Session 2 - Organisation of Blood and Lymph Systems Flashcards Preview

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Flashcards in Session 2 - Organisation of Blood and Lymph Systems Deck (71)
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1
Q

Where do the right and left common carotid arteries arise from? At what level does the right common carotid artery come from?

A

Right common carotid – arises from bifurcation of the brachiocephalic trunk. Occurs at level of right sternoclavicular joint.

Left common carotid – comes directly off the arch of the aorta.

2
Q
A
3
Q

What branches do the common carotids give off in the neck?>

A

None

4
Q

What spinal level does the common carotid split?

A

C4

5
Q

What is the carotid sinus? Where is it located? What is the carotid body? Where is it located?

A
  • Common and internal carotid are dilated, area known as carotid sinus. Involved in detecting and regulating BP
  • External to carotid sinus is the carotid body – these are peripheral CRs. Detect O2 in blood and regulate breathing rate.
6
Q

What is carotid sinus hypersensitivity? What must you do for these patients?

A

in some people, baroreceptors hypersensitive to stretch and external pressure on carotid sinus can slow HR and decrease BP, resulting in brain under perfusion and syncope. Checking pulse here not advised in these patients.

7
Q

At what point of the common carotid is a common site for atheroma formation? What could an atheroma here result in?

A

Bifurcation of common carotid.

Could result in rupture of clot and embolus travelling to brain, lodging in smaller artery and causing a stroke.

8
Q

What symptoms result from carotid artery atherosclerosis

A

Dizziness, headache, muscular weakness

9
Q

How would you assess the severity of thickness of a common carotid atherosclerosis??

A

Doppler study

10
Q

What is the name of the procedure where the carotid artery is cut open and the atheromatous tunica intima is removed?

A

carotid endarterectomy

11
Q
A
12
Q

What does the external carotid artery supply?

A

Head and neck external to cranium

13
Q

What branches of the external carotid supply:

a) superficial face structures
b) deep face structures

A

a) facial and superficial
b) maxillary

14
Q

What arteries supply blood to the scalp? Which are branches of external carotid and which are internal carotid?

A

posterior auricular, occipital, superficial temporal (external carotid)

super-orbital and supratrochlear (internal carotid arteries branches)

15
Q

Why can injuries to scalp cause excessive bleeding?

A
  1. Walls of arteries bound tightly to underlying connective tissue of scalp, preventing constriction to limit blood loss.
  2. Numerous anastomoses formed by arteries which produce a densely vascularised area
16
Q

Why do deep lacerations involving the epicranial apneurosis result in excessive bleeding?

A

Deep lacerations can involve the epicranial aponeurosis which is worsened by the opposing pulls of the occipital and frontalis muscles, resulting in opening of the wound.

17
Q

Does the skull undergo avascular necrosis after injury? Why?

A

skull does not undergo avascular necrosis due to blood from alternative source, middle meningeal artery.

18
Q

What is the middle meningeal artery a branch of?

A

Maxillary artery

19
Q

What does the MMA supply?

A

Supplies skull and dura mater.

20
Q

What is the dura mater?

A

Outer membranous layer covering the brain

21
Q

What happens in a fracture of the pterion?

A

Fracture of pterion (weakest point of skull) can damage MMA, resulting in blood collecting between the dura mater and the skull, resulting in an increase in intracranial pressure.

22
Q

How does the internal carotid artery enter the cranial cavity? Where is this thing located?

A

Carotid canal in the petrous part of the temporal bone

23
Q

What does the internal carotid supply?

A

Brain, eyes and forehead

24
Q

From where do the vertenral arteries arise from?

A

Subclavian arteries

25
Q

Through which transverse processes does the vertebral artery travel through?

A

C6 - 1

26
Q

How does the vertebral artery enter the cranial cavity? What happens after they enter?

A
  • Enters cranial cavity via the foramen magnum and then converge.
  • After conversion they give rise to the basilar arteries which supplies the brain
27
Q

Label the branches of the thyrocervical trunk

A
28
Q

What are the lateral, medial, and superior borders of the carotid triangle?

A

Superior – posterior belly of digastric
Lateral – SCM
Medial – Superior belly of omohyoid

29
Q

What are the contents of the carotid triangle?

A
  • Internal jugular vein
  • Bifurcation of common carotid
30
Q

What are the venous drainages of:

a) brain and meninges
b) scalp and face
c) neck

A

Brain and meninges – Dural venous sinuses
Scalp and face – Veins synonymous with arteries of the face and scalp. Drain into internal and external jugular veins
Neck – Anterior jugular veins

31
Q

Name the bifurcation of the external jugular vein and what they drain.

A

External jugular vein (EJV) bifurcates into retromandibular vein and posterior auricular vein:

  • Posterior auricular – Drains scalp superior and posterior to ear
  • Retromandibular vein – drains face along with maxillary and superficial temporal.
32
Q

What is the termination point of the EJV and IJV?

A

subclavian vein

33
Q

Why is the EJV vulnerable to injury? What happens in a laceration of the EJV?

A
  • EJV superficial, therefore vulnerable. Found in superficial fascia
  • If slashed open, lumen held open due to investing fascia. Air will be drawn into the vein resulting in cyanosis.
  • This can stop blood flow through the right atrium. Medical emergency
34
Q

What vein drains the anterior aspect of the neck?

