Lymphatics and Stuff Flashcards
What is the function lymphatic vessels?
- Continuous removal of remaining tissue fluid and proteins from extracellular space back to blood circulation.
- It is also a route for spread of infection and malignant disease
What is uni-directional flow of lymph?
- Tissue fluid
- Lymphatic Capillary
- Lymphatic vessels
- Lymph nodes
- Lymphatic vessels
- Lymphatic trunks
- Lymphatic ducts
- Venous system
How does the fluid flow thorough the lymphatic systems?
- Passive constriction
- Intrinsic constriction
- Fluid goes through valves
What are the causes of lymphoedema?
- Removal or enlargement of lymph nodes
- Infections
- Damage to lymphatic system such as cancer treatments
- Lack of limb movement
- Congenital issues (such as Milroy’s syndrome)
What is the key role of the lymph nodes?
-Immune surveillance and defence
How does the lymph node achieve its roles?
Highly organised centres of immune cells such as lymphocytes and macrophages. This helps it deal with the pathogens if they are present in the lymph fluid due to transfer from an infected tissue
What the common causes of an enlarged lymph node?
- Infection
- Malignancy
What does an enlarged lymph node as a result of infection feel like?
- Tender
- Mobile
What does an enlarged lymph node as a result of malignancy feel like?
- Hard
- Matted
- Non-tender
Where are specific regions in the body where lymph nodes are palpable?
- Neck (cervical)
- Armpit (axillary)
- Diaphragm
- Spleen
- Abdominal
- Pelvic
- Groin
What separates the deep and superficial lymph nodes in the neck?
Terminal node lie deep to Investing layer of deep cervical fascia
Where are lymph nodes located?
- Submental
- Sub-mandibular
- Pre-auricular
- Post auricular
- Occipital
What is waldeyer’s ring?
Annular collection of lymphatic tissue surrounding the entrance to the aerodigestive tracts
What are the tonsils that form Waldeyer’s ring?
- Pharyngeal tonsil
- Tubal tonsil
- Palatine tonsils
- Lingual tonsils
Where do lymphatics from tonsils draining the upper pharynx drain into?
Retropharyngeal Lymph Nodes
How can an atheleorscelrotic plaque in the internal carotid artery cause transient vision loss?
Ophthalmic artery is given of the internal carotid artery which result in vision loss due to lack of blood supply
Where is the common site of atherosclerosis in the common carotid artery?
Near the bifurcation of the arteries into the external and internal carotid artery
What is the action of the muscles of mastication?
Move the mandible at the temperomandibular joint
What are the branches of the external carotid artery?
- Superficial thyroid artery
- Ascending cervical artery
- Lingual artery
- Facial artery
- Occipital artery
- Posterior auricular artery
- Maxillary artery
- Superficial temporal artery
How can infections spread intracrnailaly from the facial vein?
- Facial vein is connected to the pterygoid venous plexus and the ophthalmic vein
- Infection can track back into the dural venous sinuses
- Thrombophlebitis of facial vein involves infected clot
Which vein does the facial vein drain into?
Facial vein drains into the Internal Jugular vein via Pterygoid veinous Plexus
Where does an extradural haematoma form?
Between:
- Inner table
- Periosteal layer of dura
What does the vertebral arteries supply?
- Posterior parts of the brain
- Posterior neck
What are the origin of the left and right common carotid arteries?
- Right Common Carotid Artery originates from Brachiocephalic Artery
- Left Common Carotid Artery arises from the arch of the Aorta (longer)
Where is the carotid sheath derived from?
Fusion of:
- Prevertebral fascia
- Investing layer
- Pretracheal fascia
Arteries run behind the sternocleidomastoid. Thin shath over veins and thicker sheath over arteries
What are the terminal branches of the external carotid artery?
- Superficial temporal artery
- Maxillary artery
What are some complications of a septic thrombi in the facial vein?
- Superior and Inferior ophthalmic vein connected to the facial vein
- Septic thrombi can travels to cavernous sinus
- Can cause a cavernous sinus thrombosis
Which blood vessels are more likely to be affected if damage affects the dense connective tissue and what are the implications of this?
- Artery
- If open wound, there will be profuse bleeding. Blood vessels are adhered to the dense connective tissue so less ability to vasoconstrict.
- If close wound, well localised lump form. The dense connective tissue stop spread of bleeding beyond the confines of the area of damage
Why might an incised scalp gape open if injury affects the aponeurosis?
- Aponeurosis is attached to frontalis anteriorly and occipitalis posteriorly.
- The pull of these muscles causes wound to gape open
- Profuse bleeding
Which blood vessels are likely to be damaged in the loose connective tissue and why does it spread?
- Veins
- Loose connective tissue allows the blood spread within the layer.
Which nodes is often enlarged in tonsillitis?
Jugulo digastric
What does the jugulodigastric node drain and where does it lie?
- Palatine tonsil
- Oral cavity
- Tongue
Below angle of mandible
What does the jugulo-omohyoid nodes drain and where do they lie?
