A guide to studying for the MCAT.
A guide to making a study plan for the MCAT.
Useful information and important MCAT links.
My review notes for the MCAT.
A. Respiratory System The respiratory system works with the cardiovascular system, to supply the oxygen needed for cellular respiration, which creates the energy necessarily for human life (ATP).
1. General Structure and Function The respiratory system takes air from the environment, warming it in the nose or mouth (nasal or oral cavities), moistening it and filtering pathogens out of it in the pharynx (throat), the air travels into the larynx (voice box), the trachea (wind pipe), the bronchi of the lung (left or right), down smaller and smaller tubes, into the aveoli where the oxygen in the air is passed into the capillaries in return for waste carbon dioxide (which begins the reverse path to the outside environment).
A. Gas Exchange, Thermoregulation The oxygen is exchanged for carbon dioxide, between the alveolar sacs and capillaries. Thermoregulation by the respiratory system occurs due to heat loss (due to exhaling warm air).
The diffusion of oxygen follows Henry's law, that states an equilibrium constant of the dissolved amount of oxygen is proportional to the partial pressure of the oxygen just above the surface of the solution.
B. Protection Against Disease, Particulate Matter The nose hair grabs large particles and sweeps them out of the respiratory track along with mucus. Thin cilia help move particles out of the respiratory track. Healthy alveoli have white blood cells (macrophages) to kill invaders.
2. Breathing Mechanisms The act of breathing out is effortless, since the atmosphere has less pressure then our full lungs, air rushes out. Breathing in requires contraction of the diaphragm. The concept is called negative pressure breathing.
A. Diaphragm, Rib Cage, Differential Pressure The diaphragm is a dome shaped muscle that helps the lungs expand. The rib cage has muscles (the external and internal intercostals) that also help with breathing. The rib cage usually keeps the lungs from collapsing. Our lungs always have a pressure that keeps them from collapsing. Airflow follows lower pressure.
B. Resiliency and Surface Tension Effects Healthy lungs are elastic, springing back after each breath. Too much surface tension would collapse the lung's air sacks (alveoli), surfacant (soap) produced by the lung, keeps this from happening. In emphysema the surfacant is missing and many air sacks collapse making breathing very strenuous (like checking out at a big store with only one cashier left).
1. Functions The muscle of the body is more important them just movement, also support and protection, driving blood flow, driving digestion, tramping and generating heat and also facial expressions and body language.
A. Support, Mobility The bones are cushioned by muscle, joints are stabilized by muscle, shortening of muscle pulls bones causing mobility.
B. Peripheral Circulatory Assistance The main way for veins to return blood to the heart is by muscles squeezing the blood vessels. So if people don't get much exercise blood flow in the limbs is poor, therefore lymph flow in the limbs is very poor and many disease arise (such as peripheral vascular disease).
C. Thermoregulation (Shivering Reflex) The arrector pilli muscles can generate a lot of heat by contracting (known as shivering).
2. Structural Characteristics of Skeletal, Smooth, and Cardiac Muscle; Striated versus Nonstriated Both skeletal and cardiac muscle are striated (have stripes); Smooth muscle is solid. Booth smooth muscle and cardiac muscle are involuntary and have a single nucleus; skeletal muscle is voluntary and multinucleated. Smooth muscle is "eye" shaped, cardiac muscle is branched or "Y" shaped, skeletal muscle is "l" shaped/straight. Cardiac tissue has automautaticity, it can beat on it's own apart from the body (even a small piece of heart tissue can beat on its own outside the body).
3. Nervous Control The muscles are always controlled by nerves, even during a reflex arc (even when the brain is not signaling the muscles, the nerves still do).
A. Motor Neurons The motor neurons cause motion or other effects. Also called efferent neurons. They are the actuators of the body. Somatic motor neurons provide conscious control of the skeletal muscles. The autonomic motor neurons provide unconscious control of both smooth and cardiac muscle.
