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 pathogens3) Spleen - collection of lymphocytes and macrophages -cleans the blood4) bone marrow – stem cells + lymphocytes/macrophages -cleans the blood5) 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 types1. 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 – covers temporalis muscle and runs down to the zygomatic arch

– 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 – danger space• Parapharyngeal – lymph nodes• Previsceral – nodes and cervical vessels• Space of the body of the mandible – mandible and inferior alveolar

nerve• Vestibular space of mandible• Submental space – submental nodes and anterior jugular• Buccal - fat• Pterygomandibular space of infratemporal region• Canine• 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 andperiodontium

e.g. vestibular space of the mandible – mandibular teeth andperidontium

-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

The Masticator Spaces1.Temporal space2.Infratemporal space3.Submasseteric space

Temporal space

Submasseteric space

Infratemporal 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): between the masseter & ramus of mandible

-contains the inferior alveolar nerve (V3) and inferioralveolar artery (maxillary artery)in addition to the mandibular dental plexus, mental and incisive branches of the IAN

-sublingual and submandibularspaces contain the SL and SM glandsand lymph nodes-the SL space also contains the ductsfor the SL and SM glands-the SM space contains part of the facial artery-the SL space contains part of the lingualnerve and artery + XII

Space of the body of the mandible

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 &retropharyngeal spaces

Parapharyngeal space: lateral To the pharynx-media to the medial pterygoid m.-adjacent to the carotid sheath-Contains lymph nodes-continues with retropharyngeal space

Retropharyngeal space: posterior topharynx-located between the vertebral &visceral fascia-called the danger space: extends from baseof skull into the thorax