lymphatic, immune, respiratory,urinary

The kidneys filter a lot of fluid from the bloodstream, allowing toxins metabolic wastes and excess ions to leave the body in urine while returning needed substances to the blood. The kidneys are the major excretory organs. They also act as essential regulators of the volume and chemical makeup of the blood, maintaining the proper balance between water and salts and acids and bases. Also do Gluconeogenesis during prolonged fasting, produce Renin and Erythropoietin, and Metabolizing vitamin D to its active form.

Be able to describe the functions of the kidneys

Active Humoral Immunity: When your B cells encounter antigens and produce antibodies against them. Acquired in two ways: 1. Naturally Acquired: Like when you get a bacterial or viral infection, during which time you may develop symptoms of the disease and suffer. 2. Artificially Acquired: Like when you get a vaccine. Passive Humoral Immunity: Transfer of antibodies comes from another source like a human or animal donor. Your B cells are not challenged by antigens, immunological memory does not occur, and the protection provided by the "borrowed" antibodies ends when they naturally degrade in the body. Happens naturally between a mother and fetus. Immediate response, but short lived.

Compare and contrast active and passive humoral immunity.

B Lymphocytes: Oversee humoral immunity. Become immunocompetent and self-tolerant in the bone marrow. The receptors are membrane-bound antibodies. Less is known about the factors that control B cell maturation in humans. In the bone marrow, self-reactive B cells are either eliminated by apoptosis or are given a chance to change their self-reactive antigen receptor by receptor editing. T Lymphocytes: Non-antibody-producing lymphocytes that constitute the cell-mediated arm of adaptive immunity. They are educated by a two to three day maturation process in the thymus. The receptors on T cells are not antibodies but are products of the same gene superfamily. Being matured in the thymus ensures that the T cells will be able to bind MHC molecules, since it is on these molecules that antigens are presented to the T cell for recognition. The T cell must also not react strongly to self-antigens that are normally found in the body. React with fragments of antigens that are presented to them by another cell. Become Helper T cells (stimulate cells to divide) or Cytotoxic T cells (directly attack and kill other cells).

Compare and contrast the origin, maturation process, and general function of B and T lymphocytes.

Lymph Nodes: The principal lymphoid organs in the body, cluster along the lymphatic vessels of the body. Hundreds of them, but not usually seen because they are embedded in connective tissue. Act as lymph "filters". Macrophages in the nodes remove and destroy microorganisms and other debris that enter the lymph from the loose connective tissues, effectively preventing them from being delivered to the blood and spreading to other parts of the body. They also help activate the immune system. Strategically located sites where lymphocytes encounter antigens and are activated to mount an attack against them. ONLY the lymph nodes filter lymph and have afferent lymphatic vessels where lymph enters. Each are a capsule from which connective tissue strands called trabeculae extend inward to divide the node into a number of compartments.

Compare and contrast them (lymphoid organs) with lymph nodes, structurally and functionally.

Hypoxia: Inadequate oxygen delivery to body tissues. Observed more easily in fair-skinned people because their skin and mucosae take on a bluish cast when Hb saturation falls below 75%. Emphysema: Distinguished by permanent enlargement of the alveoli, accompanied by destruction of the alveolar walls. Invariably the lungs lose their elasticity. Accessory muscles must be enlisted to breathe, and victims are perpetually exhausted because breathing requires 15-20% of their total body energy supply. The bronchioles also open during inspiration but collapse during expiration, trapping huge volumes of air in the alveoli. Causes a "barrel chest" and flattens the diaphragm. Damage to the pulmonary capillaries as the alveolar walls disintegrate increases resistance to the pulmonary circuit, forcing the right ventricle to overwork and consequently become enlarged. Asthma: Characterized by episodes of coughing, dyspnea, wheezing, and chest tightness, and panic. Marked by acute exacerbations followed by symptom-free periods-obstruction is reversible. Active inflammation of the airways comes first, then the effect of bronchospasm is vastly magnified and can dramatically reduce air flow.

