Transport (Blood and Lymph) Flashcards
Functions of blood
- transports O2, CO2, nutrients, waste, hormones, and enzymes
- protects the body with leukocytes and clotting
- regulates body systems (pH, electrolytes, body temperature)
hematopoiesis
- the formation of blood
- formed in the liver and spleen before birth
- the red bone marrow produces blood cells after 5 months of age and primary sit of them after birth
what are the components of blood
- plasma
- formed elements (Buffy coat and erythrocytes)
plasma
- a sticky, yellow, fluid
- this is the fluid portion of the blood
- the components can change quickly and frequently and it reflects metabolic activity
- this can be an important diagnostic tool
why can plasma be donated more often than whole blood
plasma is mostly water so it is easier to replace what has been lost through the donation by hydrating and eating food to make up for the lost proteins
-it is much harder to replace formed elements of the blood that are lost with blood donation
platelets
- also called thrombocytes
- these are the smallest circulating formed elements
- they are cell fragments
- they have a lifespan of about 8 days
- these clump at sites of injury and make a plug there and then release chemicals to attract fibrin and other cells
erythrocytes
- red blood cells
- no nucleus or organelles (not true cells)
- has hemoglobin
- has a 120 day lifespan
- has a biconcave shape
leukocytes
- white blood cells
- these are for defense
- a short lifespan of a few days
- they can function outside of the blood stream in connective tissue as well.
- two main types
what are the two classifications of white blood cells
- granulocytes and agranulocytes
neutrophil
- a granulocyte
- this is the most common type of white blood cell
- this is used to kill bacteria
- levels are elevated when there is a bacterial infection
eosinophil
- this is a granulocyte
- only 2-4% of the white blood cells
- this is elevated when there is a parasite (some for allergic reactions)
basophils
- this is a granulocyte
- only <1% of the white blood cells
- these are in high concentration when there is allergic reactions (and also parasites)
monocyte
- this is a type of agranulocyte
- only 2-8% of the white blood cells
- these are responsible for a non specific immune response
- they find foreign things in the body and act as a phagocyte to get rid of them
lymphocyte
- this is a type of agranulocyte
- 20-30% of the white blood cells
- this is responsible for specific immunity (t cells/b cells/NK cells)
- this gets elevated in an immune response
tunica adventitia
- thick layer composed of collagen fibers with scattered bands of elastic fibers
- the fibers blend into those of adjacent tissues to anchor and stabilize the blood vessel
- the outer most layer of the wall of blood vessels
tunica media
- the middle layer of the wall of blood vessels
- concentric layers of smooth muscles around the lumen of the vessel
- these are what allow contraction and dilation of vessels
- collagen fibers bind this layer to the two other layers of blood vessels
tunica intima
- the inner most layer of the wall of blood vessels
- composed of endothelial lining of the vessel and an underlying layer of connective tissue with elastic fibers
vasa vasorum
these are blood vessels that supply the walls of large arteries and veins
what are the layers of the walls of blood vessels
- tunica adventitia
- tunica media
- tunica intima
describe artery walls compared to the walls of veins
- arteries have thicker walls
- more smooth muscle and elastic fibers (need to be able to resist the pressure from the heart as blood is forced into circualtion
describe the difference between the lumens of arteries and veins
- veins have larger lumens
- in dissection, veins will look more distorted and flat
- in dissection, arteries will maintain their circular shape more
what is something important to remember that veins have that arteries do not
valves!
important because these are necessary for the blood to make it back to the heart from the periphery because of the low blood pressure in them
describe the difference between the vessel lining of arteries and veins
- arteries have an endothelial lining that appears pleated because when the vessel constricts it folds up because it cannot contract
- veins do not have a pleated appearance
elastic arteries
- large vessels that have a large lumen
- these have a thick intima
- these move large volumes of blood away from the heart
- has an internal elastic membrane between the media and intima to allow for stretch
- *very resilient walls with high elastic fibers and low smooth muscles
ex. aorta, pulmonary artery
muscular artery
- these are vessels that transport blood to the skeletal muscle and internal organs
- media is thick and has a lot of smooth muscle
- majority of arteries are this type.
