week 3- blood vessels and lymphatic drainage Flashcards Preview

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Flashcards in week 3- blood vessels and lymphatic drainage Deck (92):
1

Label the major vessels in the head and neck 

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2

What comes off of the arch of aorta from right to left?

  • Brachiocephalic trunk 
    • Right subclavian 
    • Right common carotid 
  • Left common carotid 
  • Left subclavian 

3

How many branches does the common carotid artery give off in the neck?

  • None 
  • it then goes on to bifurcate to give the external and internal carotid arteries 

4

What branches does the subclavian artery give off in the neck?

  • Vertebral artery 
  • Subclavian artery 
  • Internal thoracic 
  • Thryocervical trunk
    • Suprascapular 
    • Inferior thyroid 
    • Ascending cervical 
    • Transverse cervical 

5

What does the inferior thyroid artery (branch of thyrocerivcal branch of subclavian) supply?

  • The lower pole of the thyroid gland 

6

What does the vertebral artery (branch of subclavian) supply?

  • Along with internal carotid supplies brain 
  • Gives off a number of branches

7

What does the transverse cervical artery (branch of thyrocervial tunk of subclavian) supply?

The neck 

8

Where does the internal thoracic artery (branch of subclavian) pass? What can it be used for?

  • Enters the rib cage 
  • Also known as the internal mammary 
  • Can be used for coronary bypass 

9

Q image thumb

  1. Internal carotid artery 
  2. External carotid artery 
  3. Common carotid artery 
  4. Inferior thyroid artery 
  5. Vertebral artery 
  6. Thyrocervical trunk
  7. Subclavian artery 
  8. Internal thoracic artery 

10

Where do the vetebral arteries arise from? What do they ascend through? What do they supply?

  • Arise from right and left subclavian arteries 
  • Ascend in the neck through transverse foramina of cervical vertebrae 1-6
  • Supply the brain along with the internal carotid 

11

Describe the path of the internal carotid artery

  • Gives off no branches in the neck 
  • Enters the skull through the carotid canal 

12

Where does the bifurcation of the common carotid artery take place?

  • Around the level of the superior border of thyroid cartilage (under sternocleidomastoid) 

13

Where does the internal jugular vein lie?

  • Lateral to the common carotid artery 
  • Under sternocleidomastoid

14

What are the two structures found at the point of bifurcation of the common carotid artery?

  • carotid sinus 
    • Swelling at base of internal carotid artery 
    • Location of the baroreceptors (stretch receptors) which detect changes in arterial BP
  • Carotid body 
    • Peripheral chemoreceptors which detect arterial O2 
    • They have a rich blood supply and innervation 

15

Where is a common site for atheroma development in the carotid arteries? What does it cause? What can rupture of the clot cause?

  • Bifurcation of the common carotid is a common site
  • Causes stenosis (narrowing) of artery 
    • It is one of the major arteries supplying the brain so this can limit blood supply 
    • BUT due to circle of willis there may not be obvious symptoms 
  • Rupture of clot can cause embolus to travel to brain 
    • causes transient ischemic attack or stroke 

16

What is the carotid sheath closely related to? What is its contents?

  • Closely related to:
    • Pretracheal, prevertebral and investing layers of deep fasica 
  • Contents:
    • Common carotid artery 
    • Internal jugular vein 
    • Vagus nerve
    • Deep cervical lymph nodes 

17

what is the carotid triangle a subdivision of? 

  • Anterior triangle (this can be split into many smaller triangles, carotid triangle is one of these) 

18

what are the boundaries of the carotid triangle?

  • Superior boundary:
    • Posterior belly of digastric 
  • Lateral boundary:
    • Sternocleidomastoid 
  • Medial boundary:
    • Superior belly of omohyoid

19

What are the contents of the carotid triangle?

  • Internal jugular vein 
  • Bifurcation of the common carotid artery into the internal and external carotid 

20

The carotid triangle can be used in surgery to access certain structures. What are these?

  • Carotid arteries
  • Internal jugular vein
  • Vagus nerve 
  • Hypoglossal nerves 

21

Where can the carotid pulse be felt? Why might you not want to palpate the carotid pulse in some patients?

