2 Flashcards
1
Q
Which IC space does the superior border of the heart lie on?
A
2nd IC space
2
Q
At what vertebral level is the superior border of the right atrium located?
A
T4-5
3
Q
Why is the angle of Louis an important landmark?
A
It’s important because we know that this level marks the level of the intervertebral discs which lies between thoracic vertebra T4 and T5
4
Q
Where is the angle of Louis an important landmark?
A
Located at the superior border of R atrium
5
Q
Which cardiac chamber forms most of the inferior border of the heart?
A
RIght ventricle
6
Q
Which vein lies in the posterior mediastinum immediately R lateral to descending thoracic aorta?
A
Azygous vein
7
Q
Moving away from the heart, what’s the 3rd branch of the aorta?
A
3rd – L. common carotid
8
Q
What are adrenaline and noradrenaline classed as?
A
Alpha-adrenoceptor agonist
9
Q
Which structures does the ligamentum arteriosum attach to?
A
Pulmonary arteries and aorta
10
Q
What is the ligamentum arteriosum?
A
A remnant of the foetal ductus arteriosus that allowed passage of blood from the high-pressure pulmonary arteries to the aorta
11
Q
When does the ductus arteriosus close?
A
On day 1-2 of life in response to hyperoxia, it undergoes fibrosis to form the ligamentum arteriosum that inserts into the aortic arch opposite the left subclavian artery.
12
Q
What is the function of alpha-adrenoceptor agonists?
A
Induces smooth muscle and blood vessel contraction
13
Q
Which embryonic structure, is the brain derived from?
A
Neural tube
14
Q
Isoprenaline use + class
A
Use: Treatment of bradycardia, heart block, rarely for asthma.
Class: Non-selective beta-adrenergic receptor agonist
15
Q
Differentiate between: endocardium, myocardium, epicardium, pericardium
A
Endocardium – lines inside of heart
Myocardium – muscular tissue of the heart
Epicardium – visceral lining of the outside of heart
Pericardium – lines the cavity (one with epicardium)
16
Q
What endothelial ion change results in release of nitric oxide?
A
Increased calcium.
17
Q
Describe NO synthesis + how it affects blood vessels
A
Vascular endothelial cells produce NO from endothelial nitric oxide synthase (eNOS) in response to raised shear stress from blood flow.
eNOS is activated by a rise in intracellular calcium.
NO then diffuses into vascular smooth muscle cells and causes hyperpolarisation w/ a fall in intracellular Ca2+ in myocytes.
Result: vasodilatation
18
Q
How is a rise in blood pressure signalled to the CNS?
A
Increased firing in CN IX afferents from carotid sinus
19
Q
1st korotkoff sound indicates what?
A
Systolic blood pressuve
20
Q
In an ECG what does the P, Q, R, S + T represent?
A
P – Arterial depolarisation (systole)
QRS – Ventricular depolarisation (systole)
T – Ventricular repolarisation (diastole)
21
Q
What is the anterior interventricular artery a branch of?
A
L coronary artery
22
Q
Which arteries arise directly from the ascending thoracic aorta?
A
Coronary, brachiocephalic, L. common carotid, L subclavian
23
Q
What is the thymus gland anterior to?
A
Aorta, trachea, oesophagus
24
Q
What are chronotropic, and inotropic agents?
A
Chronotropic - Change the heart rate.
Inotropic - Modifying the force contraction of muscles.
25
GIve examples of positive + negative inotropic agents.
+ve = digoxin, insulin, catecholamines (A, NA)
-ve = beta-blockers
26
What does the P-R interval, S-T segment + Q-T interval on an ECG indicate?
P-R interval – Delay at AVN
S-T segment – interval between ventricular depolarisation + repolarisation
Q-T interval – Total time for ventricular depolarisation to repolarisation (prolongation or shortening increases risk of arrhythmias). It’s inversely proportional to HR
27
What is a negative chronotrope?
Something that decreases the HR
28
What class of drug is calcium-channel blockers + what effects does it have?
Negative chronotropic
- Reduces HR
- Vasodilation
Negative inotrope
- Reduce force of contraciton
- Reduce aldosterone production (blocking channels of adrenal cortex) ---> decreases BP
29
What class of drug is digoxin + what affects does it have?
Digoxin is a = +ve inotrope, -ve chronotrope
| Increases force of contraction, reduces HR.
30
What does ACh do to the HR?
| Which receptors does it target?
Targets muscarinic (M2) cholinergic receptors and decreases HR.
MoA: inhibition of T-type Ca2+ channels + activation of K+ GIRK channel. K+ efflux
--> hyperpolarised
31
What causes the 1st heart sound?
atrioventricular valve closure (mitral + tricuspid)
32
What causes the 2nd heart sound?
semilunar valve closure (aortic + pulmonary)
33
What does a larger P wave on ECG indicate?
P – Enlargement of atrium
34
What does a larger Q wave on ECG indicate?
Q – MI
35
What does a larger R wave on ECG indicate?
R – Enlarged ventricles
36
What is dromotropy?
Conduction velocity of AVN
37
What is lusitropy?
Relaxation of myocardium
38
What does the ‘x’ in the JVP waveform indicate?
Atrial relaxation
39
What does the ‘a’, ‘c’, ‘v’ + ‘y’ in the JVP waveform indicate?
a – atrial contraction
c – tricuspid bulging
v – filling of atrium
y – emptying of atrium to ventricle
40
What is stroke volume?
Vol of blood ejected by a ventricle in a single contraction
41
What is the formula to workout stroke volume (SV)?
