Cardiovascular System Flashcards
What is the cardiovascular system responsible for?
Circulating gas, nutrients and wastes
What are the components of the cardiovascular system?
Blood
Vessels
Heart
What are the three functions of blood?
Transportation
Protection
Regulation
What does the blood transport?
Gases
Nutrients
Electrolytes
Metabolic waste
Horomones
How does the blood protect?
Immune response
Clots after blood loss
What regulation does the blood do?
Body temperature
pH
Circulatory body fluid volume
What are the characteristics of blood?
A liquid connective tissue
A sticky viscous opaque fluid
55% plasma
1% buddy coat
44% solids (RBC)
What does the colour of blood indicate?
Scarlet red: high oxygen
Dark red: low oxygen
What are the characteristics of plasma?
Straw coloured sticky fluid
90% water
10% soluble components
What are the soluble components present in plasma?
Nutrients
Gases
Electrolytes
Waste
What is the name for the production of blood cells?
Haematopoiesis
Where does haematopoiesis happen?
Haematopoietic stem cells in three bone marrow.
Produces cells enter the blood through the blood sinusoids.
What does leucopoiesis produce?
Production of white blood cells/ Leucocytes
What does erythropoiesis produce?
Production of red blood cells/ erythrocytes.
What does thrombopoiesis produce?
Production of platelets.
What is the difference between granulocytes and agranulocytes?
Granulocytes= obvious granules under a light microscope
Agranulocytes= no obvious granules under a light microscope
What are the three types of granulocytes?
Neutrophils
Eosinophils
Basophils
What do neutrophils fight against?
Bacterial infection
What do eosinophils fight against?
Parasitic infection
What do basophils fight against?
Allergic reaction
What are the three types of agranulocytes?
Monocytes
Thrombocytes
Lymphocytes
What do monocytes fight against?
Bacterial infection
What do thrombocytes fight against?
Blood loss
(They clot the blood)
What do lymphocytes fight against?
Infected cells
What are the three types of low WBC counts?
Leukopenia (low WBC)
Neutropenia(low neutrophils)
Thrombocytopenia (low platelets)
What is the risk when there is leucopenia?
Risk of infection
What is the risk when there is neutropenia?
Risk of bacterial infection
What is the risk when there is thrombocytopenia?
Risk of blood loss
What could happen with a high WBC count?
Neutrophilia (high neutrophils)
Leucocytosis (high WBC)
Eosinophilia (high eosinophils)
Lymphocytosis (high lymphocytes)
Monocytosis (high monocytes)
What is neutrophilia a sign of?
Sign of bacterial infection
What is leucocytosis a sign of?
Sign of infection
What is eosinophilia a sign of?
Sign of parasitic infection
What is lymphocytosis a sign of?
Sign of viral infection
What is monocytosis a sign of?
Sign of bacterial infection in tissue
Why is the biconcous shape of RBC advantageous?
No nucleus and organelles
Large surrogate area for exchange
What are the steps in erythropoiesis?
Pluripotent haematopoietic stem cell —> proerythroblast—> erythroblast—> Recticulocyte (from bone marrow to the blood) —> erthyrocyte
What are the steps in the regulation of erythropoiesis?
Low oxygen—> kidney becomes hypoxic—> triggers EPO release—> trigger RBC production in bone marrow—> high oxygen—> Block EPO release
What does EPO stand for?
Erythropoietin
What is the life cycle of RBC?
Cannot grow, divide or replicate.
Gets older and more fragile and degenerate.
Trapped in spleen for RBC breakdown.
What do all the components turn into in RBC breakdown?
Iron- recycled and stored
Heme- degraded to bilirubin and excreted in feecces.
Globin- metabolised into amino acids and recycled
What is anaemia a sign of?
Problem and risk
No Fe2+ in the blood therefore there is low oxygen supply
What can blood loss lead to?
Anaemia
What are the four types of RBC deficiency?
Iron deficiency
Renal (lack of EPO)
Pernicious (destroy B12=RBC cannot divide)
Aplastic (injury to red bone marrow)
What are some problems for the RBC that are caused by genetics?
