Week 2 Flashcards
1
Q
What makes up interstitium?
A
Collagen and proteoglycan factors
2
Q
What is a Crystalloid?
A
Low molecular weight solutes ie. ions, easily diffuse
3
Q
What is Colloids?
A
Plasma proteins, cannot easily pass through membranes
4
Q
What is Bulk flow?
A
Distribution of extracellular fluid
5
Q
What blood component generates oncotic pressure?
A
Plasma proteins
6
Q
What is the main plasma protein?
A
Albumin
7
Q
Where is capillary hydrostatic pressure highest?
A
Arterial end
8
Q
At the beginning of the capillary, how do the different pressures result in net flow?
A
Hydrostatic out of capillary exceeds oncotic pressure in, thus net flow out
9
Q
At the end of the capillary, how do the different pressures result in net flow?
A
Oncotic in exceeds hydrostatic out, resulting in next flow of interstitial fluid back into the capillary
10
Q
Over entire capillary, what is the net flow?
A
Out, thus lymphatic’s drain the excess tissue fluid
11
Q
What are the 4 factors affecting venous return?
A
- Sympathetic innervation
- Muscle pumps
- Inspiratory movements
- Blood volume
12
Q
What is the effect of sympathetic innervation of the veins?
A
Constriction and thus increasing venous return, thus increasing cardiac output
13
Q
What is Orthostatic (postural) Hypotension?
A
- Immediate effect from going supine to erect.
- 0.5L blood goes from body to legs, decreasing venous return, decreasing cardiac output, decreasing blood pressure
14
Q
How is orthostatic hypotension opposed?
A
(postural reflex)
Vasoconstriction in legs and lower abdomen
15
Q
How many lobes does the thymus have?
A
2
16
Q
Describe the location of the thymus
A
Between the manubruim, the sternum and the pericardium. Extends between the jugular notch to the 4th costal cartilage
17
Q
Between which 2 planes do the vagus and phrenic nerves lie?
A
Between arterial and venous planes
18
Q
Which joint does the joining of the internal jugular and subclavian vein lie?
A
Posterior to the sternoclavicular joint
19
Q
Behind what structure does the passing of the LBCV infront of the aorta occur?
A
Manubruim
20
Q
RBCV and LBCV join to form the SVC posterior to what?
A
1st right costal cartilage
21
Q
Arch of the azygous vein joins the SVC posterior to what?
A
2nd right costal cartilage
22
Q
Which landmark does the SVC enter the right atrium behind?
A
3rd right costal cartilage
23
Q
Which areas does the azygous vein drain?
A
Posterior thoracic wall
24
Q
What areas does the subclavian drain?
A
Upper limb
25
What areas does the internal jugular drain?
Head and neck
26
Which vein does the anterior thoracic veins drain into?
Left brachio cephalic vein
27
Name the three branches of the aorta from right to left
Brachiocephalic trunk, left common carotid, left subclavian
28
Which vessels are known to clasp the trachea?
Left common carotid and brachiocephalic trunk
29
At what level does the pulmonary trunk divide?
T5
30
Which artery is post. to the acsending aorta?
Right pulmonary
31
Which artery is inf. to the arch of the aorta (and ant. to thoracic aorta)?
Left pulmonary
32
In right lung root, descirbe the relations between the PA and bronchus?
PA anterior to bronchus (in left it is more superior)
33
Name the vertebral levels along which the trachea extends?
C6 --> T4/5
34
Name the muscle that alters tracheal diameter?
Trachealis
35
What sub tissue is the epithelium of the lung?
Pseudostratified cilliated columnar epithelium
36
At what level does the oesaophagus begin?
C6 (same as trachea)
37
What is the thoracic duct a continuation of?
Cisternae chyli
38
Which structures does the thoracic duct lie between in the posterior mediastinum?
Aorta and azygous vein
39
At what level does the thoracic duct cross the oesophagus and which side does it cross to?
T4/5 (sternal angle) and to the left
40
Where does the thoracic duct empty into?
Left Brachiocephalic vein
41
In the superior mediastinum, on which side of the oesophagus does the thoracic duct lie?
Left
42
Around which structures are the mediastinal lymph nodes clustered around?
Around trachea and oesophagus
43
Which lymph nodes do lung and lung hilum drain to?