B. Neuromuscular Junctions, Motor End Plates The small gap between a neuron and a muscle is aptly named, the neuromuscular junction. Here the axon terminal sends neurotransmitters to the motor end plate/sarcolemma, triggering a release of calcium that causes muscle contraction.
C. Voluntary and Involuntary Muscles The voluntary muscles are skeletal. The involuntary muscles are smooth and cardiac muscle.
D. Sympathetic and Parasympathetic Innervation The sympathetic nervous system is in response to stress, threat or exercise (faster heart rate, pupil dilation, increased blood pressure, increased blood to muscles). The parasympathetic nervous system is in response to relaxation, digestion or sleep (slower heart rate, pupil constriction, lower blood pressure, and increased blood to digestive organs).
B. Skeletal System
The skeleton does more then provide a frame for movement, it is a living tissue that creates blood, helps the immune system, stores calcium, fat and other minerals, protects
1. Functions The main functions are: support, protection, blood production and calcium storage.
A. Structural Rigidity and Support The bones are made of a calcium salt crystal. Compact bone is very rigid allowing it to bear weight. Bone has a lattice structure that is strengthened by exercise, especially weight lifting.
B. Calcium Storage Bones store calcium. Calcitonin puts calcium in, parathyroid takes calcium out of the bones.
C. Physical Protection The internal organs are protected by the ribs and sternum, the brain is protected by the skull and the spinal cord is protected by the vertebrae.
2. Skeletal Structure The adult has 206 bones. Many were fused together like the sacrum.
The Skeleton Typogram
Aaron Kuehn
A. Specialization of Bone Types; Structures The types of bones include: long bones (the humerus/arm and femur/leg), short bones (the carpal/wrist bones), flat bones (the cranium/skull, scapula/shoulder, costals/ribs), irregular bones (the vertebrae/spine, the pelvic bones/the hip) and seasamoid bones (within a tendon ex. patella/knee cap).
B. Joint Structures The joints are the weak points of the body (exploited by jiu jitsu for weaker fighters to control stronger opponents), where bones connect allowing motions. All joints are slightly movable (craniosacral massage moves the skulls sutures, which actually move on their own too). Joints are called non-mobile (synarthrotic), when they move very little (usually connect bones with cartilage or fibrocartilage). Mobile joints (diarthrotic) contain synovial fluid to lubricate the bones. This fluid is kept in bursae, sacks that will burst under too much pressure trying to save the joint by giving it maximum lubrication when it is being overstretched (like during an armbar).
Ball and socket joints/enarthrosis (hip and shoulder) have the most motion.
Hinge joints/ginglymus (elbow and knee) only have motion across one plane.
C. Endoskeleton versus Exoskeleton The endoskeleton (within skeleton) is what humans have. The exoskeleton (outside skeleton) is what aliens, predators, insects and lobsters have. Exoskeletons are usually chitin.
3. Cartilage (Structure, Function) The cells are chondrocytes, the cells are scattered around a gel (matrix) that has fiber in it. It is squishy due to the matrix, flexible and tough due to the fibers (elastic and collagen). Cartilage functions in protecting bone ends from damage and supporting the vertebrata from shock. This tissue is avascular meaning no blood, it required movement to squish nutrients into its matrix and toxins out. Movement is essential for joint health.
4. Ligaments, Tendons The ligaments (link bone to bone) and tendons (tie bone to muscle) are made of tough bands of connective tissue. Avascular are well. Tendons contain Golgi body receptors that let the body know when the tendon is being stretched.
5. Bone Structure There are two types of bone structure, compact (looks like tree stumps) and cancellous bone (looks like lace). The membrane of a bone is called periosteum (containing stem cells). Marrow, blood vessels and nerves run down the center of lone bones. The cells are known as osteocytes.
A. Calcium–Protein Matrix The martix is calcium salt, collagen fibers and a gel like ground substance.
B. Bone Growth (Osteoblasts, Osteoclasts) Osteoblasts make bone. Osteoclasts destroy bone. Longitudinal growth is height, appositional growth is width.