  • In the carotid triangle 
  • Or more inferiorly (by pressing against sternocleidomastoid)

In patients with vascular of cardiovascular disease palpating the carotid pulse may cause further stenosis and limit blood supply to the brain 

22

When is a carotid sinus massage done?

  • if a patient is tachycardic
  • it stimulates baroreceptors which perceive it as high blood pressure 
  • This increases parasympathetic/ decreases sympathetic innervation to the heart causing a decrease in heart rate

 

N.B. some patients have a very sensitive carotid sinus so if you put pressure on it they faint 

23

the external carotid artery has 6 branches and 2 terminal branches. What are these?

  • 6 branches:
    • Superior thyroid 
    • Lingual 
    • Facial 
    • Ascending pharyngeal 
    • Occipital 
    • Posterior auricular
  • 2 terminal branches:
    • Superficial temporal 
    • Maxillary 

24

The blood supply to the scalp is an anastamoses of arteries. What are these?

Branches of ophthalamic artery (which is a branch of internal carotid):

  • Supra-orbital artery 
  • Supratrochlear artery 

Branches of external carotid artery:

  • Superficial temporal artery 
  • Posterior auricular artery 
  • Occipital artery 

25

Why does loss of the scalp not lead to bone necrosis? 

  • because the arteries supplying the scalp do not supply the skull 
  • The supply to the skull is mostly the middle meningeal artery 

26

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  1. Facial artery 
  2. Lingual artery 
  3. Superior thyroid artery
  4. Ascending pharyngeal artery  
  5. Occipital artery 
  6. Posterior auricular artery 
  7. Superficial temporal artery 
  8. Maxillary artery 

27

Label the blood supply to the scalp 

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  1. Supra-orbital artery 
  2. Supratrochlear artery 
  3. Superficial temporal artery 
  4. Posterior auricular artery 
  5. Occipital artery 

28

describe the venous drainage of the scalp 

  • Superficial veins accompany arteries
    • superficial temporal, occipital and posterior auricular veins 
  • Supraorbital and supratrochlear veins unite at the medial angle of the eye to form the angular vein (drains into facial vein)
  • Some deep parts of the scalp in the temporal region have veins that drain into the pterygoid venous plexus
    • This connects to other venous sinuses and can be a route for spread of infection 

29

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  1. Cavernous sinus 
  2. Pterygoid plexus 

30

Describe how infection can spread from the scalp

  • Veins of the scalp connect to diploic veins and dural venous sinuses via emissary veins
  • Emissary veins are valveless 
  • Infection from the scalp can spread into the cranial cavity and affect the meninges 

31

What is the brain covered by?

  • A double layer of dura mater
  • The outer layer is periosteal 

32

What is the middle meningeal artery a branch of? Where does it run? What does it supply?

  • Branch of maxillary artery 
  • Runs between bone and dura
    • Grooves formed by the anterior branch can be seen on the internal view of the calvaria (skull)
  • Middle meningeal suplies the skull and dura

33

When is a craniotomoy done? In which direction is the bone and scalp flap pulled? 

  • Done to releive pressure or to gain acess to the cranial cavity for surgery 
  • Bone and scalp are pulled down (reflected) inferior to preserve blood supply 
    • As blood supply comes upwards from the neck 
    • This allows the flap to be replaces afterwards (doesn't become necrotic) 

34

What are the superficial arteries of the face?

  • branches of the internal carotid:
    • Supra-orbital 
    • Supratrochlear
  • Branches of the external carotid:
    • Transverse facial 
    • Angular 
    • Lateral nasal 
    • Maxillary 
    • Superior and inferior labial 
    • Facial 

35

Where can the pulse of the facial artery be felt?

At the inferior border of the mandible as it becomes anterior to the masseter muscle

36

Q image thumb

  1. Supra-orbital artery 
  2. Supratrochlear artery 
  3. Transverse facial artery 
  4. Angular artery 
  5. Lateral nasal artery 
  6. Maxillary artery 
  7. Superior and inferior labial arteries 
  8. Facial artery 

37

Where is the dural partition?

Between the 2 cerebral hemispheres

38

Describe dural venous sinuses. Where do they form? Where do they receive blood from?

