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137 Cards in this Set

  • Front
  • Back
central nervous system
brain and spinal cord
peripheral nervous system
-peripheral nerves
-specialized nerve endings
autonomic nervous system
The sympathetic division typically functions in actions requiring quick responses. The parasympathetic division functions with actions that do not require immediate reaction.
heart rate, digestion, respiration rate, salivation, perspiration, diameter of the pupils, micturition - (the discharge of urine), and erection
schwann cells
provide myelination to axons in the peripheral nervous system (PNS). They also have phagocytotic activity and clear cellular debris that allows for regrowth of PNS neurons.
satellite cells
are small cells that line the exterior surface of PNS neurons and help regulate the external chemical environment
sensory neurons in one spot
sensory neurons
convey impulses from receptors to the CNS.
Axons of these cells are called afferent fibers.
motor neurons
convey impulses from the CNS to effector cells. These are both somatic and visceral efferent fibers.
elements of a communicating and integrating network interposed btwn the sensory and motor neurons.

More than 99% of the neurons of the nervous system are interneurons.
unipolar (pseudounipolar)
bipolar neurons: spiral ganglion
pseudounipolar neurons:T-bifurcation
neurons are ___ bodies?
Nissle bodies
Chemical synapses
most common mode of communication btwn 2 nerve cells
electrical synapses
commonn in invertebrates but rare in mammals. they have been described in the brain stem, cerebral coretex, retina of mammals, and are like the gap junctions in smooth and cardiac muscle.
Current spreads directly from cell to cell due to ion flow.
neurofilaments and microtubules
microtubules play a role in transport.
synaptic vesicles contain ? and accumulate where?
synaptic vesicles containing neurotransmitters accumulate near the pre-synaptic membrane.
pre-synaptic membrane is the cite where...
On arrival of the action potential the vesicles dock with the membrane and release their contents into the synaptic cleft by exocytosis.
synaptic cleft is where the...
where the vesicles release their contents by exocytosis
post synaptic membrane whose receptors are stimulated by?
neurotransmitter diffuses across the synaptic cleft to stimulate the receptors in the post synpatic membrane.
which neurotransmitters are excitatory?
3.glutamic acid
which neurotransmitters are inhibitory?
1.gamma-aminobutyric acid
4.endorphins and enkephalins: inhibit pain
80% of neurotransmitters dumped into the synaptic cleft will undergo?
high affinity reuptake
20% of neurotransmitters dumped into the synaptic cleft will undergo?
degradation, e.g. acetylcholinesterase degrades acetylcholine
axonal transport:

anterograde transport moves organelles, vesicles, macromolecules, and enzymes needed for neurotransmitter synthesis.
moves protein building blocks for neurofilaments, subunits of microtubules, and enzymes.
kinesis is?
a microtubule-associated protein, in involved in aterograde transport
central nervous system
brain and spinal cord
peripheral nervous system
-peripheral nerves
-specialized nerve endings
autonomic nervous system
schwann cells
form myelin sheath
satellite cells
form ganglia cells, dorsal root
sensory neurons in one spot
sensory neurons
convey impulses from receptors to the CNS.
Axons of these cells are called afferent fibers.
motor neurons
convey impulses from the CNS to effector cells. These are both somatic and visceral efferent fibers.
elements of a communicating and integrating network interposed btwn the sensory and motor neurons.

More than 99% of the neurons of the nervous system are interneurons.
unipolar (pseudounipolar)
bipolar neurons: spiral ganglion
pseudounipolar neurons:T-bifurcation
neurons are ___ bodies?
Nissle bodies
Chemical synapses
most common mode of communication btwn 2 nerve cells
dynein is involved with with axonal transport?
microtubule associated protein is involved in retrograde transport.
neuroglia: oligodendrocytes
olgodendroglia/Oligodendrocytes are cells that coat axons in the central nervous system (CNS) with their cell membrane, called myelin, producing the so-called myelin sheath. The myelin sheath provides insulation to the axon that allows electrical signals to propagate more efficiently.