Food gets chewed up, becoming a bolus, then it gets swallowed passes through the pharynx, transported down the esophagus by peristalsis, into the stomach where it is churned, through the pyloric sphincter into the small intestines (the duodenum) where enzymes from the liver and gallbladder break the food down into nutrients that are absorbed in the small intestines, feces pass through the large intestines where water is removed and then pass out of the body.
A. Saliva as Lubrication and Source of Enzymes The saliva dissolves food into starch and glycogen with amylase. The mucin in saliva helps lubricate the bolus (chewed food). Saliva contains antibodies and lysozyme to kill pathogens.
B. Epiglottal Action The epiglottis helps cover the trachea so food doesn't get into the lungs.
C. Pharynx (Function in Swallowing) The pharynx (the throat) is between the mouth and esophagus. The pharynx swallows food, allowing food into the esophagus.
D. Esophagus (Transport Function) The esophagus is the tube that food travels through on the way to digestion. Food is helped through be peristalsis.
2. Stomach The stomach helps break food down so by the time food gets to the small intestines, it can be absorbed.
A. Storage and Churning of Food The stomach has a lot of room to store and churn a meal. The stomach stretches when it is full.
B. Low pH, Gastric Juice, Protection by Mucus Against Self-Destruction The pH is usually very low in the stomach (due to parietal cells secreting HCl). The cheif cells secrete pepsin and the enteroendocrine cells secrete hormones. The stomach has a lining of mucus protecting it.
C. Production of Digestive Enzymes, Site of Digestion The stomach produces pepsin, which digests protein at a low pH. The stomach also churns food.
D. Structure (Gross) The stomach has a fundus, body and antrum draining into the deuodenum via the pyloric sphincter.
3. Liver The liver is the largest gland in the body.
A. Production of Bile The liver makes bile from cholesterol, bile then gets stored in the gallbladder and then empties into the small intestines to break down fat.
B. Roles in Nutrient Metabolism, Vitamin Storage The liver makes glycogen from glucose Gluconeogenisis from glycerol and amino acids (deamination) Breaks down fats to make cholesterol Makes lipoproteins used to transport fats Stores iron and vitamins A, D and B12
C. Roles in Blood Glucose Regulation, Detoxification If the blood sugar is low the liver regulates it through glucogenesis; too high glycogeneis. The liver detoxifies the body by removing toxins and drugs, metabolizes alcohol, and removes ammonia from the blood.
D. Structure (Gross) The liver has a large right lobe and a small left lobe.
4. Bile Bile breaks down fat. A. Storage in Gallbladder Bile is formed in the liver, stored in the gallbladder and released when needed to break down fat.
B. Function Bile breaks down fat by emulsifying it (not enzymaticly), making micelles to increase surface area for lipase action.
5. Pancreas The pancreas makes most digestive enzymes. Amylase brakes down starch. Lipase breaks down fat. Ribonuclease breaks down nucleic acids. The pancreas also make bicarbonate (HCO3-) and proteases. The islets of Langerhans have four cell types α,β, δ and PP cells.α cells make glucagon,β cells make insulin, δ make somatostatin and PP cells make pancreatic polypeptide.
A. Production of Enzymes, Bicarbonate The pancreas neutralized stomach acid by releasing bicarbonate ions into the small intestines/duodenum, so the enzymes there can work at their preferred pH of 7.
B. Transport of Enzymes to Small Intestine The pancreas transports digestive enzymes to the small intestines via a duct, therefore the pancreas has an exocrine function.
C. Structure (Gross) The pancreas lays under the stomach and drains into the small intestines.
6. Small Intestine The small intestines absorbs most of the nutrients and reabsorbs most of the water. Therefore after drinking alcohol, people don't feel the full effect until the alcohol reaches the small intestines and is absorbed by the body.
If you said pseudomyxoma peritonei syndrome with a tumor on the greater omentum and transverse colon... good job.
A. Absorption of Food Molecules and Water The food is absorbed into the cell and given to the bodies capillaries (except fat, fat goes into lacteals). Active transport is needed since there is a lot of food in the red blood cells, but they try to absorb even more food still, in order to distribute it among the body.
