week 1 Flashcards
(103 cards)
1
Q
What is the function of the heart, arteries, veins, capillaries, blood and the lymphatic system?
A
heart - Mechanical pump
Arteries - Transport blood away from the heart
Veins - Transport blood to the heart
capillaries - Site of exchange of substances
blood - Transport of cellular components and dissolved substances
lymphatic system - Return tissue fluid to systemic circulation
2
Q
describe the mammalian circulation system?
A
double closed circulation
3
Q
describe what is meant by the terms: tunica interna, tunica media, tunica externa/adventitia and lumen?
A
tunica interna - Endothelial lining
tunica media - Concentric sheets of smooth muscle
tunica externa/adventitia - Connective tissue sheath around vessel
lumen - Cavity of an organ
4
Q
describe what is meant by the terms: arterioles, capillaries, elastic arteries, muscular arteries.
A
arterioles - Small diameter, which changes in response to local conditions e.g. O2 levels
capillaries - Small diameter, endothelial layer only
elastic arteries - Conducting artery, expand during systole and recoil during diastole
muscular arteries - Medium sized, changes (vaso constriction/vasodilation) affect blood pressure
5
Q
identify structures of the heart diagram
A
answered version
6
Q
What is meant by the tricuspid, mitral, pulmonic and aortic valve?
A
tricuspid - Is an atrioventricular valve on the right side
mitral - Is an atrioventricular valve on the left side
pulmonic - Is a semilunar valve on the right side
aortic - Is a semilunar valve on the left side
7
Q
What are the 2 main parts to the cardiac cycle and what do they mean?
A
systole and diastole
During systole the heart muscle contracts
During diastole the heart muscle relaxes
8
Q
describe the steps involved in the cardiac cycle
A
- When ventricular pressure becomes lower than atrial pressure the AV valves open
- Ventricles fill with blood.
Atria contract and force more blood into ventricles - When the ventricular pressure increases above atrial pressure, the AV valve close
- The ventricles contract, increasing the ventricular pressure
- When the pressure inside the ventricles exceeds the pressure in the outgoing arteries, the semilunar valves open
- As a result of ventricular systole and opening of the semilunar valves, blood flows from ventricles into the arteries
- Pressure in ventricle drops below aortic pressure. The Semilunar valves close
9
Q
What are the functions of the cardio-respiratory system?
A
Transport – to and from metabolising tissue
Oxygen and carbon dioxide
Nutrients
Waste
Heat
Hormones
Homeostasis
pH, osmolarity, electrolytes etc
Infection
Other
Generate pressure (eg renal filtration)
10
Q
What is heart failure?
A
Heart failure is a syndrome in which the heart fails to deliver blood effectively to meet the requirements of metabolising tissues
11
Q
What is the clinical relevance of heart disease in animals compared to humans?
A
Heart disease are mostly genetic diseases but don’t often end up in heart attack very different to humans.
12
Q
What is ventricular systole and diastole? for each what does it result in, and how does it impact valves and what does it produce?
A
Ventricular systole = contraction of ventricles
Results in cardiac output
Atrioventricular valves close
The source of the first heart sound – “Lub”
Ventricular diastole = relaxation of ventricles
Results in ventricular filling
Semi-lunar valves close
The source of the second heart sound – “Dub
13
Q
How can the cardiovascular function be regulated?
A
Regulation of cardiac function
Need to consider:
Can change heart rate and contractility
Electrical activity (Electrophysiology)
Assessment of this using an ECG
Contractile function control
The important role of the autonomic nervous system
Hormonal mechanisms (local and systemic)
Regulation of the vasculature
Autoregulation - local blood flow regulation, intrinsic ability of an organ to maintain a constant blood flow despite changes in perfusion pressure.
The important role of the autonomic nervous system
Hormonal mechanisms (local and systemic)
14
Q
For cardiac function for the heart as a pump we must consider.