Glial cells provide support and protection for neurons, the other main type of cell in the central nervous system. They are thus known as the "glue" of the nervous system. The four main functions of glial cells are to surround neurons and hold them in place, to supply nutrients and oxygen to neurons, to insulate one neuron from another, and to destroy pathogens and remove dead neurons.
neuroglia:fibrous astrocytes
are non-neuronal cells that provide support and nutrition, maintain homeostasis, form myelin, and participate in signal transmission in the nervous system. In the human brain, glia are estimated to outnumber neurons by about 10 to 1.
The most abundant type of glial cell, astrocytes (also called astroglia) have numerous projections that anchor neurons to their blood supply. They regulate the external chemical environment of neurons by removing excess ions, notably potassium, and recycling neurotransmitters released during synaptic transmission.
chyroid plexus
is the area on the ventricles of the brain where cerebrospinal fluid (CSF) is produced by modified ependymal cel
The meninges (singular meninx) is the system of membranes which envelop the central nervous system. The meninges consist of three layers: the dura mater, the arachnoid mater, and the pia mater. The primary function of the meninges and of the cerebrospinal fluid is to protect the central nervous system.
blood is composed of? and is what kind of tissue?
-is derived from ?
a specialized connective tissue composed of RBCs, platelets, suspended in a fluid matrix (blood plasma).
it is derived from mesenchyme
total volume of blood in human is about ?
-has a pH of ?
-what is necessary to stop flow if the vascular tree is damaged? and how is it mediated?
6 liters
-about 7.4
coagulation is mediated by platelets and blood borne factors that transform blood froma sol to a gel.
what are the fxns of blood?
(4 fxns)
-it is a vehicle for transport of material waste products to organs of elimination, hormones and other signaling molecules to cells, O2 from lungs to cells, and CO2 from cells to lungs.
-regulates body temp
-maintains acid-base and osmotic balance
-is a pathway for migration of white blood cells btwn the connective tisse comps. of body.
what is plasma? (4 pts)
a yellowish fluid with the solid elements, organic elements, and the electrolytes suspended or dissolved in it.
-H2O is 90%, proteins 9%, inorganic salts, ions, nitrogenous compnds and gases 1% of the vol.
-fluid component exits the vessels to become extracellular (tissue)fluid
-albumin doesn't exit
albumin is responsible for?
colloid osmotic pressure of blood that maintains normal blood and interstitial fluid volumes.
erythrocytes are?
leucocytes are?
erythrocytes described...
-biconcave disks
-organelles are expelled from the cell during maturation and development before entering the circulation.
-5mill. cells/cubic mm. of blood in males, 4.5 mill.cells/cubic mm. in females.
-ave lifespan
-what determines blood type?
-what produces lysis?
-what is the Rh factor?
-120 days
-aging RBCs develop a surface coating of oligosaccharide sugars and are destroyed by macrophages of the spleen, bone marrow, and liver.
-specific inherited carb chains in the plasmalemma determine the blood grp of the indiv. A, B, AB, or O.
-ppl who lack A, B or both have antibodies against the missing antigen which produces lysis
-Rh factor is a group of antigens, 3 of which (C,D,E) are common-85% of Americans-and are considered Rh + (Individuals either have, or do not have, the Rhesus factor (or Rh D antigen) on the surface of their red blood cells)
what is lysis?
the death of a cell by breaking of the cellular membrane, often by viral or osmotic mechanisms that compromise its integrity
Leucocytes have two groups:
granulocytes with conspicuous specific granules in the cytoplam
-agranulocytes which lack granules in cytoplasm
-both groups have nonspecific (azurophilic granules thought to be lysosomes) in their cytoplasm.
are the most abundant type of white blood cells and form an integral part of the immune system.
-these phagocytes during the acute phase of inflammation, particularly as a result of bacterial infection, leave the vasculature and migrate toward the site of inflammation in a process called chemotaxis. They are the predominant cells in pus, accounting for its whitish/yellowish appearance. Neutrophils react within an hour of tissue injury and are the hallmark of acute inflammation
only 5% of WBCs
-sausage shaped, bilobed nucleus connected by a thin strand
-has large eosinophilic specific granules
-nonspecific azurophilic granules
-found in large numbers in parasitic infections and in local allergic responses.
