lecture 22: lymphatic sys Flashcards
4 major components
- lymph plasma: interstitial fluid that passes into lymphatic vessels
- lymph vessels: transport lymph, transport tissue fluid from capillaries to blood stream
- lymph organs: contains lymphocytes in lymphoid tissue
- bone marrow: contains stem cells that become immune cells
functions
- transport dietary lipids: transports lipids and fat-soluble vitamins from digestive system to the blood
- drain excess interstitial fluid: return interstitial fluid from tissue back into the blood
- carries out immune response: lymphoid tissue recruits immune cells
lymphatic pathway
- lymphatic capillaries
- afferent (arriving) lymphatic vessels
- lymph nodes
- efferent (exiting) lymphatic vessels
- lymphatic ducts
- right lymphatic duct and thoracic duct
network of vessels, nodes, and organs. responsible for transporting lymph, a fluid that contains white blood cells, throughout the body.
lymphatic vessels begin small, and merge together to form larger vessels to eventually empty into the bloodstream.
lymphatic capillaries
- highly permeable
- composed of endothelial cells
- interstitial fluid pressure > lymph plasma
- interstitial fluid enter lymphatic capillary
tiny vessels found in tissues of most organs in your body
keep consistent blood pressure and volume, and prevent fluid buildup
which of the following is not a function of the lymphatic sys:
a) return interstitial fluid back from the tissue cells into the bloodstream
b) recruit immune cells in areas of lymphoid tissue
c) transport lipid and water-soluble vitamins from the digestive sys to the blood
d) contain stem cells that mature and develop into immune cells
c) transport lipid and water-soluble vitamins from the digestive sys to the blood
location of cervical lymph nodes
- neck region
- large when immune system is working overtime
- superficial and deep
location of axillary lymph nodes
- armpit region, most of the nodes of upper limbs
location of thoracic lymph nodes
- receives lymph from left side of head, neck, chest, arm, and below ribs
- largest lymphatic vessel draining the rest of the body
- begins as cisterna chyli
location of abdominal lymph nodes
- intestinal lymph nodes
- peyer’s patches
location of inguinal lymph nodes
- groin region
- superficial and deep
- drain urogenital regions
lymphatic ducts
- drains the upper right side of the body
- empties into the right subclavian vein
largest vessels in the lymphatic sys that carry lymphatic fluid back to bloodstream: thoracic duct and right lymphatic duct
thoracic: larger and longer. originates in abdomen and collects lymphatic fluid from the lower body, left arm, and left side of the head and chest
right lymphatic duct: shorter and smaller, collects lymphatic tissue from the right side of the head and chest, and arm, and empties into venous sys
structure of the flow of lymph
- afferent (arriving) vessel
- subscapular sinus (1st compartment that incoming lymphatic fluid enters, contains macrophages to remove foreign substances)
- cortical/trabecular sinus (contains specialized cells, such as T and B lymphocytes)
- medullary sinus (responsible for producing antibodies bc it contains lymphocytes and plasma cells)
- hilum
- efferent (exiting) vessel
- lymphatic vessels
primary lymphoid organs
- thymus: serves as body’s defense mechanism providing surveillance and protection against diverse pathogens, tumors, antigens, etc
- bone marrow
second lymphoid organs
- spleen
- peyer’s patches
- appendix
- tonsils
thymus
- bilobed organ (2 lobes)
- in the superior mediastinum (above heart)
- posterior to the sternum
- between lungs
- location of T cells proliferation and maturation
primarily responsible for the production and maturation of immune cells
lower down at start of lungs -> not the thyroid**
bone marrow
- in flat bone
- in epiphyses of some long bones (femur)
- contains multipotent stem cells that develop into: B cells, immature t cells
center of most bones
red marrow contains blood stem cells that can become red blood cells, white blood cells, or platelets
which is incorrect:
a) lymph nodes are found in the cervical, axillary, thorax, abdomen, and inguinal region
b) bone marrow contains precursors to B cells and T cells
c) the thoracic duct is the largest lymphatic vessel
d) the thymus is responsible for B cell proliferation
d) the thymus is responsible for B cell proliferation
spleen
- abdominal organ
- filters and purifies blood, removes old or damaged red blood cells
- contains 2 types of lymphoid tissue: red and white pulp
- recycles and stores red blood cells
also fights infections by producing/storing immune cells
peyer’s patches
- region of large aggregated lymphoid follicles
- located in ileum of small intestine
detect and respond to pathogens that enter the body thru the GI tract
contain a variety of immune cells; T cells, B cells, and dendritic cells
appendix
- vermiform appendix has various regions of lymphatic nodules
small finger-shaped pouch attached to the large intestine in the RLQ
tonsils
- pharyngeal tonsils (not paired) - top of oral cavity
- palatine tonsil (paired) (top back of mouth)
- lingual tonsil (bottom back of mouth)
lymph functions
- transports lipids and fat-soluble vitamins (A, D, E, and K) from digestive system to the body
- return interstitial fluid from tissue back into the blood
- lymphoid tissue recruits immune cells
lymph plasma
interstitial fluid that passes into lymphatic vessels
lymph vessels
transport lymph, transport tissue fluid from capillaries to blood stream