Compare the causes and consequences of hypoxia, emphysema, and asthma.

Intrinsic/Renal Autoregulation: 1. Myogenic Mechanism reflects the tendency of vascular smooth muscle to contract when stretched. When BP decreases, mechanism relaxes and raises glomerular hydrostatic pressure. When BP increases, mechanism constricts, restricts blood flow into the glomerulus and prevents glomerular blood pressure from rising to damaging levels. 2. Tubuloglomerular Mechanism: Directed by the macula densa cells of the juxtaglomerular apparatus. When GFR increases, insufficient time for reabsorption and concentration of NaCl in filtrate is high. Release a vasoconstrictor at the afferent arteriole, so GFR decreases and more NaCl can be reabsorbed. Extrinsic/Neural and Hormonal Mechanisms: 1. Sympathetic NS: Causes major constriction of renal blood vessels to decrease GFR because of stress or blood loss, overrides autoregulation. Also stimulates granular cells to release Renin 2. Renin-Angiotensin mechanism: Triggered when various stimuli cause the granular cells to release Renin which converts to Angiotensin II, restores blood volume and blood pressure by being a vasoconstrictor and stimulates reabsorption of Na+

Compare the intrinsic and extrinsic controls of glomerular filtration rate (the volume of filtrate formed each minute by the combined activity of all 2 million glomeruli of the kidneys.)

Antigens are substances that can mobilize the adaptive defenses and provoke an immune response. They are the ultimate targets of all adaptive immune responses. Most antigens are large, complex molecules that are normally not present in the body. They are intruders/nonself. They can be Complete or Incomplete. Among the cell surface proteins that mark a cell as "self" is a group of glycoproteins called MHC proteins. Genes of the Major Histocompatibility Complex code for these proteins. Class I MHCs (CD8) are found on virtually all body cells, but Class II MHCs (CD4) are found only on certain cells that act in the immune response. Class I present fragments of an antigen outside of the cell membrane, signals to other cells that there is an invader and for them to go find it. Class II are only found on cells that are APCs (like Macrophages, Dendrites, etc). These have an extracellular antigen and take in bacteria through phagocytosis.

Define antigen and describe how they work.

Immunity conferred by activated T cells, which directly kill infected or cancerous body cells or cells of foreign grafts and release chemicals that regulate the immune response. Immunocompetent T cells are activated when the variable regions of their surface receptors bind to a "recognized" antigen. T cells also must accomplish double recognition: they must simultaneously recognize nonself (the antigen) and self (an MHC protein of a body cell). Class I and Class II MHC proteins are important to T cell activation. T cell activation is a two step process involving antigen binding and co-stimulation (before a T cell and proliferate and form a clone, it must recognize one or more co-stimulatory signals. Has to bind to the antigen on the surface of the APC as well as bind to the MHC complex on APC)

Define cell-mediated immunity and describe the process of activation and clonal selection of T cells.

Also called Antibody-Mediated Immunity, provided by antibodies present in the body's fluids. Though they are produced by lymphocytes, antibodies circulate freely in the blood and lymph, where they bind primarily to bacteria, bacterial toxins, and free viruses, inactivating them temporarily and marking them for destruction by phagocytes or complement. The Antigen Challenge, the first encounter between an immunocompetent but naive lymphocyte and an invading antigen, usually takes place in the spleen or in a lymph node. If the lymphocyte is a B cell, the challenging antigen provokes the humoral immune response, in which antibodies are produced against the challenger.

Define humoral immunity.