1% of WBCs
-S-shaped nuclues often masked by the large specific granules of the cytoplasm
-these are initiators of the inflammatory response and contribute to the anaphylactic rxn (Anaphylaxis is an acute systemic (multi-system) and severe Type I Hypersensitivity allergic reaction in humans and other mammals. )
agranulocyte: monocyte
largest cell
-large kidney shaped nucleus
-they stay in circulation only a few days and migrate thru the endothelium of venules to become macrophages
-2-6% of total WBCs
agranulocyte: lymphocyte
T cells-
B cells-
Null cells-
T cells are involved in cell-mediated immunity whereas B cells are primarily responsible for humoral immunity (relating to antibodies).
-Null cells-lymphocyte without T- or B-cell markers on its surface
-produced by?
-store what?
-key role?
-how many in blood?
small disk-shaped, non-nucleated cell fragments
-produced by megakaryocytes, giant cells of the red bone marrow, fragmentation of their cytoplasm.
-store serotonin in granules and platelet-derived growth factor in either granules.
-key role is to terminate hemorrhage (loss of blood)
-there are 250,000-400,000 platelets per cubic mm. of blood and their lifespan is less than 14 days.
-sites of, in adults?
process by which mature blood cells develop from precursor cells. *development of blood cell compartments
-sites of hemopoiesis in adults, bone marrow of:
-vertebral column
-proximal ends of femora
-before birth hemopoiesis occurs in?
-active sites of hemopoiesis ___ with age...
before birth this occurs in other places like the liver and spleen
-liver and spleen can be recalled to duty in times of need
-active sites of hemopoiesis decrease with age, but the potential remains
bone marrow is...
-the stroma contains?...
-a meshwork of vascular sinuses and branched network of reticular connective tissue
-heterogeneous pop of forming blood cells at their various stages of differentiation and maturation
-the stroma contains endothelial cells, macrophages, fibroblasts, and myeloid reticular cells. fat storing cells are plentiful.
bone marrow fxns...
in blood formation from the 5th month til death
-long bone diaphyses house only yell marrow after age 20
-vascular supply is from nutrient arteries
prenatal hemopoiesis has four phases:
1.mesoblastic (yolksac, 2 wks to 6th wk)
2.hepatic (6wks to birth)
3.splenic (2nd trimester to birth)
4. myeloid (end of 2nd trimester and increases in importance)
is the process by which red blood cells (erythrocytes) are produced. In human adults, this usually occurs within the bone marrow. In the early fetus, erythropoiesis takes place in the mesodermal cells of the yolk sac. By the third or fourth month, erythropoiesis moves to the spleen and liver. In humans with certain diseases and in some animals, erythropoeiesis also occurs outside the bone marrow, within the spleen or liver.
•what are the components of The Cardiovascular System?
The heart and blood vessels.
The Lymph Vascular System:
A system of vessels found throughout most of the body. It drains its contents into large veins of the cardiovascular system
•Circuits consist of:
* arteries
* capillaries
* veins
* arteriovenous shunts (anastomoses)
-Tunica Intima: endothelium on a basal lamina and underlying connective tissue.
-Tunica Media: a muscular layer with some connective tissue fibers.
-Tunica Adventitia: an outermost coat of mostly loose connective tissue.
ARTERIAL SYSTEM consists of 3 MAIN VESSELS *transition btwn these is gradual
-elastic arteries
-muscular arteries
elastic arteries
the aorta, innominate artery, common carotid artery, subclavian & most pulmonary arterial vessels.
muscular arteries
the main distributing branches, e.g. the radial, femoral, and cerebral arteries.
: terminal branches which supply the capillaries
muscular distsributing arteries: tunica intima
• Tunica Intima: Endothelium on the luminal border, resting upon the internal elastic lamina. The latter is a conspicuous wavy pink refractile line. The basal lamina of the epithelium lies in close apposition to this lamina.
muscular distributing arteries: tunica media
• Tunica Media: A thick circular layer of smooth muscle, consisting of smooth muscle cells and some elastic & collagen fibers as well.
