Week 2 Flashcards
What makes up interstitium?
Collagen and proteoglycan factors
What is a Crystalloid?
Low molecular weight solutes ie. ions, easily diffuse
What is Colloids?
Plasma proteins, cannot easily pass through membranes
What is Bulk flow?
Distribution of extracellular fluid
What blood component generates oncotic pressure?
Plasma proteins
What is the main plasma protein?
Albumin
Where is capillary hydrostatic pressure highest?
Arterial end
At the beginning of the capillary, how do the different pressures result in net flow?
Hydrostatic out of capillary exceeds oncotic pressure in, thus net flow out
At the end of the capillary, how do the different pressures result in net flow?
Oncotic in exceeds hydrostatic out, resulting in next flow of interstitial fluid back into the capillary
Over entire capillary, what is the net flow?
Out, thus lymphatic’s drain the excess tissue fluid
What are the 4 factors affecting venous return?
- Sympathetic innervation
- Muscle pumps
- Inspiratory movements
- Blood volume
What is the effect of sympathetic innervation of the veins?
Constriction and thus increasing venous return, thus increasing cardiac output
What is Orthostatic (postural) Hypotension?
- Immediate effect from going supine to erect.
- 0.5L blood goes from body to legs, decreasing venous return, decreasing cardiac output, decreasing blood pressure
How is orthostatic hypotension opposed?
(postural reflex)
Vasoconstriction in legs and lower abdomen
How many lobes does the thymus have?
2
Describe the location of the thymus
Between the manubruim, the sternum and the pericardium. Extends between the jugular notch to the 4th costal cartilage
Between which 2 planes do the vagus and phrenic nerves lie?
Between arterial and venous planes
Which joint does the joining of the internal jugular and subclavian vein lie?
Posterior to the sternoclavicular joint
Behind what structure does the passing of the LBCV infront of the aorta occur?
Manubruim
RBCV and LBCV join to form the SVC posterior to what?
1st right costal cartilage
Arch of the azygous vein joins the SVC posterior to what?
2nd right costal cartilage
Which landmark does the SVC enter the right atrium behind?
3rd right costal cartilage
Which areas does the azygous vein drain?
Posterior thoracic wall
What areas does the subclavian drain?
Upper limb
What areas does the internal jugular drain?
Head and neck
Which vein does the anterior thoracic veins drain into?
Left brachio cephalic vein
Name the three branches of the aorta from right to left
Brachiocephalic trunk, left common carotid, left subclavian
Which vessels are known to clasp the trachea?
Left common carotid and brachiocephalic trunk
At what level does the pulmonary trunk divide?
T5
Which artery is post. to the acsending aorta?
Right pulmonary
Which artery is inf. to the arch of the aorta (and ant. to thoracic aorta)?
Left pulmonary
In right lung root, descirbe the relations between the PA and bronchus?
PA anterior to bronchus (in left it is more superior)
Name the vertebral levels along which the trachea extends?
C6 –> T4/5
Name the muscle that alters tracheal diameter?
Trachealis
What sub tissue is the epithelium of the lung?
Pseudostratified cilliated columnar epithelium
At what level does the oesaophagus begin?
C6 (same as trachea)
What is the thoracic duct a continuation of?
Cisternae chyli
Which structures does the thoracic duct lie between in the posterior mediastinum?
Aorta and azygous vein
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
Where does the thoracic duct empty into?
Left Brachiocephalic vein
In the superior mediastinum, on which side of the oesophagus does the thoracic duct lie?
Left
Around which structures are the mediastinal lymph nodes clustered around?
Around trachea and oesophagus
Which lymph nodes do lung and lung hilum drain to?
Mediastinal
What are the three catagories of mediastinal lymph nodes?
Anterior, superior tracheobronchal and inferior tracheobronchal
Which structure do the tracheobronchal lymph nodes cluster around?
Birfurcation of the trachea
Where are the anterior mediastinal lymph nodes situated?
Around the brachiocephalic veins
Which lymph nodes do the mediastinal nodes communicate with?
Deep cervical nodes- lung tumours may be palpable in neck
Name the vertebral levels the descending aorta is confined between?
T4/5 (sternal angle) –> T12 (aortic hiatus)
Describe the side the aorta lies on in different areas of the thorax?
To the left, crossed to the midline in lower thorax
What portion of the oesophagus is supplied by oesophageal arteries?
Middle third
Name the 4 branches of the descending aorta?
- Oesphageal
- 9 posterior intercoastal arteries
- subcostal
- bronchial (usually 2 left, 1 right)
Which vein drains the middle third of the oesophagus?
Azygos vein
Which artery gives rise to the internal thoracic (mammary) arteries?