1. Filtration: Occurs in the Renal Corpuscle (Glomerulus and Bowman's Capsule), substances out of the blood and into the nephron tubule, formed elements and plasma proteins do not leave the blood, passive mechanism based on hydrostatic pressure, called Filtrate not urine yet. 2. Reabsorption: Mostly at the Proximal Convoluted Tubules, taking back things from the tubules so they can remain in the blood, transport out of lumen into peritubular capillaries, 100% of glucose and amino acids get reabsorbed, 65% Na and water, Transcellular goes through the cell, Paracellular goes in between the cells. 3. Secretion: Move substances from the blood to filtrate, OPPOSITE of Reabsorption, Most active in PCT: gets urea, creatine, H+, nitrogenous wastes. In Collecting Duct/Distal CT: K+ ions, little bit of H+ for pH regulation.

Describe 3 mechanisms in urine formation and where they occur in the nephron

1. Dissolved in plasma (7-10%). 2. Chemically bound to hemoglobin (just over 20%): Carried in the RBCs as Carbaminohemoglobin. Binds directly to the amino acids of Globin (NOT to the heme like O2). 3. As bicarbonate ion in plasma (about 70%): When dissociated CO2 diffuses into the RBCs, it combines with water, forming carbonic acid (H2CO3). This is unstable and dissociates into hydrogen ions and bicarbonate ions. Carbonic Anhydrase is the enzyme in RBCs that reversibly catalyzes the conversion of CO2 and water to carbonic acid.

Describe carbon dioxide transport in the blood.

Helper T cells (CD4 Class II MHC): Play a central role in adaptive immunity, mobilizing both its cellular and its humoral arms. Once they have been primed by APC presentation of antigen, they help activate B and T cells and induce B and T cell proliferation. Without these "director" cells, there is NO adaptive immune response. They also activate macrophages to become more potent killers, and their cytokines (chemical messengers) furnish the chemical help needed to recruit other immune cells to fight off intruders. Stimulate cells to divide. Cytotoxic T cells (CD8 Class I MHC): Only T cells that can directly attack and kill other cells. Activated Tc cells roam the body, circulating in and out of blood and lymph and through lymphoid organs in search of body cells displaying antigens that the Tc cells recognize. Their main targets are virus-infected cells. Bind to target cells, put Perforin Pores into target cell, release Granzymes that lyse the target cell and kill them off. NK cells use the same key mechanisms for killing their target cells. Check the "identity flags" of cells to see if they look the way they're supposed to Regulatory T cells: Dampen the immune response. They act either by direct contact or by releasing inhibitory cytokines. They're important in preventing autoimmune reactions because they suppress self-reactive lymphocytes in the periphery (outside of the lymphoid organs). Hope to use them to induce tolerance to transplanted tissue and to lessen the severity of autoimmune diseases.

Describe how T-cells function in the body

The gas makeup of the atmosphere is quite different from that in the alveoli. The atmosphere is almost entirely O2 and N2; the alveoli contain more CO2 and water vapor and much less O2. These differences reflect the effects of 1. Gas exchange occuring in the lungs (O2 diffuses from the alveoli into the pulmonary blood and CO2 diffuses in the opposite direction), 2. Humidification of air by conducting passages, and 3. The mixing of alveolar gas that occurs with each breath. Because only 500 ml of air is inspired with each tidal inspiration, gas in the alveoli is actually a mixture of newly inspired gases and gases remaining in the respiratory passageways between breaths. The alveolar partial pressures of O2 and CO2 are easily changed by increasing breathing depth and rate. A high AVR brings more O2 into the alveoli, increasing alveolar PO2 and rapidly eliminating CO2 from the lungs.

Describe how atmospheric and alveolar air differ in composition, and explain these differences.

Molecular O2 is carried in blood in two ways: Bound to Hemoglobin within RBCs (more common) and dissolved in plasma. The hemoglobin-oxygen combination is called Oxyhemoglobin. Hemoglobin that has released O2 is called Reduced Hemoglobin or Deoxyhemoglobin. Temp, pH, BPG, and PCO2 all influence Hb saturation by modifying hemoglobin's three-dimensional structure, and thereby changing its affinity for O2. Generally speaking, an INCREASE in any of these in blood decreases Hb's affinity for O2, enhancing O2 unloading from the blood. This causes a rightward-shift of the oxygen-hemoglobin dissociation curve. Conversely, a DECREASE in any of these factors increases hemoglobin's affinity for O2, decreasing O2 unloading. This change shifts the dissociation curve to the left.

