The Lymphatic System Flashcards
Part of the circulatory system and a vital part of the immune system, comprising a network of lymphatic vessels that carry a clear fluid called lymph directionally towards the heart.
The Lymphatic System
*Functions of the Lymphatic System
Alternate route for fluid from interstitial/tissue spaces to blood
Drainage system of circulatory system
*Functions of the Lymphatic System
Carries protein from tissue spaces and also large particulate matter
Lymph vessels from liver
*Functions of the Lymphatic System
Absorbs fats from the digestive tract
Lacteals or lymph capillaries in digestive system
*Functions of the Lymphatic System
Lymph nodes filter lymph thus removing and destroying bacteria.
Produce _________ cells – lymphocytes that destroy invading organisms from lymph before bringing it
defensive
from Latin lympha meaning _____
water
Clear, colorless fluid returned to the heart via the lymphatic system which empties into the jugular vein or cranial vena cava
Contains RBCs, WBCs, histiocytes, tissue fluids and proteins
Lymph
Numerous lymph vessels are found in the ___, _______________, ______, _________ and _____
skin, mucous membranes, spleen, intestines, and liver etc.
Lymph is Absent in the _____, __________, __________, ____________ and ____________
brain, spinal cord, bone marrow, within the skeletal muscles and spleen capsule
have thinner walls than the veins of the same size
Have more valves than veins, and when cut, they remain open longer than veins
Blockage results to lymphedema due to accumulation of lymph
Have remarkable regenerative capacities
Lymphedema (lymphatic obstruction) mostly genetic
Lymphatic Vessels
The chief channel for the return of lymph from lymph capillaries and ducts to the venous system (retroperitoneal)
Begins in the sublumbar region between the crura of the diaphragm as a cranial continuation of the cisterna chyli
Thoracic Duct
Structural and functional unit of the lymphatic system
Located in those areas where they are protected but produce minimal interference with the function of the skeletal, muscular and vascular systems
Lymph Nodes
is the structural unit of a lymph node
Lymph nodule
Functions of lymph nodes (2)
◦ Filtration of lymph
◦ Lymphocyte production in its germinal center
Types of Lymph Vessels
Afferent lymph vessels
Efferent lymph vessels
*Types of Lymph Vessels
Vessels that enter the lymph node and perforate the capsule of the node
Afferent lymph vessels
*Types of Lymph Vessels
Vessels that leave the lymph node
Efferent lymph vessels
*Parts of a lymph node
concave area but not prominent, where the efferent vessel leaves
Hilus
*Parts of a lymph node
the outer portion
Cortex
*Parts of a lymph node
the inner portion
Medullae
Maybe solitary or aggregated and mainly found in the wall of digestive tracts
◦ eg, cecum, rectum and anal canal where they are numerous
They are different from lymph nodes because lymph vessels arise in them rather than pass through them, therefore they contain ony the efferent lymphatics
Lymph Follicles
*Lymph Nodes of the Head and Neck
located near the parotid salivary gland
Parotid
*Lymph Nodes of the Head and Neck
lies ventral to the angle of jaw; around 2-3 nodes
Mandibular
*Lymph Nodes of the Head and Neck
largest node found in the head and neck; elongated and found near the ventral border of the pharynx and larynx
Medial retropharyngeal
*Lymph Nodes of the Head and Neck
located near the right side of the trachea
Superficial cervical
*Lymph Nodes of the Head and Neck
located close to the cervical portion of the trachea
Deep cervical
*Lymph Nodes of the Thoracic Limb
the only lymph node of the thoracic limb; bounded laterally by teres major; medially by transverse thoracis; and ventrally by deep pectoral muscles
Axillary
*Lymph Nodes of the Thorax
cranial to transverses thoracic medial to 2nd costal cartilage
Sternal
*Lymph Nodes of the Thorax
lies at the vertebral end of either 5th or 6th intercostal space
Intercostals
*Lymph Nodes of the Thorax
mostly associated with the large vessels of the heart
Mediastinal
*Lymph Nodes of the Thorax
all nodes that lie on the intial parts of the bronchi at the bifurcation of the trachea
Tracheobronchial
*Lymph Nodes of the Thorax
often absent
Pulmonary
*Lymph Nodes of the Abdominal and Pelvic Walls
small, lies along the aorta and caudal vena cava from the diaphragm to the deep circumflex iliac arteries
Lumbar aortic
*Lymph Nodes of the Abdominal and Pelvic Walls
associated with renal vessels
Renal
*Lymph Nodes of the Abdominal and Pelvic Walls
between the deep circumflex iliac and external iliac artery
Medial ilial or external ilial
*Lymph Nodes of the Abdominal and Pelvic Walls
small, located between the angle formed by internal iliac and median sacral artery
Hypogastric or internal iliac
*Lymph Nodes of the Abdominal and Pelvic Walls
located ventral to the body of sacrum
Sacral
*Lymph Nodes of the Abdominal and Pelvic Walls
lies on the ventral surface of the tendon of psoas minor
Deep inguinal
Lymph nodes of the abdominal viscera (4)
Hepatic
Splenic
Cranial mesenteric
Colic
*Lymph nodes of the abdominal viscera
largest of the lymph nodes of the abdominal viscera
Cranial mesenteric
*Lymph nodes of the pelvic limb
largest node of pelvic limb
Popliteal
*Lymph nodes of the pelvic limb
inconsistent in occurence
Femoral
Lymph nodes of the pelvic limb (3)
Popliteal
Femoral
Superficial inguinal
Other Lymphatic organs (4)
Spleen
Thymus
Tonsils
Liver
Lies parallel to the greater curvature of the stomach to the left of the median plane
Attached to the greater curvature of the stomach by gastrosplenic ligament
Spleen
Has 2 extremities (dorsal & ventral), 2 surfaces (parietal & visceral), 2 borders (cranial & caudal)
Bright red to dark purple in color
Firm in consistency; triangular in cross section
Spleen
Acts as a storage of blood, takes part in blood cell formation, filtration and phagocytosis
The “graveyard” of RBC
Spleen
basic unit of thymus
Small lymphocyte or thymocyte
Light gray lobulated organ in preserved specimen, pinkish in fresh material
Composed of R and L lobes
Located in the precardial mediastinal septum
Large at birth but may decrease in size as the animal matures; replaced by fat
Thymus
similar to lymph nodes, and the role of both of these structures is to fight infection.
Tonsils
There is a pair of tonsils located in small pouches or ______ at the back of the throat.
crypts
produces a large amount of lymph, which is estimated to be 25 to 50 % of lymph flowing through the thoracic duct. The hepatic lymph primarily comes from the hepatic sinusoids.
Liver
Lymph nodes of the abdominal and pelvic walls (6)
Lumbar aortic
Renal
Medial ilial or external ilial
Hypogastric or internal iliac
Sacral
Deep inguinal
Lymph nodes of the thorax (5)
Sternal
Intercostals
Mediastinal
Tracheobronchial
Pulmonary
Lymph nodes of the head and neck (5)
Parotid
Mandibular
Medial retropharyngeal
Superficial cervical
Deep cervical
Lymph node of the thoracic limb
Axillary