Mediastinal
44
What are the three catagories of mediastinal lymph nodes?
Anterior, superior tracheobronchal and inferior tracheobronchal
45
Which structure do the tracheobronchal lymph nodes cluster around?
Birfurcation of the trachea
46
Where are the anterior mediastinal lymph nodes situated?
Around the brachiocephalic veins
47
Which lymph nodes do the mediastinal nodes communicate with?
Deep cervical nodes- lung tumours may be palpable in neck
48
Name the vertebral levels the descending aorta is confined between?
T4/5 (sternal angle) --> T12 (aortic hiatus)
49
Describe the side the aorta lies on in different areas of the thorax?
To the left, crossed to the midline in lower thorax
50
What portion of the oesophagus is supplied by oesophageal arteries?
Middle third
51
Name the 4 branches of the descending aorta?
1. Oesphageal
2. 9 posterior intercoastal arteries
3. subcostal
4. bronchial (usually 2 left, 1 right)
52
Which vein drains the middle third of the oesophagus?
Azygos vein
53
Which artery gives rise to the internal thoracic (mammary) arteries?
Subclavian
54
Which artery gives rise to the anterior intercostals?
Internal thoracic
55
Which artery anastamoses with the anterior intercostals?
```
Posterior intercostalis
(coarctation of the aorta)
```
56
Which side of the aorta does the oesophagus pass?
To the right, then swings forward and to the left, placing the oesophagus anterior to the aorta at T10
57
What are the 4 oesophageal constrictions (narrowings)?
1. Upper oesophageal sphincter (17cm)
2. Arch of the aorta
3. Left main bronchus at 28cm
4. Diaphragm at 43cm
58
Which sphincter prevents air from being sucked into the stomach on inhalation?
Cricopharyngeal sphincter
59
What artery, vein, nerve and lymph supply is to the upper 1/3 of the oesophagus?
- Inf. thyroid artery,
- brachiocephalic vein
- reccurent laryngeal (vagus) nerves
- lymph drains to deep cervical nodes
60
What artery, vein, nerve and lymph supply is to the middle 1/3 of the oesphagus?
- Oesophageal and bronchial arteries direct from descending aorta
- venous drainage to azygous system (systemic)
- nerve supply is oesophageal plexus (symp. ad vagus)
- lymph to tracheobronchial nodes
61
What artery, vein, nerve and lymph supply is to the lower 1/3 of oesophagus?
- left gastric artery
- left gastric veins( thus to portal vein)
- oesophageal plexus
- left gastric and coeliac nodes
62
Which veins form an anastamosis around the middle and lower thirds of the oesophagus?
Submucosal veins
63
What is the pathological consequence of the submucosal vein anastamosis?
- Porto-systemic anastamosis
| - In cirrhotic liver disease
64
what is the clinical significance of the 4 oesophageal constrictions?
- Blockage more likely
- instruments may get stuck
- caustic substances spend longer time there
65
What structures lie anterior to the oesophagus?
- Trachea
- right pulmonary artery
- left main bronchus
- left atrium
- diaphragm
66
Which side does the pulmonary trunk divide relative to the oesophagus?
Slightly to the left
67
What is the name of the lymph nodes running along side the trachea?
Paratracheal
68
List the route taken by lymph draining from pulmonary nodes
Pulmonary --> Bronchopulmonary --> inf. and sup. tracheobronchial + posterior mediastinal --> paratracheal + parasternal + anterior mediastinal --> BRONCHOMEDIASTINAL LYMPH TRUNK
69
Name the 3 lymph node groups draining to the bronchiomediastinal lymph trunks
1. Paratracheal
2. parasternal (int. thoracic)
3. ant. mediastinum
70
Name the 3 lymph node groups draining to the paratracheal lymph nodes
1. Inf. tracheobronchial
2. Superior tracheobronchial
3. post. mediastinal
71
What lymph trunks feed into the left thoracic duct?
- Left jugular (head and neck)
- left subclavian (UL),
- left bronchiomediastinal (lef thorax)
72
Which lymph trunks feed into the right lymphatic duct?
- Right jugular lymph trunk (head and neck)
- right subclavian (UL)
- right bronchomediastinal (right thorax)
73
Which structure does the azygous vein pass posterior to before it arches into the SVC?
Right lung hilum
74
At what level does the hemi-azygous vein cross right to join the azygous?