Describe how oxygen is transported in the blood, and explain how oxygen loading and unloading is affected by temperature, pH, BPG, and PCO2.

The body's first line of defense-the skin and mucous membranes, along with the secretions these membranes produce-is highly effective. As long as the epidermis is unbroken, this heavily keratinized epithelial membrane presents are formidable physical barrier to mose microorganisms that swarm on the skin. Mucous membranes line all body cavities that open to the exterior: Digestive, Respiratory, Urinary, and Reproductive. Protective chemicals such as Skin Acidity, Stomach HCL, Lysozyme, and Mucus inhibit or destroy microbes.

Describe surface membrane barriers and their protective functions.

Ureters: Slender tubes that convey urine from the kidneys to the bladder. Walls have three layers. Incoming urine distends the ureter and stimulates is muscularis to contract, propelling urine into the bladder. Bladder: Smooth collapsible muscular sac that stores urine temporarily. In men, the prostate lies inferior to the bladder neck, which empties into the urethra. In women, the bladder is anterior to the vagina and uterus. Very distensible and uniquely suited for its function of urine storage. Urethra: Thin-walled muscular tube that drains urine from the bladder and conveys it out of the body. The male urethra is 20 cm long and has 3 regions (prostatic, membranous, and spongy). It double functions by carrying semen and urine out of the body. The female urethra is very short and external orific is close to anal opening. Only carries out urine.

Describe the general location, structure, and functions of the ureters, bladder, and urethra. Compare and contrast male and female structures

Shown by redness, heat, swelling, and pain. Swelling and pain comes from leakiness of endothelial cells, Redness and heat from vasodilation. Causes vasodilation, increased vascular permeability, and phagocyte mobilization. Prevents spreading of the injury agent, dispose of debris, and repair. 1. Leukocytosis: Rise in WBCs in conjunction with inflammation. Chemicals attract leukocytes to sites. Increase the dilation and permeability of vessels. 2. Margination: The clinging of phagocytes to the inner walls of the capillaries. 3. Diapedesis: Continued chemical signaling prompts the neutrophils to flatten and squeeze through the capillary walls. Also when Monocytes become Macrophages 4. Chemotaxis: Neutrophils follow the chemical trail being put out. First ones on the scene, within an hour are there and devouring foreign material.

Describe the inflammatory process.

The walls of the alveoli are composed primarily of a single layer of squamous epithelial cells, called Type I Cells, surrounded by a flimsy basement membrane. The external surfaces of the alveoli are densely covered with a "cobweb" of pulmonary capillaries. Together, the alveolar and capillary walls and their fused basement membranes form the Respiratory Membrane, a air-blood barrier that has gas on one side and blood flowing past on the other. Gas exchanges occur readily by simple diffusion across the respiratory membrane: O2 passes from the alveolus into the blood, and CO2 leaves the blood to enter the gas-filled alveolus. Scattered amid the type I squamous cells that form the major part of the alveolar walls are cuboidal Type II Cells that secrete a fluid containing surfactant that coats the gas-exposed alveolar surfaces.

Describe the makeup of the respiratory membrane, and relate structure to function.

The control of respiration primarily involves neurons in the reticular formation of the medulla and pons. The medulla sets the respiratory rhythm. Clustered neurons in two areas of the medulla oblongata appear to be critically important in respiration: 1. Dorsal Respiratory Group and 2. Ventral Respiratory Group. The VRG appears to be a rhythm-generating and integrative center. It contains groups of neurons that fire during inspiration and others that fire during expiration in a dance of mutual inhibition, causing the impulses to travel along the phrenic and intercostal nerves to excite the diaphragm and intercostal muscles. When the VRG's expiratory neurons fire, the output stops, and expiration occurs passively as the inspiratory muscles relax and the lungs recoil. The DRG integrates input from peripheral stretch and chemoreceptors and communicates the info to the VRG. The Pontine Respiratory Group transmit impulses to the VRG of the medulla. This input modifies and fine-tines the breathing rhythms generated by the VRG during certain activities such as vocalization, sleep, and exercise.