SV = EDV – ESV
42
What is EF?
EF (%) = SV/EDV x100
43
What is isovolumetric contraction?
Isovolumetric contraction – ventricular volume unchanged, ventricles begin to contract, intraventricular pressure rises sharply.
44
What is isovolumetric relaxation?
Isovolumetric relaxation – ventricular pressure falls, volume of blood in chamber remains the same.
45
List the stages in the cardiac cycle + the state of the AV + semilunar valves at each point.
```
Atrial systole – AV=O, SL=C
Isovolumetric contraction – AV=C, SL=C
Ventricular ejection – AV=C, SL=O
Isovolumetric relaxation – AV=C, SL=C
Ventricular filling – AV=O, SL=C
```
46
Which nerves supply the mediastinal pleura (parietal + costal) lining of the chest wall + the pericardium?
Parietal – IC nerves + phrenic nerve
Costal – IC nerves
47
Which nerve is involved in swallowing?
When the swallow response is initiated, this center causes messages to be sent to the glossopharyngeal, the vagus, and the hypoglossal nerves. The glossopharyngeal is considered the major nerve for the swallowing center
48
A patient with a stab wound to the neck may be unable to maintain ventilation because of injury to which nerve?
Phrenic nerves
49
What is the cardiac plexus?
Plexus of nerves situated at the base of the heart
Formed by cardiac branches derived from both the sympathetic + parasympathetic nervous systems
50
What does the phrenic nerve supply?
| Where does it originate from?
C3-C5
| Innervates mediastinal pleura + diaphragm!!
51
What structure does the intercostal nerve supply?
Where does it arise form?
Arises from anterior rami of T1-T11
Supplies the intercostal muscles
52
What structure does the subcostal nerve supply?
Where does it arise from?
Arises from T12.
Innervates the transverse abdominis
53
What structure does the vagus nerve supply? a.k.a. the pneumogastric nerve
Innervates the heart, lungs + digestive tract.
Parasympathetic control.
54
What do juxta-glomerular cells synthesis + secrete?
Renin
55
What do chromaffin cells in adrenal medulla secrete?
Adrenaline, NA, little DA, enkephalin and few other hormones
56
What is the pattern in AF?
Irregularly irregular.
57
What is the cardiac plexus?
Plexus of nerves situated at the base of the heart.
Formed by cardiac branches derived from both the sympathetic + parasympathetic nervous systems.
58
What is SERCA? What is its function?
Sacro-endoplasmic reticulum Ca2+ - ATPase.
Resides in Sacro-ER within myocytes.
Transfers Ca2+ from cytosol of cell to ER by ATP hydrolysis during muscle relaxation.
59
What structure secretes ADH (vasopressin)?
Posterior pituitary
60
What structure responds to low blood flow by activation of an endocrine cascade?
Juxtaglomerular kidney cells are stimulated to release renin by signally from the macula densa
61
Where does adrenaline act on in the heart?
B1-adrenoceptors via cAMP on:
```
SAN (increase rate),
Atrial muscle (increase force),
AVN (increase automaticity),
Ventricular muscle (increase automaticity + force)
```
62
Where does the superficial part of the cardiac plexus lie?
Beneath aortic arch, anterior to R pulmonary A.
63
At what vertebral level do the renal arteries branch from the aorta?
L1
64
Where may the dorsalis pedis pulse be palpated?
Lateral to extensor hallucis longus tendon on the dorsal surface of the foot
65
How does the ultrastructure of a vessel change in atherosclerosis?
Tunica intima thicken;
Little change to the adventitia.
Tunica media thickens, w/ increased elastin + muscle - this adds to the raised resistance.
66
What is the role of the atrioventricular node?
Delay atrio-ventricular depolarisation
67
What ventricular ion movements are responsible for the Q-T segment seen on ECG?
Sodium + calcium influx, potassium efflux
68
What ion movement is responsible for the pre-potential of SAN + AVN?
Na+ influx (leak channels) – are continuously open to allow sodium influx that causes gradual depolarisation
69
How does parasympathetic stimulation alter ion movements in cardiac pacemaker cells?
Increased potassium efflux.
When ACh from vagus nerve act son muscarinic receotrs
70
Which ion acts on ventricular contraction?
Calcium
Sympathetic stimulation increases sodium + calcium permeability via B1-adrenoceptor activation
71
Increased CO2 causes the oxygen-dissociation curve to shift in which direction?
Right (Bohr shift). Hb gives up oxygen more readily.
72
What is the infundibulum?
Infundibulum (a.k.a. conus arteriosus) – conical pouch formed from the upper + L angle of R ventricle in the chordate heart, from which the pulmonary trunk arises. It develops from the bulbus cordis.
Area proximal to the pulmonary valve.
73
What are the 2 contractile proteins that make up cardiac muscle?
Actin + Myosin
74
What does NA do to the heart + how in detail?
Binds to the beta-1-adrenergic receptor
Activates funny sodium channel and T-type calcium channel so sodium and calcium ions enter and depolarise SAN
75
Which complex is attached to tropomyosin?
Troponin
76
What makes up cardiac myocytes?
Myofibrils
77
What is one functional unit of the heart muscle called?
Sarcomere
78
Where does calcium ions bind on actin for muscle contraction?
TnC subunit of troponin TnI stops inhibiting myosin from binding to actin.
79
What does phospholamban activate when triggered?
Activates a pump on the sarcoplasmic reticulum (SR) which causes Ca2+ to be taken up by the SR.
80
Name the 3 subunits of troponin. What are their functions?
