lymphatic

___% everything into tissue space ends up in the lymphatic system.

___% into the venous system

10

90

how does the lymphatic system work (overview) 

plasma filters through capillaries into interstitial space

interstitial fluid absorbed by tissue cells or reabsorbed back to venous system 

if fluid is left behind, edema may occur → tissue destruction/death 

difference between mechanical and biological filtration

mechanical: block particles from progressing further through body

biological: cells remove microorganisms and particles through phagocytosis

what is lymphoid tissue

reticular tissue that contains lymphocytes and other defensive cells

what are peyers patches

aka aggregated lymphoid nodules

nodules of lymph tissue in intestinal wall and appendix

what is chyle/chyli

lymph in intestines

difference between lymph and vascular circulation 

lymph: transport tissue fluid, proteins, fats, other substances back into general circulation

• one way circulation - begins blindly in intracellular spaces  

vascular: closed ring / loop 

¾ lymoh drains through ___ before entering venous system

thoracic duct

difference between lymph and interstitial fluid?

they both resemble ___ in composition, but have a lower percentage of __.

___and ___ together constitute ___ compatrtment of body

lymph: clear, watery fluid in lymphatic vessels // IF: fluid in spaces between cells

plasma, proteins

lymph, IF, extracellular fluid

the wall of each lymphatic capillary consists of ___ cells

a single layer of flattened epithelial

(simple squamous)

what is a chylothorax

lymph in pleural space - can be a complication from a central line

describe the draining of the 2 major lymphatic trunks

right lymphatic duct: lymph from upper right quadrant - drains into right subclavian vein

thoracic duct: lymph from everywhere else - drains into left subclavian vein, joins internal jugular vein

what is the subclavian commonly used for 

central lines (drug administration, monitoring) 

catheters 

___% proteins in interstitial space can return to blood due to large size .

what happens if something is blocking lymphatic return?

50%

blood protein concentration and blood osmotic pressure drop → fluid imbalance → death if severe

what are lacteals?

what do they do?

lymph capillaries of small intestine villi

absorb fats and nutrients 

lymph in lacteals after digestin contains 1-2% fat and is called ____.

interstitial fluid contains far (more/less) fat than this new lymph substance.

chyle

less

how much lymph is moved through the thoracic duct each day?

how much total lymph is drained per day?

what are the 3 mechanisms that allow lymph flow?

3L

4L

valves, breathing movements, skeletal muscle contraction

what is lymphokinesis? 

lymphokinesis flows into central veins the quickest during (inspiration/expiration). 

rate of flow is studied via___

movement of lymph 

inspiration - abdominal pressure increases, thoracic pressure decreases, moves lymph upward

lymphangiography - inject radiographic dye into ymphatics and observe flow 

what are treatments that seemb “dumb” but do still get lymph moving?

elevation, compression, massage, ankle pumps

deep breathing, incentive spirometry

total lymph drainage into central veins is dependent on ___ and ___ of breathing

rate and depth

lymoh flow increases as much as ___ times during exercise

10-15

how much total lymph is drained per day

4 L

where can smooth muscle be present in the lymphatic system

large lymph vessels - in tunica media and externa

mostly in thoracic vessel walls

what are lymph nodes?

what vessels do they have?

like mini kidneys, act like mini spleens (1-20mm in diameter)

many afferent vessels at periphery, few efferent vessels at hilum

lymph enters the node and penetrates slowly through ___ before draining into single efferent vessel. 

one way valves are present in what vessels? 

sinuses

both afferent and efferent 

___(1) extend from covering the capsule toward the center of the node.

___(2) within sinuses are separated from each other by (1).

each (2) is packed with lymphocytes that surround a ___(3).

trabeculae

cortical nodules

germinal center

when infection is present, germinal centers release ___.

___begin their final stages of maturation in germinal center before becoming antibody producing plasma cells.

the center(___) of a lymph node is lined with macrophages that can phagocytose

lymphocytes

B cells

medulla - pathogen and particle removal

where are the more important groups of lymph nodes? 

preauricular 

submental, submandibular 

superficial cubital 

axillary *monitor for infection*

iliac, inguinal 

colorectal cancers affect what nodes?

virchow’s nodes

what areas do the preauricular nodes drain?

submental, submandibular?

preauricular: superficial tissue and skin on lateral head and face

subment/submand: nose, lips, teeth (3-6 nodes)

what areas do the superficial cervical nodes drain?

superficial cubital?

cervical: head and neck

cubital: forearm (supratrochlear/epitrochlear)

what areas do the axillary nodes drain? 

iliac, inginal? 

axillary: arm, upper thoracic wall, breast (20-30 large nodes) 

iliac,inguinal: pelvic organs, legs, external genitalia

what pathologies are common with issues with axillary lymph nodes

breast cancer, UE lymphedema

2 major functions of lymph nodes

defense - filtrarion and phagocytosis

hematopoiesis - lymphocyte and monocyte maturation

if too much of a microorganism is present, infection pf the lymph node called ___ can occur

adenitis

what is mastitis

infection of the breast tissue

why can the lymphatic system be harmful with cancer

can transport cells from primary tumor to other areas of body

2 sets of lymphatic vessels of the mammary glands

cutaneous lymphatic plexus - diffuse, superficial, drain skin over breast

subareolar plexus - deeper, drain underlying breast tissue and skin of areola

85% lymph from breast enters lymph nodes of the ___ region. 