Describe the neural controls of respiration.

Your body makes respiratory and hematopoietic adjustments via an adaptive response called Acclimatization. Decreases in arterial PO2 cause the peripheral chemoreceptors to become more responsive to increases in PCO2, and a substantial decline in PO2 directly stimulates the peripheral chemoreceptors. Ventilation increases as the brain attempts to restore gas exchange to previous levels. Within a few days, the minute ventilation stabilizes at a level 2-3 L/min higher than the sea level rate. Increased ventilation also reduces arterial CO2 levels, so the PCO2 of individuals living at high altitudes is typically below 40 mmHg. High-altitude conditions always result in lower-than-normal hemoglobin saturation levels because less O2 is available to be loaded. When blood O2 levels decline, the kidneys accelerate production of EPO, which stimulates bone marrow production of RBCs. This phase of acclimatization, provides long-term compensation for living at high altitudes.

Describe the process and effects of acclimatization to high altitude.

An immunocompetent but naive B lymphocyte is activated-stimulated to complete its differentiation-when matching antigens bind to its surface receptors and cross-link adjacent receptors together. Antigen binding is quickly followed by receptor-mediated endocytosis of the cross-linked antigen receptor complexes. This sequence of steps triggers clonal selection because it stimulates the B cell to grow and then multiply rapidly to form an army of cells all exactly like itself and bearing the same antigen-specific receptors. The antigen does the selecting in clonal selection by "choosing" a lymphocyte with complementary receptors.

Describe the process of clonal selection of a B cell.

Lymph is protein-containing fluid transported by lymphatic vessels. It becomes lymph once interstitial fluid enters the lymphatics. The lymphatic system lacks an organ that acts as a pump. Lymphatic vessels are low pressure conduits, the same mechanisms that promote venous return in blood vessels act here as well--the milking action of active skeletal muscles, pressure changes in the thorax during breathing, and valves to prevent backflow. Lymphatics are usually bundled together in connective tissue sheaths along with blood vessels, and pulsations of nearby arteries also promote lymph flow. In addition to these mechanisms, smooth muscle in the walls of the lymphatic trunks and throacic duct contracts rhythmically, helping to pump the lymph along. Still, lymph transport is sporadic and slow. When physical activity or passive movements increase, lymph flows much more rapidly.

Describe the source of lymph and mechanism(s) of lymph transport.

After lymphatic capillaries, they have the same three tunics as veins, but the collecting vessels are thinner walled, have more internal valves, and anastomose more.

Describe the structure and distribution of collecting vessels

The transport system of lymph starts with these microscopic capillaries. They weave between the tissue cells and blood capillaries in the loose connective tissues of the body. They are widespread but are absent from bones and teeth, bone marrow, and the entire CNS. Similiar to blood capillaries but they are very permeable because of MINIVALVES (flaps that overlap) and ANCHORING FILAMENTS which anchor the endothelial cells to surrounding structures so that any increase in interstitial fluid volume opens the minivalves. Proteins can enter these capillaries easily and they can develop openings that permit uptake of even larger particles such as cell debris, pathogens, and cancer cells when tissues become inflamed.

Describe the structure and distribution of lymphatic capillaries

After collecting vessels, the lymphatic trunks are formed by the union of the largest collecting vessels, and drain fairly large areas of the body. The major trunks are named mostly for the regions from which they collect lymph, such as the lumbar, subclavian, and jugular trunks. After the trunks, lymph is eventually delivered to one of two large ducts (largest vessels) in the thoracic region. The Right Lymphatic Duct drains lymph from the right upper limb and the right side of the head and thorax. The much larger Thoracic Duct receives lymph from the rest of the body. It arises anterior to the first two lumbar vertebrae as an enlarged sac, the Cisterna Chyli, that collects lymph from the two large lumbar trunks that drain the lower limbs and from the intestinal trunk that drains the digestive organs.