A
For the heart as a pump we must consider:
Cardiac Output (volume delivered into the circulation per minute)
Stroke Volume (volume delivered by the ventricle per beat)
Other pumping mechanisms (venous)
….and what control these
15
Q
For cardiac function for the distribution of blood within the heart and the vasculature we must consider.
A
For the distribution of blood within the heart and vasculature we must consider:
Vascular constriction and dilation – arteries AND veins
The maintenance of unidirectional flow in vital organs
Cardiac valves
Vascular valves
16
Q
What is meant by cardiac output and what do we need to consider about it?
A
Is the amount of blood pumped per minute
Consider the relative distribution of output to different organs
17
Q
What is venous return, and what are important controlling factors of venous return?
A
Deoxygenated blood is returned to the heart
Diastolic cardiac volume is important for cardiac output
Important controlling factors:
Sympathetic nervous system
Blood volume
Muscle (respiratory) pump
18
Q
What are portal veins?
A
portal veins are found between 2 capillary beds
19
Q
heart of different animals unlabelled version
A
labelled version
20
Q
Why do birds have a highly efficient cardiovascular system? and what are its main features?
A
Birds have a highly efficient cardiovascular system
To cope with high metabolic demands
Important for oxygen delivery and thermoregulation
Main features of the avian CVS:
4 chambered heart like mammals’
AV valves are different in structure compared to mammals
The heart is located within the cranial ventral coelom and is surrounded by air sacs
Term coelom is used because birds don’t have a diaphragm
21
Q
How do birds mainly increase cardiac output?
A
by increasing heart rate
22
Q
key points of avian cardiac function
A
Ventricles
Left sided ventricular wall 3x thicker than right
Empty almost completely on each cardiac cycle
Low end-systolic volume
23
Q
Which animals have a renal portal system and what does it do? and what is its clinical relevance?
A
Reptiles, birds, amphibians and most fish – not in mammals
Receives blood from caudal body and returns it to the heart via the kidneys
It functions to supply blood to renal tubules at all times
Portal blood flow regulated by renal portal valve.
Alters how drugs will act in these species: for example if injected in caudal half of the body then maybe metabolised before entering general circulation
24
Q
renal portal unlabelled
A
labelled
25
primitive tube unlabelled
labelled version
26
describe the fish cardiovascular system
Simple cardiovascular system
“2 chambers” to the heart
Blood flows in one direction effectively through a single atrium and ventricle (technically there are 6 chambers similar to the primitive tube)
Vasculature includes gills to accommodate oxygenation
Heart is often positioned ventral and caudal to the gills
27
describe the amphibians cardiovascular system
In anurans we start to see 2 atria – 3 chambers in total
Oxygenation occurs from lungs, skin and buccal cavity hence vasculature more complex compared to mammals
Heart is mid cranial coelom
Like birds they have no diaphragm, hence the term coelom again
28
amphibians heart unlabelled
labelled
29
describe reptiles cardiovascular system
Most reptiles have 3 chambers, with 2 atria and 1 ventricle. The ventricle is split into 3 sections by folds in the muscle wall
Crocodiles are an exception with 4 chambers but distinct differences from mammals still (2 x aortas)
All reptiles can shunt blood away from the respiratory tract when needed.
For most species the heart is mid cranial coelom, some very cranial (base of the neck).
For snakes the heart is often found in the cranial third of the body.
30
What are the principle functions of the circulatory system?
Transport
- Delivers O2 from lungs and nutrients from digestive system
- Removes waste, heat and CO2 from tissues
- Hormones
Protective function – carries WBC and Ig
Homeostasis – pH, ions, fluid volume
Pressure
31
32
local circulatory rules
answer
33
How do the kidney renal artery and efferent arterioles work in the kidneys?
Kidney renal artery to the glomerulus, efferent arterioles takes oxygenated blood to the kidney tissue
34
Compare the heart size in different species?
