Chapter 21 lymphatic system

lymph, lymphatic vessels, and primary and secondary lymphoid structures

Lymphatic system composed of _______________

Lymph

15% of fluid that left capillaries (not returned)

3 L

how much lymph is made in your body a day (fluid not returned)

Water, Ions, proteins (100-200 g), debris / pathogens

Composition of lymph

Lymphatic Capillaries

Dead end capillaries

Lymphatic Capillaries

Present among most capillary beds (except red bone marrow and epithelium)

Endothelium (overlapping)

Structure of lymphatic capillaries, act as 1 way valves

Anchoring filaments

Structure of lymphatic capillaries, hold it in place

Lymphatic Capillaries

provide Lymph movement to heart

Increases

Endothelium as one-way valves ________ pressure inside the capillary

Larger lymph vessels

resemble veins in their three tunics and valves.

Skeletal muscle pump, Respiratory pump, Pulsing of nearby arteries, & Smooth muscle contraction in large lymph vessels

Accessory pumps of Lymph movement to the heart in action- __________________________

Lymphatic trunks and ducts

two categories of large lymphatic vessels

Lymphatic trucks

smaller lymph vessels empty into these (region specific)

Lymphatic trucks

4 are paired R/L with a single intestinal trunk

Lymphatic ducts

lymphatic trucks empty into one of the two ducts

Right & thoracic

Two lymphatic ducts

Right Lymphatic duct

smallest of the ducts

Right Lymphatic duct

Empties near right subclavian vein

Right Lymphatic duct

Drains upper right quadrant of the body

Thoracic duct

largest of the ducts

Thoracic duct

Extends from diaphragm to near the left subclavian vein

Thoracic duct

Drains the remainder of the body not covered by the right lymphatic duct

Primary Lymphoid Organs– location of lymphocyte creation and maturation

Secondary Lymphoid Organs– housing locations for lymphocytes where an immune response can be initiated.

Red Bone Marrow

Primary, site of hematopoiesis

Red Bone Marrow

All formed elements

Red Bone Marrow

T-lymphocytes must first go to thymus to mature fully, then go here

Marrow

All other formed elements enter the blood stream from the _________.

Thymus

site of T-lymphocyte maturation

adipose tissue

the thymus is at maximum weight at puberty then regresses into _________

Thymus

Bi-lobed with lobes divided into many lobules

Thymus

has Lobules organized into cortex and medulla

Thymus

immunologically isolated from the body

works

Positive selection in Thymus– Cortex

ignores self antigens

Negative selection in Thymus– Medulla- receptor_______________

Naïve

__________ T-lymphocytes go to secondary lymphoid organs

Apoptosis

All other cells (not used in thymus selection) undergo _________

Lymph Nodes

Secondary Lymphoid Organ

Lymph Nodes

Filter unwanted material from lymph

Lymph Nodes

Encapsulated

Lymph Nodes

has many Afferent lymphatic vessels

Lymph Nodes

has one single Efferent lymphatic vessel

Lymph Nodes

500-700 in the body

head/neck

location of cervical Lymph node cluster

breast/axilla/upper arm

Location of axillary lymph node cluster

lower limb/pelvis

location of inguinal lymph node cluster

Trabeculae

CT ________ divide cortex into segments containing lymph nodules

Nodules

collection of leukocytes

Medulla

center portion of node containing sinuses for fluid flow

Hilum

indented portion of node, where Efferent LV leaves the node

Spleen

Secondary Lymphoid Organ

Bacteria

Functions of Spleen- Remove ________ and foreign material

RBC’s

Functions of Spleen- Remove old or defective _______ and platelets

Reservoir

Functions of Spleen- _________ for RBCs and platelets.

Spleen

25-30% of platelets and RBCs are stored here

Spleen

Largest lymphoid organ

Spleen

Concave (left); convex (hilum) right

Spleen

Fetal period through 5th month of gestation it functions in hematopoiesis

Spleen

Functionally divided into White and Red pulp

White Pulp

Nodules of T/B lymphocytes and macrophages around the central artery

Red Pulp

RBCs, platelets, macrophages and B lymphocytes

Splenic sinusoids

sinuses in spleen that filter RBC’s

Spleen blood flow

Splenic artery, Central artery, Sinusoids, Venules, Splenic vein

Tonsils

Secondary Lymphoid Organ

Pharyngeal

(adenoids/nasal)

Palatine

(throat) tonsil

Lingual

(tongue) tonsil

Tonsils

function- Protection against inhaled/ingested foreign material

Tonsils

are an Incomplete capsule

Tonsillar crypts

increase surface area to trap material

Tonsils

Contain lymph nodules

Tonsillitis

Inflamed and infected tonsils (palatine).

Tonsillectomy

Chronic tonsillitis leads to a ________

Nodules

Diffuse Lymphoid tissue

Nodules

Found to different degrees in every organ of the body

Nodules

Prominent (transitory) in small intestine (Peyer’s Patches) and appendix

Mucosa associated lumphoid tissue (MALT)

Diffuse Lymphoid tissue

Mucosa associated lumphoid tissue (MALT)

in Small intestine

Mucosa associated lumphoid tissue (MALT)

AKA. BALT (Bronchiolar-ALT) found in respiratory tract

Mucosa associated lumphoid tissue (MALT)

AKA GALT (GUT-ALT) in alimentary canal including stomach

Mucosa associated lumphoid tissue (MALT)

Transient collections of leukocytes in areas of frequent encounter with bacteria and foreign material