Describe the structure and distribution of lymphatic trunks and ducts

An elaborate system of drainage vessels that collect the excess protein-containing interstitial fuild and return it to the bloodstream. These vessels form a one-way system in which lymph flows only toward the heart.

Describe the structure and distribution of lymphatic vessels

By the time the DCT is reached, only about 10% of the originally filtered NaCl and 25% of the water remain in the tubule. Most reabsorption from this point on depends on the body's needs at the time and is regulated by hormones. In the DT, it's fine tuning here, substances reabsorbed are H20 and ions. 95% of filtrate reabsorbed here. Same thing in Collecting Duct, Aldosterone causes more Na+ to be reabsorbed and H20 follows it, by end 99% has been reabsorbed.

Discuss how sodium and water is reabsorbed and regulated in the distal tubule and collecting duct

Renin is produced by the granular cells of the JGA, Renin converts Angiotensinogen to Angiotensin I, ANG I is converted to ANG II by angiotensin converting enzyme, ANG II reaches the adrenals and stimulates production and release of Aldosterone, causes Na+ to be reabsorbed and K+ to be secreted.

Discuss the renin-angiotensin-aldosterone pathway

Abnormally high temperature that is a systemic response to invading microorganisms. High fevers are dangerous because excess heat denatures enzymes. Mild or moderate fever, however, is an adaptive response that seems to benefit the body. In order to multiply, bacteria require large amounts of iron and zinc, but during a fever the liver and spleen sequester these nutrients, making them less available. Fever also increases the metabolic rate of tissue cells in general, speeding up repair processes.

Explain how fever helps protect the body.

They take advantage of immunological memory to protect against infections. They prime the immune response by providing a first meeting with the antigen so if you ever got that infection, it wouldn't be as severe. Most vaccines contain pathogens that are dead or attenuated (living, but extremely weakened), or their components. They spare us from most of the symptoms and discomfort of the disease that would otherwise occur during the primary response. Their weakened antigens also provide functional antigenic determinants that are both immunologic and reactive. Conventional Vaccines mainly target the type of helper T cell that revs up B cell defenses and antibody formation. Lots of antibodies are formed that provide immediate protection, but cellular immunological memory is only poorly established.

Explain how vaccines work

Dilute: Tubular filtrate is diluted as it travels through the ascending limb of the loop of Henle, so all the kidney needs to do to secrete dilute urine is allow the filtrate to continue on its way into the renal pelvis. When ADH is not being released by the posterior pituitary, this is exactly what happens. The CDs remain impermeable to water and no reabsorption occurs. Concentrated: Depends on the medullary osmotic gradient and the presence of ADH. Water rapidly leaves the filtrate, followed by urea. With maximal ADH secretion, up to 99% of the water in the filtrate is reabsorbed and returned to the blood, and half a liter per day of highly concentrated urine is excreted.

Explain the formation of dilute and concentrated urine

The body uses an enormous number of nonspecific cellular and chemical devices to protect itself. All of these protective ploys identify potentially harmful substances by recognizing surface carbohydrates unique to infectious organisms. Phagocytosis: Phagocyte (Macrophage or Neutrophil) adheres to pathogens or debris, Phagocyte forms pseudopods that eventually engulf the particles forming a Phagosome, Lysosome fuses with the phagocytic vesicle forming a Phagolysosome, Lysosomal enzymes digest the particles leaving a residual body, Exocytosis of the vesicle removes indigestible and residual material. Natural Killer Cells: "Police" the body in blood and lymph, a unique group of defensive cells that can lyse and kill cancer cells and virus-infected body cells before the adaptive immune system is activated. "Pit bulls" of the defense system, can eliminate a variety of infected or cancerous cells by detecting the lack of "self" cell-surface receptors and by recognizing certain surface sugars on the target cell. Involves direct contact and induces the target cell to undergo apoptosis (cell death). Early responders

Explain the importance of phagocytosis and natural killer cells in innate body defense.