Relatively larger in small species
Approximately 0.75% of body weight
35
what are the landmarks of the heart
Ventral border of the lungs
Cardiac notch (L>R)
Lungs laterally
Phrenic nerve
Thymus cranially
Diaphragm caudally
36
what does the thymus do?
Thymus is present in young animals and regresses with age. It trains t-cells.
37
thorax landmark diagram
completed version
38
In dorsoventral view of the heart what does it show?
heart Lies in mediastinum
Divides L and R pleural cavities
60% is to L of median plane
Mediastinum is a space in your chest that holds your heart and other important structures.
39
In a lateral radiograph of the heart, what does it show?
Lateral projection is ribs 3 – 6
Base is dorsal
Apex sits in sternum – costochondral junction 6
Right ventricle is CRANIAL to left!
40
what landmark separates atria from ventricles?
coronary groove this is where the coronary arteries sit
41
what landmark separates the right and left ventricles of the heart?
subsinuosal groove cranially
paraconal groove caudally
These mark where the septum is.
42
What is the pericardium and what does it contain?
Sac surrounding the heart
Inner visceral layer on surface of the heart
Outer parietal layer
No significant lumen
with serous fluid between the layers
43
What does the Intervenous tubercule in the heart do? And what about the azygous vein?
Intervenous tubercule diverts blood into the atrium
Azygous vein plays a key role in draining deoxygenated blood from the posterior walls of the thorax and abdomen into the superior vena cava.
44
key points of the left atrium
Under tracheal bifurcation (where the trachea splits into two)
Pulmonary veins enter
In groups into 2 or 3 sites
In septal wall is scar of valve of foramen ovale
45
what is the trabecula septomarginalis and what is its role?
Trabecula septomarginalis (also known as the moderator band) ensures communication is quick on both sides
46
what chamber of the heart occupies all of apex? What does muscle is prominent in this chamber and what does it do?
left ventricle - circular in section
Prominent papillary muscles - attach to the cups of the atrioventricular valves via the chordae tendineae and prevent inversion.
47
in most animals how many cusps do the tricuspid and mitral valves have?
2 cusps
48
How about the pulmonic and aortic valve?
3 cusps
49
What is the function of the fibrous cardiac skeleton (fibrous trigone)?
supports the 4 valves, separates atria and ventricles, in some animals the fibrous trigone can undergo increasing mineralisation with age and become the os cordis bone
50
What is found within the epi- , myo- and endo- cardium
Epicardium – visceral pericardium
Myocardium – cardiomyocytes
Endocardium
51
Characteristics of cardiomyocytes.
Large, cylindrical cells
Striated (myofibrils) – like skeletal m.
Short, branched fibres
Lots of mitochondria
52
what are intercalated discs?
Cell-to-cell communication
Required for coordinated muscle contraction
53
what is Purkinje fibres?
Specialised conducting tissue
Deliver electrical activity to myocardium
54
What happens in training and injury of cardiomyocytes?
Mass increase – training/overload
Myocyte hypertrophy
No increase in cell numbers
If damaged –regeneration???
55
compare preganglionic neurones and postganglionic neurones of the SNS and PSNS?
Sympathetic nervous system
- Preganglionic neurons are relatively short and originate from the thoracic and lumber regions of the spinal cord.
- Postganglionic neurons are relatively long and extend from the sympathetic ganglia to the target organs
Parasympathetic nervous systems
- Preganglionic neurons are relatively long and originate from the brainstem and sacral (relating to the sacrum a triangular-shaped bone at the base of the back) regions of the spinal cord
- Postganglionic neurons are relatively short and extend from the parasympathetic ganglia to the target tissues.
56
What are adrenergic receptors and what are they targets of?
Adrenergic receptors are a class of G protein-coupled receptors that are targets of many catecholamines like norepinephrine and epinephrine produced by the blood.
57
What are alpha receptors and what are they targets of?
