Lecture 13 - Blood Flashcards
1
Q
Functions of blood
A
- > transportation of 02, CO2, metabolic waste, nutrients and hormones
- > regulation of body temp (vasodilation of surface vessels dump heat)
- > protection from disease and infection (contains cells of immune defence system)
2
Q
Physical characteristics of blood
A
- > average blood volume is 5L in adults, maintains BP
- > thicker/more viscous than water and slightly adhesive
- > temp 37-38 degrees
- > pH = 7.4 (7.35-7.45)
- > makes up around 8% of total body weight
3
Q
What does the colour of blood depend on
A
*depends on oxygenation status*
- > oxygen-rich blood = bright red
- > oxygen-poor blood = dark red
• appears blue in superficial veins
4
Q
Components of blood
A
55% plasma
45% cells
- 99% of cells are RBC
- less than 1% are WBC and platelets
5
Q
Components of plasma
A
- > over 90% water
- > 7% of plasma is made up of proteins which are created in liver, confined to bloodstream
- > 3% other substances; waste electrolytes etc.
6
Q
What are the plasma proteins
A
- > albumins (58%)
- > globulins (37%)
- > fibrinogens (4%)
- > 1-2 % other substances
- electrolytes (Na, Cl ions)
- Nutrients and vitamines
- hormones and waste products
7
Q
What are albumins
A
- > smallest and most abundant plasma protein (makes up 58% of total plasma proteins)
- > helps maintain a constant blood volume and pressure
- > act as transport proteins (carry ions, hormones, some lipides)
8
Q
What are globulins
A
- > second largest group of plasma proteins (makes up 37%)
- > smaller alpha-globulins and larger beta-globulins transport some water-insoluble molecules, hormones, metals and ions
- > gamma-globulins are also called immunoglobulins (or antibodies) and play a part in body’s defenses
9
Q
What are fibrinogens
A
- > make up 4% of total plasma proteins
- > contributes to blood clot formation
- > following trauma, soluble fibrinogen is biochemically converted to insoluble fibrin strands
- > plasma with clotting proteins removed is called serum
10
Q
What are the formed elements of blood
A
- > erythrocytes
- > leukocytes
* granular leukocytes
* agranular leukocytes
- > platelets (special cell fragments)
11
Q
Normal reproduction rate and lifespan of RBC
A
- > 2 million RBC/second enter circulation from red bone marrow
- > Live roughly 120 days (no repairs, no organelles)
- > worn out cells are removed by microphages in spleen and liver
12
Q
PHYSICAL Characteristics of Erythrocytes
A
- > biconcave disk (increases surface area/volume ratio and this flexible shape allows transport through narrow passages)
- > no nucleus or organelles
13
Q
Hemoglobin (Hb)
A
- > oxygen carrying protein that gives blood its colour and makes up 1/3 of RBC weight
14
Q
STRUCTURAL characteristics of hemoglobin
A
- > globin protein consists of 4 polypeptide chains
- > one heme attached to each peptide chain
- > each heme contains an iron iron (centre) that can combine reversibily with one oxygen molecule
15
Q
Oxyhemoglobin vs Deoxyhemoglobin
A
Hb + oxygen = oxyhemoglobin
Hb - oxygen = Deoxyhemoglobin
16
Q
How does Hb transport 02 and C)2
A
- > each hemoglobin molecule can carry 4 oxygen molecules from lungs to tissue cells
- > hemoglobins transports 23% of total CO2 waste from tissue cells to lungs for release (combines with amino acids in globin portion of Hb; CO2 also travels dissolved in blood plasma)
17
Q
How are the iron molecules in erythrocytes disposed of?
A
- > transported to liver by transferrin
- > bound to ferritin and homosiderin (storage proteins) and stored primarily in liver and spleen
- > once needed, iron is transported to red bone marrow to create new erythrocytes
18
Q
How are the heme groups in erythrocytes disposed of?