T9
75
At what level does the accessory hemi azygous cross right to join in the azygous?
T8
76
Structures on the right side of the mediastinum are related to?
Right atrium and veins
77
Structures on the left side of the mediastinum are related to?
Left Ventricle and arteries
78
Which cranial nerve are the vagus nerves derived from?
Cranial nerve X (10)
79
Which autonomic nervous system do the vagus nerves belong to?
Parasympathetic
80
Where do the vagus nerves arise from in the brain?
Medulla oblongata
81
Which structure do the vagus nerves pass out of the skull with?
The internal jugular veins
82
Which structure do the vagus nerves pass through the neck within, and between which structures?
Pass within the carotid sheath between the internal jugular vein and internal carotid artery
83
With what structure and at which level do the vagus nerves leave the thorax?
T10 at oesophagus
84
In what relation do the phrenics pass the lung roots?
Anterior to lung roots
85
Which nerve do the reccurent laryngeal nerves arise from?
Vagus
86
Where do the motor supply of the reccurent laryngeal nerves travel to?
Laryngeal muscles
87
Where do the sensory supply of the reccurent laryngeal nerves travel to?
Muscosal folds
88
Which structure does the right recurrent laryngeal nerve curve superiorly from under?
Right subclavian artery
89
Which structure does the left recurrent laryngeal nerve curve under?
Aortic arch, held by ligamentum arteriosum
90
Which structures surround the recurrent laryngeal nerve as it ascends to the larynx?
Oeosophagus posteriorly, and trachea anteriorly
91
In the neck, which arteries are the reccurent laryngeals related to?
Inferior thyroid arteries
92
Which embyrological arch is the right reccurent laryngeal hooked under?
4th-giving rise to right subclavian
93
Which embryological arch is the left reccurent laryngeal hookded under?
Left 4th- hooks under arch of aorta
| Left 6th- held by ductus arteriosus
94
Which location of tumour may lead to hoarseness of voice?
left lung tumours
95
What are the main post synaptic neurotransmitters of the parasympathetic system?
Acetylcholine
96
What are the main post-synaptic neurotransmitters of the sympathetic system?
Noradrenaline
97
What is the long dendrite of a sensory neurone usually referred to?
Sensory axon
98
How many neurones link CNS with the periphery in the somatic nervous system?
One
99
In the autonomic NS, how many efferent neurones link the CNS with the periphery?
2 (adrenal medulla supply being the exception)
100
Where is the cell body of somatic motor neurones located?
Anterior grey horn
101
Where is the cell body of somatic sensory neurones located?
In sensory dorsal root ganglion
102
Which cells do sensory neurones develop from?
Neural crest cells
103
Why do somatic sensory neurones give us conscious sensation?
Synapse with higher parts of the (conscious) brain
104
Why do autonomic sensory neurones give us unconscious sensation?
Synapse with lower parts of brain of which we have no awareness (can't locate visceral pain)
105
In the efferent autonomic nervous system, where is the cells body fo the primary neurone located?
(usually) Within the CNS
106
In the efferent autonomic nervous system, where is the cell body of the secondary neurone located?
(usually) In a ganglion (collection of cell bodies and synpases)
107
Where are parasympathetic nerves distributed to?
Head, neck and viscera- (NO SUPPLY TO SKIN OR LIMBS)
108
Where do the postganglionic cell bodies of the parasympathtic lie?
In special ganglia or head and neck or plexuses close to side of action. i.e. LONG PRIMARY AND SHORT SECONDARY NEURONE
109
Where specifically do preganglionic (primary) cell bodies of parasympathetic nerves lie?
Nuclei of cranial nerves III, VII, IX, X OR
| Grey matter of spinal cord S2, 3, 4
110
What other name is often given to the parasympathetic nervous system?
CRANIOSCARAL
111
What is the parasympathetic effect on the pupils?
Constrict
112
Where are the cell bodies of preganglionic sympathetic efferents?
Lateral horn, only present in spinal cord between T1 and L2
113
What is the other name given to the sympathetic nervous system?
THORACOLUMBAR
114
Where do the postganglionic cell bodies of the synpathetic NS lie?
In the sympathetic ganglia along the entire vertebral column. (SHORT PREGANGLIONIC, LONG POST GANGLIONIC)
115
Through which 3 plexuses does the SNS supply adjascent viscera?
