Lymphatic System

• Lymphatic system: system of lymphatic vessels and organs • • for the transport of

lymph lymph

: filtrate produced in tissues and NOT reabsorbed by the capillaries of the CV system – produced through large-scale filtration of plasma into tissues – carried through a system of

lymphatic vessels

and filtered through

lymph nodes

Lymphatic organs: 1

)

lymph nodes:

found at certain points along the lymphatic system -capsule surrounding an outer cortex and inner medulla -cortex contains immune cells

= lymphocytes

-medulla contains immune cells =

macrophages

-cleans lymph and fights specific pathogens

2) tonsils:

lymphatic tissue located in the pharynx (

adenoids

) or oral cavity (

palatine tonsils

) -collection of lymphocytes and macrophages -”cleans” food and drink and air -first defense against pathogens

3) Spleen -

collection of lymphocytes and macrophages -cleans the blood

4) bone marrow

– stem cells + lymphocytes/macrophages -cleans the blood

5) Thymus

– production of T cells

Lymph nodes:

-1 to 2 cm bean shaped -surrounded by a

fibrous capsule

which extend into the node to form

trabeculae

-fed by

afferent lymphatic vessels

-drained by

efferent lymphatic vessels

-made up of tissue organized as an

outer cortex and an inner medulla

-cortex contains numerous

follicles – site of T and B cells -outer cortex follicles = B cells -deep cortex = site of T cells

-number and composition of the follicles can change according to the antigen being recognized -medulla made up of

medullary cords

of lymphatic tissue =

contain B cells, plasma B cells and macrophages

-between the cords are spaces called

medullary sinuses = site of macrophages

lymph -> afferent vessel -> subcapsular sinus -> trabecular sinuses -> medullary sinuses -> efferent vessel

-cervical nodes -clavicular nodes -axillary nodes -mediastinal nodes -mesenteric nodes -inguinal nodes

Lymph nodes

• Nodes of the head and neck drain into two large groups

–

Superior deep cervical nodes (SDCs)

• Drain the external/middle ear, sinuses, nasal cavity, lacrimal gland, scalp and face • Also drains several oral structures:

floor of mouth, base of tongue, maxillary and mandibular teeth, tonsils, salivary glands, palate

–

Inferior deep cervical nodes (IDCs)

• Drains the cervical nodes (external & anterior jugular nodes) • Also drains some of the axillary nodes and the deep posterior triangle of the neck

• Refer to handouts

• •

Superficial nodes of Head & Neck

Nodes of the Head: drain to superior deep cervical nodes

– –

Figures 10-3, 10-4, 10-5 Occipital

– drain to inferior deep cervical nodes – – – –

Retroauricular Anterior auricular Superficial parotid Facial nodes

• Malar • Nasolabial • Buccal • mandibular

Nodes of the Cervical region: drain into superior or inferior deep cervical nodes

–

Retropharyngeal

– drains into SDCs – – – –

Submental

– drains into submandibular nodes

Submandibular

– drains into SDCs

External jugular

or Superficial lateral cervical nodes – drains into IDCs

Anterior jugular

or Superficial anterior cervical nodes – drains into IDCs

Cervical Nodes

-lymphatic vessels join to form two major ducts:

1) thoracic duct

(joins to the left subclavian vein as the left lymphatic duct)

2) right lymphatic duct

– connects to right subclavian vein -right arm & thorax, right side of head and neck ->

right jugular trunk

->

right lymphatic duct

-> right subclavian vein (at junction of internal jugular) -left arm & thorax, lower body, left side of head and neck ->

left jugular trunk

->

thoracic duct

-> left subclavian vein (at junction of internal jugular)

lymphatic system is ONE WAY (from tissues to heart)

Lymphatic vessels

-lymphatic vessels - for the transport of

lymph

-larger lymphatic vessels are similar to blood vessels - presence of

valves

-enters lymphatic capillaries from the tissues -low pressure system - moves by muscular contraction and breathing -capillaries join to form

lymphatic vessels

Tonsils

• not located along lymphatic vessels • drain into the superior deep cervical lymph nodes • reach their largest size during puberty • four types – known as

Waldeyer’s ring

–

Palatine

– located in oropharynx • Behind the palatoglossal arch – –

Lingual

– base on tongue

Pharyngeal

or Adenoids • located in nasopharynx –

Tubal

• located in nasopharynx

• Tonsillitis is an inflammation the tonsils in the mouth and will often, but not necessarily, cause a sore throat and fever . It may be caused by Group A streptococcal bacteria and similar appearances may also be seen in glandular fever . Most tonsilitis however is viral in origin.

• other tonsillar complications –

peritonsillar abcesses

or quinsy can eventually lead to septicaemia –

hypertrophy

of tonsils can disturb sleep, lead to snoring and mouth breath and even sleep apnea – consumption of mucus by bacteria on tonsils – produce whitish yellow deposits called

tonsilloliths

or tonsil stones – produce a sulforous odour.