TnT – keeps whole complex bound to tropomyosin
TnC – binding site for Ca2+ --> triggers contraction
TnI – inhibits myosin binding to actin
81
Describe the structure of actin filaments.
Globular actin proteins forming 2 helical strands.
Between strands = rod shaped protein (tropomyosin) cover the binding sites.
Actin = thin filament.
82
What do myosin heads contain?
2 heads that contain myosin ATPase
83
What is the hinge + tail region of myosin made up of?
Heavy alpha helix chains
84
Which is the thin filament + which one is the thick?
Actin = thin, myosin = thick
85
Why is hydrolysis of ATP necessary to allow actin + myosin to interact forming a cross-bridge?
Hydrolysis of ATP energises the molecule, cocking it as myosin heads move along the thin filament.
ADP + Pi stays attached to thick filament.
Pi is released which cocks the myosin head from 90 degrees to 45 (power stroke)
86
How does depolarisation of cardiac muscle cells differ from that of other muscle cells?
Repolarisation takes much longer to occur thus cells cannot be stimulated at high frequency.
This prevents cardiac muscles going into tetanus.
87
Which rod shaped proteins cover the myosin binging sites on the actin filament?
Tropomyosin
88
Where does Ca2+ come from before they bind to TnC?
Sarcoplasmic reticulum + external environment
89
What does spirometry measure?
Ventilation (volumes of gases in + out of lungs)
90
How many branches does are there from the bronchi to alveolar sacs?
23
91
What is dead space?
Anatomical – bits that don’t exchange gases e.g. conducting zone
Physiological – alveoli that are ventilated by not perfused by oxygen e.g. damaged walls of alveoli
92
Where does the venous sinus of the heart run along?
In the posterior AV groove
93
What is the role of 2,3-diphosphoglycerate?
2,3-DPG – by-product of anaerobic metabolism that increases oxygen delivery to tissues by reducing oxygen’s affinity w/ Hb.
Anaerobically respiring tissues produce more 2,3-DG so have greater delivery of oxygen from Hb.
94
What is the Bohr effect?
Right shift of oxygen dissociation curve
95
Why is the dissociation curve of HbF a different shape to that of HbA?
Gamma-chains cannot bind 2,3-DPG --> doesn’t reduce oxyhaemoglobin affinity --> Hb has higher affinity for O2.
96
What globin chains are present in HbF?
2 alpha + 2 gamma
97
What globin chains are present in HbA?
2 alpha + 2 beta
98
What is methaemoglobin?
Hb with oxidised iron
99
What does methaemoglobin reductase do?
Convert iron back to Fe2+ (the reduced state for oxygen to bind to haemoglobin)
100
What is carboxyhaemoglobin?
Hb with carbon monoxide bound
101
What is the shape of the myoglobin-oxygen dissociation curve?
Hyperbolic – because there is only one molecule to bind + after that it becomes fully saturated
102
What is the shape of the haemoglobin-oxygen dissociation curve?
Sigmoidal – because there are 4 oxygen molecules to bind at they show co-operative binding.
103
How do oxygen saturations change in anaemia?
No change in oxygen saturation.
Anaemia = a reduction in the conc. of haemoglobin per volume of blood. Oxygen carrying capacity reduced.
104
What is the name given to the process by which oxygen shifts the CO-Hb dissociation curve right?
Haldane effect – describes the relationship between the Hb-CO2
105
What percentage composition of whole blood, is cells?
45%
106
What is the haematocrit?
Percentage of whole blood that is RBCs
107
What is the most prevalent plasma protein + what are its functions?
Albumin – synthesised in the liver
| Exerting oncotic pressure to maintain of intravascular volume + binding of substances to aid in their transport.
108
What is C-RP?
1 of the acute proteins involved in activating complement.
109
What is blood serum?
Whole blood w/ all cells + clotting factors removed
110
How are platelets produced?
Budding off megakaryocytes.
111
What type of tissue is blood?
Connective
112
What ratio of water to solutes are in blood plasma?
91:9
113
Define haemopoiesis.
| Where does it occur + what is involved?
The formation of blood cells from haemopoietic stem cells in red bone marrow.
114
What do myeloid stem cells form?
RBCs, platelets, granulocytes, monocytes.
115
What do lymphoid stem cells form?
Lymphocytes
116
What is a cord-blood transplant?
In a cord-blood transplant, stem cells from the placenta are removed from the umbilical cord.
117
Where does the R + L atrium receive blood from?
R – Superior + inferior vena cava + coronary sinus
| L – 4 pulmonary veins (oxygenated blood)
118
Where + what is the fossa ovalis?
On the interatrial septum.
It’s an oval depression, the remnant of the foramen ovale, an opening in the interatrial septum of the foetal heart that normally closes soon after birth
119
What is the fibrous skeleton of the heart made up of?
Dense connective tissue surrounding + supporting heart valves
120
In embryonic folding, folding on the horizontal + median plane produces what?
Median – head fold + tail fold
Horizontal – 2 lateral folds
Overall curves embryo into a C shape.
121
What lies above the developing brain then moves down?
Cardiogenic mesoderm
122
What is the main force responsible for embryonic folding?
The different rates of growth of various parts of the embryo, especially the rapid longitudinal growth of the neural tube.
123
On the median plane the neural fold strengths to form what?
The beginning of the CNS.
124
Where does the oropharyngeal membrane form?
At the head end.
125
Where does the cloacal membrane form?
At the tail end.
126
What does the primitive gut differentiate into?
Anterior – foregut, intermediate – midgut, posterior – hindgut
127
What does the diaphragm develop from?
