Term
| The cardiovascular system consists of three things |
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Definition
1. A fluid (blood)
2. A pump (heart)
3. Hoses around the body (blood vessels) |
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Term
| Describe connective tissue |
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Definition
Fills internal spaces
Provides structural support for other tissues
Transports materials within the body
Stores energy reserves |
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Term
| What are the three classifications of connective tissue? |
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Definition
Connective tissue proper - Connective tissue with many types of cells and extracellular fibres in ground substance. Loose connective tissue (fat) & dense connective tissue (tendons
Fluid connective tissue - Distinctive populations of cells suspended in watery matrix that contains dissolved proteins (blood & lymph)
Supporting connective tissue - Different to connective tissue proper as it has less diverse cell populations and a matrix that contains more densely packed fibres (bone and cartilage only) |
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Term
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Definition
1.Transportation: Dissolved gases,
nutrients, hormones and metabolic
wastes
2.Regulation of pH and ion composition
of interstitial fluids
3.Restriction of fluid loss at injury sites
(clotting)
4.Defence against toxins and pathogens
5.The stabilisation of body temperature |
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Term
Blood is a fluid connective tissue
composed of: |
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Definition
1.Matrix
Plasma
Plasma proteins are in solution
(not insoluble fibres)
Plasma is slightly denser than water
2.Formed elements (cells)
Red blood cells (erythrocytes)
White blood cells (leukocytes)
Platelets (cell fragments) |
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Term
| Three major types and purposes of plasma proteins |
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Definition
1.Albumins
Osmotic pressure
Transport
2.Globulins
Antibodies
Transport globulins
3.Fibrinogen
Blood clotting |
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Term
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Definition
The percentage of whole blood volume that is made up of formed cells
Males 46%
Females 42%
VPRC - Volume of packed red blood cells
PCV - Packed cell volume |
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Term
| Describe the structure of a red blood cell |
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Definition
Extremely specialised cells for their job
Biconcave disc:
Thin central region
Thicker outer margin |
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Term
Three benefits of biconcave disc: |
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Definition
1.Large surface area-to-volume ratio
Increases speed of exchange between RBCs interior and surrounding plasma
2.Can form stacks to get through narrow blood vessels (rouleau)
Single cells would jam together
3.RBCs can bend and flex
They can pass
through capillaries
narrower than
themselves |
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Term
| Describe the unique organelles of red blood cells |
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Definition
No Nuclei (can’t divide)
No Ribosomes (can’t
synthesis proteins or
repair cell)
Short lifespan of 120 days
No Mitochondria (low
energy demands and
keep oxygen for other
cells not RBCs)
Still have cytoskeleton |
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Term
| Describe the purpose and structure of Haemoglobin |
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Definition
Enables oxygen and carbon dioxide transport
Protein that makes up
95% of RBCs’
intracellular proteins
It is a quaternary protein
structure
Contains four globular
polypeptide subunits
2 alpha chains
2 beta chains |
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Term
| Describe the chains within Haemoglobin |
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Definition
Each haemoglobin chain has one molecule of heme(4 chains = 4 heme molecules)
Non-protein pigment complex
Each heme unit holds an iron (Fe) ion
Iron interacts with oxygen to form oxyhaemoglobin
When iron is not bound to oxygen = deoxyhaemoglobin
Completely
reversible |
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Term
| Describe oxygen transport via RBCs |
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Definition
Oxygen has limited solubility in plasma
Therefore it must be transported by RBCs
98.5% of oxygen transported in blood is bound to haemoglobin
As oxygen partial pressures (PO2) increases more oxygen is bound
If PO2 decreases oxygen is released by haemoglobin |
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Term
| Describe carbon dioxide transport |
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Definition
Carbon dioxide also binds to haemoglobin
About 23% of the CO2 carried in the blood is carried this way |
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Term
| Describe four main points of red blood cell formation |
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Definition
Red blood cell formation erythropoiesis
About 3 million new RBCs enter the system each second
Only occurs in red bone marrow
Under extreme circumstances (e.g. Severe blood loss) yellow marrow can change to red marrow |
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Term
| Describe the steps of RBC maturation |
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Definition
Hemocytoblasts (hemo = blood, cyte = cell,
blast = germ or precursor) produce
Myeloid stem cells (which divide
to produce RBCs and some WBCs)
Cells that will become RBCs
differentiate into proerythroblasts
Then they pass through several
stages of erythroblasts
Before they become a normoblast