- Tongue
- Oral cavity
- Trachea
- Oesophagus
- Thyroid gland
Any infection affecting these areas results in the nodes swelling
What is trosier’s sign?
Enlarged, hard, left supraclavicular lymph nodes secondary to metastatic abdominal malignancy
Which tonsil is readily seen on routine examination of a patient?
Palatine tonsils
Which tonsils are known as adenoids?
- Pharyngeal tonsils
- Located in roof of nasopharynx behind the uvula
How can pharyngeal tonsils contribute to ear infections?
- Close to the Eustachian Tube
- Can block the tube when enlarged thereby contributing to middle ear infection
Why does the bleed from the loose connective tissue cause ecchymosis?
- The loose connective tissue is under the aponeurosis.
- The aponeurosis is attached to the frontalis muscle anteriorly. Frontalis muscle is attached to obicularis oculi and subcutaneous tissue.
- Blood can track in this layer to the extraoccular muscles
- Causes ecchymosis
What is the path of the vetebral arteries?
- Arise from the subclavian arteries on the right and left
- Ascend in the neck through transverse foramina in cervical vertebrae 6-1 and pass through the foramen magnum
- Form the basilar artery
Where does the internal jugular vein lie?
Lateral to the common carotid and mostly under the sternocleidomastoid
Where does the common carotid artery bifurcate?
- C4
- Level of the superior border of the thyroid cartilage
What commonly forms at the birfurcation of the carotid artery and what is the effect?
Atheromas.
-This causes stenosis of the artery. Also rupture of the clot can cause an embolus to travel to the brain. Leading to a transient ischameic attack
Why is the swelling more bulbous at the region of the bifurcation?
Carotid Sinus at the region of the bifurcation
Baroreceptors for detecting changes in arterial blood pressure.
What is located in the carotid body?
Peripheral chemoreceptors which detect arterial O2.
What are the borders of the carotid triangle?
Superior: Posterior belly of the digastric muscle.
Lateral: Medial border of the sternocleidomastoid muscle.
Inferior: Superior belly of the omohyoid muscle.
What is the importance of the carotid triangle?
- Important for surgical approach to the carotid arteries or internal jugular vein
- Access the vagus and hypoglossal nerves
- Carotid pulse can felt in just below the birfurcation
- Carotid sinus massage
How can you terminates a supraventricular tachycardia at the carotid sinus?
- A carotid massage increase pressure in the artery
- This means that the glossopharyngeal nerve is stimulated and send signal to the brain.
- The efferent signal to slow the heart down from the brain is transmitted by the vagus nerve
What are the contents of the cavernous sinus?
- Plexus of extremely thin-walled veins on upper surface of sphenoid
- Internal carotid artery
- Oculomotor nerve
- Trochlear nerve
- Abducent nerve
- Opthalmic and Maxillary nerve of the trigeminal nerve
What is the blood supply to the scalp and their roots?
From internal carotid artery
- Supra-orbital artery
- Supratrochlear artery
From external carotid artery
- Superficial temporal artery
- Posterior auricular artery
- Occipital artery
Where do the blood vessels in scalp lie?
In subcutaneous connective tissue layer
How is constriction of the blood vessels limited in dense connective tissue layer and what are the issues of this?
- Walls of the arteries are closely attached to dense connective tissue.
- You can get profuse bleeding as a result of an open scalp wound
The Loss of the scalp results in bone necrosis. True/False
False. Blood supply to the skull is mostly via the middle meningeal artery
Where can the facial artery pulse be felt?
- Inferior border of mandible
- Anterior to the masseter muscle
What is the clinical relevance of the Kiesselbach area?
Common site of nose bleeds. (epitaxis)
What are the most important branches of the kiesselbach area?
- Septal branch of sphenopalatine artery
- Anterior ethmoidal arteries
What are the shapes of the extradural and subdural haemorrhage?
- Extradural: Pear
- Subdural: Banana shape. Slim
What is the venous drainage of the scalp?
- Superficial temporal veins
- Occipital vein
- Posterior auricular veins
- Supraorbital
- Supratrochlear
What is the connection between the venous drainage of the scalp and dural venous sinuses?
Several emissary veins connect the veins of the scalp then to the dural venous sinuses. Can act as a potential route for infection to spread.
What is the effect of the spread of infection from the scalp to the cranial cavity?
It can affect the Meninges
What is special about emissary veins and the veins of the face?
They are valveless
Which is a better indicator of the pressure of the right atrium? IJV or EJV
Internal Jugular Vein is better indication pressure in the right atrium
How do you measure the jugular venous pressure?
- Use the right Internal jugular vein
- Patient at a 45 degree angle with the head slightly to the left
- Pulsations are observed through the sternocleidomastoid muscle which hide the internal jugular vein
- The height measured in 5cm from the sternal angle
- MEasured in cmH2O
What are some important branches of the maxillary artery?
- Middle meningeal
- Sphenopalatine