1. oesophageal
2. cardiac
3. pulmonary
116
What is the name of the 2 lines of linked sympathetic ganglia?
Sympathetic trunks
117
Between which levels do the primary sympathetic neurones emerge from the spinal cord?
T1 to L2
118
Through which structure do the primary sympathetic neurones pass into the sympathetic ganglia?
White rami comunicante (WRC)
119
Through what structure do secondary sympathetic neurones leave the sympathetic trunk?
Grey rami comunicantes (GRC)
120
From the sympathetic ganglion, what three routes can the Sympathetic neurone take?
1. Synapse at that level and exit through the grey ramus cominicante of the same level
2. synpase at a superior level in a cervical ganglion above T1 and secondary neurones exit at that GRC with the cervical spinal nerves > UL, head and neck
3. synpase at ganglion below L2 and secondary neurones exit through GRC w/ lumbar/sacral spinal nerves to distribute to LL
121
What is the name of the fusion of the two sympathetic trunks?
Ganglion impar
122
What often fuses too from the stellate ganglion?
Sympathetic inf. cervical ganglion and the T1 sympathetic ganglion
123
What are the exeptions to the sympathetic neurones synapsing at the sympathetic ganglia?
Some pass straight through the trunk without synapsing, following the 3 splanchnic nerves and synapse in the coeliac, sup. and inf. ganglia/plexus
Also- adrenal medulla recieves primary fibres as itself acts as a ganglion
124
What levels are the head an neck supplied from in the sympathetic system?
T1-3
125
What levels are the upper limb supplied by sympathetically?
T4-T6
126
What levels are the thoracic and abdominal walls supplied by sympathetically?
T1-12 WHICH MATCHES DERMATOME PATTERN AS SECONDARY NEURONES RUN WITH THE SAME SPINAL NERVE AS THEIR LEVEL
127
What levels are the lower limb supplied from sympatheticallY.
T12-L2
128
Where do the 'unnamed' sympathetic branches travel to and supply?
Pass from ganglia to the oesophageal, cardiac and pulmonary plexuses to supply thoracic viscera (symp. contribution)
129
What levels is the heart and lungs supplied by sympathetically?
T1-T5 this ref. pain to neck and arm
130
Where do the unamed fibres suppling the heart ad lungs synapse?
Ascend trunk to synpase at T1 in the middle and inferior cervical ganglia
131
What do the sympathetic cardiac branches supply?
SA and coronary vessels, T1-T5, thus referred pain to T1/2 dermatome
132
What do the sympathetic pulmonary branches supply?
Pulmonary plexus- dilated bronchi and bronchial vessels from T2-T4
133
What level are the sympathetic oesophageal branches derived from?
T4-T6
134
What level is the sympathetic stomach supply derived from?
T7-T9
135
What level is the sympathetic supply of the midgut and gonads derived from?
T10-11
136
What level is the hind gut sympathetic supplied by?
T12
137
What would the effect of a pancoast tumour at the left apex of the lung have the on the face?
Horner's syndrome affecting left side (if affecting sympathetic trunk or stellate ganglion)
- Ptosis (drooping of upper eyelid)
- Pupillary constriction
- Anhydrosis (no sweating)
- Flushing of face
138
How much can nervous control increase arterial perssure by in 5-10s?
2x normal
139
How much can nervous control decrease arterial pressure in 10-40s?
50%
140
What are the is the internal variable in the reflex control of blood pressure?
Arterial BP
141
What are the two main locations of baroreceptors in systemic circulation?
1. Aortic arch
| 2. Carotid sinus
142
Which nerve do the afferent fibres from the walls of the aorta follow?
Vagus cranial nerve X (10)
143
Which nerve do afferent fibres from the carotid artery follow?
Glossopharyngeal IXth (9) cranial nerve
144
Describe the change to firing rate when BP increases?
Stretch recpetors increase firing rate
145
How can body interpret firing rate of barorecpetors as high or low?
Callibrated around a set point (can change)
146
What is the primary purpose of baroreceptors?
Reduce the minute to minute variations in blood pressure/arterial pulse
147
Where are the cardiopulmonary baroreceptors located?
Atria, ventricles, veins and pulmonary vessels
148
What do cardiopulmonary barorecpetors detect?
