Blood Cells & Vessels Flashcards
(106 cards)
1
Q
Hematopoiesis
A
Formation of blood cellular components
2
Q
Components formed by hematopoiesis
A
All blood cells
Extracellular components
Blood vessels
Lymphoid tissues (CT)
3
Q
How much blood do most adults have at a given time?
A
About 6L of blood
Approx 7-8% of total body weight
4
Q
Blood
Functions
A
Transportation throughout the body (O2, waste, CO2) Delivery of hormones Maintain homeostasis Acts as a buffer Acts as a coagulant Participates in thermoregulation
5
Q
Blood
Components
A
Cells and their derivatives
Plasma: protein-rich fluid
6
Q
What are all blood cells derived from?
A
Hematopoietic stem cells
7
Q
How many blood cells are formed daily?
A
10^11 - 10^12
8
Q
Hematopoietic stem cells
A
Reside in bone marrow
Give rise to all mature blood types and tissues
Self-renewing
Give rise to myeloid stem cells and lymphoid stem cells
9
Q
Location of hematopoietic stem cells
A
Fetal, infants, toddlers: spleen and thymus
Adults: spleen, marrow cavity of long bones
10
Q
Adult Hematopoietic stem cells
A
In the red bone marrow (spleen remains active in maturing and differentiating lymphoid cells) Most hematopoietic stem cells in adults resides in: Pelvis Cranial bones Vertebrae Sternum Ribs
11
Q
Fetal, infants, toddlers hematopoietic stem cells
A
Located in spleen and thymus
A boarding school for T-cells
When long bones gain medullary cavity, function switches over to there
12
Q
Myeloid stem cells
A
Become myeloblasts
13
Q
Blood cell lineages
A
Three:
Erythroid cells
Lymphoid cells
Myelocytes (granulocytic lineage)
14
Q
Erythroid cells
A
Form RBC’s
15
Q
Lymphoid cells
A
Form lymphocytes = WBC’s
16
Q
Myelocytes
A
Form granulocytes = WBC’s
17
Q
Do dipole have marrow?
A
Yes
Red marrow
(spongy inside compact bone)
18
Q
Plasma
Composition
A
Fluid component of blood
90% water, 10% dissolved solutes
3 Main plasma proteins
19
Q
Lymph nodes
A
Filter substances that travel through the lymphatic fluid contain lymphocytes (WBC) to fight infections
20
Q
Main plasma proteins
A
Three groups:
Albumin
Alpha, beta, and gamma globulins
Fibrinogen
21
Q
Solutes
A
Composed of the following: Plasma proteins 7% Inorganic salts 0.9% Organic compounds 2.1% (amino acids, vitamins, hormones) Gases
22
Q
Albumin
A
Group of plasma proteins
Largest component
Primary role: maintain blood osmotic pressure
Made by liver
23
Q
Alpha, beta, and gamma globulins
A
Group of plasma proteins
Gamma: immunoglobulins (antibodies)
Released by plasma cells (lymphocytes)
Alpha and beta: transport proteins
Made by liver;
fat soluble vitamins
24
Q
Fibrinogen
A
Group of plasma proteins Clotting protein Made by liver Circulates in an inactive form (can be activated to form a clot for wound healing)
25
Lipids
Not soluble
Still may be transported
Bound to hydrophobic portions of transport proteins
26
Formed elements of blood
Blood cells
Include:
Erythrocytes
Leukocytes
Platelets
27
Erythrocytes
```
Red blood cells
Biconcave discs (7.5 um)
Thin centers appear lighter than edges
Small enough to be transported along
Anaerobic
Anucleate
Essentially no organelles
```
Bags of hemoglobin (gas transport)
Some peripheral proteins line inner sides of plasmalemma (maintain shape and flexibility)
28
Reticulocytes
Immature RBC's
Recently released by bone marrow
May show sparse stained granules
Normally comprise 1% of RBC's
When they mature, they lose their:
Mitochondria, ribosomes, nucleus, etc.