1. Disposing of substances such as certain drugs and metabolites that are tightly bound to plasma proteins. 2. Eliminating undesirable substances or end products that have been reabsorbed by passive processes, such as urea and uric acid. 3. Ridding the body of excess K+ 4. Controlling blood pH: secrete more H+ when acidic and secretes HCO3- when more basic. Also gets rid of NH4+, creatinine, and certain organic acids.

Explain the importance of tubular secretion and which substances are secreted

Nasal cavity, Pharynx (Nasopharynx, Oropharynx, Laryngopharynx), Larynx, Trachea, Bronchii-Bronchioles, Alveolar Ducts, Alveolar Sacs, Alveoli.

Identify the structures of the respiratory tract in order until the alveoli

ADH: Controls the reabsorption of water from filtrate in the collecting ducts in order to adjust the body's osmolality. Inhibits urine output. Released from the posterior pituitary when the body is dehydrated. Stimulates the collecting duct of the glomeruli to reabsorb more water from the filtrate. Angiotensin II: Made from the Renin released by granular cells in the JGA. Vasoconstrictor that raises mean arterial blood pressure, also stimulates reabsorption of sodium by acting on renal tubules and by triggering the release of Aldosterone from the adrenal cortex. Because water follows sodium, blood volume and blood pressure rise. Aldosterone: Released from the adrenal cortex when body is dehydrated, when blood Na+ is low, when blood K+ is high, and when stimulated by ANG II. Stimulates the DCT and CD to reabsorb more Na+ from filtrate, which causes water to be reabsorbed by osmosis, thereby hydrating the body. Also causes the secretion of K+ ions into the filtrate.

Know the effects of ADH, angiotensin II, and aldosterone on urine formation. Know where each is produced.

It does quiet background work so that the cardiovascular system keeps working and to keep the immune system from being impaired. It picks up fluid for the Cardiovascular system, it absorbs fat that can't be absorbed by the bloodstream by picking it up by Lacteals and carrying it for the Digestive system, it is also a filter for pathogen and debris for the Immune system. The lymphoid organs house phagocytic cells and lymphocytes, which play important roles in the body's defense mechanisms and its resistance to disease. The lymphatic system and the lymphoid organs and tissues provide the structural basis of the immune system.

List the functions of the lymphatic system

Lymphocytes: The main warriors of the immune system, arise in red bone marrow. Mature into two main varieties of immunocompetent cells: T cells: Protect the body from antigens (foreign invaders), manage the immune response and some directly attack and destroy infected cells. B cells: Protect the body from antigens, produce plasma cells that secrete antibodies into the blood. Macrophages: Play a crucial role in body protection and in the immune response by phagocytizing foreign substances and by helping to activate T cells. Dendritic Cells: Capture antigens and bring them back to the lymph nodes. Reticular Cells: Fibroblast-like cells that produce the reticular fiber stroma, which is the network that supports the other cell types in the lymphoid organs and tissues.

Name and describe the lymphoid cells of the body.

Lymphoid organs are aggregates of lymphoid tissue in the body. All are composed of reticular connective tissue and help protect the body. Typically have efferent lymphatics draining them, but lack afferent lymphatics. Spleen: Largest lymphoid organ, soft and blood rich, located on the left side of the abdominal cavity just beneath the diaphragm. Provides the site for lymphocyte proliferation and immune surveillance and response. It also plays a big role in blood-cleansing and RBC production in a fetus. Can live without one and can often repair itself. Thymus: Has important functions primarily during the early years of life. Site where T lymphocyte precursors mature to become immunocomptent lymphocytes, they become able to defend us against specific pathogens in the immune response. Tonsils: Simplest lymphoid organs, clusters of lymphatic cells. The paired Palantine tonsils are located on either side of the oral cavity, they're the largest of the tonsils and the ones most often infected. Lingual tonsils are on the back 3rd of the tongue. Pharyngeal tonsil is in the posterior wall of the nasopharynx. The Tubal tonsils surround the openings of the auditory tubes into the pharynx. The tonsils gather and remove many of the pathogens entering the pharynx in food or in inhaled air. Peyer's Patches: Large clusters of lymphoid follicles, structurally similar to the tonsils. Follicles also heavily concentrated in the wall of the Appendix. Both destroy bacteria and generate many "memory" lymphocytes for long-term immunity.

