Session 3 Flashcards
Session 3 Head and neck
Describe the major blood vessels supplying and draining the head, neck and face and appreciate their general route and location. LO
- The arterial supply to the head and neck arises from branches of the?
right and left common carotid arteries and the vertebral arteries.
Q. 1. The vertebral arteries are branches of?
- Supply?
- General route?
A. subclavian arteries
- posterior neck and posterior parts of the brain (e.g. brainstem, cerebellum).
- -Artery ascends through the transverse foramina of the cervical vertebrae (except C7)
- Enters the subarachnoid space just between the atlas and occipital bone
- Passes up through the foramen magnum, curving around the medulla, to join the vertebral artery from the other side to form the basilar artery.
- The basilar artery runs along the anterior (ventral) aspect of the brainstem (namely the pons)
Q. Which common carotid artery is longer? Why?
A. - left common carotid artery
- The right common carotid artery originates from the brachiocephalic artery behind the right sternoclavicular joint, whilst the left common carotid arises directly from the arch of the aorta.
Q. Each common carotid artery ascends up through the neck enclosed within the ?
A. carotid sheath
Q. The carotid sheath is a fascial envelope enclosing the?
Most of the carotid sheath runs deep to the ? and is derived from fusion of ?
The sheath is ? over the vein but ? around the artery.
- State the position of the contents of the carotid sheath in relation to the sheath.
- where does the sympathetic trunk lie?
A. - carotid artery, internal jugular vein and vagus nerve
- sternocleidomastoid muscle
- a) the prevertebral layer of cervical fascia (posteriorly), b) the pretracheal layer (anteromedially) and c) the investing layer of cervical fascia (anterolaterally)
- thin, thicker
- The artery lies medially within the sheath whilst the vein is lateral and the nerve behind and in between the vessels.
- outside of the sheath, medially and behind it
Q. Which artery supplies intra cranial structures and which supplies extracranial structures? How do you know?
A. The internal carotid artery is distinguished by a lack of branches in the neck as it ascends to supply intra-cranial structures.
External carotid artery, is the major source of blood supply to extra-cranial structures of the head and neck region, and gives rise to eight branches.
Q. The external carotid artery divides into its terminal branches, the maxillary and superficial temporal arteries at which anatomical landmark?
A. At a level behind the neck of the mandible, within the substance of the parotid gland.
Q. Many of the branches of the external carotid artery make a loop at their origin; why do you think this is?
Q. Name the branches of the thyrocervical trunk and what they supply
A. • Ascending cervical & transverse cervical supply the neck
• Suprascapular supplies shoulder (posterior aspect of the scapula)
• Inferior thyroid supplies lower pole of the thyroid gland
Q. What are the borders of the carotid triangle and what makes up these borders?
A. Superior: Posterior belly of the digastric muscle.
Lateral: Medial border of the sternocleidomastoid muscle.
Inferior: Superior belly of the omohyoid muscle.
Q. What is the clinical significance of bifurcation of common carotid artery?
A. • Bifurcation of the carotid artery is a common site for atheroma formation
• Causes narrowing (stenosis) of the artery
• Rupture of the clot can cause an embolus to travel to brain
– TIA or stroke
Q. What is the Carotid sinus? Function?
What is the carotid body? Function?
A. Carotid sinus:
– swelling at region of bifurcation
– Location of baroreceptors for detecting changes in arterial BP detect arterial O2 (stretching opens channels results in action potentials)
Carotid body:
– Peripheral chemoreceptors which detect arterial O2
Q. What is the clinical significance of the carotid triangle? (4)
A. • Important for surgical approach to the carotid arteries or internal jugular vein (i.e. removal of a plaque)
• Can also access vagus and hypoglossal nerves via carotid triangle
• Carotid pulse can be felt in carotid triangle just below bifurcation
– may also be palpated more inferiorly (only do it one at a time)
• Carotid sinus massage (Reverse supra ventricular tachycardia due to increased vagus input to the heart. Sensitive can cause syncope)
Q. What is the cavernous sinus? What else does the cavernous sinus contain?
A. Plexus of extremely thin-walled veins on upper surface of sphenoid
– Internal carotid a
– CNIII oculomotor
– CNIV trochlear
– CNVI abducent
– 2 branches of trigeminal
• CNV1 ophthalmic and CNV2 maxillary
Q. What happens if an infection traces into the cavernous sinus?
A. Infections tracing into region - several structures it can impact on
Q. This image shows radio opaque dye within the internal carotid arteries what can you tell about the structure of these arteries?