-• The outer border of the media is marked by the external elastic lamina, which is less conspicuous and appears less continuous than the internal elastic lamina.
muscular distributing arteries: tunica adventitia
Thickness varies, and consists mostly of elastic fibers, but with some collagen. It is provided with vasa vasorum and lymphatic vessels too.
elastic arteries: tunica intima
• Tunica Intima: Thicker than in muscular arteries and appears paler than the media. Many fenestrated elastic laminae and elastic fibers lie in the subendothelial layer between the endothelium and the internal elastic lamina. Smooth muscle cells and fibroblasts are also present.
elastic arteries: tunica media
A thick wall of many fenestrated elastic membranes interleaved with smooth muscle cells and an indistinct external elastic lamina.
elastic arteries: tunica adventitia
This is thin, and is composed mostly of elastic and collagen fibers. It is provided with vasa vasorum and lymphatic capillaries.

thick or thin walls?
-intima is ?
-media is?
-adventitia is?
Wall is thick relative to the lumen & is almost as wide as the diameter of the lumen.
•Intima is endothelium and basal lamina apposed to the internal elastic membrane.
•The media is only one to two layers of smooth muscle cells.
•The adventitia is only a few elastic & collagen fibers, and both elastic laminae may be lacking
-in most of the body endothelial cells are interconnected by ?
-in most of the brain endothelial cells are interconnected by ?
•Capillaries in most of the body: endothelial cells are interconnected by fascia occludens.
•In most of the brain: endothelial cells are interconnected by zonula occludens.

•Capillaries may be continuous or fenestrated; however, most are continuous.
•Fenestrated capillaries are found in most endocrine organs and the connective tissue of the absorptive lining of the intestine.
•Thin membranes fill these openings except in renal glomerular capillaries.
pericyte is?
•are intimately associated with the basal lamina of endothelial cells.
-is a mesenchymal-like cell, associated with the walls of small blood vessels. As a relatively undifferentiated cell, it serves to support these vessels, but it can differentiate into a fibroblast, smooth muscle cell, or macrophage as well if required.
sinusoids are?
are thin-walled, capillary-like venous blood vessels with an unusually wide lumen and an associated population of macrophages.
•They are common in myeloid tissue, the spleen, and the liver.
venous system
• Postcapillary venules
appear similar to capillaries, a thin endothelium surrounded by reticular fibers & pericytes.
medium-sized veins
the tunica adventitia is the thickest tunic, smooth muscle of the media is loosely organized & associated with collagen fibers.
large veins
Most large veins, except major vessels lack a t. media. They have a thick subendothelial layer and t. adventitia.
lymphatic system
-a separate part of what system?
-it is a body wide network of ?
-it's role is to?
-collected lymph empties into the ? via the ?
•a separate part of the circulatory system.
• It is a body-wide network of vessels with closely associated masses of encapsulated lymphoid tissue called lymph nodes.
• Its role is to withdraw excess tissue fluid from the intercellular fluid compartment, filter this through lymph nodes and return it to the blood.
• The collected lymph empties into the junction of the subclavian and internal jugular veins on the left and right sides of the body via the thoracic duct and the right lymphatic duct respectively.
lymphatic capillaries
-they resemble ?
with these exceptions:
1. does not have a complete or any ?, which therefore...
2. one end of the capillaries ends ?
-matrix fibers hold vessels ? in face of ?
• They resemble blood capillaries except:
• Interstitial macromolecules may pass into the lumen due to an incomplete or absent basement membrane.
• One end of lymphatic capillaries ends blindly.
• Fine extracellular matrix fibers hold the vessels open in the face of edema
edema is?
the increase of interstitial fluid in any organ — swelling
lymphatic vessels
-do not have?
-made up of what tissues?
-which vessels have tunics?
• They resemble small or medium-sized veins.
• Red blood cells are absent, but a few lymphocytes may be present.
• Small lymphatics have an endothelium and a thin connective tissue coat of loose connective tissue.
• Medium and large-sized vessels have 3 tunics, but they are hard to discern.
the heart
-the heart wall is made up of ? similar to that of ?