Central blood volume (ie. low pressure)
149
What does a decreased cardiopulmonary baroreceptor firing signify?
Low blood volume
150
What is the result of a low cardiopulmonary barorecpetor firing?
Increase SNS output and decrease PSN output
151
Which set of barorecpetors has the ability to override the other?
The cardiopulmoary barorecepetors can override the systemic baroreceptors if they detect a large increase in blood volume
152
What is the name of the reflex which overrides aortic/carotid baroreceptor responses?
Bainbridge/atrial reflex
153
Where is the intergration centre for baroreceptor input?
Medullary cardiovascular "vasomotor" centre (MCVC)
154
What does the sensory area of the MCVC recieve?
Impulses from the baroreceptors
155
What is found in the lateral portion of the MCVC?
Efferent sympathetic nerves
156
What is found in the medial portion of the MCVC?
Efferent parasympathetic (vagal) nerves
157
At rest, which autonomic nervous system has predominate tone over the heart?
Parasympathetic
158
What is the CNS ischaemic response?
- Emergency pressure control system, when blood flow to the MCVC itself becomes very low, it acts to increase the peripheral resistance, almost occluding some peripheral vessels.
- It increases sympathetic stimulation on the heart and so increases the systemic arterial blood pressure, it can be as high as 250mmHG for up to 10 minutes
159
What is the myogenic theory of safe control of blood flow? (Acute auto regulation)
Stretch induced vascular depolarisation of smooth muscle due to increased arterial pressure
160
What is the metabolic theory of safe control of bood pressure? (Acute auto-regulation)
Increased arterial pressure increases the O2 content of the blood and washes out local factors.
161
What is the affect on urine production when arterial pressure increases?
Urine production increases
162
What are the 2 primary determiinants of long term regulation of blood pressure?
1. renal output curve of salt and water
| 2. intake of salt and water
163
What does the equillibruim point on a renal output curve for salt and water represent?
When salt and water input= salt and water output
164
What property of blood does ADH (vasopressin) affect?
Water content (osmolarity)
165
What 3 things cause ADH release?
1. Increased osmotic pressure
2. Hypovolemia
3. Angiotensin II
166
What is the effect of increased ADH release?
Increases water permeability in renal collecting ducts, therefore decreasing urine production
167
Where is ADH released from?
The pituatary gland
168
Where is the increase in osmotic pressure detected?
Hypothalmic osmoreceptors
169
What is the basal tone effect of atrial barorecpetors on the release of ADH?
Inhibitive tone
170
What effect does a decreased blood volume have on atrial baroreceptors and therefore ADH release?
Decreased barorecpetor firing, therefore decreased inhibition of ADH release= INCREASE in ADH
171
Which cells release Renin?
Juxtoglomerular cells in the kidney
172
What kind of protein is Renin?
Enzyme
173
What is the subtrate for renin?
Angiotensinogen
174
Where is angiotensinogen produced?
Liver
175
What does renin do to angiotensinogen?
Cleaves to form angiotensin I
176
What happens to angiotensin I?
Converting enzymes in lungs turn it into the active form angiotensin II
177
What is the name of the enzyme that deactivates angiotensin II?
Angiotensinase
178
What are the effects of angiotensin II on the kidney?
- Acts directly through the kidneys by constricting renal arteries, reducing hydrostatic pressure of blood out
- Renal retention of salt and water (through 2 hormones)
179
Which two other hormones are released due to increased angiotensin II?
- Aldosterone from the adrenal glands, which increases salt and water retention
- ADH from pituatary, which increases permeability of collecting duct to water
180
What is the name of the hormone which opposes the action of the RAAS system?
Atrial-natriuretic hormone (peptide)
181
Where is atrial-natruetic hormone systhesised and stored?
Muscle cells fo the atria
182
When is atrial natruetic hormone released?
In response to stretch of the atria due to increased blood volume
183
What would result in loss of whole blood?
Haemorrhage
184
What would result in a loss of plasma?
Burns
185
What would result in a loss of salts/sodium?
Vomiting
186
class 1 shock
10-15% loss
187
class 2 shock
15-30% loss
188
class 3 shock
30-40% loss
189
class 4 shock
>40% loss
190
What are the immediate reflex effects in response to hypovolemia?
BARORECEPTOR REFLEX
191
What is the intermediate/ later response to hypovolemia?