Arteries have a tortuous structure
Q. The ophthalmic artery (OA) is the first branch of the ? distal to the cavernous sinus. Branches of the OA supply all the structures in the orbit as well as some structures in the nose, face and meninges. Occlusion of the OA or its branches can produce sight-threatening conditions.
A. internal carotid artery
Q. Six Branches (external carotid artery):
Plus 2 Terminal Branches (external carotid artery):
A. 1. Superior thyroid 2. Lingual 3. Facial 4. Ascending pharyngeal 5. Occipital 6. Posterior auricular
1. Superficial temporal 2. Maxillary
Q. • Rich blood supply with many anastomoses
• Largely branches of ?
• Except ? which arises from the ?
A. external carotid artery, supratrochlear and supraorbital arteries (branches of the opthalmic artery), internal carotid artery
- Vessels of the scalp lie in the ?
- Why might there be profuse bleeding in the scalp if lacerated?
- subcutaneous connective tissue layer
- • Walls of arteries closely attached to connective tissue, limits constriction – can get profuse bleeding
• Numerous anastomoses – profuse bleeding
• Deep lacerations involving epicranial aponeurosis cause profuse bleeding because of opposing pull of occiptofrontalis
Q. Blood supply to skull mostly ? – loss of scalp does not lead to bone necrosis
A. middle meningeal artery
Q. All arise from the external carotid except ? which are from internal carotid artery (via ?) Facial artery pulse can be felt at ?
A. supra-orbital and supratrochlear, ophthalmic,
inferior border of mandible, anterior to the masseter muscle
Q. The maxillary artery has many branches supplying muscles and deeper structures in face. Middle meningeal Sphenopalatine. Complete the diagram
Q. What is this image showing complete the diagram. What is the orange are called? Most important branches? Clinical significance?
A. • Anastomosis of arteries in Kiesselbach area
• Most important branches:
– Septal branch of sphenopalatine artery (from maxillary artery)
– Anterior ethmoidal arteries (from ophthalmic artery)
• Kiesselbach area common site for nose bleed (epistaxis)
What provides blood supply to the dura and skull?
Q. Clinical significance of this artery ?
A. An injured middle meningeal artery is the most common cause of an epidural hematoma. A head injury (e.g., from a road traffic accident or sports injury) is required to rupture the artery. Emergency treatment requires decompression of the haematoma, usually by craniotomy (Bone and scalp flap
reflected inferiorly to preserve blood supply). Subdural bleeding is usually venous in nature.
Describe the major blood vessels supplying and draining the head, neck and face and appreciate their general route and location LO
Q. The veins draining the head and neck either lie superficial or deep to the ? in the neck. Note, in the face, there are no distinct fascial layers, with muscles attaching between bone and skin. A series of veins drain the scalp, forehead and face.
A. investing layer of deep cervical fascia
Q. The facial vein, which runs with the facial artery from the medial angle of the eye towards the inferior border of the mandible drains most structures of the face before draining into the internal jugular vein. The facial vein has a number of important anastomoses with veins draining deeper structures within the skull. For example,
A. the facial vein receives blood from the superior and inferior ophthalmic veins, which have a direct connection with the cavernous sinus and the pterygoid venous plexus. The cavernous sinus lies intra-cranially and is part of the intra-cranial venous system.
Q. This connection has implications for infections involving the face, as they have a potential route to track to ? Give two examples of veins which bacteria can use to pass extra to intra cranially.
A. deeper intra-cranial structures
The formation of septic thrombi in the facial vein, secondary to infection (particularly if it occurs near the angle of the eye ), can also pass into the cavernous sinus, leading to a cavernous sinus thrombosis.
Another important anastomosis between the extra-cranial veins and intracranial veins, is that between the veins of the scalp and the intra-cranial (dural) venous sinuses. Emissary veins, which run through the skull, between these blood vessels provide a potential route for infection of the scalp to spread into the cranial cavity.
Q. Venous drainage of the scalp
• Superficial veins generally accompany arteries e.g.
• Supraorbital and supratrochlear veins unite at medial angle of eye to form ? which drains into the ?
• Some deep parts of scalp in temporal region have veins which drain into the ?
A. – Superficial temporal veins
– Occipital veins
– Posterior auricular veins
angular vein, facial vein
pterygoid venous plexus
Q. How do the veins of scalp connect to diploic veins of skull? State a key feature of these veins. Infection from scalp can spread to the cranial cavity and affect meninges.