arterioles
these are used to control blood flow between arteries and capillaries
- considerably smaller than arteries
- thin adventitia
- media is only one or two layers of smooth muscle
capillaries
- smallest and most delicate
- only vessels that walls allow for exchange of nutrients and wastes
- blood flow through these is slow to allow for adequate diffusion time
continuous capillaries
- found in all tissues but epithelia and cartilage (most common type)
- epithelium forms a complete lining and and the cells are connected by tight junctions and desmosomes
fenestrated capillaries
- these are made of simple squamous epithelial cells but also have pores in them
- allow for more exchange of nutrients (allow some small proteins and peptides)
sinusoids
these are discontinuous capillaries
- made of simple squamous epithelial cells that have large gaping holes in them (allow large things like blood cells through)
- the basil lamina is thinner
- these are common in the spleen
precapillary sphincters
- these regulate blood flow to tissues
- can open of close to regulate blood flowing through the area (allows or bipass if necessary)
thoroughfare channel
- these connect arterioles with postcapillary venules in the capilary bed
- this allows for the blood to be distributed someplace else when the precapillary sphincters are closed
- this runs through the capilary bed and occurs after the meta arteriole
arteriovenous anastomoses
- directly connect arterioles and venules
- these are common in organs and around joints
- allow for a way around the capillary bed
- regulate blood flow
muscle pump
- this is one of the ways that veins combat gravity
- some veins are situated near muscles and when the muscle contracts it squishes the vein and this pushes the blood through the vein
respiratory pump
- this is one of the ways that veins combat gravity
- when someone breathes in, the thoracic cage expands, and creates low pressure gradient against high pressure areas (blood vessels) and the blood gets pulled toward the heart
Valves
-this is one of the ways that veins combat gravity
these allow blood to flow through but cannot flow back through
Varicose veins
-nonfunctional valves cause blood to pool most common in superficial veins of the lower limbs because they don’t have a muscle that they sit in
what determines blood type
- the surface antigens that are present on the blood vessels
- you can have A,B, both, or none
- you can also have a different antigen known as RH that determines if you are positive or negative
If you have A type blood, what antigens and antibodies do you have
-you will have a antigens on the blood cells and then in the blood you will have anti-B antibodies in the blood
if you have AB type blood, what antigens and antibodies do you have
- you will have A antigens and B antigens on the blood cells and then in the blood you will not have anti-B antibodies or anti-A antibodies in the blood
- you are a universal acceptor
what does Rh factor do
- this is the additional antigen
- this is important for pregnancy
- if a mother is Rh- and the baby is Rh+ then the babies Rh+ blood can cross over and enter circulation
- this causes the mother to create Rh+ antibodies that circulate in the blood
- if the mother gets pregnant again with a baby that is Rh+ then the baby will be rejected by the mother
- they test for this around week 12 and give an immunoglobulin that prevents this
- this also affects the type of blood someone has and who they can donate
what changes about who you can donate to when you take into account Rh factor
- if you have Rh factor (making you positive) then you can only donate to other people that are positive
- if you are negative then you can donate to people that are positive or negative
metarterioles
a structure that guards the entrance to capillaries by containing the precapillary sphincters and will shunt blood to the thoroughfare channel is the sphincters are closed
collateral circulation
- alternative pathways for delivering blood to a region of the body critical with blockage of a vessel
arterioarterial anastomoses
provides collateral circulation to many organs and body regions
- this would be between two arteries
functions of the lymphatic system
- maintain normal blood volume and the normal composition of the interstitial fluid
- provide an alternative route for the transport of hormones, wastes, and nutrients
- lymphocytes production, maturation and distribution
- works with the immune system to generate an immune response against antigens in the interstitial fluid
primary lymphatic structures
- these are the sites where lymphocytes are produced and mature
- the thymus and the red marrow
secondary lymphatic structures
- these are critical for beginning defense for an immune response
- considered to be the “front line” of defense
- sites where lymphocytes are activated to produce additional lymphocytes of the same type
(spleen, lymph nodes, spleen)
lymphatic capillaries
- close ended tubes interspersed around blood capillary beds
- receive fluid from connective beds
- highly permeable (has overlapping cells that allow things to enter so easily)
- overlapping endothelial cells act as one-way valves
- clefts between endothelial cells
how is lymph propelled to heart
- muscle pump