Thalassemia
Sickle cell anemia
What is thalassemia?
Globin chain in Hb is absent or malfunctioning
What is sickle cell anaemia?
Mutation to Hb
Crescent shape
One acid amino is wrong
What is polycythaemia?
Too many red blood cells in the blood.
What is haemostasis?
Physiological process to stop bleeding
What are the three steps in haemostasis?
- Vascular spasm
- Playlet activation
- Coagulation
What happens during vascular spasm?
Smooth muscle contraction
Triggering clotting chemicals needed
Directed to the site of injury
Responding to pain stimulation
What happens during platelet activation?
Exposed collagen is projected in injury site
Platelets stick to exposed collagen
Stress platelets expand to block the bleeding
Platelets stimulate ADP, thromboxane A2 and serotonin
What happens during coagulation?
Clotting factors in liver, vitamin K activate- biosynthesis clotting factors
What happens during clot retraction?
The actin and myosin in platelets contract and pull on fibrin strands
What are platelet derived factors (PDGF)?
Stimulate smooth muscle and fibrin division
What are vascular endothelial growth factors (VEGF)?
Rebuild endothelial lining by multiplying endothelial cells.
What is thrombosis?
Blood clotting in arteries, veins or capillaries
What is embolism?
Blood clot moving in the blood vessel and obstructing blood flow.
What are the two bleeding disorders?
Liver dysfunction
Haemophilia
What is haemophilia hereditary?
Prolonged bleeding in joint cavaties
What are the three types of circulation?
Pulmonary
Coronary
Systemic
What is pulmonary circulation?
Starting from heart to lungs to heart
What is coronary circulation?
Blood circulating around the heart
What is systemic circulation?
Blood circulating around the body
In what direction does the artery take the blood?
Away from the heart
In what direction does the vein take the blood?
Towards the heart
What pressure can the arteries take?
Higher
~90mmHg
What pressure can the vein take?
Lower
~8-10mmHg
What is the structure of the artery?
Tunica externa
Tunica media
Tunica interna
Lumen
What is the structure of the vein?
Externa
Interna
Lumen
What does the lumen do?
Carries the blood
What are the stages the blood has to flow through to go from artery to vein?
Artery
Arterioles
Pre-capillary
Capillaries
Venule
Vein
What are the three types of capillaries?
Continuous
Fenestrated
Sinusoids
What are continuous capillaries?
Endothelial cells in the smooth and skeletal muscle packed very tightly for restricted access
What are fenestrated capillaries?
Endothelial cells that allow for movement of molecules. Have higher permeability to larger bio-molecules
What are sinusoid capillaries?
Endothelial cells which are loosely packed to allow exchange
What is the architecture of the capillaries?
Capillaries are lined with endothelial cells for smooth flow and exchange of O2 and CO2.
Bundles of smooth muscle spread out at the pre-capillary which provides elasticity to the capillary system.
What are the layers of the heart?
Pericardium
Pericardial cavity
Myocardium
Endocardium
What is the function of pericardium?
Provides elasticity and protects
What is the function of the pericardium cavity?
Filled with shock absorbing fluid
What is the function of the myocardium?
Contracts and relax.
Thicker on left side as it needs more pressure to pump the blood around the body.
What is the flow of blood in the left side of the heart? (Structures)
Pulmonary vein
Left atrium
Bicuspid/ Mitral valve (atrio-ventricle valve)
Left ventricle
Aortic/ semi-lunar valve
Aorta
What is the flow of blood in the right side of the heart? (Structure)
Vena cava
Right atrium
Tricuspid valve
Right ventricle
Pulmonary valve
Pulmonary artery
What is the venous return?
Flow of blood back to the heart’s right atrium
What are the three types of venous return?
Calf/skeletal muscle pump
Pulsate arteries adjacent to vein
Respiratory (thoracic) pump
How does the capillary control perfusion when there is high O2?
Stimulate endothelial cells to release endothelin
Platelets secretions and prostoglandins
Vasoconstriction of precapillary sphincters
What does the capillary do to control perfusion when there is low O2?
Stimulate endothelial cells to release NO
Vasodilation of precapillary
What happens when there is mid-late diastole?