Name and describe the lymphoid organs of the body discussed in class.

Lymphoid (Lymphatic) Tissue: Important component of the immune system because it houses and provides a proliferation site for lymphocytes and furnishes an ideal surveillance vantage point for lymphocytes and macrophages. Largely composed of reticular connective tissue, dominates all the lymphoid organs except the thymus. Diffuse Lymphatic Tissue: Found in virtually every body organ, larger collections appear in the lamina propria of mucous membranes and in lymphoid organs. Lymphoid Follicles: Solid spherical bodies consisting of tightly packed reticular elements and cells. Have lighter-staining centers called Germinal Centers where proliferating B cells predominate, centers enlarge dramatically when the B cells are dividing rapidly and producing plasma cells.

Name and describe the lymphoid tissues of the body discussed in class.

Antigen binds to a receptor, activated B cells make clones which then break into the 2 different cells. Plasma Cells: Most cells of the clone differentiate into these. Antibody-secreting effector cells of the humoral response. Rapid production, short lived. Memory Cells: Slow production but long lived. Can mount an almost immediate humoral response if they encounter the same antigen again at some future time.

Recount the roles of plasma cells and memory cells in humoral immunity.

Boyle's law says that at constant temperature, the pressure of a gas varies inversely with its volume. When inspiration occurs, the diaphragm and intercostal muscles contract, causing the volume of the thoracic cavity to increase and the pressure inside the lungs to decrease. The drop in pressure and increase in volume causes air to rush in from the atmosphere because gases always flow down their pressure gradients. During expiration, the muscles relax and both the thoracic and intrapulmonary volumes decrease. This volume decreases compresses the alveoli and causes the pressure inside to become a little higher than the atmospheric pressure, causing the pressure gradient to force gas out of the lungs.

Relate Boyle's law to the events of inspiration and expiration.

Renal artery splits off into Segmental artery-Interlobar artery-Arcuate artery-Afferent arteriorles-Glomerulus-Efferent arteriole (more like a venule)-Peritubular capillaries-Venules-Arcuate veins-Interlobar veins-Renal vein-Inferior Vena Cava

Trace the blood supply to the kidneys as described in class

They are highly specialized lymphatic capillaries that are present in the fingerlike villi of the intestinal mucosa. They play a major role in absorbing digested fats from the intestine. The fatty lymph called CHYLE is also delivered to the blood via the lymphatic stream.

What are Lacteals and what do they do?

Lymphedema: Accumulation of interstitial fluid because of some sort of blockage in the lymphatic vessels. Get super swollen wherever the obstruction is. No cure, but can be controlled by compression. Lymphatic Filariasis (Elephantiasis): Form of Lymphedema, contracted by a parasitic worm carried by mosquitos, there is a cure for it. Abnormal enlargements of body parts, causing pain and severe disability. Hodgkins Lymphoma: Affects young adults and old people, diagnose by blood sample. Good if caught early. Caused by tumors in the lymph nodes. Non-Hodgkins Lymphoma: More common, 5th leading cause of cancer death, abnormal development of B-cells. Common in middle age, associated with AIDS.

What is lymphedema, lymphatic filariasis, Hodgkins and non-Hodgkins lymphoma

1. Lymphatic Vessels, 2. Lymph Nodes, 3. Lymph

What makes up the Lymphatic System?