A. several emissary veins and thus to dural venous sinuses,
Valveless,
Q. Connection of facial veins with ?
• Veins of the face are ? (Clue: structure)
• At medial angle of eye, facial vein communicates with superior ophthalmic
– Drains into ?
• Deep facial veins drain into ?
– Infection from facial vein can spread to dural venous sinuses
– ? (inflammation of the vein causing blood clots which would them embolism) of facial vein
What is the problem with having these clots?
A. cavernous sinus and pterygoid venous plexus,
valveless,
cavernous sinus,
pterygoid venous plexus,
Thrombophlebitis
infected clot can travel to intracranial venous system
Q. What is this image trying to explain?
A. Infections in this region of the face can spread through the venous system to the dural venous sinuses
Q. The sigmoid sinuses continue as the ?, leaving the skull through the ?
A. internal jugular veins, jugular foramina
Identify clinically relevant pulses in the neck, namely for palpation of the carotid artery and the location and purpose of inspecting the jugular venous pulsation. LO
Q. • EJV vein much easier to see
• IJV under sternocleidomastoid
Which vein is a better indication of pressure in right atrium
A. IVJ
Q. Which vein do you use to measure pressure in the right atrium? How should the patient be positioned for you to examine them? What is this vein hidden by? Measured in?
A. - Use Right Internal Jugular Vein
- Patient at 45o angle – head slightly to left
- IJV largely hidden by sternocleidomastoid (Pulsations observed through muscle)
- Measured in cmH2O
- Height from sternal angle + 5cm
(Inbetween the two heads of sternocleidomastoid)
Might be at the level of the jaw if raised
Height of the IJV and add 5 cm
Moves higher up would be the IJV
Q. How does the JVP change with respiration and why?
A. The JVP usually decreases with deep inspiration. Physiologically, this is a consequence of the Frank–Starling mechanism as inspiration decreases the thoracic pressure and increases blood movement into the heart (venous return), which a healthy heart moves into the pulmonary circulation.
Q. Clinical significance of a raised JVP?
A. The JVP and carotid pulse can be differentiated several ways:
multiphasic - the JVP “beats” twice (in quick succession) in the cardiac cycle. In other words, there are two waves in the JVP for each contraction-relaxation cycle by the heart. The first beat represents that atrial contraction (termed a) and second beat represents venous filling of the right atrium against a closed tricuspid valve (termed v) and not the commonly mistaken ‘ventricular contraction’. These wave forms may be altered by certain medical conditions; therefore, this is not always an accurate way to differentiate the JVP from the carotid pulse. The carotid artery only has one beat in the cardiac cycle.
non-palpable - the JVP cannot be palpated. If one feels a pulse in the neck, it is generally the common carotid artery.
occludable - the JVP can be stopped by occluding the internal jugular vein by lightly pressing against the neck. It will fill from above.
varies with head-up-tilt (HUT) - the JVP varies with the angle of neck. If a person is standing, his JVP appears to be lower on the neck (or may not be seen at all because it is below the sternal angle). The carotid pulse’s location does not vary with HUT.
varies with respiration - the JVP usually decreases with deep inspiration. Physiologically, this is a consequence of the Frank–Starling mechanism as inspiration decreases the thoracic pressure and increases blood movement into the heart (venous return), which a healthy heart moves into the pulmonary circulation
Q. The cardiac cycle can be split into 7 phases
A. 1) Atrial Contraction
2) Isovolumetric Contraction
3) Rapid Ejection
4) Reduced Ejection
5) Isovolumetric Relaxation
6) Rapid Filling
7) Reduced Filling
Q. Explain the wiggers diagram
Causes of aortic valve stenosis?
A. Causes:
• Degenerative (senile calcification/fibrosis)
• Congenital (bicuspid form of valve)
• Chronic rheumatic fever –inflammation- commissural fusion
Key symptoms/ effect on heart
How will the heart sound on auscultation
- How does this effect the carotid pulse?
- Where would you auscultation to hear the aortic murmur?
- Causes of aortic regurgitation
- Explain the effect regurgitation has on the heart and signs of the patient
- Reduced volume
- Right second intercostal space
3.• Aortic root dilation (leaflets pulled apart)
• Valvular damage (endocarditis rheumatic fever)
- • Blood flows back into LV during diastole
• Increases stroke volume
• Systolic pressure increases
• Diastolic pressure decreases
• Bounding pulse (head bobbing, Quinke’s sign)
• LV hypertrophy
- Why does the patient have a bounding pulse?
- Where do you auscultate?
Q. Mitral valve regurgitation
- What normally prevents mitral regurgitation?