  • Endothelium lined spaces between periosteal and meningeal layers of the dura
  • Form at dural septae 
  • Receive blood from large veins draining the brain 

39

What are the dural venous sinuses?

  • Superior saggital sinus 
  • Inferior saggital sinus 
  • Cavernous sinus 
  • Sigmoid sinus 
  • Transverse sinus 

40

Describe the caverous sinus and its contents

  • A plexus of extremely thin-walled veins on the upper surface of the sphenoid, either side of the pituitary gland 
  • Contains:
    • Internal carotid artery 
    • CNIII (occulomotor)
    • CNIV (trochlear) 
    • CNVI (abducent)
    • 2 branches of trigeminal 
      • CNVI- ophthalmic 
      • CNV2- maxillary 

41

What is unusual about facial veins 

  • They are valveless 
  • So blood can flow in both directions 

42

At the medial angle of the eye what does the facial vein communicate with? What do they drain into? 

  • The superior ophthalmic vein
  • Drain into the cavernous sinus 
    • this communicates with the pterygoid venous plexus 
    • N.B. if there is infection in the cavernous sinus it can affect all the structures in it 

43

What do deep facial veins drain into? Where can infection from the facial veins spread to? What about thrombophlebitis of the facial vein?

  • They drain into the pterygoid venous plexus 
  • Infection can spread into the dural venous sinuses 
  • Thrombophlebitis of the faical vein can lead to an infected clot traveling to the intracranial venous system 

44

What is the danger triangle of the face?

  • An area sort of over and around the nose where infection can spread into the pterygoid plexus and cavernous sinus 

45

what is easier to see; the internal jugular vein or the external jugular vein?

  • The external jugular vein (as it courses over sternocleidomastoid) whereas IJV is beneath it 

46

Why do we measure JVP from the right internal jugular vein?

  • It is in direct communication with the right atrium (no valves between them) so pressure in the right IJV gives a good indication of pressure in the right atrium 

47

How do we measure JVP? What is a normal JVP?

  • From right internal jugular vein 
  • Patient at 45 degree angle 
  • Measure height from the sternal angle then add on 5cm to give height from the right atrium 
  • Normal= 3-4cm above sternal angle 
    • This is 8-9cm above right atrium 

 

48

what is raised JVP a sign of? What about low JVP?

  • Raised JVP
    • Fluid overload
  • Low JVP 
    • Dehydration 

N.B. often we do not see th JVP at all unless it is raised 

49

Describe, generally, the lymphatic system and lymphatic organs

  • The lymphatic system is a network of drainage vessels carrying lymph that passes through lymph nodes and other lymphoid organs (e.g. spleen, thymus and tonsils)
  • Lymphoid organs 'house' lymphocytes and act as sutes for lymphocyte activation 

50

The lymphatic system is throughout the whole body except where?

  • Eyeball (cornea and lens)
  • Inner ear
  • Cartilage 

51

Describe the formation and reabsorption of tissue fluid 

  • At the arteriole end of the capillary bed:
    • hydrostatic pressure > oncotic pressure 
    • Fluid then moves from the capillary into interstitial space 
    • Large proteins remain in the blood but small proteins and bacteria can move with the fluid 
  • At the venule end of the capillary bed:
    • Oncotic pressure> hydrostatic pressure 
    • Fluid moves from the interstitial space into the capillaries 
    • Not all of the fluid is reabsorbed. Around 3-4L is not. This would remain in the interstitial space along with small proteins, cell debris and bacteria if it wasn't for the lymph system

 

52

What is tissue fluid?

Tissue in the interstitium 

53

How much lymphatic fluid is produced a day?

  • 3-4L
  • This is the difference between the net filtration of fluid and net reabsorption of tissue fluid

54

what happens to the tissue fluid that is not reabsorbed?

  • it moves into lymphatic capillaries 
  • As soon as this occurs it is known as lymph 

55

what is lymph formed of?