ARTERIOLAR CONSTRICTION-
- Decrease hydrostatic pressure in the capillaries
- greater fluid reabsorption so increased venous return and increased arterial pressure.
- only temporary redistribution
- decreased renal blood flow
- baroreceptors increase thirst
192
What may be given to replace lost fluid?
Colloid gel (starch, gel, albumin), hartmann's, blood
193
What are 3 other factors affect blood pressure control?
1. Cortex- conscious emotions, cortex sends nerves to the medullary CVC centre
2. Time of day- diurnal changes in cortex/hormones
3. Respiration- mechanical movements, chemoreceptors (changes in 02 conc.)
194
What reasons do sokol and bergson list for causing basic errrors?
- stress
- fatigue
- covering for colleagues
- professional culture (unwillingness to ask for help)
- feeling decisions must be made alone
- unable to admit uncertainty
195
Is there a legal difference between avoidable and unavoidable mistakes?
No, the only difference is a moral one
196
What is the duty of candour? (2015)
Apology= statement of sorry or regret, not an admission of guilt that would hold up in court
197
What key report was influencial in the duty of candour legislation?
Francis report
198
What 4 things does the duty of candour state health care professionals must do?
1. Tell patient (or carer if appropriate) when something has gone wrong
2. Apologise to patient
3. Offer an appropriate remedy
4. Explain fully to patient the short and long term effects of what has happened
199
What may happen in response to errors or inadequate health care? (3)
1. Negligence (legal approach)- patient may take leagal action
2. NHS complaints procedure- Patient may make complaint
3. GMC (Professional body)- Disciplinarary action or removal from the register
200
What three things must claimant establish for a successful negligence case?
1. He/she is owed duty of care from defendent (easy)
2. That defendent breached that duty by failing to provide reasonable care
3. The breach of duty caused the claimants injuries (causation), and the cause is not too remote (proximity) i.e. can't have long chain of events
201
What is causation?
- Clear link between the action/ inaction of the doctor and the harm the patient expirienced.
- PROXIMITY IS KEY FACTOR
- Must show probabliliy not just possibility
202
What is the bolam test?
Doctor has acted in accordance with normal practice accepted by skilled medics of that area at that time
203
What is the bolitho test?
Actions must standup to logical analysis
204
What are the problems with the bolotho test?
Problem of inexpirienced doctors- held up to same standard?
205
What three questions must be answered yes to, after the impact of the montgomery case?
1. Does the patient know about the material risks of the proposed treatment?
2. Does the patient know about the reasonable alternatives to this treatments?
3. Have I taken reasonable care to ensure the patient actually knows this?
206
Can an honest mistake equate to misconduct?
- YES
- GMC protects against malicious and incompetent.
- Prioritises patient safety
207
What is the person-centred apprach to learning from errors?
Focused on individual doctor
208
Why is person centred approach innefective?
Human error is unintentional and therefore difficult to deter
209
What is the systems-based approach for learning from errors?
Considers environment and seeks to minimise OPPOURTUNITIES for error.
Relies on errors not being random but fitting a pattern
210
How does medicine address some of the failing in the current system?
- Dedicated centres for particular procedures, so patients directed to doctors with concentrated expertise
- Requirement to retain for new procedures and techniques
- Data collection of incidents
- Improved incident design
- Protocols and guidelines
- Checklists
211
What were the aims of the national patient safety agency?
Collect data on patient safety and incidents to improve patient safety
212
How are arteries affected by vascular disease?
Arteriosclerosis (atherosclerosis)
213
How are veins affected by vascular disease?
Phlebothrombosis, thrombophlebitis, varicosities
214
How are all vessels (generalised) affected by vascular disease?
Vasculitis, radiation damage, tumours
215
What are 3 age related vascular changes that occur affecting likelyhood of vascular disease?
1. Fibrosis of intima and media
2. Accumulation of ground substance
3. Fragmentation of elastic lamellae
216
Which kind of vessels are affected by atherosclerosis?
Large and medium sized elastic and muscular arteries
217
What are complications of atherosclerosis?
- cerebral infarction
- myocardial infarction
- carotid atheroma
- Aortic aneurysm
- peripheral vascular disease
- gangrene
218
What is peripheral vascular disease?
Atheroma of distal aorta/ illiac/ femoral arteries, causing ischaemia of lower limbs
219
What are the effects of peripheral vascular disease?