- respiratory pump
- valves
- tunica media contraction
- arterial pulsation
describe lymph movement
- the lymphatic capillaries are first to receive lymph
- next, collecting lymphatic vessels
- then lymph trunks
- finally lymph ducts empty into the veins of the neck
lymphatic capillaries vs vascular capillaries
lymph are:
- larger in diameter
- have thinner walls
- have an irregular outline
- they have anchoring filaments connecting it to connective tissue to keep capillaries open
- have greater permeability
lymphatic vessels vs veins
lymph have:
- thinner walls
- larger lumens
- tunicas are harder to distinguish (they also have the same three layers)
- larger lymph vessels have a lot more valves than veins
right lymphatic duct
this only collects lymph from the right side of the head and neck, right upper limb and the right side of the thorax
thoracic duct
- it begins just inferior to the diaphragm
- begins at the cisterna chyli
- collects lymph from the rest of the body (lower limbs, left arm, left side or throax) that the right duct doesn’t collect
lymphoma
cancerous growth of a lymph node
why is it important to know lymphatic drainage patterns
the lymphatic capillaries allow large cells to enter (including cancer cells) and they can get lodged in lymph nodes
lymphocytes
- this is a type of agranulocyte
- 20-30% of the white blood cells
- this is responsible for specific immunity (t cells/b cells/NK cells)
- this gets elevated in an immune response
- these are the primary cells of the lymphatic system
- they respond to
- foreign things
- pathogens
- cancer cells - they travel throughout the body and through the blood or through lymphatics
- 3 types: T cells, B cells, NK cells
T-cells
- these are thymus dependent cells
- these are responsible for cell mediated immunity
- they find foreign cells, detect it and attack it directly
b cells
- mature and grow in the bone marrow
- these have antibody mediated immunity
- this is a longer process for recognizing an invader because the cell divides into daughter cells that will later recognize the invader to destroy it
NK cells
-these find things that could be viruses or cancer and react immediately by secreting toxins
diffuse lymphatic tissue
-these are lymphocytes loosely aggregated within connective tissue (mucous membrane of respiratory tract, urinary tract)
lymphatic nodules
- these are the collections of lymphatic tissue and these are what we focus on
- lymphocytes aggregated within supporting framework of reticular fibers ( in the walls of segments of the digestive tract
- have a germinal center (which contains lymphocytes)
mucosa associated lymphoid tissue (malt)
collection of lymphatic tissue within epithelia of the digestive, respiratory, urinary, and reproductive systems
tonsils
- these monitor what passes through the nasal and oral cavities
- these then create a response with either T, B or NK cells
- these are very active when we are young and then become less active when we grow up because our immune system has developed more
appendix
creates responses to the foreign things found within fecal matter
lymphatic organs
separated from surrounding tissue by a fibrous capsule
- lymph nodes
- thymus gland
- spleen
why do lymph nodes become inflamed
- they become inflamed or enlarged when sick because doing extra work to fight things off
lymph nodes
- they are one of the first things to filter the lymph
- these are in line with the vessels so the lymph goes directly through
- has an outter fibous capsule and an internal sinusoidal system
thymus
- site of t cell maturation
- superior to heart and anterior to the trachea
spleen
largest lymphatic organ
- filters blood coming through it
- located in the upper left quadrant
- highly vascularized
- has red pulp and white pulp
red pulp
80% contains mostly erthrocytes, platelets, macrophages, an some plasma cells
-filters the blood
white pulp
islands of lymphoid tissue, lymphocytes, and macrophages
- site of response to things
- can have immuno responses here
mononucleosis
this causes the the spleen to enlarge
- very dangerous because if the organ is enlarged and gets hi it could rupture and with it being so vascularized, you could bleed to death
sickle cell anemia
this is caused by abnormal blood protein
- its a genetic disorder
- most common blood disease in the US
- disproportionately affects black individuals
sickle cell trait
this is when someone is a carrier and in times of stress it can lead to the sickle cell shape
afferent lymphatic vessels
these carry lymph to the node
-there can be many afferent tubes
efferent lymphatic vessels
- these carry lymph away from the node
- there is only on efferent leaving each
collecting lymphatic vessels
these collect lymph fluid from loose connective tissue and return it to the bloodstream (veins)
lymphatic ducts
empty into viens of the neck
describe what happens to the t cells after migrating from the red bone marrow
- must go and gains immunocompetence in thymus
- travels through bloodstream and is established in lymphoid tissue
- recognizes and binds to its specific antigen (antigenic challenge)
- proliferates rapidly to produce identical mature lymphocytes capable of responding to the same pathogens in peripheral tissue
fibrosis
the formation of scar tissue