-walls are primarily made up of ? and ?
-? is usually considered part of the pericardium.
• The heart wall is made up of three layers or tunics, in some ways similar to that of the vessels.
• The walls of the heart are primarily made up of myocardium and endocardium.
• The epicardium is usually considered part of the pericardium.
-is the equivalent of which tunica?
-lines ?
-consists of ? and ? with underlying ? tissues and ? cells
: The equivalent of the tunica intima.
• It lines the chambers of the heart, covers its various one-way valves, and is in continuity with the tunica intima of vessels entering or leaving the heart.
• It consists of a layer of endothelium and basement membrane, with underlying loose and then deeper dense connective tissue, followed by fat cells.
-constructed primarily of ?
-the endomysial loose connective tissue supplies them with ?
-the branching chains of muscle cells are joined by ? junctions
-the junctions allow ?
This is primarily constructed of cardiac muscle fibers.
• The endomysial loose connective tissue lying between muscle fibers supplies them with abundant capillaries and lymphatics.
• The branching chains of muscle cells are joined end to end by intercalated disks with adhering and gap junctions.
• The adhering junctions counteract cell separation and the gap junctions allow direct electrical continuity for the excitation waves.
-relative to which tunica layer?
-consists of ?
corresponds to the tunica adventitia.
• It consists of a layer of fibroelastic connective tissue with blood and lymph vessels, nerves, and fat tissue that merges with the endomysium of the myocardium.
• This is overlain with a superficial meso- thelium of squamous epithelial cells.
pericardium and epicardium
-the heart is enclosed by ?
-serous pericardium lines ?
•The heart is enclosed by a 2-layered sac of connective tissue, the pericardium, with a fibroelastic outer layer, the fibrous pericardium, and an inner delicate mesothelial lining, the serous pericardium.
• The latter reflects over the surface of the heart as the epicardium or visceral serous pericardium. The serous pericardium lining the fibrous pericardium is called the parietal serous pericardium.
& AV BUNDLE consists of ?
• The SA and AV nodes are small masses of specialized cardiac muscle fibers and associated fibroelastic connective tissue.
• Both nodes are supplied with efferent postganglionic fibers from both autonomic divisions.
-• The AV Bundle (of His) consists of specialized cardiac muscle fibers that enter the interventricular septum, branch and become Purkinje fibers.
purkinje fibers
-are located ?
-contain few ?
-have a central core around the nucleus that contains ?
• They lie in the deepest layer of the endocardium.
• They are wider than ordinary ventricular fibers.
• They contain fewer myofibrils.
• They have a pale wide central core around the nucleus that contains much glycogen
cardiac valves
-heart valve is ? and is vascular or avascular ?
-which fibers are present?
• Each ventricle has inlet and outlet valves, both of the flap (leaflet) type.
• The heart valve leaflet is an intimal sheet with a core of dense irregular connective tissue that is mostly avascular.
• Elastic fibers are present.
• The fibrous core is attached to the cardiac skeleton.
the immune system is composed of ?
-tissues are placed ?
•Lymphatic Organs and Tissues
-tissues are places where the lymphocytes proliferate, differentiate, and mature.
lymphocytes become immunocompetent where ?
• In the thymus, bone marrow, and gut-associated lymphatic tissue (GALT)
immunocompetent cells can ?
can distinguish between “self” (molecules normally present within an organism) and “nonself” (foreign molecules).
immune defenses are either:
1. non-specific
• These consist of physical barriers, e.g. the skin and mucous membranes, or:
1• Various chemical substances that neutralize foreign cells
2• The antibody or humoral response: The production of proteins that mark invaders for destruction by other immune cells.
• The cellular immune response: This targets transformed and virus-infected cells for destruction by lymphocytes.
Lymphocyte T cells
-originate from ?
-there are ?% of blood lymphocytes
-how many types ?
-destroy antigens by activating ? cells
• T lymphocytes arise from lymphocytes that are carried from the bone marrow to the thymus gland, where they mature and become immunocompetent.
• They are 60-80% of blood lymphocytes.
