Chapter 20 Lymphatic Flashcards
Lymph
Interstitial fluid once it enters lymph vessel. Slow, one way flow back to the heart.
Lymphatic Cells (Lymphatics)
Collects interstitial fluid that is forced out the arterial end of the capillaries, not reabsorbed back through the venous end of the capillaries. (~L/day)
Scattered throughout the body
Lymph tissues and organs
Lymphatic capillaries distribution
Everywhere except bone, teeth, CNS, and bone marrow
Lymphatic capillaries blind ended
Interwoven between blood capillaries; extremely permeable to fluid due to mini valves (which are endothelial cells loosely overlapping each other).
Lacteals
In intestinal wall; absorb digested fats for seperate transport back to the cardiovascular system.
Lymphatic collection vessels
Layers the same as veins, but thinner
Lymphatic trunks
Union of largest collection vessels
Lumbar trunks
Lower body
Bronchomediastinal trunks
Thorax
Subclavian trunk
Arms
Jugular trunks
Head
Intestinal trunk
Digestive organs
Lymphatic ducts
Union of trunks; empty into subclavian veins at internal jugular vein junction
Right lymphatic duct
Drains right arm; right chest and right head
Thoracic duct
Drains rest of body
Cisterna chyli
Start of thoracic duct draining both lumbar and intestinal trunks
Lymph transport
Similar to blood flow in veins.
Respitory pump with breathing, skeletal muscle pump, one way valves, smooth muscle contraction
Lymphocytes
Involved with immune reactions fighting against antigens (Foreign Substances)
B Cells
Become plasma cells and make antibodies against antigens
T Cells
Directly attack foreign cells/tissues
Macrophages
Phagocytize foreign substances and help activate T cells
Reticular connective tissues make
Fibers for the internal framework (stroma) of lymph tissues and organs
Lymphatic tissue consists of
Reticular connective tissue
Diffuse lymphatic tissue
Lymphatic follicles
Mucosa associated with lymphatic tissue
Reticular connective tissue
Loose internal framework that makes up all lymphoid organs except thymus
Diffuse lymphatic tissue
Collections of lymphoid cells found anywhere
Lymphatic follicle (nodules)
Spherical areas found anywhere and in lymph organs
Germinal center
Center of follicles where B lymphocyte cells reside and multiply
Mucosa associated lymphatic tissue
Tonsils
Peyers Patches
Appendix
Tonsils function
Guard entrance to the throat (pharynx) by removing pathogens in food and air
Location of Palantine tonsils
On the sides of the soft palate in the oral cavity
Lingual tonsils location
At the base of the tongue
Pharyngeal tonsil (adenoids) location
Posterior walls of the nosopharynx
Crypts (tonsils)
Invaginations of epithelium into tonsils trap bacteria for destruction and memory
Peyer’s Patches
Isolated collection of lymphatic follicles embedded in small intestine wall
Appendix
Heavy concentration of lymphatic follicles
Bronchi walls contain
Lymphatic follicles to protect the Respitory system
Lymphatic organs
Contain fibrous capsule around discrete lymph tissue
Primary lymph organs (red bone marrow and thymus)
Sites where lymphoid cells originate and colonize other lymph tissues and organs
Secondary lymph organs (lymph nodes and spleens)
Sites where immune responses occur, along with lymph tissues
Thymus Location
Superior mediastinum overlaying the heart; size shrinks with age
Thymus structure
Contains many lobules containing the cortex and medulla.
Cortex
Densely packed T lymphocytes; no B cells or follicles
Function of Thymus
T cell maturation
No immune surveillance (doesn’t direct fight antigens)
Lymph Node
Hundreds clustered along lymphatic vessels. Especially concentrated in cervical, ancillary, and inguinal regions
Lymph node function
Protects by:
Filtering lymph
Immunology
Filtering lymph
Macrophages clean debris, dead cells and microbes
Immunology
Lymphocytes detect and mount immune response against antigens
Lymph node size and shape
Been shape less than one inch w/ a fibrous connective tissue capsule
Trabeculae
Inward extensions of the capsule divide node into sections
Cortex
Outer denser part of lymph node. Contains lymphatic follicles with their lighter germinal center of rapidly dividing B lymphocytes
Medulla
Inner, less dense area of lymph node.
Contains medullary cords and sinuses
Medullary Cords
Contains B lymphocytes
Medullary Sinuses
Lymph capillaries spanned by reticular fibers; lubed with macrophages
Afferent lymphatic vessels
Lymph comes in on convex side
Efferent lymphatic vessels
Lymph leaves at hilus (indented region).
Less than afferent vessels
Swollen Glands
Nodes overwhelmed by bacteria or viruses
Secondary cancer site
Metastasize spread from primary site and grows there.
Spleen Appearance
Blood, red organ the size of a fist
Location of spleen
Left superior abdominal cavity.
Just below the diaphragm and left of the stomach
Hilus
Concave area where splenic artery enters and splenic vein leaves
Spleen contains
Fibrous connective tissue capsule and Trabeculae projections that partition organ
White pulp areas
Circular areas of lymphocytes.
Function of immunologic
Red pulp areas
Rest of spleen surrounding white pulp areas contain venous sinuses of blood, reticular connective tissue and macrophages.
Function of red pulp areas
Macrophages break down and dispose of worn out erythrocytes rearming iron and globin. Also stores platelets
Splenectomy
Removal when spleen ruptures, due to spongy nature or would bleed to death.