Their nucleus is shed(reticulocyte) and they become mature
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Term
| How is Erythropoiesis regulated? |
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Definition
Requires vitamin B12
Without B12 normal stem cell division does not occur and pernicious anaemia results
Erythropoisesis is stimulated directly by erythropoietin (EPO) a peptide hormone
Released by kidneys and liver in response to hypoxia (low tissue oxygen levels)
Erythropoietin travels to areas of red bone marrow where it stimulates stem cells and developing RBCs |
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Term
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Definition
| boosts the number of oxygen carrying blood cells, but simultaneously increase viscosity of blood and heart work rate |
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Term
| Describe the recycling of RBC components |
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Definition
Macrophages of the liver, spleen and bone marrow monitor RBC quality and engulf RBCs that are wearing out
—Each component of the haemoglobin molecule is recycled
—Globular proteins are disassembled into their amino acids and release for other cells to use (bone marrow)
—Heme units are stripped of their iron and turned into biliverdin (green in bruises)
—Biliverdin is turned into bilirubin (orange/yellow of jaundice) and transported to the liver where it is excreted as bile |
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Term
| What are antigens and antibodies? |
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Definition
Plasma membranes contain surface antigens
These antigens enable the immune system to recognise them as ‘self’
Antibodies in the plasma recognise antigens as ‘self’ or ‘foreign’ |
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Term
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Definition
a classification determined by the presence and absence of antigens on red blood cell plasma membranes |
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Term
| What antigens are contained in A, B, AB & O blood types? |
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Definition
Type A – surface antigen A only
Type B – surface antigen B only
Type AB – both surface antigen A and B
Type O – neither surface antigen A or B |
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Term
| Describe the antigens in Rh+ and Rh- |
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Definition
Rh positive (Rh+) indicates the presence of the Rh antigen on the surface of the RBC
Rh negative (Rh-) is the absence of this surface antigen
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Term
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Definition
AB+ is actually A and B and Rh surface antigens
O+ is actually neither A nor B but with Rh surface antigens (most common blood type)
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Term
| What is required for a Rh- individual to have anti Rh antibodies? |
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Definition
The plasma of Rh negative individual will only contain Anti-Rh antibodies if they have been sensitised by exposure to Rh-positive RBCs (e.g. Haemolytic disease of the new born)
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Term
| What would occur in a cross-reaction in a transfusion? |
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Definition
When a plasma antibody meets its surface antigen the RBCs agglutinate (stick together) and haemolyse (rupture)
Clumps and fragments of RBCs can then block small blood vessels
Compatibility of donor and recipient is essential
Surface antigens on the donor’s RBCs are more important than antibodies in the donor’s plasma
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Term
| Describe Haemolytic disease of the new born |
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Definition
When an Rh-negative woman is carrying an Rh-positive fetus, blood mixes, stimulates mother to produce anti-Rh antibodies, these can cross the placenta and attack the fetus' red blood cells
Results is a dangerous anemia and high levels of bilirubin producing jaundice, without treatment - death
If there is an Rh-negative mother and an Rh-positive father (fetus can be Rh-positive)
Administer anti-D antibodies to mother during pregnancy and after delivery will destroy fetal RBCs that enter the maternal circulation
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Term
| Describe the function and structure of white blood cells |
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Definition
Defend the body against invasion from pathogens and remove toxins, wastes, and abnormal or damaged cells
WBCs have nuclei and other organelles but no haemoglobin
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Term
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Definition
Granular leukocytes
Neutrophils
Eosinphils
Basophils
Agranular leukocytes
Monocytes
Lymphocytes
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Term
| Categorise the functions of the 5 types of leukocytes |
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Definition
Nonspecific defences
Neutrophils
Eosinphils
Basophils
Monocytes
Specific defences
Lymphocytes
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Term
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Definition
70% of circulating WBCs
Plasma contains pale granules that are hard to stain
The granules contain lysosomal enzymes and bactericide
Dense segmented nucleus with 2-5 bead shapes lobes
Active and specialise in attacking and digesting bacteria
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Term
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Definition
2-4% of circulating WBCs
Similar size to neutrophils
Easy to identify:
Deep red granules
Bilobed (two-lobed) nucleus
Primary mode of attack is the exocytosis of toxic compounds
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Term