Alpha receptors stimulate effector cells and are responsible for vasoconstriction and increasing blood pressure.
Targets of norepinephrine and epinephrine.
58
What are beta receptors and what are they targets of?
Beta receptors relax effector cells and are responsible for vasodilation and decreasing blood pressure.
epinephrine and norepinephrine
59
What is the adrenal medulla and what does it produce?
Adrenal medulla is the inner part of the adrenal gland.
Produces epinephrine and norepinephrine.
Norepinephrine is also produced by nerve endings
60
what are muscarinic acetylcholine receptors?
Muscarinic acetylcholine receptors are a type of acetylcholine receptors that are G protein-coupled receptors.
61
What is the difference between a nerve fibre beaning cholinergic or adrenergic?
Adrenergic receptors are a class of G protein-coupled receptors that are targets of many catecholamines like norepinephrine and epinephrine produced by the blood.
A cholinergic neuron, receptor, or drug involves acetylcholine.
62
What neurotransmitter, designation and receptor is involved in the following nerve fibres?
Pre-G SNS
Pre-G pSNS
Post-G SNS
adrenal medula
Pre-G PSNS
look at nerve fibres table
63
questions for SNS
1) In what circumstance is the sympathetic NS activated?
2) What outflow from the CNS does it have?
3) Where are the ganglia located?
1) It is activated in situations that require a fight or flight response, such as stress, physical activity, emergency situations and excitement.
2) It has a thoracolumbar outflow as the SNS originates from the thoracic (T1 to T12) and lumbar (L1 to L2) segments of the spinal cord.
3) The ganglia in the SNS are located in specific regions that facilitate the relay of signals from the CNS to target organs.
Paravertebral ganglia (sympathetic chain ganglia) are on either side of the spinal column and extend from the base of the skull to the coccyx (tailbone). These are closely associated with the thoracic and lumbar regions of the spinal cord where the preganglionic neurons originate.
Prevertebral ganglia are located anterior (towards the front of) to the vertebral column, near major arteries
Adrenal medulla acts as a modified ganglion. It releases adrenaline and noradrenaline directly into the blood stream in response to sympathetic stimulation.
64
questions for PNS
1) When is this system activated?
2) How does the outflow differ in the parasympathetic NS?
3) Which cranial nerves are involved?
4) Where are the ganglia located?
1) The PSNS is activated during rest-and-digest situations, promoting relaxation, recovery, and maintenance of the body’s homeostasis. Specific circumstances causing this include relaxation, eating, resting and reproductive activities.
2) For PSNS you have a craniosacral outflow, the PSNS originates in the brainstem and the sacral (relating to the sacrum, a triangular-shaped bone at the base of the back) region of the spinal cord.
3) The preganglionic neurons of the PSNS arise from the cranial nerves (oculomotor, facial, glossopharyngeal and Nictitans) as well as the sacral nerves which arise from the sacral spinal cord segments S2 to S4 and innervate the lower abdominal and pelvic organs.
4) In the PSNS, the ganglia are located closer to or within the target organs they innervate. This is different from the SNS, where the ganglia are generally located near the spinal cord.
65
What are autonomic reflexes involved in and how do they work? And what is their function?
Neural regulation of the ANS occurs by reflexes. The reflexes are called autonomic reflexes.
They work through feedback mechanisms, which involve the afferent nervous system.
Their function is to maintain homeostasis.
e.g. Heart rate regulation, Respiratory rate, Digestive processes, Pupil dilation and constriction
66
The SNS has 2 effects on the heart, what are they?
What is the effect of the SNS on the lungs?
1) The 2 primary affects the SNS have on the heart is:
Increased heart rate (positive chronotropy) – SNS releases norepinephrine which binds to beta-1 adrenergic receptors in the heart. This interaction increases heart rate by accelerating the rate of depolarization of the SA node, the hearts natural pacemaker.
