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A & P - Cardiovascular System 1
Week 1 Cardiovascular System
48
Anatomy
Undergraduate 1
09/05/2012

Additional Anatomy Flashcards

 


 

Cards

Term
The cardiovascular system consists of three things
Definition

1. A fluid (blood)

2. A pump (heart)

3. Hoses around the body (blood vessels)

Term
Describe connective tissue
Definition

Fills internal spaces

Provides structural support for other tissues

Transports materials within the body

Stores energy reserves

Term
What are the three classifications of connective tissue?
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)

Term
5 Functions of blood
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
Term
—Blood is a fluid connective tissue
composed of:
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)
Term
Three major types and purposes of plasma proteins
Definition
1.Albumins
—Osmotic pressure
—Transport
2.Globulins
—Antibodies
—Transport globulins
3.Fibrinogen
—Blood clotting
Term
What is Haematocrit?
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

Term
Describe the structure of a red blood cell
Definition
—Extremely specialised cells for their job
—Biconcave disc:
—Thin central region
—Thicker outer margin
Term
—Three benefits of biconcave disc:
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
Term
Describe the unique organelles of red blood cells
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
Term
Describe the purpose and structure of Haemoglobin
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
Term
Describe the chains within Haemoglobin
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
Term
Describe oxygen transport via RBCs
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
Term
Describe carbon dioxide transport
Definition
—Carbon dioxide also binds to haemoglobin
—About 23% of the CO2 carried in the blood is carried this way
Term
Describe four main points of red blood cell formation
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
Term
Describe the steps of RBC maturation
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

Term
How is Erythropoiesis regulated?
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
Term
Describe EPO Abuse
Definition
boosts the number of oxygen carrying blood cells, but simultaneously increase viscosity of blood and heart work rate
Term
Describe the recycling of RBC components
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
Term
What are antigens and antibodies?
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’ 
Term
What is blood type?
Definition

a classification  determined by the presence and absence of antigens on red blood cell plasma membranes

Term
What antigens are contained in A, B, AB & O blood types?
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
Term
Describe the antigens in Rh+ and Rh-
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

 
Term
What is AB+ and O+?
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)

 
Term
What is required for a Rh- individual to have anti Rh antibodies?
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)

 
Term
What would occur in a cross-reaction in a transfusion?
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

 
Term
Describe Haemolytic disease of the new born
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 
 
 
 
Term
Describe the function and structure of white blood cells
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
 
Term
5 types of leukocytes
Definition

Granular leukocytes

Neutrophils

Eosinphils

Basophils

 

Agranular leukocytes

Monocytes

Lymphocytes

 
Term
Categorise the functions of the 5 types of leukocytes
Definition

Nonspecific defences

Neutrophils

Eosinphils

Basophils

Monocytes

 

Specific defences

Lymphocytes

 
Term

Neutrophils

 
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 

 
Term

Eosinophils

 
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 

 
Term

Basophils

 
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 

 
Term
 
Monocytes (agranular)
 
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

 
Term

Lymphocytes (agranular)

 
Definition

20-30% of circulating WBCs

Larger than RBCs

Lack abundant, deeply staining granules

Large round nucleus surrounded by a halo of cytoplasm

 
Term

Never

Let

Monkeys

Eat

Bananas

Definition

Neutrophils

Lymphocytes

Monocytes

Eosinphils

Basophils

Term
Describe and give the function of platelets
Definition

Cell fragments that look like flattened discs

Primary function- Clotting and haemostasis

 
Term
Describe the conditions associated with high and low platelet count
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)

 
Term
Define haemostasis
Definition

Cessation of bleeding

Haemostasis (haima = blood, stasis = halt)

Framework for tissue repair

Term
What are the three phases of haemostasis?
Definition

Vascular phase

Platelet phase

Coagulation phase

 
Term
Describe the Vascular phase of haemostasis
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

 
Term
Describe the platelet phase of haemostasis
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

 
Term
Describe the coagulation phase of haemostasis
Definition

Coagulation or blood clotting

Circulating fibrinogen is converted into fibrin

Fibrin network covers platelet plug

Forms blood clot

30 seconds after injury

 
Term
Name the five classes of blood vessels
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

 
Term
Describe the three layers of blood vessel walls
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

 
Term
What is the Vasa Vasorum?
Definition
Walls of large blood vessels contain their own blood vessels
Term
What is the difference between continuous and fenestrated capillaries?
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

Term
Describe capillary beds
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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