- Causes: (4)
- Effect on heart architecture
- High systolic pressure and even lower diastolic pressure in the artery leads to bounding pulse
- 2nd intercoastal space on the right
A. 1. Chordae tendineae & papillary muscle normally prevent prolapse in systole
2. • Myxomatous (Beijing tumour of connective tissue) degeneration can weaken tissue leading to prolapse
• Other causes:
• Damage to papillary muscle after heart attack
• Lest sided heart failure leads to LV dilation which can stretch valve
• Rheumatic fever can lead to leaflet fibrosis which disrupts seal formation
3. As some blood leaks back into LA, this increases preload as more blood enters LV in subsequent cycles…can cause LV hypertrophy
How does the heart sound on auscultation
Q. Mitral stenosis
- Causes:
- How it effects blood flow
- Effect on heart and patient (3)
- How is it heart heard on auscultation
A. 1. Main cause = Rheumatic fever (99.9% cases)
• Commissural fusion of valve leaflets
2. Harder for blood to flow LA -> LV
Q. Define
- Afterload –
- Preload –
- Total peripheral resistance –
A. Afterload – The load the heart must eject blood against (roughly equivalent to aortic pressure)
- Preload – Amount the ventricles are stretched (filled) in diastole – related to the end diastolic volume or central venous pressure
- Total peripheral resistance – sometimes referred to as systemic vascular resistance – resistance to blood flow offered by all the systemic vasculature
Q. Explain how the pressure changes in the cardiovascular system
A. A-> atrial contraction
C -> RV contracts tricuspid bulges up
X -> atrial relaxation and filling
V - > venous filling tricuspid valve closed
Y -> emptying of atrium into ventricle
Always acxvy!!
- Why may you have a raised JVP? (Normal waveform)
- Large ‘a’ wave (increased atrial contraction pressure)
- Bradycardia
Fluid overload
Heart Failure - Tricuspid stenosis
Right heart failure
Pulmonary hypertension
Head and neck session 3 lecture 2
Describe the anatomy and function of the lymphatic system within the body LO
Q. Give the name of fluid, drainage vessels and examples of lymphatic tissues & organs in the lymphatic system.
A. Fluid (lymph)
Drainage vessels (lymphatics)
Lymphatic tissues and organs e.g. lymph nodes
• Spleen
• Tonsils (Waldeyer’s ring)
• Thymus Other lymphoid organs
Q. Which of the below are facts is not wholly true? Give evidence.
Network of drainage vessels
Throughout the body
Series of nodes along vessels
Return a fluid (lymph) to the venous blood circulation
A. The lymphatic system is seen throughout the body
*a few exceptions e.g. eyeball (cornea, lens), inner ear, cartilage
Q. Which of the below are facts is not wholly true? Give evidence.
Network of drainage vessels
Throughout the body
Series of nodes along vessels
Return a fluid (lymph) to the venous blood circulation
A. The lymphatic system is seen throughout the body
*a few exceptions e.g. eyeball (cornea, lens), inner ear, cartilage
Q. How is tissue fluid formed?
A. At the arteriole end the hydrostatic pressure is greater than the oncotic pressure thus fluid leaves the capillary into the tissues. Small proteins/debris/bacteria also move into the interstituim. At the venous end the hydrostatic pressure is reduced due to resistance with the capillary walls etc. Here the oncotic pressure has increased due to the large proteins left in the venous end. Tissue fluid is reabsorbed at the venous end.
- Why do we have a lymphatic system?
- What are the constituents of lymph?
- Net filtration of fluid ≠ Net reabsorption of fluid
- • Tissue fluid PLUS
• Small proteins
• Damaged cells
• Bacteria
• Cancer cells
• Lipids (chylomicrons from gut lymphatics)
Q. Tissue fluid (fluid in interstitium) -> lymphatic capillary =
A. Lymph
Q. Why can’t all the tissue fluid be absorbed back into the venous end?
A. Small proteins are in the tissue fluid because of this not all fluid in the interstitial space can be absorbed. More easier for proteins to move into the lymphatic capillary as it is more pourous compared to the venule?