Increased force of contraction (positive inotropy) –norepinephrine binding to beta-1 adrenergic receptors also enhances the force of contraction of the heart muscle. This increases the volume of blood ejected with each beat improving the overall cardiac output.
2) The SNS has several effects on the lungs, primarily through the activation of beta-2 adrenergic receptors in the bronchial smooth muscles,
The main effects: - bronchodilation – SNS stimulates the release of norepinephrine, which binds to the beta-2 adrenergic receptors in the bronchial smooth muscles. This leads to the relaxation of these muscles, causing the airways to widen. Bronchodilation increase the airflow into and out of the lungs, which is especially important during physical activity or stressful situations when the body’s oxygen demand is higher.
Decreased secretions –SNS can reduce mucus secretion in the airways, helping to keep them clear and improve airflow. This is achieved by inhibiting the activity of certain glands in the respiratory tract.
67
What are the relative lengths of pre and post ganglionic fibres of the SNS, and where do these extend from?
Pre-G fibres are relatively short in length
Post-G fibres are relatively long in length
Preganglionic fibres extend from the spinal cord to the sympathetic ganglia, which are located near the spinal cord in the SNS
Postganglionic fibres extend from the sympathetic ganglia to the target organs in the SNS.
68
Where are baroreceptors located? and which does each monitor?
- carotid sinus
- aortic arch
The carotid sinus is located at the base of the internal carotid arteries, just above the bifurcation (division of something into two branches) where the common carotid artery splits into the internal and external carotid arteries. The baroreceptors in the carotid sinus monitor the blood pressure of the blood flowing to the brain.
Aortic arch is the part of the aorta that curves as it leaves the heart. The aortic arch baroreceptors monitor the blood pressure of the blood flowing through the systemic circulation.
69
Chemoreceptors are also involved in homeostasis.
What process do they control?
They detect changes in the chemical composition of the blood and other bodily fluids
70
What is the location of these chemoreceptors? and what does each control?
1. Peripheral chemoreceptors (carotid bodies, aortic bodies)
2. Central chemoreceptors
Carotid bodies are small clusters of chemoreceptors located at the bifurcation of the common carotid arteries into the internal and external carotid arteries. They monitor the levels of oxygen, carbon dioxide, and ph in the blood.
Aortic bodies are located near the aortic arch and similarly monitor blood levels of oxygen, carbon dioxide and ph. They are less sensitive than carotid bodies but contribute to respiratory regulation.
Central chemoreceptors are located on the ventral surface of the medulla oblongata in the brainstem. They primarily monitor the ph of the cerebrospinal fluid which indirectly reflects the levels of carbon dioxide in the blood. These chemoreceptors play a crucial role in regulating the rate and depth of breathing.
71
Where di post ganglionic nerves of the SNS go to involving the heart?
Post-G fibres go directly to the heart. The sympathetic cardiac nerves are found within the cardiac plexus.
Post-G fibres go to the SA Node and AV Node (in the walls of the heart) this controls rate and rhythm. What is another term for this:
= +ve cardiac regulation effect
Post-G fibres also go to the myocardium this controls the force of contraction
= +ve intropic effect
72
What is the effect of the PSNS on the heart and lungs? Which nerves are involved in going to the heart and lungs?
Heart- negative chronotropy (decreased heart rate), negative inotropy (slight reduction in contractility)
Lungs – bronchoconstriction (narrowing of the airways), increased mucus secretion.
Pre-G fibres travel in branches of the recurrent laryngeal and vagal nerves to the cardiac plexus. The post-G fibres end in the atrial walls.
73
In both the sympathetic and parasympathetic system, what receptors are stimulated or inhibited in the lungs?
SNS - primarily B2 adrenergic receptors. Primarily on bronchial smooth muscle causing bronchodilation
PSNS - primarily musacrinic M3 receptors. Primarily on bronchial smooth muscle and glandular tissue. Causes bronchodilation and increased mucus secretion.