Subclavian
Which artery gives rise to the anterior intercostals?
Internal thoracic
Which artery anastamoses with the anterior intercostals?
Posterior intercostalis (coarctation of the aorta)
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
What are the 4 oesophageal constrictions (narrowings)?
- Upper oesophageal sphincter (17cm)
- Arch of the aorta
- Left main bronchus at 28cm
- Diaphragm at 43cm
Which sphincter prevents air from being sucked into the stomach on inhalation?
Cricopharyngeal sphincter
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
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
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
Which veins form an anastamosis around the middle and lower thirds of the oesophagus?
Submucosal veins
What is the pathological consequence of the submucosal vein anastamosis?
- Porto-systemic anastamosis
- In cirrhotic liver disease
what is the clinical significance of the 4 oesophageal constrictions?
- Blockage more likely
- instruments may get stuck
- caustic substances spend longer time there
What structures lie anterior to the oesophagus?
- Trachea
- right pulmonary artery
- left main bronchus
- left atrium
- diaphragm
Which side does the pulmonary trunk divide relative to the oesophagus?
Slightly to the left
What is the name of the lymph nodes running along side the trachea?
Paratracheal
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
Name the 3 lymph node groups draining to the bronchiomediastinal lymph trunks
- Paratracheal
- parasternal (int. thoracic)
- ant. mediastinum
Name the 3 lymph node groups draining to the paratracheal lymph nodes
- Inf. tracheobronchial
- Superior tracheobronchial
- post. mediastinal
What lymph trunks feed into the left thoracic duct?
- Left jugular (head and neck)
- left subclavian (UL),
- left bronchiomediastinal (lef thorax)
Which lymph trunks feed into the right lymphatic duct?
- Right jugular lymph trunk (head and neck)
- right subclavian (UL)
- right bronchomediastinal (right thorax)
Which structure does the azygous vein pass posterior to before it arches into the SVC?
Right lung hilum
At what level does the hemi-azygous vein cross right to join the azygous?
T9
At what level does the accessory hemi azygous cross right to join in the azygous?
T8
Structures on the right side of the mediastinum are related to?
Right atrium and veins
Structures on the left side of the mediastinum are related to?
Left Ventricle and arteries
Which cranial nerve are the vagus nerves derived from?
Cranial nerve X (10)
Which autonomic nervous system do the vagus nerves belong to?
Parasympathetic
Where do the vagus nerves arise from in the brain?
Medulla oblongata
Which structure do the vagus nerves pass out of the skull with?
The internal jugular veins
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
With what structure and at which level do the vagus nerves leave the thorax?
T10 at oesophagus
In what relation do the phrenics pass the lung roots?
Anterior to lung roots
Which nerve do the reccurent laryngeal nerves arise from?
Vagus
Where do the motor supply of the reccurent laryngeal nerves travel to?
Laryngeal muscles
Where do the sensory supply of the reccurent laryngeal nerves travel to?
Muscosal folds
Which structure does the right recurrent laryngeal nerve curve superiorly from under?
Right subclavian artery
Which structure does the left recurrent laryngeal nerve curve under?
Aortic arch, held by ligamentum arteriosum
Which structures surround the recurrent laryngeal nerve as it ascends to the larynx?
Oeosophagus posteriorly, and trachea anteriorly
In the neck, which arteries are the reccurent laryngeals related to?
Inferior thyroid arteries
Which embyrological arch is the right reccurent laryngeal hooked under?
4th-giving rise to right subclavian
Which embryological arch is the left reccurent laryngeal hookded under?
Left 4th- hooks under arch of aorta
Left 6th- held by ductus arteriosus
Which location of tumour may lead to hoarseness of voice?
left lung tumours
What are the main post synaptic neurotransmitters of the parasympathetic system?
Acetylcholine
What are the main post-synaptic neurotransmitters of the sympathetic system?
Noradrenaline
What is the long dendrite of a sensory neurone usually referred to?
Sensory axon
How many neurones link CNS with the periphery in the somatic nervous system?
One
In the autonomic NS, how many efferent neurones link the CNS with the periphery?
2 (adrenal medulla supply being the exception)
Where is the cell body of somatic motor neurones located?
Anterior grey horn
Where is the cell body of somatic sensory neurones located?
In sensory dorsal root ganglion
Which cells do sensory neurones develop from?
Neural crest cells
Why do somatic sensory neurones give us conscious sensation?
Synapse with higher parts of the (conscious) brain
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)
In the efferent autonomic nervous system, where is the cells body fo the primary neurone located?
(usually) Within the CNS
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)
Where are parasympathetic nerves distributed to?
Head, neck and viscera- (NO SUPPLY TO SKIN OR LIMBS)
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
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