• There are 4 main types of T lymphocytes.
• T lymphocytes destroy antigens by cytotoxic action or by activating B-cells.
B Cells
-comprise ?% of blood lymphocytes?
-are involved in?
-become immunocompentent where?
• They comprise 20-30% of blood lymphocytes.
• They are involved in the production and secretion of circulating antibodies (immunoglobulins).
• They mature and become immunocompetent in the bone marrow and the GALT
Natural Killer cells
-develop from?
-comprise ?% of blood lymphs
-recognize ?
-release ? which make these cells ?
• Develop from same precursors as the others.
• Constitute 5-10% of blood lymphocytes.
• Genetically programmed during develop-ment to recognize virus-infected or tumor cells.
• They release perforins and fragmentins which induce these cells to self-destruct
antigen presenting cells
-most APCs are ?nuclear ?
• Interactions of antigens directly with B and T lymphocytes is not sufficient to destroy the antigen.
• APC’s break down antigens to peptides which bind to MHC II molecules, and the complex is displayed on the plasma membrane of the APC.
• Now the immune process can proceed.
• Most APC’s are mononuclear phagocytes.
diffuse lymphatic tissue
-lymphocytes and other cells are located where?
-what does the presence of eosinophils and plasma cells indicate?
The alimentary canal, respiratory passages, and genito-urinary tract are guarded by accumulations of lymphatic tissue not enclosed by a capsule.
-• Lymphocytes and other cells of this system are located in the lamina propria of these tracts.
-• Plasma cells and eosinophils in this tissue indicates antibody production and chronic inflammation and hypersensitivity respectively
primary lymphoid organs
•Fetal Liver
•Prenatal & Postnatal Bone Marrow
• These lymphoid organs are responsible for the development and maturation of lymphocytes into mature immuno- competent cells, not to facilitate immune responses.
2ndary lymphoid organs
•Lymph Nodes
•Mucosa Associated Lymphoid Tissue (MALT and GALT)
•Postnatal Bone Marrow
-is a ? that lies mostly in the ?, but early on may extend into the ?
• This is a bilobed endocrine gland that lies mostly in the superior mediastinum, but early on may extend into the anterior mediastinum.
-during childhood is it active or inactive?
-from puberty to old age, it undergoes ? and produces more or less T cells?
During childhood it is very active, but from puberty to old age undergoes progressive atrophy and produces declining numbers of T cells.
thymus produces and contains ? that support proliferation and differentiation of ?
-also contains ? of ? epithelial reticular cells
• The thymus also produces a number of hormones that support proliferation and differentiation of T cell progenitors (prothymocytes).
- • It contains densely packed differentiating T cells, as well as a loose network of thymic epithelial reticular cells (-supported by a connective tissue capsule)
The outer region of the thymus is the cortex,which produces ?
-•The epithelial reticular cells of the cortex form three populations, which differentiate ?
and they leave the thymus via ? venules and ? lymphatics.
• The cortex produces three hormones, thymosin, thymulin, and thymopoietin and some differentiation-inducing cytokines
-Types I, II, and III.

-• T cells differentiate in the cortex in response to the hormones.
-• Many of them pass into the medulla for further selection and maturation.
• T cells leave the thymus via medullary venules and efferent lymphatics.
the inner region of the thymus is the ? and the epithelial cells within it are arranged in ? structures called ?
• In the thymic medulla, the epithelial cells are partly arranged in spherical structures called thymic (Hassal’s) corpuscles.
thymus is incompletely divided into ?
incompletely subdivided into lobules by trabeculae that extend inward from the capsule.
Type I cells of the cortex
separate the capsule and trabeculae from the cortex and surround cortical vascular elements.
• The cells form occluding junctions with each other to isolate the cortex from the remainder of the body
Type II cells of the cortex
form desmosomal junctions with each other to form small compartments full of lymphocytes.
Type III cells
form occluding junctions that isolate the cortex from the medulla.
• These isolation measures are intended to prevent differentiating T cells from encountering foreign antigens until they are needed to react to an invader.
• The medulla stains lighter because it has mostly large lymphocytes, but has 3 more types of epithelial reticular cells.