Intermittent claudication, pain, ulcers, gangrene
220
What is an aneurysm?
Locallised, permenant, abnormal dilation of blood vessels/ heart
221
Name the types of aneurysm (according to how blood vessel wall is) ?
```
true= sacular or fasicular
false= haematoma, dissection
```
222
Name types of anuerysm based on cause?
Atherosclerotic, dissecting, berry, micro-aneurysm, syphilitic, mycotic
223
Describe atherosclerotic anuerysms?
Usually abdominal aorta distal to renal arteries, saccular or fusiform, 15-25cm, wall diameter increased by over half. freq. contains mural thrombus due to turbulance
224
Name the clinical consquences of atherosclerotic aneurysms?
Thrombosis, emobolism (to legs), rupture, occlusion of branch vessel>ischaemic injury, impingement on adjascent structure
225
How is an atheroscleoritc aortic aneurysm presented?
Pulsatile abdominal mass
226
What is a dissecting aortic aneurysm?
Blood escaping between the tunica media and intima, usually initates with an initial tear, 1-2cm from aortic valve. tear can extend into hear or along aorta.
227
What are risk factors for an aortic dissection?
Men 3x more likely, hypertension, younger people with systemic or locallised abnormalities of connecting tissue
228
How will an aortic dissection appear on an x ray?
'Double lumen aorta'
229
What are the clinical symptoms of a dissecting aortic aneurysm?
- Sudden onset of excruciating pain, beginning in the anterior chest radiating to the back between scapulae, moves downwards as the dissection progresses.
- Can be confused with MI
- Most common cause of death is rupture of dissection outwards into pericardial, plural or peritoneal cavities
230
What is a berry anuerysm?
Aneurysm of the circle of willis
231
Who is likely to be affected by berry aneurysms?
Young people.
| Hypertensive patients, asosciated with sub arachnoid haemorrhage
232
What are capillary micro aneurysms?
Small aneurysms of the middle cerebral artery, associated with intracerebral haemorrhage
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What other health problems are capillary micro aneurysms associated with?
Hypertension and diabetes mellitus
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Where do syphillitic aneurysms usually affect?
Thoracic aorta
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What causes mycotic aneurysms?
Wall of artery being weakened by bacterial or fungal infection, often in brain secondary to an embolism
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What are Varicose veins?
Dilated, often tortous veins produced by prolonged increased intraluminal pressure and loss of vessel wall support.
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What are the risk factors for varicose veins?
Age, sex, hereditary, posture, obesity
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What causes varicose veins?
Venous valve incompetence leads to stasis, congestion, odema, pain and thrombosis.
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What area is usually affected by varicose veins?
Lower limb, usually saphenous system
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What issues can arise due to varicose veins in legs?
Cosetic problems, aching in legs, stasis dermititis, skin ulceration and bleeding
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What is vasculitis?
Inflammation and necrosis of blood vessels
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What causes vasculitis? (5)
1. cell immune-mediated inflammation
2. deposition of immune complexes
3. direct attack by circulating antibodies
4. Direct invasion of vascular walls by infectious pathogens
5. often part of multi-system disease
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What are 4 types of vasculitis?
1. Giant cell (temporal) vasculitis,
2. Takaysu arteritis (pulseless disease),
3. Polyarteritis nodosa (PAN)
4. Kawasaki disease
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What is giant cell vasculitis?
Granulomatous inflammation of large and small sized arteries (temporal, opthalmic, vertebral)
Cord like nodular thickening
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What is takayasu vasculitis?
Granulomatous vasculitis of medium/ large sized arteries of upper limbs
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What is polyarteritus nodosa (PAN)
Medium and small sized muscular arteries of the kidney, heart, liver, GI. Fibrinois necrosis can be fatal is not treated with steroids
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What symptoms are associated with kawasaki disease?
High fever, conjunctival and oral leisions. self limited
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What symptoms are associated with takayasu disease?
Dissiness, visual disturbances, dyspnoea, intermittent claudication of upper limb, asymmetric BP
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Name 4 types of benign angioma?
1. juvenile (strawberry)
2. capillary (ruby spots)
3. Cavenous (port wine stains)
4. Lymphangioma (capillary and cavenous)
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What is the name of the malignant artery tumour?
| Where does it affect?