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Definition
< 1% of circulating WBCs
Numerous granuels
Stain deep purple or dark blue with basic dyes
Smaller than neutrophils and eosinophils
Accumulate in damaged tissue
Release histamine (dilates blood vessels) and heparin (reduces blood clotting)
Attracts more WBCs
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Term
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Definition
2-8% of circulating WBCs
Large cells (twice the size of a RBC)
Even larger in blood smears
Nucleus is large and oval or bean-shaped
Aggressive phagocytes
Attract more phagocytic cells
Attract fibrocytes that produce scar tissue
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Term
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Definition
20-30% of circulating WBCs
Larger than RBCs
Lack abundant, deeply staining granules
Large round nucleus surrounded by a halo of cytoplasm
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Term
Never
Let
Monkeys
Eat
Bananas |
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Definition
Neutrophils
Lymphocytes
Monocytes
Eosinphils
Basophils |
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Term
| Describe and give the function of platelets |
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Definition
Cell fragments that look like flattened discs
Primary function- Clotting and haemostasis
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Term
| Describe the conditions associated with high and low platelet count |
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Definition
Thrombocytopenia (low platelet count, signs include bleeding in digestive tract, skin and sometimes CNS)
Thromocytosis (high platelet count, accelerated platelet formation due to infection, inflammation or cancer)
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Term
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Definition
Cessation of bleeding
Haemostasis (haima = blood, stasis = halt)
Framework for tissue repair |
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Term
| What are the three phases of haemostasis? |
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Definition
Vascular phase
Platelet phase
Coagulation phase
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Term
| Describe the Vascular phase of haemostasis |
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Definition
Once the blood vessel wall is cut smooth muscle in the wall contracts (vascular spasm)
Lasts 30 minutes = vascular phase
Changes to the endothelial cells at the injury site:
Contract exposing basal lamina to blood stream
Release chemical factors and local hormones
Endothelial plasma membranes become sticky
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Term
| Describe the platelet phase of haemostasis |
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Definition
Platelets attach to:
Sticky endothelial surfaces
Basal lamina
Exposed collagen fibres
Platelet adhesion: Platelets attach to exposed surfaces
Platelet aggregation: Platelets sticking to each other (starts 15 seconds after injury)
Forms a platelet plug
Must be controlled
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Term
| Describe the coagulation phase of haemostasis |
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Definition
Coagulation or blood clotting
Circulating fibrinogen is converted into fibrin
Fibrin network covers platelet plug
Forms blood clot
30 seconds after injury
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Term
| Name the five classes of blood vessels |
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Definition
Arteries carry blood away from the heart
Arterioles are smaller arterial branches
Capillaries are where diffusion occurs between blood and interstitial fluid
Venules small blood vessels beginning the return of blood to the heart
Veins are larger vessels that return the blood to the heart
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Term
| Describe the three layers of blood vessel walls |
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Definition
Tunica intima inner most layer.
Endothelial lining and
Underlying layer of connective tissue
Tunica media middle layer
Concentric sheets of smooth muscle in a framework of loose connective tissue
Thickest layer (generally)
Tunica externa outermost layer of the blood vessel
Sheath of connective tissue
Merges with tissue fibres of adjacent tissues stabilising the blood vessel
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Term
| What is the Vasa Vasorum? |
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Definition
| Walls of large blood vessels contain their own blood vessels |
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Term
| What is the difference between continuous and fenestrated capillaries? |
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Definition
Continuous capillaries
The endothelial lining is a complete lining
Most regions of the body
Allow diffusion of water, small solutes, and lipid-soluble materials into the surrounding interstitial fluid
Prevents the loss of blood cells and plasma proteins
Fenestrated capillaries
Contain windows or pores that penetrate the endothelial lining (Fenestra = window)
Allows rapid exchange of water and solutes as big as peptides between plasma and interstitial fluid
Examples: Choroid plexus, hypothalamus, intestine |
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Term
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Definition
Interconnected network
Guarded by precapillary sphincter that can stop blood flow
Several direct connections between arterioles and venules
The capillary beds may receive blood from more than one artery (collaterals)
The fusion of these collaterals that supply a capillary bed is referred to as arterial anastomoses
Insurance in case one vessel is blocked
Example: Anterior and posterior interventricular arteries |
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