Lecture 23: Heart Vessels and Microstructure Flashcards Preview

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Flashcards in Lecture 23: Heart Vessels and Microstructure Deck (36):
1

What is hematopoiesis

The process by which hematopoietic stem cells (HSC) differentiate into blood cells

2

mobilization of hematopoietic stem cell

The process by which they can leave the bone marrow and enter the blood stream

3

Hematopoietic stem cells location

Found in bone marrow of mature adults,

4

How do we maintain hematopoietic stem cells (HSC) throughout life?

can undergo self renewal

5

How many RBC replaced every day

10x10^12

6

RBC life span

4 months, very short lived but they are the longest lived of all the blood cells.

7

yellow marrow vs. red marrow

red marrow contains HSC, yellow contains lipocytes

8

Three major types of blood cells and function

RBC --> Delivers oxygen to tissue
WBC --> Fights infection
platelets --> Clotting, maintaining hemostasis

9

Non-cellular component of blood, and its contents

Plasma:
Electrolytes --> maintain tonicity
Proteins --> albumin, globulin (antibodies), clotting factors
Lipids
Serum

10

What is an erythroblast?

It's an immature RBC found in the bone marrow, still nucleated. Nucleus is excluded from the cell before it's let out of the bone marrow into the blood. It can be polychromatophilic or orthochromatic (one step further in development, smaller nucleus, but in my opinion still looks purplish so idk why it's called chrom.)

11

Polychromasia

RBC that has just left bone marrow, are larger and more purple under H&E because still producing protein in RER which it has to for hemoglobin

12

What stain precipitates RNA, what is it's function

Methylene Blue, can tell polychromatic RBC apart from fully matured RBC bc RNA in RER precipitates out and looks like dark blue granules. Then called reticulocytes when imaged this way. Done for patients that could have anemia.

13

Size/shape of RBC, why are they this shape

The same size as WBC, but concave disk shown by white spot in the middle histologically. Helps increase surface area:volume ratio, which helps with gas exchange, and deformable which can help 7-8 micron diameter cells pass through 2 micron capillaries. Impaired deformability can be clinically relevant.

14

Components of normal RBC membrane

lipid bilayer, integral membrane proteins (chloride bicarbonate exchange), cytoskeleton proteins

15

erythrocyte qualities

Mature RBC.
Is anucleate and lacks organelles, which maximizes space for hemoglobin, but means that they have to use anaerobic respiration without mitochondria.

16

Hexose Monophosphate Shunt

Reduce oxidants, which are often the chemicals present in the blood, and could damage cells.
They also keep hemoglobin in a reduced state, for O2 binding.

17

Hemoglobin is made of?
What's its function?

Two alpha globin chains and two beta globin chains, four heme molecules with with iron in center of each. Binds O2 and CO2, transports them between tissue and lungs. Very soluble in water compared to other proteins

18

Types of RBC irregularities

Sickle Cell anemia, Microcytes, Spherocytes, Elliptocytes

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Thrombocytes

Another name for platelets

20

Megakaryocyte properties

Largest cell in the bone marrow, the cell doesn't divide but is hyper-diploid as nucleus continues dividing into lobes, with each lobe being 2n.

21

How to megakaryocytes make cells

Parts of cytoplasm break off and become platelets

22

Platelet clumping

Happens in-vitro, is artifact of putting blood in test-tube. Causes platelet counts to be artificially low.

23

Platelet cellular properties

They are anucleur but have all of their organelles. Are filled with electron dense granules that stain acidophilically.
Microtubules are a canalicular system leading to the cell membrane, needed to release all of the granules into the blood systematically.
There are some contractile proteins (actin and myosin) and membrane proteins GP Ib, IIb, IIIa

24

Function of platelets

First line of defense in homeosis with blood loss caused by vessel injury--> Adhesion, Activation, Aggregation
Platform for fibrin/clot formation
Mediates inflammation, vascular constriction through releasing serotonin, and fibroblast production.

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Thrombocytopenia

too few platelets

26

Another name for WBC

Leukocytes

27

Types of Leukocytes

Neutrophils (~60%, most prominent), eosinophil, basophil, monocyte, lymphocyte

28

Neutrophil properties

Also called polymorphonucleur leukocyte.
6 hr life span in blood, 1-5 days in tissue.
Multilobed nucleus, pink cytoplasmic granules.

29

Band neutrophil

One step less mature than neutrophil, has a horseshoe shaped nucleus. Can be seen in blood occasionally.

30

Function of neutrophils

Are able to mobilize to site of infection/inflammation, are attracted there by signaling proteins chemotaxins.
Phagocytosis/endocytosis, activated by antigen-IG complexes/coating.

31

neutrophilia

A high number of neutrophils in the blood

32

What causes neutrophilia

Endotoxin is released from the bacteria cell wall, and causes G-CSF and GM-CSF to be released from the marrow stromal cells which triggers neutrophilia

33

granulocytosis

Too many granulocytes, including neutrophils, can be caused by chronic myelogenous leukemia

34

Granulocytes

Neutrophil, Basophil, Eosinophil, NOT monocyte, NOT lymphocyte

35

Eosinophils qualities

Bilobed nucleus
Very pink granules in cytoplasm
Circulate for several hours then enter some skin/digestive/pulmonary mucus.

36

Function of eosinophil

Have receptors for IgE, and phagocytize antigen-antibody receptors. There are increased numbers in inflammation and allergic reactions.