Atria goes from diastole to systole
Ventricle is in diastole
A trio-ventricle valves are open
Aortic valves are closed
What happens during ventricular systole?
Atria is diastole
Ventricle is in systole
Atrioventricular valves are closed
Aortic valves are open
What happens during early diastole?
Atria is in diastole
Ventricle is in diastole
Atrioventricular valves are open
Aortic valves are closed
What does systole mean?
Heart contraction
What does diastole mean?
Heart relaxation
What are the key properties of cardiac muscle?
Auto-rhythmicity
Excitability
Conductivity
Contractibility
What is auto-rhythmicity?
Ability to initiate heartbeat, consistent and continuous at a regular pace without any external stimuli
What is excitability?
Ability to respond to stimuli of adequate strength and duration.
Ability to generate and process action potential
What is conductivity?
Ability to conduct and transmit impulse through the cardiac tissue.
What is contractibility?
Ability to contract in response to stimuli
What are the steps in excitation-contraction coupling in contractile myocytes?
- AP from adjacent cell excites myocites membrane depolarisation in T-tubules
- Calcium enters the cells via voltage gated channels
- Calcium binds to Ryondine Receptor (RYR) and induce calcium release from SR
- Calcium binds to troponin and triggers acting-myosin complex contraction
- Calcium unbinds from troponin and pumped back into SR
- Calcium unbinding cause relaxation and excess Ca2+ exchanged with Na+
- Na+ gradient is maintained by sodium-potassium ATPase pump
What is a sinus rhythm?
A wave of depolarisation that begins on the SA node and spread over the heart.
What does the P in an ECG represent?
Atriole contraction
What does QRS represent in an ECG?
Ventricle depolarisation
What does the T represent in an ECG?
Ventricle repolarisation
What is blood pressure?
Pressure generated from the ventricle exerted on the walls of the blood vessels (arterial).
What is the systemic blood pressure?
120/80mmHg
What is the pulmonary blood pressure?
25/8mmHg
What is the venous blood pressure?
6-8mmHg
What are the factors that make up blood pressure?
BP= Cardiac out put x Peripheral resistance
What are the factors of cardiac output?
Heart rate x stroke volume
What are the three main types of regulation of blood pressure control?
Auto regulation
Neural
Hormonal
What is auto regulation of blood pressure control?
Changes in blood flow detected by the local receptors during micro perfusion.
What is neural regulation of blood pressure control?
Short-term regulation of the blood pressure, especially in responses to the transient changes in arterial pressure, via baroflex mechanisms.
Where are the baroreceptors and what do they do in neural regulation of blood pressure?
They are in the aortic arch carotid sinus.
These send signals via glossopheraryngal nerves to the brain stem.
What happens with neural regulation when there is low blood pressure?
Signalled by baroreceptors
Reduces firing rate
Signals the cardiovascular centre
Sympathetic cardiac activity
Release adrenaline
Increase heart contraction
Suppress vagal activity
Increase heart rate
Vasoconstriction
What is hormonal regulation of blood pressure control?
Long term regulation of blood pressure
What does RAAS stand for?
Renin-angiotensin-aldersterone system
What does ACE stand for?
Angionotensin converting enzyme
What happens during RAAS when there is low blood pressure?
Liver produces angiotensinogen which combines with the renin made from the kidney to make angiotensin. This combines with ACE that was produced by the lungs to make angiotensin II.
In the blood there is also aldosterone made from the adrenal cortex.
What happens during RAAS when there is high blood pressure?
Liver produces angiotensinogen, however the kidney does not produce renin.
Na+ is secreted out of the kidney
Vasodilation decreases
Peripheral decreases
What happens when antidiuretic hormone is released during hormonal regulation of blood pressure control?
Hyperolemia: increase in tissue fluid osmolarity trigger ADH release
ADH signals kidney to reabsorb more water
What produces Atrial Natriuretic Hormone and what does this promote and suppress?
High blood volume and extreme stretching of the cardiac cells trigger ANH.
Promotes loss of sodium and water from the kidneys.
Suppresses renin, aldosterone and ADH production and release.