B. Function and Structure of Villi The small intestines have finger like projections (villi and microvilli) giving them more surface area to absorb food.
C. Production of Enzymes, Site of Digestion The small intestines absorbs most of the nutrients and drinks most of the water.
*The small intestines make protease and amylase.
D. Neutralization of Stomach Acid *The pancreas neutralized stomach acid by releasing bicarbonate ions into the small intestines, so the enzymes there can work at their preferred pH of 7.
E. Structure (Anatomic Subdivisions) The small intestines structure consists of the duodenum, the jejunum and the ileum.
7. Large Intestine The small intestine takes in most of the nutrients, the large intestine absorbs water and stores feces. The regions of the large intestines are cecum (appendix is here), ascending colon, transverse colon, descending colon, sigmoid colon and rectum.
8. Rectum (Storage and Elimination of Waste, Feces) Other then smuggling things into prison or transporting drugs, the rectum also stores feces, during defecation the sphincter relaxes and feces are passed, mostly by gravity.
9. Muscular Control Muscular control of the digestive system is a pleasant thing to have. Yoga can teach people how to help move their digestive system in a helpful way, I learned how to do that in Brazil (DeRose Method).
A. Sphincter Muscle Sphincter muscles of the digestive track include, the gastroesophageal (cardiac) sphincter between the esophagus and stomach, the pyloric sphincter between the stomach and small intestine and the anal sphincter.
B. Peristalsis A rhythmic squeezing of the intestines, by smooth muscle cells to move food along.
Day 18:
B. Excretory System
The kidneys, urinary track and surrounding arteries and veins form the renal or excretory system.
1. Roles in Homeostasis The kidneys control fluid balance (controlling blood pressure, pH and many ions such as sodium, chloride, potassium, calcium,m and phosphate).
A. Blood Pressure The kidneys can keep water (by reabsorbing water or making less urine) or shed water (by reabsorbing less water or creating more urine), thus affecting the total vascular pressure.
Low Blood Pressure:
Renin is released, forming angiotensin II, stimulating aldosterone release from the adrenal glands, which raises blood pressure by causing the distal tubules in the kidney to reabsorb more Na+ (which leads to more water reabsorption).
Antidiuretic Hormone released from storage in the pituitary, causes more water reabsorption in the distal kidney tubules, which raises blood pressure. Vasoconstriction also occurs causing less fluid to go into the kidney tubules.
High Blood Pressure:
Atiral natriuertic peptide is released by the heart, causing vasodilation and more excretion of
Na+ and water (in the kidney).
B. Osmoregulation The kidneys can control how much re-absorption of ions occurs in the tubules.
Blood plasma is mainly Na+ and Cl-, Na+ and Cl- are the main determining factors of osmoregulation. K+ and Ca2+ are also regulated by the kidneys. Aldosterone causes K+to be excreted in the urine as Na+ is retained. Calcium and phosphate are regulated by parathyroid hormone. Parathyroid hormone causes reabsorption of Ca2+ in the kidneys.
2. Kidney Structure A pair of bean shaped organs that eliminate waste by filtering the blood of toxins, waste and excess. They regulate fluid balance. There are more then a million nephrons in each kidney.
A. Cortex The outer part of the kidney, where there are convoluted tubules.
B. Medulla The inner part of the kidney, where the loop of Henle exists.
3. Nephron Structure The nephron is the functional unit of the kidney, where blood fluid gets filtered. Afferent arterioles drain fluid into the bowman's capsule, fluid travels down the proximal tubule, into the loop of Henle, through the distal tubules and into a collecting duct shared by other nephrons (by that time the fluid is urine).
A. Glomerulus The glomerulus is a collection of fenestrated capillaries.
B. Bowman’s Capsule The bowman's capsule ensheaths the glomerulus.
C. Proximal Tubule The next to the bowman's capsule is the proximal convoluted tubule, where reabsorption of nutrients, salt and water takes place. Secretion takes place also.