Q. How much lymph does the body produce a day?
A. 3- 4 L lymphatic fluid produced per day* (120 - 180 mL/hour) (2-3 mL/ min)
Q. Function of lymphatic Vessels
A. Continuous removal of remaining tissue fluid (and macromolecules such as proteins) from the extracellular space (via a series of lymph nodes) back to blood circulation
Q. Clinical significance
A. spread of infection and malignant disease
Q. Complete the flow diagram showing the flow in the lymphatic system
Lymphatic capillary->
A. Lymphatic capillary -> lymphatic vessels -> lymph node -> lymphatic vessels -> lymph node -> lymphatic vessels -> Lymphatic Trunks (right (right lymphatic duct) & left (Left thoracic duct) -> Venous System -> Lymphatic Ducts (right & left)
Q. How is the flow of lymph reduced in the lymph nodes?
A. Many vessels entering but only one efferent vessel. Useful as it allows the lymph node to filter the lymph
Q. Three features of the lymphatic system
A. One directional flow
Low pressure system (allows blood to return to the venous system)
No central pump
Q. Lymphatic vessels have valves. What other feature do lymphatic vessels have to allow blood to flow uni directionally?
A. Passive constriction*: Contraction of the muscle or pulsation of artery will squash the outside of the vessel will push the fluid in a certain direction
Intrinsic constriction: If you stretch lymphatic vessels then will automatically constrict
Q. Name the two lymphatic ducts and state the name of the vein they drain into
A. Right lymphatic duct -> right subclavian vein
Thoracic duct -> left subclavian vein
(Ultimately lymphatic system ends in two main lymphatic ducts which drain into subclavian veins)
Q. What does the right lymphatic duct drain?
A. Half head, right side of Thorax and right upper limb
Q. What is Lymphoedema
A. Abnormal collection of protein-rich fluid causing tissue swelling due to compromised lymphatic system
Lymphoedema
Q. Causes? (5)
A. – Removal or enlargement of lymph nodes
– Infections (e.g. certain parasites)
– Damage to lymphatic system e.g. cancer assists movement of lymph fluid) treatments
– Lack of limb movement (recall muscle contraction
– Congenital e.g. Milroy’s Syndrome (rare)
- How can you tell this is not due to heart failure?
- What is lymphadenopathy? Causes? How to differentiate?
- Bilateral in heart failure and pitting (don’t think it is as protein rich as proteins can still be removed)
-
Enlarged lymph node(s)
Infection (most common) -> tender, mobile
Malignancy -> Hard, matted Non- tender, craggy
Q. If a lymph node is found to be enlarged:
A. • Comprehensive history • Examine the area of tissue it drains • If systemic disease/malignancy suspected examine other lymph nodes and body systems
Q. Lymph nodes within the body can be classified into two groups:
A. – Regional (drain specific areas)
– Terminal (receive drainage from number of regional nodes
Q. Complete the diagram showing specific regions in body where collections of lymph nodes may be palpable
Q. • 800 lymph nodes in body
– ? are in the neck!
• Enlarged ? lymph nodes most common cause of swelling in the neck
– Enlarged lymph node = ?
• Superficial (regional) & deep (terminal) lymph nodes
– Separated by? investing layer of deep cervical fascia of neck
A. 300, cervical, lymphadenopathy,
Q. Describe the general location of the superficial and deep cervical lymph nodes & the general areas of the head and neck that these drain.
Describe the general location of the superficial and deep cervical lymph nodes & the general areas of the head and neck that these drain LO
- State the superficial lymph nodes of the head and neck
- Head: submental, submandibular, pre auricular, post auricular/mastoid, occipital
Neck: Cervical lymph nodes:
- Superficial: EJV
- Posterior: EJV
- Anterior: AJV
Label the diagram with the superficial lymph nodes
HOW TO REMEMBER : WHAT DO YOU PALPATE ON A RESP EXAM to PAS (posterior, anterior & superficial)
Q. What are the deep lymph nodes of the neck?
2. Relation to IVJ and SCM?
A. 1. - Jugulo-digastric
- Jugulo-omohyoid
- Supraclavicular lymph nodes (within supraclavicular fossa)
2. • Deep to SCM
• Closely related to IJV and carotid sheath - *How to remember: DO not watch JUG + what else do you palpate on a patient?
- Jugular – digastric
- Jugular – omohyoid
- Supraclavicular lymph nodes**
Q. Label 9, 10 and 11 of the deep cervical lymph nodes
A. 9. Jugulo-digastric
- Jugulo-omohyoid
- Supraclavicular lymph nodes (within supraclavicular fossa)
Q. Function of supraclavicular lymph nodes (on the right and left)
A. • Oversee transport of lymph from thoracic cavity and abdomen
• Left node: abdomen and thorax - Virchow’s node often enlarges with Gastric cancer
• Right node: mid section chest, oesophagus and lungs
Q. In the neck the superficial lymph nodes are in the ? and the deep nodes lie deep to the investing layer of ?
A. superficial cervical fascia
deep cervical fascia
What areas of the head and neck do the superficial lymph nodes drain?
