cardiovascular Flashcards
1
Q
3 reasons why large organisms need a transport system
A
- to ensure effective diffusion
- cells metabolically active; system needs to deliver oxygen, nutrients and remove waste products
- platelets, immune cells and chemical messengers need to move to where they are needed
2
Q
what 6 things are included in the cardiovascular system
A
- blood (liquid tissue)
- heart
- arteries
- vein
- capillaries
- lymphatics
3
Q
where does the right side of the heart pump blood to
A
- the lungs
4
Q
where does the left side of the heart pump blood to
A
- the rest of the body
5
Q
what are the two systems of the heart called
A
- pulmonary and systemic
6
Q
how many chambers does the heart have and what are they called and where are they found
A
- heart has 4 chambers
- top = atria
- bottom = ventricles
7
Q
what is the role of atria
A
- atria receive blood returning from the body (right atrium) and from the lungs (left atrium)
- responsible for pumping blood into ventricles
8
Q
what is the role of ventricles
A
- ventricles pump blood out of the heart to the lungs (right ventricle) and rest of body (left ventricle)
9
Q
what is the cardiac muscle that separates the left and right side of the heart and what is its role
A
- atrial or ventricular septum
- ensures blood flows in a single direction through the heart
10
Q
what is the process when deoxygenated blood enters the heart
A
- returns to heart via superior vena cava or inferior vena cava
- flow into right atrium
- heart contracts blood is forced through tricuspid valve into right ventricle
- blood pumped through pulmonary valve into pulmonary artery
11
Q
what is process of oxygenated blood
A
- oxygenated blood comes to left atrium via pulmonary veins
- left atrium pumps blood to left ventricle through bicuspid valve
- contraction of left ventricle blood flows through aortic valve into aorta and rest of body
12
Q
is the pulmonary system high or low pressure system
A
- low pressure system as only goes to lungs
13
Q
what is it termed when heart is relaxing and filling
A
- diastole
14
Q
what is systole
A
- when heart is contracting and pumping
15
Q
what is contraction of the heart initiated by
A
- group of cells known as pacemakers
16
Q
structure of pacemakers
A
- small, round cells
- contain little or no contractile proteins meaning they do not contribute to the contraction of the heart
17
Q
what are pacemakers cells responsible for
A
- generating an action potential
18
Q
which two regions are pacemakers cells clustered in
A
- sino - atrial node (SA)
- atrio - ventricular node (AV)
19
Q
does the SA node have a stable membrane potential and what does this mean
A
- the cells within the SA have an unstable membrane potential they then generate action potentials 100 times per minute
- SA node cells are tightly electrically coupled to contractile cells (myocytes) via gap junctions therefore the action potential generated by SA node is rapidly passed throughout the atria
- this is the electric trigger which signals myocytes to contract
- once action potential has propagated through the atria, causing atrial contraction it progresses to ventricles
20
Q
why can action potentials only reach the ventricles by passage through the AV node
A
- cells within the AV node slow the transmission of action potential
- leading to a delay between atrial and ventricular contraction
- this allows for the blood to full leave atria before ventricles contract
21
Q
once action potential leaves AV node what happens
A
- rapidly transmitted to the bottom of the ventricles through conductive cells known as bundle of his and purkinje fibres
- the action potential then travels up through ventricles
22
Q
where are atriaventricular valves found and purpose
A
- between atria and ventricles
- prevents blood from going back to the atria when heart contracts
23
Q
what do semi lunar valves prevent
A
- prevents back flow of blood into ventricles
24
Q
what two things do you need to measure blood pressure
A
- systolic / diastolic
- systolic represents how hard blood is pumping
- diastolic represents resistance within blood vessels
25
what do the structure of blood vessels depend on
- where they are located
| - what pressure they are under
26
in what way do blood vessels differ
- diameter
- wall thickness
- constituents
27
what are the three main layers of blood vessels and where are they found
- intrima (inner most lining)
- media (middle layer)
- adventitia (layer of connective tissue outside)
28
why do capillaries only have intrima
- they need thin walls so exchange can occur
29
arteries structure
- thick wall
- high amounts of elastic and smooth tissue
- large diameter
- lower resistance
30
arterioles structure
- smaller arteries
- small diameter
- major role in blood pressure regulation
31
capillaries structure
- smallest blood vessels
- single tube of endothelial cells
- v close to cells that need oxygen, nutrients and to get rid of waste
- efficient diffusion
- leaky or tight - different capillaries in different parts of the body
- holes in leaky are big enough for cells to come out
32
venules and veins
- low pressure
- large lumen
- veins return blood to heart
- unidirectional valves (blood under low pressure so valves prevent back flow)
33
what is the lymphatic system and what is its role
- system of vessels and nodes
- removes interstitial fluid to circulation (fluid that cells sit in)
- lymphatic system plays a role in immunity
- lymph contains lymphocytes
- concentrated in nodes - no. of lymphocytes can be increased and go to site of infection
- tumours can spread to lymph nodes
34
homeostasis
- receptor - control center - effector
35
what are the receptors involved in cardiovascular homeostasis
- baro receptor (detect pressure)
| - chemoreceptor ( detects changes in chemicals in blood eg oxygen, ph)
36
where is the control centre in cardiovascular homeostasis
- medula oblongata
37
what are the effectors
- heart rate
- stroke volume
- vascular tone
38
what two ways can the heart be controlled
- intrinsic (signals within the heart)
| - extrinsic (signals coming from other parts of the body)
39
what is the frank starling response
- instrinic response
- mechanism of controlling cardiac output
- law states stroke volume increases as the filling of heart with blood increases
- as blood pressure increases the volume of blood increases
40
extrinsic factors which affect heart rate
- age and exercise
- ions - increased potassium or sodium leads to a reduction in heart rate
- hormones (epinenine, thyroxin)
- nervous stimulation from branches of autonomic nervous system
41
what is vasoconstriction
- lumen gets smaller - increase blood pressure by reducing blood volume
42
what is vasodilation
- lumen gets bigger - reduction in blood pressure
43
how are the cardiovascular and respiratory system linked
- they work together
- chemoreceptors in the aorta, carotid and brain
- constantly measuring oxygen, co2 and ph
- changes in those leads to increased breathing
- heart then beats faster
44
what is aortic disease
- wall of aorta becomes weakened and bulged due to increased blood pressure
45
what is peripheral artery disease
- affects blood vessels other than aorta and coronary heart vessels
46
what is a stoke and transient ischaemic attack
- bleed or clotting in brain
47
how can a heart attack happen
- when blood vessels supplying heart become narrowed and not enough oxygen reaching heart and heart tissue begins to die
48
what is atherosclerosis and blood clots
- blood vessels become obstructed - arteries becomes narrowed as fat deposited
- blood clots form in body preventing blood getting to certain positions
49
what factors of lifestyle lead to risk factors for cardiovascular disease
- smoking, weight, diet
- family history and ethnic background
- age
- diabetes - twice as likely to have hypertension, obesity and low activity - more likely to have a poor lipid profile and have low lipid density
50
what is hypertension
- blood pressure always higher
- damages arteries therefore increase deposition of fat increasing risk of aneurysm
- heart has to work harder therefore increase risk of haemorrhage stroke
51
what are therapeutic agents and examples
- help fight high blood pressure and cardiovascular disease
; renin - angiotensin
; anticoagulants - reduces clotting
; beta - adrenergic blocking agents - reduces interferes with nervous stimulation of heart
; ca channel blockers - causes blood vessels to dilate increasing volume, decreasing pressure and heart rate
; statins - cholesterol lowered drugs - reduce bad cholesterol and improves lipid profile
