Session 8 - Specialized Blood Groups Flashcards
What are the 5 classification of bones?
Long - Longer than they are wide (femur, phalanges, metatarsals and metacarpals etc.)
Short - About the as wide as they are long, squarish (tarsals and carpals)
Flat - Somewhat flattened (occipital, sternum, ribs)
Irregular - Complex shape (vertebrae, sacrum)
Sesamoid - small round bones found in tendons of hands, knees and feet (patella)
What are the 2 types of bone and what are their different names?
Cortical/ Compact - forms the external surfaces of bones and comprises of ~80% of the skeletal mass
Cancellous/Spongy/Trabecular - forms a network of fine bony columns or plated to combine strength with lightness (filled with bone marrow)
What is bone marrow and what does it do?
Red bone marrow - Heamopoeisis, rich blood supply
Yellow bone marrow - Poor blood supply, full of adipocytes, acts as a shock absorber and energy source, can convert to red marrow
Describe the structure of cancellous bone
Spongy structure made up of many interwoven trabeculae. Each trabecula consists of numerous osteocytes embedded within irregular lamellae of bone.
Osteoblasts and osteoclasts on their surface act to remodel them
Name 7 major corpuscles circulating in the blood and how they are grouped
1) RBC - erythrocytes
2) Platelets (released by megakaryocyte breakup)
White Blood cells:
- Granulocytes:
- Basophils
- Eosinophils
- Neutrophils
- Agranulocytes:
- Lymphocytes
- Monocytes
What is the difference between the systemic and pulmonary circulation?
Systemic carries blood around the body to supply oxygen. Pulmonary send deoxygenated blood to lungs to be oxygenated
Describe the route new blood cells take into circulation and maturation
RBCs - travel from bone marrow through venule to intermediate vein to larger vein to vena cava.
It takes 2 days during circulation for RBCs to become mature (i.e. haemoglobin becomes active and can up take O2)
WBCs - take same route. but immature cells need to be activated:
- T cells need activating in thymus and lymphatic system
- B cells are already mature
How is blood flow in capillaries controlled?
Flow in capillaries is controlled by precapillary sphincters.
- These are small rings of smooth muscle that are located between arterioles and capillaries
A metarteriole acts as a shunt for blood to pass through the thoroughfare channel and bypass the capillary bed
Arteriovenous Anastomosis - allows for large cells to bypass the capillary bed that other-wise wouldn’t fit
What are the 3 main layers of a vien?
1) Tunica Intima - Endothelial Cells
2) Tunica Media - Elastic fibres and smooth muscle
3) Tunica Externa - Elastic fibrous capsule
Veins can be categorised into 4 main types, what are they?
Pulmonary - Carry oxygenated blood from lungs to left atrium
Systemic - return oxygen- depleted blood from lungs to right atrium
Superficial - Located near surface of the skin, not located near a corresponding artery
Deep - Located deep between tissues and are typically located near a corresponding artery with same name
What are the 3 main layers of an artery?
Tunica Intima - Elastic membrane lining and smooth endothelium
Tunica media - Composed of smooth muscle and elastic fibres, 2 distinct elastic layer
Tunica Externa - Strong outer layer of collagen and elastic fibres
What are collateral blood vessels?
These are vessels (usually arterioles) that provide an alternative path for blood flow. They are normally generated from chronic diseases as they take time to develop
What is the difference between vasculogenesis and angiogenesis?
Vasculogenesis - is the formation of new blood vessels (occurs during embryo development and newly formed cancers)
Angiogenesis - The formation of blood vessels from existing blood vessels (FGF and VEGF)
Explain the 2 types of vasculogenesis during embryogenesis
1) (the common step) - production of a single vessel, VEGF produced by endoderm forms primary plexus which folds into the primary vessel
2a) Spouting - Angiogenesis - FGF produced by mesenchymal cells
2b) Division of primary vessel: Intussusception - twinned vessels (explains why veins and arteries can be so close)
What is a pericyte and what is it’s role?
Function: They prevent endothelial cell proliferation and maintain tight capillary junctions
Structure: Immature “smooth muscle-like” cell, have contractile properties, and can differentiate into endothelial, smooth muscle or a fibroblast
Erythropoietin, Thrombopoietin, Interleukins and G-CSF are hormones that regulate the production of blood corpuscles what specifically are they?
Erythropoietin - Common Myeloid Progenitor to RBC
Thrombopoietin - Common Myeloid Progenitor to Megakaryocyte (platelet)
Interleukins - Common Lymphoid Progenitor to Lymphocytes
G-CSF =Granulocyte - Colony Stimulating Factor - Increasing number of circulating neutrophils
Outline the adaptations RBCs have to make them efficient oxygen transporters
- Biconcave shape to increase surface area for diffusion of gases
- No nucleus/minimal organelles to maximise holding capabilities
- No mitochondria to ensure O2 is not being used up. Only respire anaerobically
- Haemoglobin to increase affinity of oxygen
What are reticulocytes?
They are immature circulating RBCs. They contain a small amount of RNA which helps to make haemoglobin. This is removed in 1-2 days
High amounts of reticulocytes can be present in the blood when the body is recovering from blood loss
How is RBC generation stimulated?
The kidney senses hypoxia and releases erythropoietin. This acts on erythrocyte progenitors and acts to stop apoptosis.
What are granulocytes/polymorphonuclear cells?
Sub-group of white blood cells that fight infection/inflammation and get there name due to the presence of granules within their cytoplasm.
Neutrophils, Basophils, Eosinophils
What are neutrophils and outline their function
Most abundant form of granulocytes, multilobed nucleus, 3 granule types
They phagocytose pathogens, signal for an immune response and present antigens
What are basophils?
- They are stained by basic dies (haematoxylin)
- Release histamine stimulating inflammation (as such they mediate hypersensitivity reactions like asthma)#
- Bilobed nucleus
What are eosinophils?
- Phagocytose pathogens
- 2 nuclear lobes
- Acid loving granules (stained by acidic dyes like eosin)
What is the role of a monocyte/macrophage?
Monocyte in the blood - Macrophage in the tissue
- Phagocytose pathogens, cell debris, senescent cells
- Antigen presenting
- Unilobular “horseshoes” shaped nucleus
- Largest of all mature blood cells
What are B lymphocytes?
- Main function resolves around the production of antibodies (each B cell is specific to an antigen)
- Can activate T cells
- Play a part in humoral adaptive immunity
What are T lymphocytes?
- Kill virus-infected cells, neoplastic cells and transplanted tissue
- They carry out cell mediated immunity
- Proliferation and activation caused by IL 2
- Microscopically indistinguishable from B cells
Describe how platelets are generated
The liver produces thrombopoietin to upregulate the formation of megakaryocytes and as such their break down and platelet formation
- Platelets contain vast amounts of proteins and clotting factors as well as surface receptors that allow for the formation of platelet aggregates
What may be of concern for someone with Alcoholic Liver Disease?
Lack of blood clotting as the liver doesn’t produce enough thrombopoietin to stimulate platelet production. Also the liver isn’t producing enough clotting factors. As such the blood isn’t clotting well leading to the rick of blood loss.