D. Loop of Henle The loop of Henle is where the countercurrent multiplier mechanism occurs. In the descending limb water is reabsorbed, in the ascending limb salt is reabsorbed.
E. Distal Tubule The distal convoluted tubule reabsorbes salts and water and secretes K+. The amount of reabsorption is controlled by hormones. The amount of secretion is controlled by aldosterone.
F. Collecting Duct The urine of many nephrons collects in the same duct. Like a sewer drains sewage from many houses. Antidiuretic hormone can affect reabsorption of water or salt in the collecting duct.
4. Formation of Urine The formation of urine, out of blood, is what rids the body of toxins that enter in the food or are a byproduct of living reactions. This mechanism is damaged for people of dialysis or with renal failure. High blood pressure and diabetes impair kidney function.
A. Glomerular Filtration The fluid pressure of blood pushes anything small enough to fit through the fenestrations of the capillaries into the nephrons.
B. Secretion and Reabsorption of Solutes The goal of secretion is to rid the body of creatinine and uric acid. The goal of reabsorption is to keep the body's water, ions and nutrients.
C. Concentration of Urine
The distal convoluted tubes all carry urine, which becomes more concentrated in the collecting duct. The loop of Henle's high concentration is what drives reabsorption of water in the collecting duct.
D. Countercurrent Multiplier Mechanism (Basic Function)
Using an NaCl pump on the ascending limp of the loop of Henle, a concentration gradient is made allowing urine to become concentrated in the collecting duct. The countercurrent is, the descending limb (water flows out, salt stays constant) and the ascending limb (salt flows out, water stays constant).
5. Storage and Elimination (Ureter, Bladder, Urethra)
The kidneys send waste through the ureters into the bladder (made of transitional epithelium to allow expansion), from there urine goes through the urethra to exit the body.
The circulatory system delivers nutrients and building materials, and removes waste from the cells.
1. Functions (Circulation of Oxygen, Nutrients, Hormones, Ions, and Fluids; Removal of Metabolic Waste) Circulation creates an area for diffusion to occur, like a swap-meet. The vendors are cells, the money is nutrients, the items for sale are waste, the buyers are circulation cells such as red blood cells. Nutrients are exchanged for waste in stationary cells that depend on the circulating cells to keep functioning.
Oxygen is taken into the body from the environment, travels to the circulatory system via the lungs, into the capillaries, where the oxygen binds to hemoglobin on red blood cells. Red blood cells travel through the body and back to the heart exchanging oxygen for waste. Oxygen is needed to make ATP though cellular respiration.
Nutrients are absorbed mainly by the small intestines and then transported to the blood stream. Cells such as the liver can also release nutrients into the bloodstream. Cells can uptake nutrients (some require hormones, Ex. glucose needs insulin).
Hormones need to travel in the circulatory system to get to their target.
Fluids and ions circulate making them available to cells (regulation of water and salt occurs in the kidney). Waste in the form of urea travels in the blood, to the kidney to become urine.
2. Role in Thermoregulation Vasoconstriction conserves heat by keeping heat near the core, vasodilation cools the body by letting blood (with heat) near the surface of the body (where heat is lost to the outside enviornment).
3. Four-Chambered Heart (Structure, Function) The heart must pump blood with oxygen to all the cells for cellular respiration to occur. The four-chambered heart does not allow oxygenated and deoxgenated blood to mix. Blood gets pumped faster and oxygen is absorbed better by the lungs. Blood travels through: the vena cava, right atrium, tricuspid valve, right ventricle, pulmonary valve, pulmonary artery, lung, pulmonary vein, left atrium, bicuspid (mitral) valve, left ventricle, aortic valve, aorta. TP-BA.
4. Systolic and Diastolic Pressure Systolic pressure = left ventricle contracts (highest system pressure) Diastolic pressure = left ventricle relaxes (lowest system pressure) When taking blood pressure, the first sound that is heard (when the heart's pressure surpasses the cuff's resistance) is called the first Korotkoff sound. Diastolic pressure, the left ventricle relaxes, is measured when no more sound is heard.