Septum transversum (central tendon), pleuroperitoneal membranes, dorsal mesentery of oesophagus, muscular components from somites at C3-5 levels.
128
What is the yolk sac a precursor to?
Umbilical cord
129
What does the parietal + visceral mesoderm cover?
Visceral – serous membranes covering organs.
Parietal – walls of peritoneal, pleural, pericardial cavities. They are continuous at the roots of each organ in their cavities.
130
Where is the septum transversum initially located?
Opposite cervical segments C3, C4, C5; muscle cells for diaphragm + phrenic nerve arises from these segments.
131
What cavities does the diaphragm separate?
The thoracic + abdominal cavities.
132
What does the specialised bit of mesophilia of gut allow?
Allows gut to move away from the body wall brining the blood vessels with it.
133
Pericardial + peritoneal cavities communicate via what?
Pericardioperitoneal canal – a tubular space.
134
What are invaginations of the ventral gut wall cranial to the septum transversum?
Lungs
135
The septum transversum is incomplete where?
Dorsally
136
Which nerve(s) innervates the diaphragm?
C3,4,5
137
What is the respiratory diverticulum (lung bud)?
An embryological structure of endodermal origin that develops into organs of resp system (larynx, trachea, lungs).
138
How does the thoracic cavity separated into the pleural + pericardial cavities?
Blood vessels + phrenic nerve on either side of diaphragm moves in towards the midline forming pleuropericardial folds.
139
Lungs expand in which direction when growing.
Laterally + ventrally
140
What does the respiratory diverticulum form?
Elongates its distal ends + enlarges to form a globular tracheal bud (which gives rise to trachea)
141
What does the tracheal bud divide into?
The bronchial buds which branch repeatedly + develop w/ bronchi.
142
At what day/week/month has all major elements of the lungs formed? + what hasn’t?
Day 64
| Everything except the respiratory bronchioles, alveolar ducts + alveoli. Foetus can’t survive if born now.
143
Differentiate between type 1 + type 2 alveolar cells.
Type 1 – main site of gas exchange
Type 2 – surfactant-producing cells
144
What lies between the visceral + parietal pleura?
Pleural cavity (has small amount of lubricating fluid).
145
What is congenic diagrammatic hernia + what does it cause?
When the pericardioperitoneal canal fails to close causing the gut to pop up into thoracic cavity --> lung stops developing properly.
146
What is ventilation + the 2 types of respiration?
Pulmonary ventilation – breathing
Pulmonary respiration – gaseous exchange between alveoli + blood in pulmonary capillaries.
Physical process. Blood loses CO2 + gains O2.
Tissue respiration – gaseous exchange between blood in systemic capillaries + tissue cells. Metabolic process. Blood loses O2 + gains CO2.
147
Strenuous exercise increases O2 usage by how much?
15-20-fold in normal healthy adults
148
When are the intercostal muscles used?
Internal – only used in exercise for expiration. Normally exhalation is a passive process.
External – inspiration
149
What is the main muscle of breathing?
The diaphragm – innervated by the phrenic nerve
150
What alters the size of the thorax?
The action of the breathing muscles (which contract due to nerve impulses from respiratory centre of the brain + relax in the absence of nerve impulses)
151
Where is the medullary respiratory centre + pontine respiratory group?
Medulla oblongata + pons
152
Which 2 collections of neurons are the medullary resp centre made of?
DRG – inspiratory movements + rhythm, quiet + forced breathing, when DRG inactive ---> muscles relax
VRG – inspiratory + expiratory centre, forced breathing.
153
When does the VRG become inactive?
During quiet breathing
154
Name the accessory muscles of inhalation.
Sternocleidomastoid, scalenes, pectoralis minor
155
Name the accessory muscles of exhalation.
Internal intercostal, external oblique, internal oblique, transversus abdominis, rectus abdominis
156
Name the primary muscles of inhalation.
Diaphragm – phrenic nerves
| Ext. intercostal muscles – intercostal nerves
157
When is the PRG active?
During inhalation + exhalation.
158
What controls ventilation? Is it voluntary/involuntary?
ANS w/ limited voluntary override
159
How are we able to voluntarily alter our RR?
Cerebral cortex has connections w/ resp centre
160
Why are we able to alter our respiratory pattern?
Protective – prevent H2O, irritating gas entering lungs.
161
When pCO2 + H+ increases, what happens?
DRG neurons of medulla are strongly stimulated, impulses sent along phrenic + intercostal nerves to inspiratory muscles --> breathing resumes
162
Where are chemoreceptors found?
Central – in/near medulla oblongata in CNS
• CO2, H+
Peripheral – aortic bodies, carotid bodies
• CO2, H+ (pH), O2
163
What do chemoreceptors monitor?
Levels of CO2, H+ (pH), O2
164
Which axons innervate aortic + carotid bodies?
Aortic – vagus nerves
| Carotid – glossopharyngeal nerves
165
How is CO2 concentration + pH linked?
CO2 is lipid-soluble, it diffuses into cells + combines w/ water to form carbonic acid (H2CO3) which breaks down into H+ + HCO3-
More CO2 more H+ lower the pH more acidic
166
What is hypercapnia?
Increase in pCO2
167
What happens in respiratory failure?
CO2 accumulates so the chemoreceptor trigger zones get down regulated. As CO2 accumulates, body maintains more bicarbonates in kidneys to balance the acidosis.
168
When does peripheral chemoreceptors respond to changes in pO2?
When pO2 in arterial blood falls below 100mmHg but is still above 50mmHg
169
Name + explain the 2 types of respiratory failure.
