Head And Neck Session 2 Flashcards Preview

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Flashcards in Head And Neck Session 2 Deck (93):
1

Which blood vessel is used to measure right atrial pressure and why?

Internal jugular vein as it is straighter therefore gives a better indication

2

Which jugular vein is more visible?

External

3

What is the difference in position of the internal and external jugular veins in relation to SCM?

External is superficial, internal is deep to SCM

4

How is jugular venous pressure calculated?

Height from sternal angle +5 cm

5

What structure gives the level of the bifurcation of the CCA?

Superior border of the thyroid cartilage

6

Which branches does the subclavian artery give rise to?

Thyrocervical trunk
Vertebral artery
Internal thoracic artery

7

What are the branches of the aorta in the neck?

Brachiocephalic trunk --> subclavian and common carotid

8

Describe the passage of vertebral arteries from the subclavian artery to the brain.

Ascend through L&R transverse foramina of C6-1 to anastomose with the internal carotid artery to form basilar arteries

9

Which branch of the CCA does not have any branches in the neck?

Internal

10

Describe the path of the internal carotid artery.

Through carotid canal to anastomose in the circle of Willis

11

What is the carotid sinus?

Swelling at the region of the carotid bifurcation where baroreceptors are located

12

What is a carotid body?

Peripheral chemoceptor with rich vascular supply that can detect arterial pO2

13

Why is the CCA bifurcation a common site for atheroma formation?

Turbulent flow occurs here

14

What percentage occlusion of the carotid artery must be achieved before it becomes symptomatic?

>70%

15

What is the clinical importance of the carotid triangle of the neck?

Pulse point
Surgical access to carotid artery, IJV, vagus and hypoglossal nerves
Carotid sinus massage in SVT pts

16

Which are the terminal branches of the external carotid artery?

Superficial temporal and maxillary

17

What are the branches of the external carotid artery?

Maxillary
Facial
Lingual
Superior thyroid
Ascending pharyngeal
Occipital
Posterior auricular
Superficial temporal

18

What are the two branches of the superficial temporal artery?

Frontal and parietal

19

What are the layers of the scalp?

Skin
Dense CT
Aponeurosis
Loose CT
Periosteum

20

In which layer of the scalp do the blood vessels lie?

Dense CT

21

Which arteries supply the scalp?

Superficial temporal
Occipital
Posterior auricular
Supratrochlear
Supraorbital

22

What are the supraorbital and supratrochlear arteries branches of?

Ophthalmic artery, a branch of the ICA

23

Why does the scalp bleed profusely if damaged?

Close attachment of artery walls to dense CT limits constriction
Numerous anastomoses

24

How can a deep laceration to the scalp cause profuse bleeding?

Opposing pull of occipitofrontalis via the epicranial aponeurosis holds arteries open

25

Why does loss of scalp not lead to bone necrosis?

Blood supply to the skull is mostly via the middle meningeal artery so this will be maintained

26

What forms the angular vein at the medial angle of the eye to empty into the facial vein?

Supraorbital and supratrochlear veins

27

Where do the veins in the deep part of the scalp empty?

Pterygoid venous plexus

28

Why can infection in the scalp spread to the cranial cavity and meninges?

Veins of scalp connect to diploid veins through several valveless emissary veins and thus to dural venous sinuses

29

What forms a groove near the coronal suture that is visible on internal view of the skull?

Anterior branch of middle meningeal artery

30

What is the pterion?

Relatively weak area of skull formed by fusion of temporal, frontal, sphenoid and parietal bones

31

Why can fracture of the pterion cause extradural/epidural haemorrhage?

Can rupture middle meningeal artery (especially anterior branch)

32

How is blood supply to the dura and skull preserved during craniotomy?

Reflect bone and scalp flap inferiorly to preserve MMA and superficial temporal artery

33

Where do the superficial arteries of the face arise from?

All from ECA except supraorbital and supratrochlear from the ICA

34

Where can the facial artery pulse be felt?

Inferior border of mandible, anterior to masseter

35

Which is the major branch of the maxillary artery?

MMA

36

What are the branches of the facial artery?

Superior and inferior labial
Lateral nasal
Angular

37

What is the danger triangle of the face?

Area between bridge of nose and corners of the mouth that allows retrograde infection from the nasal area to the brain

38

What can be the result of retrograde infection in the danger triangle of the face?

Cavernous sinus thrombosis
Meningitis
Brain abscess

39

What are dural venous sinuses?

Endothelium-lined spaces between the periosteal and meningeal layers of dura formed at dural septae that receive blood from large veins draining the brain

40

How many dural venous sinuses are there?

5

41

What are the names of the dural venous sinuses that converge at the posterior of the skull?

Superior sagittal
Inferior sagittal
Transverse
Cavernous
Sigmoid

42

Where does the sigmoid sinus empty into?

IJV to leave skull through the jugular foramina

43

What is the cavernous sinus?

Plexus of extremely thin-walled veins on the upper surface of sphenoid

44

What are the contents of the cavernous sinus?

ICA
CN: II-oculomotor, IV-trochlear, VI-abducent and 2 branches of the trigemnial V1-ophthalmic and V2-maxillary

45

Do veins in the face have valves?

No

46

What does the facial vein communicate with at the medial angle of the eye to empty into the cavernous sinus?

Superior ophthalmic

47

Where do the deep facial veins drain into?

Pterygoid venous plexus

48

How is the internal jugular vein positioned in relation to the other carotid sheath structures?