  • Tissue fluid plus:
    • Small proteins 
    • Lipids (chylomicrons from gut lymphatics)
    • Damaged cells 
    • Pathological substances:
      • Bacteria 
      • Cancer cells 
      • (these are associated with enlarged lymph nodes) 

56

Describe generally the role of the lymphatic system

  • Continuous removal of remaining tissue fluid (and macromolecules such as proteins) from extracellular space back to the blood circulation 
  • Also a route for the spread of infection and malignant disease

57

What is the order of lymphatic flow

  • Tissue fluid becomes lymph vessels once it enters lymphatic capillaries
  • Then goes through:
    • Lymphatic vessels (afferent)
      • These are smaller than lymphatic capillaries but after this point the vessels get bigger
    • Lymph nodes
    • Lymphatic vessel (efferent)
    • Lymphatic trunks
    • Lymphatic ducts 

58

Describe the structure of lymph nodes

  • Connective tissue structures:
    • Tough, fibrous outer capsule
    • Reticular connective tissue inside 
  • Contain large collection of lymphocytes (B+T) and macrophages

59

What may lymph draining into lymph nodes contain?

  • Pathogens from infected areas of tissue so lymph nodes play a key role in the immune defence

60

There are many vessels entering each lymph node (afferent) and only 1 leaving (efferent). Why is this?

  • This slows down flow of lymph through the node and so allows more time for it to carry out its function 

61

What are the 3 main features of the lymph system?

  • One directional flow 
  • Low pressure system 
  • No central pump 

62

One reason for unidirectional flow in lymph vessels is that they have valves. What else ensures flow in only one direction despite the fact that it is a low pressure system with no central pump?

  • Passive constriction 
    • Small lymph vessels run with veins 
    • Larger ones run with arteries 
      • Contraction of arteries pushes blood 
    • Lymph vessels run through muscles and so as the muscles contract this pushes lymph fluid through the vessel towards the part of the circulation it needs to get to
  • Intrinsic constriction 
    • Some larger lymph vessels have smooth muscle cells in their lining which respond to stretch by contracting 

63

The lymphatic system ends in 2 main lymphatic ducts which drain into subclavian veins. What are these? What areas do they drain?

  • Thoracic duct
    • Into left subclavian vein
    • Most lymph 
  • Right lymphatic duct  
    • Into right subclavian vein
    • lymph from right side of the face, right arm and right hemithorax 

64

why does lymph drain into veins and not arteries?

  • As the lymphatic system is low pressure and so it would be very difficult to move lymph into arteries which are high pressure

65

What is lymphoedema? What is the difference between this and oedema caused by heart failure?

  • Lymphoedema- abnormal collection of protein-rich fluid causing tissue swelling due to compromised lymphatic system 
  • Oedema due to heart failure is more to do with too much tissure fluid formation. 
    • Oedema due to heart failure is also pitting whereas lymphoedema is not 

66

What chronic conditions can lead to lymphoedema?

  • Removal or enlargement of lymph nodes
  • Infections e.g. parasites
    • not so common in the developed world 
  • Damage to lymphatic system e.g. cancer treatment 
  • Lack of limb movment 
    • Doesn't cause it but makes it worse as muscle contraction aids lymph movement 
  • Congenital e.g. Milroy's syndrome (rare)
    • This is a problem with the development of the lymph system

67

In what 2 ways can cancer treatment lead to lymphoedema?

  • Lymph node removal 
  • Radiotherapy can cause fibrosis of lymphatic vessels and blockage of lymph flow 

68

What is another word for swollen lymph nodes?

  • Lymphadenopathy

69

All substances transported in the lymph pass through more than one lymph node. What do these nodes do? 

  • Act as a physical barrier (reticular connective tissue)
  • Act as a phagocytic filter (macrophages)
  • It is full of lymphocytes which activate and proliferate in response to antigens
    • This causes the node to swell 

70

What can cause lymphadenopathy? What will the lymph node be like in each case?

  • Infection (most common)
    • Tender 
    • mobile mass
  • Malignancy 
    • hard 
    • matted
    • non-tender 

71

If enlarged lymph nodes are found what should we do? 

  • Take a comprehensive history 
  • Examine the area of tissue it drains 
  • If malignancy is suspected you should examine other lymph nodes and body systems

72

What is the difference between regional and terminal lymph nodes?

  • Regional nodes
    • These are superficial
    • They drain specific areas
  • Terminal nodes
    • These are deep
    • They receive drainage from a number of regional nodes

73

What are regional (superficial) and terminal (deep) lymph nodes separated by in the neck?