A

Anterior jugular vein

35
Q

How does the IJV exit the skull?

A

Jugular foramen

36
Q

What is jugular venous pressure? What does it provide an estimation of?

A
  • Pulsations of IJV
  • Provides estimate of right atrial pressure. Contraction of heart results in an observable pressure wave that passes outwards. No valves in brachiocephalic or subclavian veins.
37
Q

What are dural venous sinuses? From where do they collect blood?

A
  • Dural venous sinuses are spaces between periosteal and meningeal layers of dura mater, which are lined by endothelial cells.
  • Collect venous blood from veins that drain the brain and skull, and drain into IJV
38
Q

Where is the cavernous sinus located?

A

Lateral aspect of sphenoid bone

39
Q

Where does the cavernous sinus receive blood from?

A

Receives blood from superior and inferior ophthalmic veins, middle superficial cerebral veins, and from sphenoparietal sinus

40
Q

The internal carotid artery passes through the cavernous sinus before reaching the brain. Why?

A

Cools the blood.

41
Q

What nerve crosses the sinus?

A

6th CN - Abducens

42
Q

What nerves are located in the lateral wall of the cavernous sinus?

A

the oculomotor (III), trochlear (IV), ophthalmic (V1) and maxillary (V2) nerves

43
Q

Explain the existence of the danger triangle of the face.

A
  • If cavernous sinus becomes infected these nerves at risk of damage.
  • Facial vein is connected to cavernous sinus via superior ophthalmic vein. Facial vein is valveless, allowing blood to reverse direction and flow from facial vein to cavernous sinus. Therefore, infection of face (in danger triangle of face) can spread to the venous sinuses.
44
Q

Is lymph transudative or exudative? What is its pH?

A

Transudative

alkaline

45
Q

What is the condition called where lymph vessels are blocked?

A

lymphoedema

46
Q

What proportion of fluid in the extracellular space returns via the lymphatic system?

A

1/10th

47
Q

State the components of the lymphatic system

A

Microscopic lymphatic capillaries –> Lymphatic vessels –> lymph node –> lymphatic vessels –> Lymphatic trunks –> Collecting Ducts –> Drains into Subclavian vein

48
Q

What are the lymph organs?

A
  • Bone marrow
  • Spleen
  • Thymus gland
  • Lymph Nodes
  • Tonsils
49
Q

how many lymph nodes does the average adult have? How many are in the abdomen and pelvis?

A

total = 450

Abdo and pelvis = 230

50
Q

How do lymph nodes clean up lymph?

A

Nodes inhabited by phagocytes and macrophages that clean it

51
Q

How are superficial and deep structures drained by lymph?

A

Separate systems

Superficial drains into deep

52
Q

What are the 2 lymphatic ducts of the body and where do they enter?

A

Right lymphatic - enters via right venous angle into right brachiocephalic vein

Thoracic duct - enters via left venous angle into left brachiocephalic vein

53
Q

What areas of the body do the 2 lymphatic ducts drain?

A

Right lymphatic duct - upper rght quadrant

Thoracic duct - everything else

54
Q
A
55
Q

What other 2 ways do clinicians classify lymph nodes?

A

Regional and terminal - Regional drains specific part of body. Terminal recieves drainage from regionals.

Horizontal and vertical - horizonal occurs as clusters. Vertical occur on a vertical plane.

56
Q

Where is the outer and inner circle of superficial lymph nodes found?

A

Outer - Collar around the lowe rmargins of the head

Inner - Lies within outer circle. Surrounds upper airway passages and openings of alimentary passage

57
Q

What structure does this lymph node drain - occipital

A

back of scalp

58
Q

Where do deep lymph nodes of the H&N lie?

A

within carotid sheath inside deep fascia. Surrounding whole length of IJV

59
Q

Which node is enlarged in infections of the tonsils?

A

Jugulodigastric aka tonsillar node

60
Q

What are the inferior deep cervical nodes? Where do inferior deep cervical nodes lie?

A

Jugulo-omohyoid node AKA lingual node - deep to SCM and above inferior belly of omohyoid.

Supraclavicular node - above clavicle

61
Q

Which nodes are paired and unpaired?

A
  • Paired - palatine tonsil, tubal tonsil
  • Unpaired – pharyngeal (adenoid) tonsil, lingual tonsil
62
Q

Where does pus accumulate in a retropharyngeal abscess? What happens in a retropharyngeal abscess?

A

In a retropharyngeal abscess, puss accumulates in space between prevertebral fascia and buccopharyngeal membrane. Can result in compression of pharynx à dysphagia and dysarthria (difficulty speaking).

63
Q

What is lymphadenitis?

A

infection of lymph nodes

64
Q

What is lymphangitis?

A

Inflammation of lymph nodes

65
Q

What is lymphoedema?

A

Pooling of lymph in tissues

66
Q

What is lymphocytosis?

A

High lymphocyte count from infection, lymphoma, or autoimmune disease

67
Q

What is lymphoma?

A

Hodgkins and non hodgkins disease. Blood cancer

68
Q

What is the sternal angle

A

Where manubrium joins sternum at T4/5 IV disc

69
Q

What significant landmarks are at the sternal angle?

A

tracheal bifurcation, aortic arch, ligamentum arteriosum

70
Q

What is the main symptom of an aneurysm of aortic arch?

A

hoarseness due to compression of recurrent laryngeal

71
Q
A