74
How does increased sympathetic activity result in more forceful contraction?
Increased sympathetic activity causes increased epinephrine in blood and increased norepinephrine from sympathetic nerve endings. This stimulates primarily beta-1 adrenergic receptors. Causing an increased generation of cyclic AMP. Which increases phosphorylation of voltage gated calcium 2+ channels. Which increases opening time of the channels, which increase ca2+ influx from extracellular fluid, resulting in an increased ca2+ induced ca2+ release from the sarcoplasmic reticulum resulting in more forceful contractions.
75
How does increased sympathetic activity result in shorter contraction time?
increased sympathetic activity increases epinephrine in blood and increases norepinephrine from sympathetic nerve endings. This stimulates primarily beta-1 receptors. Causing an increase generation of cyclic AMP, which increases the phosphorylation of phospholamban, which increase transport of ca2+ from cytosol and back to the sarcoplasmic reticulum which results in a shorter contraction time.
76
What are heart mumurs?
Heart murmurs are unique heart sounds produced when blood flows across a heart valve or blood vessel.
77
What causes a heart murmur?
Turbulent flow causes a heart murmur. So not a calm smooth manner. The turbulence occurs because there is a hole in the heart between two chambers or two arteries that are not normally connected: these are mostly ventricular septal defects. Another cause is narrowing (stenosis) within a chamber or vessel through which the blood has to squeeze through.
78
What is the difference between a systolic and diastolic heart murmur?
The difference lies at the timing of the abnormal heart sounds during the cardiac cycle.
Systolic heart murmur– occurs between the lub and the dub noise, during ventricular contraction.
Diastolic heart murmur – occurs after the dub noise and before the lub noise, during ventricular relaxation.
79
What is generally meant when we say blood pressure?
aortic pressure
80
What are the important elements of the cardiac cycle?
Chamber pressure – blood flows high to low
Resistance – pre-load or afterload will affect filling
Heart valves (only AV) open/close according to pressure difference between chambers
81
What is a cardio phonogram?
A cardio phonogram is where in the cycle you can hear the noise of the heart.
82
What happens in S1 and S2?
S1 closing of the AV valves
S2 closing of the semilunar valves
(reverberation from the sudden block of flow)
83
Which of the following options describes the state of the heart valves during the ejection phase of the cardiac cycle?
A – Atrioventricular valves closed , semi-lunar valves open
B – Atrioventricular valves closed, semi-lunar valves closed
C – Atrioventricular valves open, semi-lunar valves closed
D – Aortic valve open, mitral valve open
E – Atrioventricular valves open, semi-lunar valves open
A
84
What are the 4 phases of the cardiac cycle? and what happens in each?
Filling phase (i.e. ‘diastole’)
Ventricles fill during diastole (and atrial systole).
Isovolumetric contraction phase
Ventricles contract, but volume remains constant because the heart valves are closed. Pressure builds.
Outflow phase (i.e. ‘systole’)
Ventricles contract, valves open, blood into aorta/pulm art.
Isovolumetric relaxation
Ventricles relax, ready for refill with blood in the next filling phase
85
Which events occur during systole or diastole? (isovolumetric contraction, rapid ejection, reduced ejection, atrial systole, isovolumetric relaxation, rapid ventricular filling, diastasis)
systole - isovolumetric contraction, reduced ejection, rapid ejection
diastole - atrial systole, isovolumetric relaxation, rapid ventricular filling, diastasis
86
What happens during atrial systole?
Last phase of diastole
(ECG (electrodiagram) P to R-wave)
Depolarisation of the atria leads to atrial contraction (see the ‘a’ wave on the atrial pressure curve).
A tiny amount of ‘topping off’ completely fills the ventricle.
87
What happens during isovolumetric contraction?