Angiosarcoma affecting- skin and soft tissue, breast, bone, liver, spleen
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What disease is kaposi's sarcoma associated with?
Immunosupressed HIV/AIDS
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What cells is an angioproliferative tumour derived from?
Endothelial cells
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What is the equation for the fick principle for determining cardiac output?
CO= (Rate of O2 consumption in ml/min) / (AV O2 difference in ml/L)
254
Describe the way blood flow is distributed through the lungs?
- If alveolar O2 reduces, the local alveolar blood flow decreases (opposite to normal tissues, in which decreased O2 would stimulate vasodilation to increase flow)
- Enables lungs to bypass bloodflow away from poorly perfused areas
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What are the 4 issues with coronary blood flow during exercise?
- Myocardium cannot function anaerobially
- Arterioles close mechanically during systole
- There is a decreased diastolic filling period during exercise
- There is an increased O2 and metabolic demand during exercise
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How can increased metabolic demand be met by coronary blood flow? (ie. increased 02 or increased blood flow)
Increased blood flow, as cardiac O2 extraction is at maximum at rest
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What is the primary controller of coronary flow?
LOCAL METABOLISM:
Which is in proportional to cardiac musculature need for O2, i.e. adenosine produced in metabolism is a potent vasodilator
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What is the secondary controller of coronary flow?
SYMPATHETIC INNERVATION
Directly- Direct innervation of coronary blood vessels which induce dilation
Indirectly- increases heart rate and contractility which increases metabolism
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What receptor and what affect does norodrenaline act on?
- alpha 1 receptors
| - causing vasoconstriction in skeletal muscles
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What receptor and what affect does adrenaline have an effect on?
- beta 2 receptors
- causing vasodilation in skeletal muscles
- has an overriding effect over the alpha 1 receptors, favouring vasodilation on exercise
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What are the three factors increasing venous return during exercise?
1. Increase skeletal muscle pump activity
2. Increase frequency and depth of inspiration, increasing the respiration pump activity
3. Increase venous tone through sympathetic innnervation (constricting)
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What is the increase in cardiac output from rest to moderate exercise?
5L/min to 15L/min
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Explain the chain of events leading to vasodilation in skin?
Increased exercise --> increase core body temperature detected in the hypothalumus --> decreases sympathetic tone on blood vessels in the skin --> increasing vasodilation and heat loss
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What prepatory changes are made prior to exercise?
- Decreased PNS and increased SNS tone result in increased cardiac output and decrease in TPR.
- ADH is also released to promote retention of water and decrease urine output
- Resets baroreceptors higher to mute the effect of increased arterial pressure
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What causes vasodilation of blood vessels supplying muscle tissue?
Increasing activity increases the metabolic activity, resulting in the accumulation of local factors that stimulate vasodilation (active hyperaemia).
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What is the problem with vasodilating the blood vessels supplying muscles?
Greatly reduces total peripheral resistance, decreasing blood pressure
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How is the effect of of vasodilating the blood vessels in muscles compensated for?
- Increasing vasoconstriction to non-essential organs to increase TPR.
- Cardiac output must also increase to maintain arterial blood pressure
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How is cardiac output mainly increased on moderate exercise?
Increased SNS and decreased PNS input = increase cardiac output by increasing HR and increasing contractility which increases stroke volume.
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What contributes to a minor increase in EDV
Increased venous return due to muscle/respiration pumps and sympathetic constriction of veins,
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How is blood flow to the kidneys affecting during excersie and what is the effect of this?
Redistribution of CO decreases blood flow to the kidneys, resulting in decreased urine production and increased water retention, in addition to the hormones released during exercise
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How is mean arterial blood pressure effecting during moderate exercise?
Depends on balance on the increase of cardiac output and decrease in TPR.
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How is pulse pressure affected by exercise?
May increase due to increase in systolic pressure (increase in contractility/SV)
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Why is there a mild decrease in diastolic pressure during exercise?
Due to decreased afterload, due to decreased TPR
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Explain the large increase in MABP during static exercise ?
Mechanical compression of arteries and veins results in an increase in TPR and venous return. This increases Stroke volume and cardiac output. There is also an increase in metabolic local factors signalling to the heart to increase CO, resulting in increased contractility and further increase in cardiac output.
Increase in both TPR and CO