- *Pre auricular:** lateral part of the face and scalp, including the eyelids
- *Submandibular**: Lymph from the upper lip and lateral parts of the lower lip
- *Submental**: Lymph from the chin and central part of the lower lip (lecture she said Tip of tongue flor of mout & lip) – check lecture
- *Post auricular:**
Q. Lymph from the pre auricular nodes drains to the?
A. Deep cervical lymph nodes which surround the IJV
Q. What is this image of? What is it drained by? Why is this important?
A. Ulcer
Sub mental
If cancer. In these areas enlarged nod
Q. What is this image of? What is it drained by?
A. Conjunctivitis
Pre auricular
Q. What is this image of? What is it drained by?
A. Palatine tonsils
Jugular digastric -> deep
Q. The tongue is drained by mainy lymph nodes. State the lymph nodes its drained by. Use the diagram to help
Explain the purpose Waldeyers ring and describe the structures that form it.
Describe the location of the lymphatic structures of waldeyer’s Ring and be able to identify their general location when viewing the head and neck in a saggital plane. LO
Identify which structures of Waldeyer’s ring are readily visible on inspection of a patients oropharynx LO
Q. What is Waldeyer’s ring?
A. Annular collection of lymphatic tissue (nodules) surrounding the entrance to the aerodigestive tracts
Q. As well as lymph nodes, there are lymphatic tissues/lymphatic nodules (no fibrous outer capsule) which are the lymphatic organs which ? , including the spleen and thymus. A collection of lymphatic nodules around the ? are known as Waldeyer’s ring connected by MALT.
A. produce lymphocytes, pharynx,
Q. What structures form Waldeyer’s ring? LO
A. - Pharyngeal tonsil (adenoids)
- Palatine tonsils (2)
- Lingual tonsils (2)
- Tubal tonsils (2) (where Eustachian tube enters)
(There also normally is a good amount of mucosa-associated lymphoid tissue (MALT) present between all these tonsils (intertonsillar) around the ring, and more of this lymphoid tissue can variably be found more or less throughout at least the naso- and oropharynx)
- Lymphatics from tonsils draining the upper pharynx can drain into
- Where are the pharyngeal tonsils located?
- Where are the palatine tonsils located?
- Where are the lingual tonsils located?
- Where are the tubal tonsils located?
- Which structures of Waldeyers ring are readily visible on inspection of the oropharynx?
- retropharyngeal lymph nodes
- Inferior to the sphenoid sinus
- Between anterior and posterior pillar (oropharynx)
- Posterior aspect of tongue
- where Eustachian tube enters
- Palatine tonsils
- The Eustachian tube is found in the nasopharynx (back of the nose) :what is its function?
- Why is it less likely to have middle ear problems when the adenoids enlarge when you are older?
- grommets- little ventilation tubes placed through the tympanic membrane (or ear drum), which forms one of the ‘walls’ of the middle ear cavity . These grommets act to provide an alternative way of ventilating the middle ear and ensuring equilisation of pressure between middle ear and external environment.
-
ventilate and drain the middle ear cavity
- equalisation of pressures between the middle ear cavity and external atmospheric pressure.
The pharyngeal tonsils, or adenoids, are closely related to the opening of the Eustachian tube (ET) as you rightly state. Enlargement of the adenoids can therefore impede the function of the ET (or pharyngotympanic tube as it is also known) leading ultimately to a build up of fluid in the middle ear. This combined with the lack of ventilation makes an ideal breading ground for bacteria.
-
ventilate and drain the middle ear cavity
- Adenoids atrophy with age
- A common condition, in children particularly, is “glue ear” (or otitis media with effusion), which is commonly caused by ET dysfunction; Usually this is self limiting, but if persistent and troublesome it can be treated with?
- clinical signs present in patients who have raised ICP e.g.
Describe the anatomy and function of the lymphatic system within the body LO
- How many litres of fluid does the lymphatic system drain a a day?
- papilloedema, decreased conscious level
- 3 L (20l at arteriole & 17 at venous)
Q. The lymphatic system consists of;
- Fluid called?
- Vessels called?
- Contains what cells?
- Tissues e.g.?
- Organs e.g.?