29
Lifespan of RBC's
Approx. 120 days
| Worn out cells removed by macrophages of spleen
30
Sickle cell disease
```
Example of RBC dysfunction
Inherited disorder
RBC's become flattened from the side
Inflexible and fragile
Leads to anemia
Shortened lifespan
```
31
Hematocrit
The volume of packed erythrocytes in a sample of blood
32
RBC Energy
Energy obtained from glucose
| Anaerobic generation of ATP
33
Leukocytes
WBC's
Specific and non-specific defense
Involved cellular and humoral defense
Move about in suspension of plasma
Can become motile and exit to the bloodstream
Two classifications: granulocytes and agranulocytes
34
Rh System
Looks for presence of absence of Rh factor (antigen)
In cell membrane of RBC's
Important in blood donation and pregnancies
35
Antigens
Two kinds, A and B
| On surface of RBC's
36
Antibodies
Are in plamsa
37
Granulocytes
```
Classification of leukocytes
Polymorphonuclear leukocytes
"many shapes of nucleus"
Have lobed nuclei
Usually pertains to neutrophils
```
Contain nuclei with two or more lobes and have specific granules that have specific functions
38
Agranulocytes
Classification of leukocytes
Mononuclear leukocytes
May have lysosomes
39
Types of granulocytes
Neutrophils
Eosinophils
Basophils
40
Types of agranuloctes
Lymphocytes
| Monocytes
41
What is the histological hallmark of acute inflammation?
Neutrophil presence
Lots of chemicals
Inflammation is a nasty process to clean up!
They collect in large numbers if something wrong.
Process could be minutes to days
42
Neutrophils
```
Type of granulocytes (leukocytes)
60-70%
12-15 um
Typically have 3-lobe nucleus
Lobes linked by chromatin threads
Numerous visible granules
Lifespan: 6 hours in bloodstream
```
43
Chromatin threads
Link the lobes of nucleus in neutrophils
44
What cells account for half of WBC's?
Neutrophils
45
Immature vs. old neutrophils
Have non-segmented, horse-shoe nuclei
| More than five lobes may occur in old neutrophils
46
Function of Neutrophils
Defense against microorganisms
(motility means they can exit blood stream into CT and act there)
Can phagocytize bacteria and fungi
Kill bacteria with a respiratory burst
"Bacteria specialists" - oxygen used to produce potent substances such as bleach and hydrogen peroxide
47
Eosinophils
Type of granulocytes (leukocytes)
2-4%
12-15 um
Poorly developed ER, Golgi complex, mitochondria
Contain large, elongate specific granules that contain enzymes (which attack parasites)
They DON'T know speicif antigens, just follow chemical patterns
```
Can be found in:
Underlying CT of skin
Bronchi
GI tract
Uterus
Vagina
```
Lifespan: 8-12 days
48
Function of Eosinophils
```
Regulate function of other leukocytes
Attack parasitic worms
Destroy antigen-antibody complexes
Inactivate some inflammatory mediators
(reactive leukotrienes and histamine)
```
49
Basophils
Type of granulocytes (leukocytes)
0.5%
12-15 um
Numerous granulocytes
Histologically and functionally similar to mast cells
Lifespan: several hours to days
50
Basophils
Contain granules with histamine and heparin
Can release granules in response to antigens
Mostly seen in bloodstream, but can migrate to CT
51
Mast cells
Contain granules with histamine and heparin
Can release granules in response to antigens
Only found in CT
Have more oval nuclei
52
Histamine
Vasodilator
53
Heparin
Anticoagulant
54
What has to occur before healing can happen?
Inflammation has to end!