Type 1: O2 deficiency
| Type 2: high CO2 levels (more common)
170
What can very high levels of CO2 act as?
A narcotic
171
What affect does NA have on RR?
NA causes us to breathe more – sympathetic NS
172
How does hyperventilation cut of cerebral blood flow?
Too much CO2 blown off --> contracting due to alkalosis
173
What is the only use of adrenaline in humans?
Prevent hypoglycaemia
174
How does progesterone affect ventilation?
Causes hyperventilation (increases ventilation rate)
175
What are present in peripheral joints relating to the respiratory system?
Sensory mechanoreceptors. When joints move, body anticipates greater need for oxygen.
176
What does the vagus nerve innervate?
Larynx (via laryngeal nerve), pharynx, lung, heart, liver, guts + is the nerve in the aortic body.
177
What is the volume of air left in the chest after a full expiration called?
Residual volume
178
What is the volume of air left in the chest after a normal expiration called?
Functional residual capacity
179
What is the functional residual capacity?
Volume of air that is still present in the lungs at the end of passive expiration.
180
What is FVC + FEV1?
FVC – forced vital capacity
| FEV1 – forced expiratory volume in 1 second.
181
In obstructive lung diseases (such as asthma, COPD + chronic bronchitis) how is the FEV1/FVC ratio affected?
FEV1/FVC ratio reduced because FEV1 is reduced but FVC is normal.
182
In restrictive lung diseases (such as pulmonary fibrosis + scoliosis) how is the FEV1/FVC ratio affected?
Approx. normal because both FEV1 + FVC reduced.
183
Pulmonary irritant receptors (cough receptors) in the epithelium of the respiratory tract are sensitive to what?
Mechanical + chemical stimuli.
184
Where are pulmonary irritant receptors mainly located?
Trachea, pharynx, carina of trachea
185
When the cough receptors are triggered where does the impulse travel?
Via the recurrent laryngeal nerve --> superior laryngeal nerve --> vagus nerve --> medulla --> glottis, external intercostal nerves, diaphragm, etc. via vagus + superior laryngeal nerves.
186
What is partial pressure of a gas a measure of?
The concentration of a gas in a mixture of gases. Measured in mmHg or kPa.
Dissolved gasses exert partial pressure on other surfaces exerting pressure.
187
What is vital capacity (VC) + residual volume (RV)?
Total lung capacity (TLC)
188
What is tidal volume (VT) + IRV + ERV?
Vital capacity
189
What can’t be measured by spirometry?
RV + FRC. A helium dilution method is used or plethysmography.
190
What does the coronary sinus receive + where from?
Left – great cardiac vein
| Right – small + middle cardiac veins
191
When does an increased residual volume (RV) occur?
In emphysema, COPD, sometimes asthma
192
What is peak expiratory flow rate (PEFR)?
Measures airway obstruction by measuring FEV1
193
What is the driving force of gas transport?
Pressure gradients: -ve intrathoracic pressure --> ventilation + partial pressure differences.
194
Why is pressure in alveolar air lower than inspired air?
Water vapour dilutes amount of pressure exerted on gases. Rapid diffusion of air in alveoli.
195
What affects rate of diffusion of O2 + CO2 from aqueous lining of alveoli to blood?
Partial pressure of the gas, solubility of the gas in liquid, area available for exchange, thickness of alveolar membrane
196
Is pulmonary A. blood, oxygenated or deoxygenated?
Deoxygenated like systemic vein
197
In haemoglobin, what state is iron in?
Ferrous state (Fe2+)
198
What is the Haldane effect?
Left shift of the haemoglobin-oxygen dissociation curve
199
What is 2,3-DPG?
A by-product of anaerobic respiration.
200
What is pre-load?
Initial stretching of the cardiac myocytes prior to contraction.
Vol being returned to R side of the heart from systemic circulation.
201
What is after-load?
Degree of resistance that the L ventricle must overcome to pump blood out of the heart. Afterload is squeeze.
202
In which form(s) is CO2 transported in the blood?
70% - bicarbonate (HCO3-)
23% - carbaminohemoglobin (HbCO2)
7% - dissolved in blood (CO2)
203
Under what conditions does CO2 readily bind to Hb?
In low O2 environments (respiring tissues) – Haldane effect.
204
What does carbonic anhydrase catalyse?
These are reversible reactions, it catalyses both.
H2O + CO2 --> H2CO3 --> HCO3- + H+ (tissues)
HCO3- + H+ --> H2CO3 --> H2O + CO2 (lungs, kidney)
205
How does: hyperventilation, hypoventilation, diabetic ketoacidosis, renal failure + vomiting change pH?
Hyperventilation, vomiting – alkalosis
Hypoventilation, ketoacidosis, renal failure – acidosis
206
Explain what happens in respiratory acidosis.
```
Lungs retain CO2
HCO3- rises + pH falls
Kidney compensates by excreting H+ + retaining HCO3-
This increases pH to normal levels
But HCO3- + pCO2 remain high
```
207
Explain what happens in respiratory alkalosis.
```
Lungs lose excess CO2
HCO3- falls + pH rises
Kidney compensates by retaining H+ + excreting HCO3-
This decreases pH to normal levels
But HCO3- + pCO2 remain low
```
208
Anatomically what is the upper respiratory tract?
Nose, nasal cavity, paranasal sinuses, pharynx
209
Functionally what is the upper respiratory tract?
Conducting zone: nose, pharynx, larynx, trachea, bronchi, bronchioles
210
Anatomically what is the lower respiratory tract?
Larynx, trachea, bronchi, lungs
211
Functionally what is the lower respiratory tract?