the rest enters nodes around the edge of the ___

axillary region 

sternum (perasternal nodes)

what is the axillary tail?

a ___ is the first lymph node to which a cancerous tumor can spread

large nodes in contact with breast tissue

SLN (sentinal lymph node) - biopsy can determine metastases

what are tonsils

masses of lymphoid tissye in a protective ring under mucus membranes of mouth and pharynx

what does the pharyngeal lymphoid ring do?

where are palatine tonsils?

pharyngeal tonsils?

lingual tonsils?

tubal tonsils?

ring: protect against bacteria that may invade oral and nasal cavities

palatine: at side of throat 

pharyngeal: aka adenoids when swollen, near posterior opening of nasal cavity 

lingual: at base/root of tongue 

tubal: near opening of eustachian tube

what is the primary organ of the lymphatic system?

where is it?

what is involution?

thymus - 2 pyramidal lobes 

mediastinum, upinto neck 

involution: thymus largest during puberty, gradually atrophies with age, replaced by fat 

2 major functions of thymus

lymphocyte development before birth: fetal marrow develops immature lymphocytes → into thymus for maturation → circulate to spleen, nodes, tissues

thymosin secretion: thymosin lets lymphocytes develop into mature T cells

___% T cells matured each day are released into bloodstream.

what do T cells do?

what happens to them with age?

by 50yo, ___% functional thymus remains.

5%

attack foreign cells, regulate immune function

decreased new T cells (smaller thymus) → higher rate of disease

10%

what does the spleen do? 

what are accessory spleens? 

filter, breakdown old deficient blood cells, lymphocyte maturation, store blood 

lasceration → cells released → grow accessory spleen on pancreas/vessels 

what and where is the white pulp in the spleen?

red pulp?

white: in compartments - dense masses of developing lymphoctes

red: outer region of compartment - network of reticular fibers submerged in broken RBCs

what should you think of when you see the word “reticular”

filtration, mesh

splenomegaly can be seen in what pathology? 

infectious mononucleosis - needs to be normal size before returning to activity 

describe defense system in spleen

macrophages in sinusoids phagocytize and remove microorganisms in blood

describe tissue repair in spleen

monicytes in WBCs mobilized with tissue damage → migrate to injured tissue and assist in healing and repair

*myocardial infarction and cerebrovascular accident

describe hematopoiesis in the spleen

nongranulocytes (monocytes and lymphocytes) develop and activate in spleen

RBCs formed in spleen before birth - RBCs formed in cases of extreme hemolytic anemia after birth

describe RBC and platelet destruction in spleen

macrophages remove damaged RBCs and breakdown Hb to salvage iron → return to bloodstream → store in liver

describe the blood reservoir in the spleen

storing ~350ml blood at any given time

1 minute of sympathetic activation → 200ml blood back into circulatory system 

relationship between hemolytic anemia and the spleen

overactive spleen or splenomegaly → breakdown healthy RBCs

→ splenectomies 

what complication can happen if the spleen is ruptured or damaged? 

how to stop this complication?

released blood reservoir → internal bleeding → death if severe 

surgical removal or repair can stop hemorrhaging and save life 

what is in the right hypochondriac region?

epigastric region?

left hypochondriac?

right - liver, gallbladder, right kidney, small intestine

epi - stomach, liver, pacnreas, duodenum, spleen, adrenal glands

left - spleen, colon, left kidnet, pancreas

what is in the right lumbar region? 

umbilical region? 

left lumar region? 

right - gallbladder, liver, ascending colon 

umb - navel, small intestine, duodenum 

left - descending colon, left kidney 

what is in the right iliac region?

hypogastric region?

left iliac?

right - appendix, cecum

hypo - bladder, sigmoid colon, female reproductive organs

left - descending colon, sigmoid colon

what is lymphedema?

how does it happen?

swelling of tissues or extremities associated with blocked lymphatic system

proteins in tissue space → fluid follows —> lymphedema

most common type of lymphedema?

what can happen with chronic lymphedema?

how to treat chronic lymphedema

congenital lymphedema

frequent infection, high fever, chills

diuretics, massage, elevation - surgical removal or shunting if not responsive

describe the 4 stages of lymphedema 

1: asymptomatic, reduced lymphatic flow, no swelling - monitored with doppler or ultrasound

2: swelling, reversible if caught early → exercise, compression, elevation

3: permanent, not relieved with elevation, some changes in skin (fibrosis)

4: lymphostatic elephantiasis - permanent deformation of limb from swelling, thickened skin, scarring - no drainage possible

what are filaria 

small parasitic worms infecting lymph vessels → rapid progression to stage 4/elephantiasis 

*often seen in tropics - frequent bouts of infection 

what is lymphangitis?

how does it present?

acute inflammation of lymphatic vessels from infection → rapid progression to sepsis

thin, red streaks from infected region toward lymph nodes → tender nodes → tissue necrosis (infection spreading through lymph system)

what is lymphoma

tumor of lymphatic tissue cells

often malignant - originate in lymph nodes, can involve lymph in liver/spleen/GI

spreadys quickly through anastamoses

describe the 2 types of lymphoma 

hodgkin: malignancy due to exposure to chemicals or pathogen induced tumor - starts as painless enlarged lymph at neck/axilla

• considered most curable form of cancer

nonhodgkin: malignancy caused by virus (AIDS, immunedeficiencies) - involve CNS

• treated with radiation/chemo