Chapter 17 (Lecture) [Blood] Flashcards
1
Q
Functions of Blood
A
- Transportation of dissolved gases, nutrients, hormones and metabolic wastes
- Regulation of pH and ion composition of interstitial fluids.
- Restriction of fluid losses at injury sites
- Defenses against toxins and pathogens
- Stabilization of body temperature
2
Q
Proteins in Blood Plasma
A
- Albumins
- Globulins
- Fibrinogens
- Other stuff
- Electrolytes & ions
- Organic nutrients (Lipids, Amino acids, etc.)
- Organic Wastes (Urea, uric acid, creatine, etc.)
3
Q
Why do Erythrocytes have a short life span?
A
Erythrocytes do not have a nucleus, meaning they can’t maintain the cell.
4
Q
What eats worn out blood cells?
A
- Macrophages monitor conditions of RBCs in bloodstream, and engulf any before they hemolyze (burst).
- Iron is extracted from heme, either stored in phagocyte or released to transferrin proteins.
- Heme unit is converted into Biliverdin (green) then into Bilirubin and released into the bloodstream.
- Bilirubin that was released by the macrophages binds to albumin & transported to the liver
- Bilirybin is then excreted by bile, & then ultimately out of the body through defecation.
- If bilirubin is NOT processed, it will diffuse into peripheral tissues & lead to jaundice.
5
Q
Hemoglobin
A
- Quaternary structure
- 2 alpha helices & 2 beta sheets per subunit (4 subunits)
- Each helix and sheet contains a molecule of heme.
- 95% of a RBC’s proteins
- Abbrievated Hb
6
Q
Heme
A
- Iron ion is held in such a way that it can interact with an oxygen molecule.
- The bond between O2 and Fe is weak and is easily reversible.
- When bound: oxyhemoglobin → bright red
- When released: deoxyhemoglobin → dark red
7
Q
Where is blood made?
A
Hematopoeiesis
Produced in the Red Bone Marrow
- Found in:
- Sternum
- Vertebrae
- Ribs
- Skull
- Scapulae
- Pelvis
- Proximal limb bones
8
Q
Oxygenated Blood
A
-
Found in:
- Pulmonary Vein
- Systemic Artery
-
Color
- Bright Red
9
Q
Deoxygenated Blood
A
-
Found in:
- Pulmonary Artery
- Systemic Vein
-
Color
- Dark Red
10
Q
Plasma
A
- Makes up between 46%-63% blood
- Similar to interstitial fluid, same for O2 & CO2 content & types of proteins within.
- Proteins of plasma are too large to leave bloodstream.
11
Q
Properties of Blood
A
- Temperature is slightly above normal body temperature. (~100)
- Thicker than water by about 500% (Due to proteins, formed elements, & water molecules in plasma)
- Slightly basic. Normal pH range is 7.35-7.45
- Average adult has 5 liters of blood (Can sustain loss of up to 40%)
12
Q
Albumins (In Plasma)
A
Majority of proteins, contribute to osmotic pressure of blood.
13
Q
Globulins (In Plasma)
A
- About 35% of plasma proteins, include antibodies & transport globulins (mostly ions, hormones, lipids, etc.)
- Play a role in immune system
14
Q
Fibrinogen (In Plasma)
A
About 4% can interact to form large strands of fibrin, the basic network for blood clots.
15
Q
Formed Elements of Blood
A
- Erythrocytes (99.9%)
- Leukocytes (<0.1%)
- Thrombocytes (<0.1%)
16
Q
Functional Characteristics of RBCs
A
-
Large surface-to-volume ratio
- Allows O2 to be bound & released quickly
-
RBCs can form stacks
- Allows for easier flow through capillaries, a single stack can pass through vessels a cell wide
-
Flexibility
- Allows them to squeeze into said capillaries
17
Q
How are RBCs produced?
A
- Prerythroblasts
- Erythroblasts
- After 4 days, Normoblasts
- Shed nucleus and become Reticulocyte
- After 2 days in bone marrow, reticulocytes enter bloodstream. After 24 hours in circulation, the reticulocytes complete their maturation & become indistinguishable from other mature RBCs.