Respiratory zone: respiratory bronchioles, alveolar ducts, alveoli
212
What are the anterior + posterior apertures of the nose + nasal cavity?
Anterior – anterior nares (nostrils)
| Posterior – posterior naris (choanae posterior – which open into the nasopharynx)
213
What is the nasal cavity separated into + from?
Into 2 nasal cavities – midline nasal septum
From oral cavity – hard palate
From cranial cavity – frontal, ethmoidal + sphenoidal bones
214
What are conchae (turbinates)?
Walls that divide both nasal cavity into 4 air channels by 3 curved shelves of bone (conchae) (project medially across nasal cavity).
215
What are the functions of the nasal cavity?
Olfaction; filter, humidify + warm inhaled air; provide an airway as a resonating chamber for speech
216
Name the 3 conchae + 4 nasal meatuses/recesses.
```
Spheno-ethmoidal recess
Superior concha
Superior nasal meatus
Middle concha
Middle nasal meatus
Inferior concha
Inferior nasal meatus
```
217
What is the function of the conchae?
Increase the surface area of contact between tissues of the lateral wall + inspired air.
218
Which 3 bones create the choanae (posterior aperture)?
Palatine bone, vomer, sphenoid bone
219
Name the 4 paranasal air sinuses.
Frontal sinuses, ethmoidal sinuses, spheroidal sinuses, maxillary sinuses.
220
Where are openings of the paranasal sinuses?
On the lateral wall + roof of nasal cavities.
221
What are paranasal sinuses lined by?
Respiratory mucosa (same as nasal cavity) – ciliated + mucus secreting
222
What innervates sinuses?
Branches of the trigeminal nerve (CN V)
223
What are the functions of sinuses?
Lighten skulls, increase resonance of voice, produce mucus
224
Where does the maxillary sinuses drain into nasal cavity?
Through a small hole to middle meatus.
225
Where does the sphenoidal sinuses drain into the nasal cavity?
Into the spheno-ethmoidal recess.
226
Where does the posterior ethmoidal sinus drain into?
Into the superior meatus.
227
Where does the frontal sinus + maxillary sinus drain into?
Into the middle meatus.
228
Where does the anterior + middle ethmoid air sinuses drain into?
Into the middle meatus.
229
Where does the nasolacrimal duct drain into?
Into the inferior meatus
230
What is the nasolacrimal duct?
When you cry, tears drain into the nasal cavity down the lacrimal sac, through nasolacrimal duct, into inferior meatuses of nasal cavity.
231
What is sinusitis?
Inflammation of the sinuses. Sinuses are mucous lined so if there is a blockage, fluid will build up + infections can spread.
232
What are the most important arteries of the nasal cavity?
Septal branch of the: anterior + posterior ethmoidal artery, sphenopalatine, nasal artery from superior nasal labial artery + terminal part of greater palatine artery.
233
What is epistaxis + where does it occurs usually?
Bleeding from the nose, occurs at junction between septal branches of the superior nasal labial artery + sphenopalatine arteries.
234
What is the respiratory mucosa made up of?
Pseudostratified ciliated columnar epithelium + goblet cells.
235
What is the function if the respiratory mucosa?
Traps + moves unwanted bodies in correct direction (cilia) + warm inhaled air (mucus)
236
What specialised lining can be found in the nasal cavity?
Olfactory mucosa.
237
How is the pharynx bound?
Anteriorly – not bound
Inferiorly – cricoid cartilage
Superiorly – base of skull
Posteriorly – oesophagus
238
What are the 3 openings of the pharynx?
Nasal cavity, oral cavity, larynx.
239
How many regions does the pharynx have + what are they?
Nasopharynx – inferior to posterior apertures, bound by base of skull to uvula + soft palate.
Oropharynx – soft palate to epiglottis.
Laryngopharynx – epiglottis to cricoid.
240
What is the otitis media?
The inner ear
241
What role do tonsils play?
First line of defence against pathogens.
242
Where do adenoids (pharyngeal tonsils) lie?
Base of cranial cavity, on nasopharynx
243
Where do palatine tonsils lie?
Behind the uvula, below soft palate
244
What is the larynx inferior, superior + anterior to?
Inferior to – cricoid cartilage
Superior to – laryngeal inlet
Anterior to – oesophagus
245
What does the larynx connect?
The pharynx to the trachea
246
What is the larynx commonly known as?
The voice box
247
What 3 regions Is the larynx divided into?
Supraglottis, glottis, subglottis
248
Name the 9 cartilages that join to form larynx.
3 unpaired – epiglottis, thyroid, cricoid
| 3 paired – arytenoid, cuneiform, corniculate
249
What the Adam’s apple?
Thyroid cartilage
250
What is the primary function of the larynx?
Vocalisation
251
What are the false + true vocal cords?
True folds – true vocal cords
| False folds – vestibular folds (superior to true folds)
252
How does phonating work?
Vocal folds + arytenoid cartilages are adducted + air is forced through the close rima glottis.
Causes vocal folds to vibrate against each other + produce sounds.
253
What is the secondary function of the larynx?
Help w/ breathing, protection during swallowing
254
What narrows the rima glottidis?
Laryngeal muscles attached to the cartilages + elastic ligaments of vocal folds’ contract, they move the cartilage + pull elastic rights, narrowing the rima glottidis.
255
What occurs during deglutition?
Swallowing. Backward motion of the tongue forces epiglottis over glottis’ opening + prevent swallowed material entering the larynx + then the lungs.
256
Which nerve innervates the larynx?