Fascia

• • • Two types 1. Superficial 2. Deep

Superficial fascia

– Connects skin to underlying structures – Can contain copious amounts of fat

Deep fascia

– two divisions – A. face & jaws – B. deep cervical

Fascia

• •

Face & jaws:

continuous with deep cervical fascia – – –

Temporal

arch – covers temporalis muscle and runs down to the zygomatic

Masseteric-parotid

– below the zygomatic arch • Covers the masseter and parotid gland

Pterygoid

– found on the medial side of the medial pterygoid muscle

Deep cervical:

all continuous with each other and with the fascia of the face and jaw – – –

Investing

– most external layer • Surrounds the musculature of the neck • Completely encloses the submandibular and parotid glands (continuous with the masseteric-parotid fascia), the sternocleidomastoid and the trapezius

Carotid sheath

– encloses the external carotid, the internal jugular and the vagus nerve

Visceral

– encloses the thyroid gland, trachea, esophagus • Near the skull this fascia is known as the buccopharyngeal fascia –

Vertebral

– deepest layer • encloses the deep musculature of the vertebral column and the vertebral column itself (e.g. semispinalis, longissimus, spinalis)

Fascial spaces

• Spaces created by the deep fascia of face, jaws and cervical regions • All interconnected with each other

• •

With the exception of the parotid space Parotid space

– Contains the parotid gland and facial nerve branches, external jugular branches and retromandibular vein • http://flashcarddb.com/cardset/124977-fascial-spaces lect-5-mod-4-flashcards

• • • • • • • • • • • • • Contain specific anatomical structures

Retropharyngeal Parapharyngeal Previsceral

nerve – danger space – lymph nodes – nodes and cervical vessels

Space of the body of the mandible

– mandible and inferior alveolar

Vestibular space of mandible Submental space

– submental nodes and anterior jugular

Buccal Pterygomandibular space of infratemporal region Canine

- fat

Sublingual

– sublingual gland and ducts, submandibular ducts, lingual nerve and artery, cranial nerve XII

Submandibular

– submandibular nodes and gland, facial artery

Masticator space – temporal space + submasseteric space + infratemporal space

–

Infratemporal space

– maxillary artery, mandibular nerve, pteygoid plexus

Vestibular space

-these spaces communicate directly with the eponymous teeth e.g. vestibular space of the maxilla – maxillary molars and periodontium e.g. vestibular space of the mandible – mandibular teeth and peridontium

-buccal space:

between the buccinator and masseter muscles -contains fat -covered by part of the parotid fascia -communicates with the canine and pterygomandibular spaces & space of the body of the mandible

-canine space:

anterior border is the orbicularis oris -posterior border is the levator anguli superioris -located above the upper lip and to the side of the maxillary canine -sits below muscle that lift the upper lip: the levator labii superioris, orbicularis oris, zygomaticus muscles

Temporal space Infratemporal space The Masticator Spaces 1. Temporal space 2. Infratemporal space 3. Submasseteric space Submasseteric space

Masticator spaces

• General term for the area of the mandible & associated muscles of mastication –

1. temporal space (fig. 11-7):

between the fascia that covers the temporalis muscle and the actual muscle – 2.

infratemporal space (fig. 11-8):

found in the infratemporal fossa • Medial border – lateral pterygoid m.

• Lateral border – mandible and temporalis m.

• Superior border/roof – greater wing of sphenoid • Anterior border – pharynx • Contains the

pterygomandibular space (fig 11-8) – contains the inferior alveolar nerve

• Contains part of

maxillary artery, mandibular nerve & branches, medial and lateral pterygoid muscles

–

3. submasseteric space (fig. 11-9):

ramus of mandible between the masseter &

Space of the body of the mandible

-contains the

inferior alveolar nerve (V3

) and

inferior alveolar artery

(maxillary artery) in addition to the

mandibular dental plexus, mental and incisive branches of the IA

N -sublingual and submandibular spaces contain the

SL and SM glands and lymph nodes

-the SL space also contains the

ducts for the SL and SM glands

-the SM space contains

part of the facial artery

-the SL space contains

part of the lingual nerve and artery + XII Sublingual & Submandibular spaces

Submental & Submandibular spaces -submental space:

roof is the mylohyoid m.

-floor is the superficial fascia that covers the suprahyoid m.

-lateral border is the anterior belly of digastric m.

Parotid space

Parapharyngeal space:

To the pharynx lateral -media to the medial pterygoid m.

-adjacent to the carotid sheath

-Contains lymph nodes

-continues with retropharyngeal space

Retropharyngeal space:

pharynx posterior to -located between the vertebral & visceral fascia

-called the danger space:

of skull into the thorax extends from base

Parapharyngeal & retropharyngeal spaces