What are the effects of hypotension?
Light headed ness or dizziness
Feeling sick
Blurred vision
General.y feeling weak
Confusion
Fainting
What are the effects of hypertension?
Severe headaches
Nosebleeds
Fatigue/confusion
Vision problems
Chest pain
Difficulty breathing
Irregular heartbeat
What are the general functions of RBCs, the five types of leukocytes and platelets?
RBCs transport O2 and CO2
Neutrophils phagocytise bacteria
Eosinophils kill parasitic worms
Basophils release histamine and contain heparin
Lymphocytes initiate the immune response
Monocytes phagocytose substances, and develop into macrophages in tissues
Platelets function in blood clotting
How does EPO regulate erythropoiesis?
Erythropoietin (EPO)is released by the kidneys in response to low blood PO2. EPO stimulates pro-erythroblasts to transform into erythroblastosis, which then function as ribosome-producing factories
How does the leukopoiesis process differ for granulocytes and agranulocytes?
Granulocytes are produced by the common myeloid progenitor pathway. They develop in five stages within the bone marrow. The agranulocytes are produced by both pathways; the lymphocytes by the common lymphoid progenitor pathway, and the monocytes by the common myeloid progenitor pathway. Both monocytes and lymphocytes begin development in the bone marrow, but travel to the lymphoid tissue to mature.
How does the development of anti-Rh antibodies and anti-A and anti-B antibodies differ?
A persons plasma contains antibodies towards the agglutinogens that aren’t present on their own RBCs. For example, a person with Group A blood type will have anti-B antibodies in their plasma. Anti-Rh antibodies only develop if an Rh- person is exposed to Rh+ blood.
What is the structure of the haemoglobin?
haem- contains 4 irons which each bond to o2.
globin-4 polypepetid (2 alpha and 2 beta)
Why do males have a higher blood count?
testosterone increases EPO release which allows for the production of more RBCs
How is iron bound, stored and transported after use in RBCs?
bound with a protein
stored as ferittin and haemosiderin
transported by binding with transferittin
What is haem degraded to after use in RBCs?
biliruben which is secreted in urine
stercoblin which is secreted in bile
What is globin degraded to after use in RBCs?
amino acids
What are the electrical nodes in the heart that control the ‘pump’ of the heart? Pace makers
Atria-ventricla
Sino-atrial
What can cause hypovolaemia?
heamorage
diarrheoa
dehydration
burns
diuretics
What can cause structural dysfunctions in hypotension?
valves disease
ischemia
myopathy
pulmonary hypertension
pericardial disease
What can cause arrythmias?
sinus bradycardia
AV nodal block
ventricular fibrillation
What can cause systemic vasodillation?
sepsis
autonomic dysfuntion
anaphylaxis
neurogenic
What can cause obstruction?
pulmonary embolism
What can cause Sodium homeostasis?
renal disease
nephropathy
reduced nephron number
GFR
What can cause hormonal imbalance?
renin
angiotensin ii
aldosterone
erythropoietin
adrenaline/noradrenaline
what can cause systemic vasoconstriction?
stress
autonomic dysfunction
what can cause structural dysfunction in hypertension?
obesity
endothelial dysfunction
altered cell membrane
venous constriction
what is the function of albumin?
exerts osmotic pressure to maintain water balance
what are the functions of alpha and beta globulins?
transports proteins that bind to lipids, ions and fat-soluble vitamins
what are the functios of clotting proteins?
include fibrinogen and prothrombin
what are the functions of gamma globulins?
antibodies released by plasma cells during an immune response
how is iron storred for reuse?
ferritin
what does the metabolisation of heme result in?
the production of carbon monoxide
are platelets larger than RBCs?
yes
when activated what shape do platelets turn into?
star-shaped
do platelets contain mitocondria?
yes
do platelets contain a nucleus?
yes
what is the saying to remeber the order of leukocytes?
never let monkeys eat bananas
(neutrophils, lymphocytes, monocytes, eosinophinls, basophils)
what are the stages in the production of platelets?
myeloid stem cells
megakaryoblast
megakaryocyte
platelets