Sensory + motor branches of the vagus nerves:
| Recurrent laryngeal nerve + superior laryngeal nerve
257
Which muscle pulls the clavicles + rib cage upward?
Sternocleidomastoid.
258
In blood vessels, higher resistance + higher pressure gradient causes what?
Higher resistance – lower the flow.
| Higher pressure gradient – higher the flow.
259
What does impulses from the vasomotor nerves do to the blood vessels?
Vasoconstriction
260
All the intrinsic muscles (except cricothyroid) are innervated by which nerve?
Inferior (recurrent) laryngeal nerve – terminal branch of superior laryngeal nerve
261
What nerve is the cricothyroid innervated by?
External branch of superior laryngeal nerve.
262
Name the intrinsic laryngeal muscles.
Posterior cricoarytenoid, lateral cricoarytenoid, thryoarytenoid, cricothyroid.
263
What are the extrinsic laryngeal muscles comprised of?
Suprahyoid + stylopharyngeus – elevate the larynx.
| Infrahyoid – depress the larynx
264
What do the extrinsic laryngeal muscles act to move the larynx?
Move the larynx superior + inferiorly.
265
What do the intrinsic laryngeal muscles control?
Shape of rima glottidis, length + tension of vocal folds.
266
Flow is proportional to what?
To the 4th power of the resistance.
So, if you double the diameter of a tube, flow increases by 24 = 16-fold.
267
Tissue flow is determined by what?
Determined locally by tissue demand.
268
What is resistance?
The impediment to blood flow along a vessel.
269
Why do tissues manipulate the resistance of blood flow?
BP is kept consistence + the tissues still get the flow they need.
270
How do tissues control flow?
By contracting + relaxing precapillary sphincters around the arterioles.
271
Where are arterial baroreceptors located?
Walls of the carotid arteries + aortic arch.
272
How is BP controlled in the long-term?
Pressure diuresis: increase urine output + reduce blood volume thus reducing BP
Renal control: RAAS
Other hormones: natriuretic peptides, ADH
273
What does renin do?
Renin turns Angiotensinogen to Angiotensin I.
274
Where is angiotensinogen released from?
Angiotensinogen release from liver.
275
Where is renin from?
Renin from juxtaglomerular cells in kidneys
276
Aldosterone leads to what?
Sodium + water retention.
277
What can you treat hypertension with?
Diuretics, beta-blockers -olol, calcium antagonists -ipine, ACE inhibitors -pril, ARBs (Ang receptor blockers) -sartan, Aldosterone inhibitors (spironolactone)
278
List the functions of blood vessels.
Distribution of blood around body, site of gas transfer, site of solute transfer, role in haemostasis + inflammatory processes
279
Which vessel layer has smooth muscle?
Tunica media. Also has external elastic lamina + associated connective tissue w/ collagen + elastin fibres
280
Where is vasa vasorum found?
Tunica externa
281
In which blood vessel layer is the endothelium found?
Tunica intima
282
Where is internal + external elastic lamina found?
Internal – between tunica intima + media
External – between tunica media + externa
283
Which arteries does the great, middle + small cardiac veins run along?
Great – anterior IVS
Middle – posterior IVS
Small – right marginal
284
Which arteries does the great, middle + small cardiac veins run along?
Great – anterior IVS
Middle – posterior IVS
Small – right marginal
285
What makes muscle contraction in smooths vessels (like blood vessels) different from skeletal muscle?
Smooth muscles don’t have sarcomeres; is a single cell, more sustained contraction, uses minimal ATP, can contract over a large range whereas skeletal muscle can only contract the size of the sarcomere.
286
What is the epithelium of vascular system made up of?
Simple squamous epithelium.
287
What are elastic arteries + muscular arteries?
Elastic – tunica media rich in elastin (large arteries)
Muscular – tunica media have more smooth muscle (smaller arteries + arterioles)
288
In which vessels is the tunica media almost absent?
Capillaries
289
Name the 3 types of capillaries.
Continuous (generic type), fenestrated, discontinuous (sinusoid).
290
Where are discontinuous (sinusoid) capillaries found?
In tissues where cell + molecules exchange (liver, spleen).
291
Where are fenestrated capillaries found?
In tissues w/ high exchange function (small intestines, kidney, endocrine glands).
292
Where are continuous capillaries found?
CNS, lungs, muscle tissue + skin.
293
When hydrostatic pressure is lower than blood colloidal osmotic pressure, what happens to fluid in peripheral tissues?
Fluid absorbed
294
What happens when hydrostatic pressure is greater than osmotic?
Fluid is filtered (exits capillaries)
295
What are cardiac myocytes joined via?
Intercalated disc containing gap + adherens junctions providing electrochemical coupling + mechanical linking
296
Which chamber(s) make up the left border of the heart?
LEFT ventricle
297
Which chamber(s) forms the right border of heart?
Right atrium
298
ANother name for coronary sulcus
atrioventricular groove
Divides atria from ventricles
299
In 60% of humans, which vessel supplies the SAN?
Right coronary artery. The AVN is also supplied by the right coronary artery in 80% of humans.
300
At which vertebral level does the inferior phrenic, celiac, superior mesenteric, middle suprarenal, renal, gonadal, lumbar, inferior mesenteric, media sacral + common iliac arteries branch off the abdominal aorta?
Inferior phrenic – T12, Celiac – T12, Superior mesenteric – L1,
Middle suprarenal – L1, Renal – L1, Gonadal – L2, Lumbar – L1-4,
Inferior mesenteric – L3, Median sacral – L4, Common iliac – L4
301
What is the function of the sinuses of Valsalva?