First phase of systole
Begins at the peak of the R-wave of the ECG
No real change in the volume of the ventricles during this phase
First heart sound (‘lub’) = closing of the A-V valves, associated blood turbulence when ventricular pressure exceeds atrial pressure
88
What happens during isovolumetric contraction?
During ST segment
When ventricular pressure exceeds that in the aorta or the pulmonary artery, semilunar valves open and rapid ejection (2/3) from the ventricles starts
‘c’ wave in the atrial pressure curve is caused by slight (due to papillary muscles) distension of the A-V valves into the atria (normally not measurable)
89
What happens during isovolumetric contraction?
Final phase of systole
Coincides with the T-wave of the ECG (ventricular repolarisation)
Blood flow out of the ventricles continues, but more slowly (hence, ‘reduced ejection’)
Eventually, pressure in the ventricle falls below that in the arteries. Semilunar valves close
90
What happens during isovolumetric relaxation?
First phase of diastole
Atria have been filling with blood (atop the closed A-V valves) and atrial pressure has been rising gradually
Blood flow out of the ventricles stops (hopefully the ventricles are sufficiently empty)
2nd heart sound (‘dup’) occurs when the semilunar valves close
91
What happens during rapid ventricular filling?
When ventricular pressure falls below atrial pressure, the A-V valves open.
This allows blood to flow from the atria into the ventricles.
sometimes a sound heard – indicative of congestive heart failure ? (atrial press. too high)
92
Which of the following best describes what happens during the isovolumetric contraction phase of the cardiac cycle
A – Both ventricles contract simultaneously, causing a pressure increase but no change in blood volume in the heart
B – Both ventricles contract simultaneously, causing blood to be ejected from the ventricles into the pulmonary artery/aorta
C – Blood flows into the ventricles from the atria passively (diastole and actively (atrial systole)
D – Both atria contract simultaneously, causing blood to enter the ventricles
E – The ventricles relax and the pressure in the pulmonary artery/aorta exceeds the ventricular pressure, causing the semi-lunar valves to close
A
93
Which of the stages of the cardiac cycle corresponds to the ST segment on an ECG?
A – Isovolumetric Contraction
B – Rapid Ventricular Ejection
C – Reduced Ventricular Ejection
D – Isovolumetric Ventricular Relaxation
E – Rapid Ventricular Filling
B
94
What role does venous return play in forming venous pulses?
Increased venous return elevates right atrial pressure and can exaggerate waveforms.
Decreased venous return diminishes the magnitude of the pulses.
95
Why is the venous pulse important?
The venous pulse is a dynamic reflection of the pressure changes in the right atrium caused by the phases of the cardiac cycle.
Careful observation of the venous pulse can offer critical insights into cardiac function and potential pathologies
96
What does the venous pulse waveform typically consist of?
the venous pulse waveform typically consists of three positive waves (a, c, and v wave) and three descents (x, x’, and y descent), each linked to specific phases of cardiac function…
97
What does the left ventricular pressure- volume loop graphically represent?
The ventricular pressure-volume (PV) loop graphically represents the relationship between pressure and volume in the left ventricle during a single cardiac cycle. This loop is instrumental in understanding cardiac mechanics, as it delineates the phases of ventricular filling, isovolumetric contraction, ejection, and isovolumetric relaxation
Look at image in folder
98
When will arterial and venous pulsee be felt?
Arterial pulse will be felt at max ventricular pressure (ejects into arterial network)
Venous pulse will reflect atrial pressure (and will not be as obvious)
99
What is an angiogram?
An angiogram is a type of X-ray used to examine blood vessels. They don’t show up on ordinary X-rays so a special dye is injected into the area being examined.
100
If something is tracheal pinch positive what does that mean?
He may gently rub the trachea to cause the pet to cough so he can listen to the sound (an elicited cough is known as a 'positive tracheal pinch').
101
fetal circulation unlabelled
labelled
102
Post natal circulation unlabelled
labelled
103