Investing layer of deep cervical fascia of the neck 

74

Where are palpable lymph nodes found?

  • Neck (cervical)
  • Armpit (axillary)
  • Diaphragm 
  • Spleen 
  • Abdominal 
  • Pelvic
  • Groin (femoral) 

75

What is the most common cause of swelling in the neck?

  • Enlarged cervical lymph nodes 

76

Where are the superficial and deep cervical lymph nodes found generally?

  • Superficial are in superficial cervical fascia (they are more readily palpable)
  • Deep are mostly within the carotid sheath 

77

How many lymph nodes do we roughly have in our body? How many of these are found in our neck?

  • 800 in the body 
  • 300 in the neck 

78

This image shows the superficial lymph nodes in the head (green) and neck (purple). What is each group called? 

Q image thumb

  1. Sub-mental 
  2. Submandibular 
  3. Pre-auricular 
  4. Post-auricular
  5. Occipital
  6. Superifical cervical  
  7. Posterior cervical (in posterior triangle)
  8. Anterior cervical (in anterior triangle)

79

What can cause enlargement of the sub-mental lymph nodes?

Ulcers

80

This image shows the deep lymph nodes of the head and neck. What is each group called?

Q image thumb

9) Jugulo-digastric 

10) Jugulo-omohyoid 

11) supraclavicular 

81

Where are the supraclavicular (deep) lymph nodes found? what is their role?

  • In supraclavicular fossa
  • They oversee the transport of lymph from the thoracic cavity and abdomen 
    • The left node: drains from the abdomen and thorax and is Virchow's node
    • The right node: drains from the mid section of chest, oesophagus and lungs 

Abdominal and thoracic malignancies can present as enlarged supraclavicular lymph nodes 

82

What is Waldeyer's ring?

  • A collection of lymphatic tissue surrounding the superior pharynx
  • It responds to pathogens that may be ingested/inhaled 

83

What are the tonsils that make up Waldeyer's ring? 

  • Lingual tonsils (2) 
    • On posterior base of tongue 
    • Form the antero-inferior ring 
  • Palatine tonsils (2) 
    • On each side beween palatoglossal and glossopharyngeal arches 
    • Form part of lateral part of ring
  • Tubal tonsils (2)
    • Located where each eustachian tube opens into the nasopharynx
    • Form part of lateral part of ring 
  • Pharyngeal tonsil (1)
    • Also called adenoid and nasopharyngeal tonsil 
    • Located in roof of nasopharynx, behind the uvulva
    • Forms postero-superior part of ring 

84

What area do the submandibular (superficial) lymph nodes drain? 

  • Upper lip and teeth
  • Lateral lower lip 
  • Most of face  
  • Anterior nasal cavity
  • Tongue (middle) 
  • Submandibular and sublingual glands 

85

What area do the submental (superficial) lymph nodes drain?

  • Lower lip 
  • Central teeth
  • Anterior chin 
  • Tip of tongue
  • Floor of mouth

86

What do the anterior, posterior and superficial cervical lymph nodes drain? 

  • Skin of the neck 

87

What area do the pre-auricular (superficial) lymph nodes drain?

  • Scalp 
  • Anterior part of ear (auricle) 
  • Parotid gland 

88

What area do the post-auricular/mastoid (superficial) lymph nodes drain?

  • Scalp
  • Posterior part of of ear (auricle) 
  • Ear canal 

89

What area do the occipital (superficial) lymph nodes drain? 

  • occipital area of the scalp and neck 

90

What do the superficial lymph nodes of the head and neck drain into?

  • The deep cervical nodes
  • These surround the IJV then drain into the subclavian vein via the thoracic duct 

91

Which of the deep cervical lymph nodes is most often enlarged? Where does it receive drainage from? 

  • Jugulo-digastric (most often enlarged) 
  • Drains from:
    • Palatine tonsil
    • Oral cavity 
    • Posterior 1/3rd of tongue 
    • Pharynx
    • Larynx  

92

Which tonsil do we see as enlarged in tonsilitis? 

  • The palatine tonsil 
  • This is one of Waldeyer's ring