Promote coronary artery blood flow during diastole
302
Where does the anterior + posterior interventricular sulci run?
Vertically on their respective sides of the heart.
303
Where is the transverse pericardial sinus found?
Superiorly on to left atrium, anterior to the superior vena cava, posterior to the ascending aorta + pulmonary trunk
304
Where is the oblique pericardial sinus found?
Posterior surface of the heart. It’s a blind ending passageway (‘cul de sac’)
305
What can the transverse pericardial sinus be used for?
To identify + subsequently ligate the arteries of the heart during coronary artery bypass grafting.
306
Where is the mediastinum located?
Central compartment of the thoracic cavity, between the 2 pleural sacs
307
What makes up the floor of the mediastinum?
Floor – diaphragm
308
What makes up the posterior border of the anterior mediastinum?
Pericardium
309
Where is the thyroid gland located?
In the anterior neck – C5 to T1
310
What does azygous mean?
Unpaired
311
What does the azygous vein carry?
Runs up the side of the thoracic vertebral column, drains into superior vena cava.
Carries deoxygenated blood from posterior walls of thorax + abdomen.
312
Which vessels anastomose to form the posterior interventricular artery?
Right coronary and left circumflex
313
Which vessels does the left main stem divide into?
Anterior interventricular and left circumflex
314
Where does the coronary sinus lie?
Posterior atrio-ventricular groove
315
Vertebral arteries are direct branches of which artery?
Subclavian
316
Where does the posterior surface of the heart lie?
Between T5 + T8
317
WHat's another name for visceral pericardium?
EPicardium
318
What lies between the 2 left + 2 right pulmonary veins?
Oblique pericardial sinus
319
What is the auricle?
Protrusion of the surface wall of each atrium.
320
What is the crista terminalis?
The junction between the sinus venosus + the heart
321
Where does the coronary sinus drain into + what does it drain?
Receives blood from 3 main cardiac veins: great, middle + small. Drains into posterior of R atrium.
322
What are the musculi pectinati?
Parallel ridges in the walls of the atria of the heart.
323
What is the smooth + rough walls of the atrium called?
Smooth – sinus venarum. Rough – musculi pectinate
324
What is the crista terminalis?
A chest which separated rough + smooth walls.
325
Which valves have no chordae tendineae or papillary muscles?
Semilunar
326
How many pulmonary veins drain into the left atrium?
4
327
Where does the SAN lie?
Crista terminalis.
328
What is the function of the papillary muscles + chordae tendineae?
Papillary muscles are in ventricles, they attach to cusps of AV valves (tricuspid + mitral) via the chordae tendineae.
Papillary muscles contract, prevents inversion/prolapse of these valves, blood flow back to atria, on systole (ventricular contraction).
329
When the papillary muscles relax, what happens?
The atrioventricular valves close.
330
What happens when the papillary muscles contract?
The chordae tendineae become taut + close AV valves.
331
What are chordae tendineae?
Cord-like fibrous tendons.
Attach to mitral/tricuspid valves on one end + papillary muscles on the other.
332
What arteries does the R coronary artery give off?
```
Marginal A. – branches off at inferior border to apex
Posterior descending (interventricular) A.
```
333
What does the R coronary artery run along?
The R atrioventricular groove
334
What does the R coronary artery supply?
R atrium, R ventricle,
| posterior 1/3 of interventricular septum
335
What does the L coronary artery supply?
L atrium, L ventricle,
| anterior 2/3 of interventricular septum
336
Where does the visceral + partial pleura join?
Hilum
337
How many lobes and fissures does the right lung contain?
2 fissures: horizontal + oblique (horizontal more superior)
| 3 lobes: superior, middle, inferior
338
How many lobes and fissures does the left lung contain?
1 fissure: oblique
| 2 lobes: superior + inferior
339
Which lobe of the lung is entirely at the front?
RML (right middle lobe)
340
In which position is the pulmonary artery relative to the bronchus in the R + L hilum?
R hilum – pulmonary A. anterior to bronchus
| L hilum – pulmonary A. superior to bronchus
341
List the 3 main divisions of the celiac trunk.
L gastric A.; common hepatic A.; splenic A.
342
Which arteries supplies the duodenum?
Superior part – celiac artery
| Inferior part – superior mesenteric artery
343
Name the main branches of the abdominal aorta.
Celiac trunk; Superior mesenteric A.; Inferior mesenteric A
344
What does the superior + inferior mesenteric arteries anastomose via?
Marginal artery of colon
345
Where does the R gastric A. arise from?
The proper hepatic artery
346
Name the branches of the L gastric A.
Oesophageal branch + stomach branch.
347
Which arteries give off the supra renal arteries?
Inferior phrenic
348
Which arteries supply the lungs?
Bronchial arteries
349
Which arteries supplies the lungs deoxygenated blood?
Pulmonary arteries.Pulmonary arteries.
350
Which phrenic nerve innervates diaphragm from above + which innervates from below?
L – above
| R – below
351
What is oncotic pressure?
The force exerted by attraction of water molecules to plasma proteins that are unable to pass through capillaries.
352
What is hydrostatic pressure?
Pressure that blood exerts in the capillaries so fluid moves out through pores into the interstitial space.
353
Why are ribs 11 + 12 known as the floating ribs?
Because they do not attach to the sternum at all.
354
Which ribs are known as the true ribs + why?
1-7; because they attach to sternum via their own costal cartilage
355
Which ribs are known as the false ribs + why?
8-12; because they don’t attach to sternum via their own costal cartilage.