55
Lymphocytes
```
Type of agranulocytes
Second most numerous leukocytes, 20-30%
5-18 um
Spherical nuclei
Vary widely in size
```
Three types:
Natural killer cells (NK cells)
T cells
B cells
56
Monocytes
Type of agranulocytes
Largest leukocyte in size
12-24 um
Lifespan: hours to days in blood
Live for months as macrophages in CT (important)
Turn over regularly in the blood
Differentiate into larger macrophages
Active in phagocytosis
Require not previous exposure (innate)
57
Natural killer cells
```
Type of lymphocyte
Large, granular
Protect body from tumors
Protect body from virally infected cells
Release cytotoxic granules
```
No previous exposure needed (innate)
Lifespan: hours to years
58
T cells
Type of lymphocyte
Major part of adaptive immune response
Produce antibodies
Shorter lifespan
Involved in direct encounters and collaboration
Differentiate into plasma cells or memory cells
Main player in recognizing something different and targeting it with antibodies
59
B cells
Type of lymphocyte
Major part of adaptive immune response
Longer lifespan
Differentiate into plasma cells or memory cells
Main player in recognizing something different and targeting it with antibodies
60
Memory cells
Store info about antigens (like vaccines)
| Formed by T and B cells
61
Macrophages
Great collaborative of immune systems
Phagocytosis
"Collectors"
Doesn't need exposure (innate)
62
Platelets
```
Thrombocytes
2-4 um
Annucleate
Disc shaped cell fragments
Actually fragments of megakaryocytes
```
Clump together in stains
Lifespan: 5-10 days
63
Megakaryocytes
Huge myeloid cells
64
Function of platelets
```
Active blood clotting
Granules contain serotonin (vasoconstrictor)
Adenosine diphosphate (attracts more platelets)
```
65
Red bone marrow
| Components
```
Contains:
Stroma
Matrix is collage I & II
Glycoproteins (fibronectin, hemonectin)
Proteoglycans
Hematopoietic stem cells
Sinusoids
```
66
Stroma
Delicate network of reticular fibers
Contains stem cells and macrophages
Inside red marrow
67
Sinusoids
In red marrow
Thin endothelia
Mature cells may migrate in at thinnest regions
68
Functions of red marrow
Produces blood cells
Breaks down old RBC's
Storage or iron (from hemoglobin)
69
Yellow bone marrow
Appears yellow as child, due to increased storage of adipose cells
May covert to red marrow (hypoxia and bleeding)
70
Blood vessels
| Development
Develop from blood islands
Central cells form erythrocytes
Peripheral cells flatten and form endothelial lining
71
Blood islands
Visible patches of condensed mesenchyme
Central cells in them differentiate into erythrocytes
Peripheral cells flatten and form endothelial lining
72
Heart
| Development
Some similarities to blood vessel development
Forms from cariogenic cords that canalize to form a lumen
Once canalized, there are heart tubes
73
Layers of blood vessels
Tunica intima
Tunica media
Tunica adventitia
74
Tunica intima
Layer of blood vessels
Endothelium
Simple Squamos Epithelium
In larger vessels, a subendotheliual layer of loose CT connects intima to media
An elastic membrane (internal elastic lamina) may be present
75
Tunica media
Layer of blood vessels
Mostly circular arrangement of smooth muscle
Elastic fibers in lamellar sheets
Reticular fibers, proteoglycans are present in variable amounts
Vasomotor nerves
Baroreceptors
76
Tunica adventitia
Layer of blood vessels
Collagen type I and elastic fibers
In larger vessels, vasa vasorum is present here.
Lymphatic capillaries penetrate this layer
Can have external elastic lamina
77
Lymphatic capillaries
Penetrate the tunica adventitia only in arteries
| Greater pressure in arteries could compress lymph vessels
78
Internal elastic lamina
An elastic membrane that may be present in some arteries
Muscular and elastic
This "smooths out blood pressure level"
79
Vasomotor nerves
Inside tunica media layer of blood vessels
| Sympathetic
80
Baroreceptors
Inside tunica media layer of blood vessels
Sense pressure
In the aortic arch and carotid sinus
81
Vasa vasorum
Can be located in tunica adventitia
Tiny vessels that nourish the outermost parts (adventitia, media) of vessels (veins, where oxygen and nutrition levels are low)
82
External elastic lamina
Can be present in tunica adventitia in some larger arteries (muscular)
May separate media and adventitia
Is thinner than internal elastic lamina
83
Elastic arteries
Aorta and major branches
Largest amount of elastin
In all three layers, but mostly tunica media
Kept under continuous pressure*
Relatively thin tunica adventitia in large arteries
84
Muscular arteries
```
Extension of the elastic arteries
Proportionally the thickest tunica media
More smooth muscle than elastin
It's less elastic
Mor vasoconstrictive
Has intermediate elastic laminae
```
85
Arterioles
| General and Function
Very small!