5. Pulmonary and Systemic Circulation Pulmonary (the lungs) circulation: blood comes from the heart via right ventricle, into the lungs via pulmonary arteries, then back to the heart (left atrium) via pulmonary veins.
Systemic (the whole body) circulation: blood comes form the heart via left ventricle, into the body via the aorta, back to the heart via the inferior and superior vena cava into the right atrium.
6. Arterial and Venous Systems (Arteries, Arterioles, Venules, Veins)
Elastic Arteries: have elastic tissue, they are not active in vasoconstriction, their layers are endothelium, smooth muscle and connective tissue.
Muscular Arteries: are somewhat active in vasoconstriction, have a lot of muscle and distribute blood to specific organs.
Arteriole: controls blood flow to capillaries, most active in vasoconstriction.
Capillary: single cell of endothelium, diffusion occurs between blood and tissue solutes.
Venule: conduct capillaries to veins.
Vein: have valves to prevent the back flow of blood, layers endothelium, smooth muscle and connective tissue, vasoconstriction may occur, muscle movement (muscle milking) helps blood flow back to the heart.
A. Structural and Functional Differences Veins have anti-back flow valves, arteries have more smooth muscle (thus are thicker). Arterioles and venules are smaller versions of arteries and veins. Arteries always go away from the heart, veins go to the heart (sometime oxygenated, Ex. the pulmonary veins).
B. Pressure and Flow Characteristics Arteries have high pressure, veins have low pressure. Veins flow evenly, arteries flow turbulently.
7. Capillary Beds Oxygen and carbon dioxide are exchanged. Nutrients and wastes are exchanged. Heat can be lost due to dilation of capillaries in the extremities.
A. Mechanisms of Gas and Solute Exchange Diffusion is the main mechanism of gas and solute exchange, which is why high surface area is important at a cellular level (facilitating diffusion).
Continuous Capillary: Ex. Blood-brain barrier (seals clefts by tight junctions) and skin and muscle, no pores on endothelial cells, may have clefts.
Fenestrated Capillary: Ex. Small intestines, endocrine organs, kidneys (allow blood filtration), pores allow fluid out, but not blood cells.
Sinusoidal Capillary: Ex. Lyphoid tissue, liver, spleen and bone marrow, large pores allow blood cells to leak out, facilitation their travel.
B. Mechanism of Heat Exchange Capillaries expand in the extremities to give off extra heat (they constrict to save heat in cold environments). More warm blood near the surface of the body causes greater heat loss to the outside environment. Counter current exchange of heat occurs in the kidneys of mammalia, not sure how much this affect humans...
8. Composition of Blood 55% plasma (top layer), 44 % red blood cells (no nucleus, bottom layer), 1% white blood cells (middle layer with platelets). White blood cells: 60% neutrophils, 40% T and B lymphocytes.
A. Plasma, Chemicals, Blood Cells There are water molecules, ions, gases, hormones, wastes, nutrients and clotting factors in the blood plasma. Chemicals in blood include clotting factors or hormones. Blood cells can be red blood cells (erythrocyte), that carry oxygen and carbon dioxide or white blood cells (leukocyte), that fight pathogens. Platelets are not cells, but are fragments of huge cells used for clotting.
B. Erythrocyte Production and Destruction (Spleen, Bone Marrow) The bone marrow has stem cells that make myeloid stem cells, which then make erythrocytes. The spleen, liver and bone marrow destroy damaged erythrocytes. Iron is recycled, heme turns into bilirubin, then bile and is excreted in the feces, globin is broken down into amino acids to be reused.
C. Regulation of Plasma Volume The volume of fluid in the body is regulated by sensing the blood osmolarity (which is why drinking too much water really fast can kill you). Osmolarity is kind of like stickiness, (it really refers to amount moles of dissolved contents, but usually that makes a fluid more thick or sticky). Higher blood osmolarity causes water to flow naturally (through osmosis) out of the cells and into the blood, to dilute the blood. That results in higher blood volume, lower interstitial volume. Low blood osmolarity causes water to flow into the tissues and interstitial space, lowering blood volume.