Deep to SCM and lateral to CCA, deep cervical lymph nodes and the vagus nerve

49

What is the lymphatic system?

Network of drainage vessels throughout the body with a series of nodes that return lymph to the blood circulation

50

Where are lymph vessels not found?

Avascular areas

51

Is the lymphatic system present in the CNS?

Yes

52

Why does a small amount of fluid remain in the intersticium during tissue fluid formation?

High hydrostatic pressure at arteriole end pushes out small proteins that cannot move back at the venule end as the oncotic pressure is not small enough

53

How much lymph is formed per day?

3-4 l

54

Why is lymph needed?

To prevent development of oedema due to the accumulation of small proteins as net filtration is not equal to net reabsorption

55

What is tissue fluid In a lymphatic capillary called?

Lymph

56

What does lymph contain?

Depends on location: damaged cells, bacteria, cancer cells, chylomicrons

57

How does the flow of lymph compare to that of blood?

Much lower, 2-3 ml vs 5000 ml per minute

58

Describe the order of lymphatic flow.

Tissue fluid --> lymphatic capillary --> lymphatic vessels --> lymph nodes --> lymphatic vessel --> lymphatic trunks --> thoracic/R lymphatic ducts

59

Which duct drains the majority of lymph in the body?

Thoracic

60

How many lymphatic vessels enter and exit each lymph node?

Several afferent enter but only one efferent exits

61

How is the one-directional flow, low pressure system with no central pump able to achieve return of tissue fluid to blood circulation?

Valves, passive constriction by muscles and arteries and intrinsic constriction by reflexively contracting smooth muscle cells

62

What is lymphoedema?

Chronic condition of fluid retention and tissue swelling due to compromise of the lymphatic system

63

What can cause lymphoedema?

Removal/enlargement of lymph nodes
Infection e.g. Parasites
Damage to system e.g. Cancer (itself or Tx)
Lack of limb movement
Congenital

64

Describe the tissue structure of a lymph node.

Tough fibrous outer capsule with reticular CT inside

65

What do lymph nodes contain large numbers of?

Lymphocytes and macrophages

66

How do lymph nodes play a key role in immune defence?

Physical filter
Phagocytic filter
Lymphocytes for immune surveillance

67

What size can a lymph node normally be?

Anywhere from microscopic to 2.5 cm

68

What shape are lymph nodes normally?

Bean

69

What can cause swollen lymph nodes?

Infection or malignancy

70

How can a swollen lymph node to due infection be differentiated from one due to malignancy?

Infection: tender, firm and mobile
Malignancy: hard, matted and non-tender

71

What does presentation with a swollen lymph node require?

Comprehensive history
Examination of area drained by node
Examine other lymph nodes and body systems if cancer is suspected

72

How are lymph nodes organised?

Regional/superficial nodes that are readily palpable drain specific areas and empty into terminal/deep nodes that receive lymph from multiple regional nodes

73

Where are superficial lymph nodes palpable?

Neck
Armpit
Abdomen
Pelvis
Groin

74

How many lymph nodes are there in the neck?

300

75

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

Enlarged cervical lymph nodes

76

What separates cervical lymph nodes into superficial and deep?

Investing layer of deep cervical fascia

77

Where are most of the deep cervical lymph nodes found?

In the carotid sheath associated with the IJV

78

What are the 8 groups of superficial cervical lymph nodes?

Submental
Submandibular
Preauricular
Postauricular
Occipital
Superficial (EJV)
Posterior cervical
Anterior cervical

79

What are the three groups of deep cervical lymph nodes?

Jugulo-digastric (tonsillar)
Jugulo-omohyoid
Supraclavicular

80

Which muscle are the deep cervical lymph nodes deep to?

SCM

81

Where do the L&R supraclavicular lymph nodes receive lymph from?

R: mid-section chest, oesophagus, lungs
L: abdomen and thorax

82

What is the alternative name for the left supraclavicular node?

Virchow's node

83

What areas of the face do the submandibular lymph nodes receive drainage from?

Upper lip and teeth
Lateral lower lip
Most of face
Anterior nasal cavity
Cheeks
Middle tongue
Submental and lingual glands

84

Which areas of the face do the submental nodes receive drainage from?

Lower lip and teeth
Anterior chin
Tip of tongue
Floor of mouth

85

Which areas of the head do the preauricular lymph nodes receive drainage from?

Middle posterior scalp
Skin of lateral ear
Parotid gland

86

Which areas of the head do the postauricular lymph nodes receive drainage from?

Posterior scalp
Cranial surface of pinna
Back of external acoustic meatus

87

Which region of the head do the occipital lymph nodes receive drainage from?

Posterior scalp and neck

88

Where do the superficial cervical (including anterior and posterior) lymph nodes receive drainage from?

Skin of neck
Preauricular, postauricular and occipital nodes

89

Where do the entire head and neck superficial lymph nodes drain into?

Deep cervical nodes

90

Where do the jugulo-digastric nodes receive drainage from?

Palatine tonsil and posterior 1/3 of tongue

91

Where do the jugulo-omohyoid nodes receive their drainage from?

Anterior 2/3 tongue, oral cavity, trachea, larynx, oesophagus and thyroid gland

92

What is Waldeyer's ring?

Ring of lymphoid tissue in the naso- and oropharynx consisting of pharyngeal tonsils, 2 eustaschian tonsils, 2 palatine tonsils, 1 or more lingual tonsils and lots of MALT

93

Why is the lymphoid tissue in Waldeyer's ring considered tissue instead of nodes?

Lack fibrous CT surrounding them