Leads to the front end of capillary bed
Mostly smooth muscle in tunica media
Small ones barely have tunica adventitia
Function:
Vasoconstriction (dictate where blood is)
86
Capillaries
| General
```
A little larger than arterioles
Just enough for erythrocytes
One has tunica intima
Usually very porous (fenestrated), some are not.
One cell thick
```
Function:
Site of oxygen exchange and other nutrients from the bloodstream to other tissues
87
Venules
```
Initially only tunica intima
Very porous
Larger
Fairly simple
Have thin media and adventitia
```
88
Veins
Larger than arteries in diameter, but thinner walls
(because not as much pressure)
Thin walls
All three layers present, kind of merge together
Large lumens
Have valves
89
Blood brain barrier
Example of a capillaries due to tight junctions
90
Sinusoidal capillaries
Extremely thin and leaky (liver, marrow)
91
Menschymal cells
Have long cytoplasmic proteins around capillaries and venules
Have actin, myosin, tropomyosin which suggest mobility
They proliferate following tissue injury to differentiate into new blood vessel endothelial cells
Important to granulation tissue!
92
Atherosclerosis
```
Most common form of arteriosclerosis
Primarily affects the elastic arteries
(aorta, carotid, iliac) &
Large muscular arteries
(coronary, popliteal)
Accounts for more deaths/serious illness in Western world than ANYTHING else.
```
93
Arteriosclerosis
The thickening and hardening of the walls of the arteries
Typically occurs in old age
Different types
94
Atheromas
A necrotic core of lipid, debris, and T-cells
Basic lesions involved
Lipid cores of a surrounding fibrous cap
In small vessels, these are occlusive
95
Lesions
Lipid cores of a surrounding fibrous cap
Initial lesions are fatty streaks (flat or minimally elevated) and contain accumulation of lipid in tunica intima
Macrophages with large amount of stored lipid (foam cells) accumulate here
96
Aneurysm
In large vessels
Atheromas weaken the walls & can cause
(aneurysms, ruptures, or predispose to thrombosis)
Can also occur due to genetic syndromes (Marfans) or vasculitis
Infections can occur in rarer causes
97
Marfan syndrome
Can cause aneurysms
Inherited disorder affects CT
Affects heart, eyes, blood vessels, and bones
98
Diabetes-related vascular disease
Hyalinization
Tissue degenerates into a translucent, glass-like substance
99
How does continuous pressure in elastic arteries work?
They always have continuous pressure.
| Elastic recoil propels blood after ventricular contraction.
100
Fenestrated capillaries
Very porous
| Inflammation can cause fenestrations to enlarge
101
Non-fenestrated capillaries
Don't have pores
Specialized for transport of macromolecules to and from tissues (via pinocytotic vesicles)
These continuous capillaries have tight junctions
Small intercellular clefts present
Ex: muscle tissue, exocrine glands, nervous tissue
102
Pericytes
Long cytoplasmic proteins
| Multi-functional cells that wrap around capillaries and venules
103
Valves
```
Also called "venous valves"
Inside veins (mostly of limbs)
Folds of tunica intima
Prevent back flow/overcome gravity in low BP conditions
Muscular activities encourage flow
```
104
Incompetent Valves
Located in inferior vena cava and coronary sinus
105
Fibrous cap
A layer of CT that is thicker and less cellular than usual subendotheilial CT
Contains lipid-satiated macrophages and smooth muscle cells
106
Vasculitis
Inflammation of the blood vessels that causes changes in the vessels walls
Can cause walls to thick and narrow which cuts off vital blood supply