A. 1. Lymph
2. Lymphatics
3. Lymphocytes (B cells, T cells and Natural Killer (NK) cells)
– Supporting cells, in particular follicular dendritic cells and macrophages
4. – Diffuse, mucosal associated lymphatic tissue (MALT), this includes gut-associated lymphatic tissue (GALT) and bronchus-associated lymphatic tissue (BALT)
– Lymphatic nodules which include Tonsils, Peyer’s patches and the vermiform appendix
5. – Lymph nodes
– Thymus
– Spleen
Q. What helps move the lymph in the lymphatic system?
A. Passive and intrinsic constriction
- Adjacent arteries and veins
- deep lymphatics pass through muscles. Muscle contraction within the deep compartments is critical to lymph circulation
- stretch lymphatic vessel wall will constrict
- Larger lymphatics, in the abdomen or thorax for example contain SM in their walls. Contraction of this smooth muscle is an important contributor to lymph flow at these sites
Q. What is the common cause of appendicitis in children and in adults?
A. Children: inflammation if forgot
Adults: feacal material obstructing the appendix
Q. State how lymphatic vessels, veins and arteries leave and enter the lymph node
Q. What is located in the germinal centres? What is the function of what is contained in the germinal centre?
A. Follicular dendritic cells:
• Antigen antibody complexes adhere to their dendritic processes & the cell can retain antigen for months
• Follicular dendritic cells cause proliferation of B cells, in particular memory B cells
Q. Apart from follicular dendritic cells lymph nodes also contain what other immune cell?
A. T and B cells and macrophages. B cells and macrophages are antigen presenting cells. Which can prime naïve T cells. Unlike T cells, B cells recognise antigens in the absence of presentation
Q. The initial reaction of the body to an antigen is an ? Mediated mainly by ? Degradation of the antigen may lead to ?
A. inflammatory response, neutrophils and/or macrophages, presentation of a portion of the antigen to elicit a specific immune response
Q. The specific immune response is usually a mixture of humoral and cell-mediated.
Humoral immunity involves what main cell? What is the function of this cell?
A. B lymphocyte mediated and involves antibody production by B lymphocytes that transform into plasma cells that synthetise and secrete a specific antibody.
Q. Cell-mediated immunity is T cell mediated. T cells need antigen presenting cells (macrophages, B lymphocytes) to recognise antigen.
Cell-mediated immunity is important in defence against:
A. – viral, fungal and mycobacterial infections
– tumour cells
– transplant rejection
Q. How do the majority of lymphocytes enter the lymph nodes?
A. feeding artery (a few in lymph) and the majority leave in the efferent lymphatics
Q. What is the function of the spleen
A. The spleen filters blood in the same way that lymph nodes filter lymph. It has functions in both the immune and haemopoietic systems
Immune functions:
– Antigen presentation by APCs
– Activation and proliferation of B and T lymphocytes, production of antibodies
– Removal of macromolecular antigen from blood (macrophages do this) e.g. Silicon
Haemopoietic functions:
– Removal and destruction of old, damaged and abnormal erythrocytes & platelets
– Retrieval of iron from erythrocyte haemoglobin
Q. The spleen has a very rich blood supply, it is also relatively fragile. A ruptured spleen can easily lead to death through exsanguination. Surgeons often remove the spleen (e.g trauma).
- What takes over its function of removing & destroying old RBC?
- Splenectomy increases the risk of what?
- In the same way that lymph nodes enlarge in response to infection (usually localised), the spleen may enlarge in response to?
A. 1. The liver and bone marrow
2. - Infection by encapsulated bacteria (e.g the meningococcus) and malaria
– DVT & PE threefold (partly due to increased platelet count?)
3. systemic infection (glandular fever, malaria, septicemia)
Outline common and important pathology affecting the lymphatic system and disease, which may give rise to lymphadenopathy (e.g. infection, malignancy) & lymphoedema LO
- Define lymphadenopathy
- Infectious lymphadenitides affecting lymph nodes in the neck are often called ?
- Lymphadenopathy is a common and nonspecific sign. Common causes include:
- is disease of the lymph nodes, in which they are abnormal in size, number, or consistency
- scrofula
- infections (from minor ones such as the common cold to dangerous ones such as HIV/AIDS),
- autoimmune diseases
- cancers (Hodgkin vs Non-Hodgkin lymphoma)
- infections (from minor ones such as the common cold to dangerous ones such as HIV/AIDS),
Nonhodkins for non continuous and no Reed-Sternberg cells
Q. What are reed Sternberg cells?
A. Reed–Sternberg cells are different giant cells found with light microscopy in biopsies from individuals with Hodgkin’s lymphoma (a.k.a. Hodgkin’s disease, a type of lymphoma). They are usually derived from B lymphocytes
- Define lymphoedema
- Causes:
- condition of localized fluid retention and tissue swelling caused by a compromised lymphatic system, protein rich fluid, non pitting,
- Inherited or can be caused by a birth defect, though it is frequently caused by cancer treatments & by parasitic infections, clearance
1.1 What is the anatomical surface landmark that relates to the dotte d line
labelled A- B in the image?
