur

A

Bone marrow

9
Q

Will damage to the kidney cause anemia

A

Yes

*bodies use oxygen levels in kidneys to determine how many RBC’s we need

10
Q

What is the function of hypoxia inducible factor (HIF)

A

*regulates amount of oxygen in body by interaction with kidney

  • if O2 is adequate then it is ubqinuated and destroyed
  • if O2 is low then it accumulates and acts as an transcription factor to increase erythropoietin gene to make RBC and transferrin to get more iron
11
Q

Where is erythropoietin produced? Released to ? And brought for action?

A

Kidneys

Liver

Bone marrow

12
Q

What does erythropoietin do ?

A

*JAK2/STAT5 pathway

  • acts on stem cells (differentiate to proerthyroblasts)
  • increases maturation of RBC precursors
  • prevents apoptosis of erythroid stem cells

*MAKES RBC’s

13
Q

How may oxygens can bind to hemoglobin

A

4

14
Q

The _______ influences how well oxygen can bind to heme in hemoglobin. Mutations in this will change oxygen binding

A

Peptide chain

*there are 4 peptide chains of hb [ porphyrin ring ]

15
Q

In the stomach the acidic environment favors the ____ form of iron, and that form will move into the intestine in this form

A

Ferric (3+)

Therefore moves into the intestine in the ferric state
*but enter the enterocyte in ferrous state

16
Q

T/F

Heme iron is removed from the heme by enzymatic degradation

A

True

17
Q

Iron def = ___ anemia

B12/folate def = ____ anemia

A

Microcytic

Macrocytic

18
Q

What stimulates EPO production in the kidneys?

A
  1. Anemia
  2. Low renal blood flow
  3. Central hypoxia
19
Q

What is the oxygen carrying capacity of hemoglobin

A

1.34mL O2 / g of Hb

20
Q

Total amount of oxygen that can be carried in our blood by heme assuming every available heme has oxygen bound to it

A

Oxygen capacity

21
Q

What is the oxygen capacity equation

A
  1. 34 x ___ hb/dL blood =

* given value

22
Q

The amount of oxygen that is actually being carried in our blood

A

Oxygen content

23
Q

% of available here’s with oxygen bound

A

% saturation

*determined by oxygen availability

24
Q

What is the oxygen content equation?

A

Oxygen capacity x %saturation = oxygen content

*will get O2 capacity from previous equation where you multipled by 1.34 and you willl be given %saturation

25
Q

What does RBC use ATP for?

A
  1. Flexibility of membrane
  2. ATPase (ion transport)
  3. Maintain Fe3+ state (not Fe2+)
  4. Prevent oxidation of hemoglobin
26
Q

What happens to the RCB remnants when RBC under hemolysis ?

A

Phagocytosis:

  • in spleen
  • macrophages
  • Hb recycled (made to bilirubin and recycled)
27
Q

Decreased RBC or Hb causes

  1. Decreased O2 capacity/content
  2. Decreased O2 delivery
  3. Increased heart work load (too compensate)
A

Anemia

28
Q

Iron overload from inadequate hepcidin (genetic mutation) causes:
1. Cardiomyopathy

A

Hemochromatosis

*normal O2 capacity/content and hemoglobin

29
Q

does oxygen saturation decrease in hemochromatosis or anemia

A

No, it in unchanged

30
Q

When iron is low transferrin is _____

A

High

31
Q

Too many RBC’s is called

A

Polycythemia

32
Q

What are the effects of polycythemia

A
  • increased O2 capacity/content
  • THICK BLOOD (increased viscosity)
  • heart has to work harder
33
Q

What is secondary polycythemia ? (Physiological polycythemia)

A

[too many RBCs]

  • normal bone marrow
  • heart or lung problem
34
Q

What is primary polycythemia?

A

[too many RBC’s]
*abnormal bone marrow
(Making to much RBC)
*thrombopoietin mutation

35
Q

What is physiological polycythemia?

A

[too may RBC]

  • normal bone marrow
  • body is responding to low oxygen levels (maybe from altitude)
36
Q

T/F

Hemoglobin Oxygen saturation will not change even if the oxygen availability changes a lot

A

True

Seen by Hb-O2 curve of

37
Q

What does a left shift in the Hb-O2 curve mean? Right shift ? What are they caused by

A

LEFT

  • increased hemoglobin affinity for O2
  • low CO2
  • High Ph
  • decreased temp

RIGHT

  • decreased affinity for O2 (binds less)
  • high CO2
  • low Ph
  • high temp
  • increased 2,3 DPG (metabolites)
  • IMPORTANT FOR EXCERCISE SO HB CAN LET GO OF O2 AND IT CAN GO TO THE TISSUES WHERE ITS NEEDED
38
Q

What is caused by large amounts of met-hemoglobin in the body?
(Hemoglobin with Fe3+ not Fe2+)

A

Methemoglobinemia

  • left shift in the curve
  • blood is chocolate colored
  • cyanosis occurs

*hemoglobin does not want to let go of this oxygen because of the iron state