A
- converted within microphages into green pigment, biliverdin
- evenutally converted yellowish pigment, bilirubin
- bilirubin is converted to urobilinogen in small intestins
- ( Option 1) urobilinogen is converted into sternocobilin (brown pigment expelled from body in feces, shit)
- (Option 2) urobilinogen is converted into urobilin (yellow pigment excreted by kidneys; piss)
19
Q
How do erythrocyte antigens relate to their blood type
A
*Presence/ absence of surface antigens determines ABO blood type*
Type A - > erythrocyte with surface antigen A
Type B - > erythrocytes with surface antigen B
Type AB - > erythrocyte with both antigens
Type O - > erythrocytes with neither antigen
20
Q
How do plasma antibodies determine blood type
A
Surface antigens accompanied by specific plasma antibodies:
Type A - > blood has anti-B antibodies in the plasma
Type B - > blood has anti-A antibodies in the plasma
Type AB - > blood has neither antibodies in the plasma
Type O - > blood has both antibodies in the plas
21
Q
What is the Rh blood factor and how does it relate to pregnancy
A
*surface antigen D, appears when Rh- person is exposed to Rh+ blood*
When present - > Rh+
When absent - > Rh-
- > if a woman is Rh- and husband is Rh+, baby is Rh+, mother will build up anti D antibodies which will attack embryo, causing a misscarriage
22
Q
General characteristics of leukocytes
A
- > help defend body againts pathogens
- > contains nucleus and organelles
- > do not contain hemoglobin
- > motile and flexible
23
Q
diapedesis
A
the movement of leukocytes through endolithial cells of blood vessels
- > WBC change their shape, worm their way into tissues to fight infection (can be neutrophils or monocytes)
24
Q
chemotaxis
A
atrraction of leukocytes to infection site
- > molecules/chemicals released from damaged cells (injury site) and attract WBC
25
Granular vs agranular clasification of WBC
based off the presence of cutoplasmic granules made visible by staining
Granulocytes - \> neutrophils, eosinophils or basophils
Agranulocytes - \> monocytes or lymphocytes
26
Neutrophils
- \> makes up 50-70% of leukocytes
- \> polymorphonuclear leukocytes (PMNs); type
- \> Nuclei: 2-5 lobes connected by thin strands
- \> function: enters tissue spaces to phagocytize pathogens
27
Eosinophils
- \> makes up 1-4% of WBC
- \> nucleus: 2 lobes
- \> large, uniform-sized granules
- \> granules contain enzymes that end allergic reactions (antigen-antibody complexes)
- \> active in fighting parasitic worm infection
28
Basophils
- \> make up less than 1% of leukocytes
- \> irregular, multi-lobed nuclei
- \> secretes histamine and heparin
29
Lymphocyte
- \> makes up 20-40%
- \> no granules, large nucleus + some cytoplasm
- \> resides in lymphatic tissues (thymus,lymph glands)
- \> T cells manage immune response
- \> B cells become plasma cells and secrete antibodies
- \> NK cells attack abnormal and infected cells
30
Monocytes
- \> Make up 2-8% of leukocytes
- \> nucleus is shaped like a C or kidney bean
- \> largest WBC in circulating blood
- \> transform into large phagocytic cells, macropahges
- \> phagocytize bacteria, viruses, debris
31
Histamine
anti inflammatory/ anti allergen
32
Heparin
Blood thinner, pervents blood clotting
33
Emigration & Phagocytosis in WBC
- \> WBC roll along endothelium, stick to it and sqeeze between cells:
* adhesion molecules (selectins) near ingury site help WBCs stick to endothelium
* molecules (intergrins) found on neutrophils assist in movement through wall
- \> Neutrophils & macrophages will phagocytize bacteria and debris
34
Platelet Anatomy
\*thrombocyte\*
- \> formed from large cells called megakaryocytes
- \> circulates for 8-10 days
35
Explain hemostasis
- \> process of blood clotting
- \> stops blood escape through injured vessel wall
- \> three overlapping phases: vasoconstiction, platelet plug formation, clot formation
36
Explain the steps of hemostasis
37
What is the sympathetic NS response to blood loss
If greater than 10% of blood lost:
- \> sympathetic response initiated.
- \> causes increased vasoconstriction, heart rate, force
of heart contraction.
- \> blood redistributed to heart and brain.
- \> effective in maintaining blood pressure until 40%
of blood lost
38
What are the different types of blood doping
1. self donation of erythrocytes
2. pharmaceutical EPO
39
Explain self donation of erythrocytes and how it inproves performance
- \> blood removed pror to competition
- \> increases EPO production by kidneys
- \> erthrocytes transfuced back prior to competition, you have increased hemoglobin
40
dangers of pharmaceutical EPO
- \> increased blood viscosity
- \> heart required to work harder
- \> may cause permanant cardiovascular damage
41
EPO
Erythropoietin - \> hormone that is produced naturally by the human body. EPO is released from the kidneys and acts on the bone marrow to stimulate red blood cell production. An increase in red blood cells improves the amount of oxygen that the blood can carry to the body's muscles.
42
Destruction of globin and erythrocyte membrane proteins
- \> both are broken down into free amino acids and used by the body for protein synthesis