1.2 Name the components of the aorta illustrated as H, I and J.
1.3 Name the blood vessels labelled C, D E, F and G.
1.4 What important cranial nerve branch courses under (i) the arch of the aorta
and (ii) around blood vessel E?
1.5 What would be the consequence of unilateral damage to the nerves you have
given in answer to question Q1.4?
A. 1. Sternal also angle
2. H- ascending aorta
I -arch of the aorta
J- descending aorta
3. C- brachicephalic (trunk)
D- right common carotid artery
E - right subclavian artery
F- left common carotid artery
G- left subclavian artery
4. • Left recurrent laryngeal nerve
• Right recurrent laryngeal nerve
5. • Left/right- hoarseness of voice, raspy voice damage to one side to get symptoms
• lesion to both loss of voice
Q. 1. What anatomical landmarks help to locate the bifurcation of the common carotid artery into its two terminal branches? Where is this on your own neck and why might palpating the carotid pulse be easier in this area?
2. What physiological response might arise if you were to put pressure on the carotid pulse in the area of the carotid sinus? How might this be utilised clinically when treating patients?
3. In examination of the cardiovascular system and prior to performing carotid sinus massage, why would a doctor wish to listen over the carotid artery with a stethoscope?
Using the bell side of a stethoscope, listen over your own carotid artery; what do you hear?
4. Why might it be helpful to ask the patient to hold their breath during auscultation of the carotid arteries?
Remind yourself how and where you would identify the jugular venous pressure on a patient: demonstrate or describe the technique on your colleague.
5. On the image below, label the branches of the external carotid artery. You will have met some of these branches before during your study of the scalp anatomy (self-study). What are the arteries labelled A, B, C and D?
A. 1. Carotid triangle
Superior border of the thyroid
Lateral to the superior border of the thyroid cartilage
Not beneath the sternocleidomastoid
2. Pressing the carotid pulse in the carotid sinus would lower the blood pressure due to the carotid sinus being located here.
When you have supraventricular tachycardia you could do a carotid massage slows the heart rate
3. Bruit noise turbulent flow (atheroma)
Reduced blood flow to the brain further reduce blood flow may faint
4. Prevent listening to the flow of air through conducting airways
5. A: INTERNAL CAROTID
B: VERTEBRAL
C: THRYOCERVICAL
D: RIGHT SUBCLAVIAN
SLFOAMPS
Q. An elderly lady presents to the Emergency Department with a 2 day history of increasing confusion.
Working with your group, create a list of possible causes for why someone could present with confusion (i.e. a differential diagnosis). Think as broadly as possible and without using the internet (i.e. recalling what you have learnt in previous Units)!
A. Vascular
Inflammatory
Traumatic - concussion (CT scan
Autoimmune
Metabolic
INFECTION - UTI (dysuria) pain, blood, frequent urea dip
Neoplastic
Degenerative-
Idiopathic-
Congenital
Brain tumour - normally secondary so ask if you had cancer, vomiting due to raised intracranial pressure, headache
Alcohol consumption and withdrawel - delirium seizures
B12 defiency - confusion screen peripheral neuropathy, macrocytic anaemia
Encephalitis can cause confusion
Q. What else in the patients history might narrow your diagnosis?
A. Drug history
Medication
Age
Previous medical history
Social background
Q. What Investigations could you have to narrow your differential diagnoses?
A. HBA1C glycated haemoglobin stable marker long term
FBC
Electrolytes ( U + E )
BP
Auscultation of the heart and valves?
(Extra info from group work:
Cresenteric (bana shaped subdural haemorrhage (
Hyperdensed
Blood on the right side
Blood on a CT acutely will show up white then will show up white
Right side acute sub dural haemorrhage
Braiding veins emissary veins
Shifted to the left of the falx cerebri
Right acute subdural haemorrhage with a midline shift
Mass effect pressure
Black area is big CSF filled areas in the brain are ventricles one on the left none on the right
Low density are are CSF filled
Extradural - lens shaped white so acute bleeding and inflammation local , sutures limiting the haemorrhage lambdoid
Middle meningeal of the anterior branch (maxillary -> external carotid artery)