Types IV and V have ? roles
Type VI is the ?, whose function is unknown
• Type VI is the Hassal’s corpuscle, whose function is unknown.
• The loose connective tissue of the epithelial linings of the digestive, respiratory, and urinary tracts commonly contains
lymphoid follicles and nodules
lymphoid follicles are mostly ? in size, dependent or independent, and discrete or indiscrete?
Most are small, solitary and discrete.
•At some places, lymphoid follicles are large, multiple and confluent.
•Places with large aggregates of follicles include:
• The Tonsils
• Peyer’s Patches
• The Appendix
large lymphoid follicular aggregations receive ? that penetrate ? and diffuse through the ?
• Permanent large aggregations like this receive foreign antigens that penetrate the epithelium and diffuse through the lamina propria.
a preliminary stage in the production of antibody-producing plasma cells:
•The epithelia of the tonsils, Peyer's Patches, the Appendix contain flat epithelial cells (M cells or FAE cells) that ingest antigen and deliver them to APC’s of the GALT.
lymph nodes are ? shaped structures with 3 things:
• Kidney-shaped structures with a capsule, cortex, and medulla.
lymph node cortex contains ? and ? passes to the medulla
-follicles that contain ? cells are present in the ? zone of the cortex
-the ? cortex, the deeper cortex, contains ? cells
• Cortex contains follicles & B cell progeny pass to the medulla
-• B cell containing follicles are present in the outer zone of the cortex.
-•The deeper cortex (paracortex) contains T cells.
•in lymph nodes, Numerous macrophages remove
bacteria and particulate matter.
? lymph vessels penetrate the capsule, ? lymph vessels leave the ?
• Afferent lymph vessels penetrate the capsule, efferent lymph vessels leave the hilum (the junction at which the splenic vessels enter and leave the organ)
? centers are sites of antigen-elcited B cell proliferation
-•Also present here are ? cells, a type of APC.
•Germinal centers
-follicular dendritic cells
these contain large numbers of plasma cells that live there for 3 days and release their antibodies into the efferent lymph:
•Medullary cords
? cells are also found in the medullary cords
-? cells are formed from activated ? cells in the cortex
• Some B cells are also found there.
•Plasma cells are formed from activated B cells in the cortex.
the spleen is ?
-like the thymus, it contains only ? lymphatics
-it has a loose or dense fibroelastic capsule?
-islands of white pulp are scattered within ? and are primarily ?
-red pulp is full of ? and serves as ?
•The largest lymphoid organ.
•Like the thymus, it contains only efferent lymphatics.
•It has a dense fibroelastic capsule.
•It has red pulp, internally supported by reticular fibers and appears bright red.
•Islands of white pulp are scattered through the red pulp.
•Islands of white pulp are primarily lymphoid follicles.
•The red pulp is full of erythrocytes and serves as a blood filter.
the spleen/red pulp cleans out:
and the internal circulatory system is a unique
It removes:
• Worn out blood cells
• Platelets
• Suspended particulate matter.
• The internal circulation is a unique open system.
red pulp is composed of ? and functions
"sinuses" (or "sinusoids") which are filled with blood
* "splenic cords" of reticular fibers
* "marginal zone" bordering on white pulp
-Removes unwanted materials from the blood, including senescent red blood cells.
white pulp is composed of ? and functions to ?
Composed of nodules, called Malpighian corpuscles. These are composed of:
* "lymphoid follicles" (or "follicles"), rich in B-lymphocytes
* "periarteriolar lymphoid sheaths" (PALS), rich in T-lymphocytes Helps fight infections.

Other functions of the spleen
-helps to fight infection
does the spleen create RBCs?
yes and...
Production of opsonins, properdin, and tuftsin.
Creation of red blood cells. While the bone marrow is the primary site of hematopoeisis in the adult, up until the fifth month of gestation, the spleen has important hematopoietic functions.
spleen's chief functions:
-formation of ? and destruction of ?
• Antibody formation: splenic B cells make lots of plasma cells. It is the chief source of circulating antibodies.
• Disposal of defective red blood cells.