18
Q
Properties of WBCs
A
- Spend most of their time in loose & dense connective tissues (Reticulate tissue)
- Bloodstream is used for primary transport
- All WBCs can squeeze through many cells, & can adhere to the lining of veins & arteries
- All WBCs are attracted to chemical stimuli
- Live about 3-5 days on average
19
Q
5 WBCs
A
- Neutrophils
- Lymphocytes
- Monocytes
- Eosinophils
- Basophils
20
Q
Neutrophils
A
- 50-70% of WBCs
- Phagocytic: engulfs pathogens or debris in injured or infected tissue
- Release cytotoxic enzymes
- Move into tissues after several hours
- 1st responders
21
Q
Eosinophils
A
- 2-4% of WBCs
- Phagocytic: engulf antibody-labeled materials
- Release cytotoxic enzymes
- Increase in allergic reactions & parasitic infections
- Move into tissues after several hours
22
Q
Basophils
A
- <1% of WBCs
- Enter damaged tissues
- Releases histamine & other chemicals that promote inflammation
- Assit mast cells in producing inflammation
- Most raise temperature in the body
23
Q
Monocytes
A
- 2-8% of WBCs
- Enter tissues & become macrophages
- Phagocytic: engulfs pathogens & debris
- Move into tissues in 1-2 days
24
Q
Lymphocytes
A
- 20-30% of WBCs
- Provide defense against specific pathogens or toxins
- Circulate from blood tissues & back
- 3 types
- NK Cels
- B Cells
- T Cells
25
Hemocytoblasts
* Main stem cell for all blood
* Lymphoid
* Myoloid
26
Lymphoid
Make Lymphocytes
27
Myoloid
Makes everything but lymphocytes
28
Where are WBCs produced?
Red Bone Marrow
29
Platelets
* Clump together & stick to damaged vessel walls
* Release chemicals that stimulate blood clotting
* Circulate for about 9-12 days before being consumed & replaced
30
Blood Clotting
* Technical term: Hemostasis
* Stopping blood loss through the walls of damaged vessels
* Establishes framework for tissue repairs
* Traditionally divided into 3 phases:
* Vascular
* Platelet
* Coagulation
* However, it is still a complex event in which many things happen at once & all of them interact in some way
31
Vascular Phase
* Lasts for 30 minutes
* The endothelial cells contract, exposing basal lamina
* Endothelial cells release chemical factors & local hormones
* Release endothelins which stimulate smooth muscle contraction & vascular spasms
* Endothelins also stimulate cell division to aid in tissue repair
* Endothelial tissue plasma membranes become sticky to provide partial seals & groundwork for platelets.
32
Platelet Phase
* Platelets attach to sticky endothelial surfaces, basal lamina, exposed collagen fibers & to each other
* ADP is released by platelets to stimulate platelet aggregation & secretion
* Chemicals that stimulate vascular spasms
* Platelet factors are released to assist in blood clotting
* Platelet derived growth factors (PDGF), a protein that promotes vessel repair
* Calcium ions assist in platelet aggregation & the clotting process
33
Coagulation Phase
* Starts 30 seconds after or more after vessel damage
* A complex series of events involving several clotting factors
* The activation of one factor triggers the activation of another (Chain reaction or cascade)
* Extrinsic & Intrinsic Pathways → Common Pathway
34
Iron Deficiency Anemia
* Lack of iron makes normal hemoglobin synthesis impossible
* RBCs will be smaller than normal
* Women need higher amount of iron in diet due to iron reserves being half that of typical men
35
Sickle Cell Anemia
* Due to a mutation in amino acid sequence, altering the shape of the beta chains in Hb
* Fragile & easily damaged RBCs
* More likely to clump in capillaries
* Resistance to malaria
36
Hemophilia
* Genetic blood disorder that affects 80-90% of males
* Caused by reduced production of a single clotting factor
* Severity depends on reduction
* In severe cases, minor contact can induce extensive bleeding, & it can occur in joints
37
Malaria
* Protozoan *Plasmodium*
* Transmitted primarily by mosquitoes (Blood born)
* Initially infects the liver, then RBCs
* Dead RBCs can block blood vessels resulting in tissue death
*
38
Extrinsic Pathway
Damage to vessel
39
Intrinsic Pathway
Platelets come together
40
Common Pathway
Release Factor X (Fibrinogen → Fibrin)