Vasopressin/Antidiuretic Hormone (ADH) keeps fluid in the body by preventing urination and reabsorbing more water in the kidneys (the exact opposite of a "water pill"/diuretic, that causes frequent urination). Aldosterone causes increased salt reabsorption, which causes the same effect as ADH, greater water reabsorption in the kidney and thus higher blood volume.
D. Coagulation, Clotting Mechanisms, Role of Liver in Production of Clotting Factors Clotting is a positive feedback mechanism. Clotting, leads to more (not less) clotting. Platelets are sticky pieces of megakaryoctyes, they contain enzymes for clotting. Clotting factors are produced in the liver (fibrinogen), which then circulates in the blood plasma. When a wound occurs, the platelets pile up onto it (platelet plug) and release chemicals that activate the fibrinogen. The fibrinogen follows are series of reactions becoming fibrin (a mesh that seals the clot during coagulation. Retraction and repair occur as the clot contracts (the clot dissolves after the wounded blood vessel is repaired).
9. Oxygen and Carbon Dioxide Transport by Blood Transport of oxygen and carbon dioxide in the blood is carried out by red blood cells, which contain hemoglobin to bind the gases to the protein.
A. Hemoglobin, Hematocrit
Hemoglobin is the molecule in red blood cells that carries oxygen. Each red blood cell has millions of hemoglobin molecules.
Hematocrit is the percentage of blood that is made red blood cells (by volume).
B. Oxygen Content Each hemoglobin can have up to four oxygen molecules (one for every iron atom).
Hematocrit (the percent of blood that is red blood cells and can carry oxygen) is normally 40-50% for men, 36-45% for women.
C. Oxygen Affinity The more oxygen binds onto hemoglobin, the easier it is for more oxygen to bind due to a relaxed conformation of the other subunits. Carbon monoxide binds to hemoglobin better then oxygen, ruining red blood cells in cases of carbon monoxide poisoning (the blood still looks bright red).
10. Details of Oxygen Transport: Biochemical Characteristics of Hemoglobin Hemoglobin contains 4 heme groups (which contain iron), allowing up to 4 molecules of oxygen to bind to hemoglobin (allowing transport to cells for cellular respiration). Carbon dioxide is also transported by hemoglobin as well as nitric oxide. Hemoglobin is famous for having a quaternary structure composed of 4 protein subunits in a tetrahedral arrangement.
A. Modification of Oxygen Affinity Conditions of stress (high temperature, low pH, and high carbon dioxide) cause lowering of oxygen affinity to hemoglobin, thereby allowing it to be delivered to cells that need it.
B. Lymphatic System
The lymphatic system probably describes the chi. Chi is the commander of blood, blood is the mother of chi. The bloods leaking fluid creates the lymph, the lymph cleans the fluid and returns it to the blood. Chi stagnation is the root of illness, as is lymphatic stagnation.
According to the LymphaticResearch Foundation: "The well being of every individual depends on the health of the lymphatic system.... The lymphatic system plays an integral role in the immune functions of the body. It is the first line of defense against disease. This network of vessels and nodes transports and filters lymph fluid containing antibodies and lymphocytes (good) and bacteria (bad). The body's first contact with these invaders signals the lymphatics, calling upon this system to orchestrate the way the infection-fighting cells prevent illness and disease from invading microorganisms."
Transport of molecules too large to fit in blood capillaries (fat and protein) to the veins.
Immune function (lymphocytes produced in the bone marrow live inside lymphoid tissue (growing and changing), such as lymph nodes, the thymus, tonsils, Peyer's patches and various organs. The lymphocytes kill foreign invaders that pass through the lymph nodes and lymph fluid.
A. Equalization of Fluid Distribution Blood fluid pressure is higher then interstitial fluid pressure, therefore it leaks out through capillary pores into interstitial space if that fluid has higher pressure than the lymph, it will flow into the lymphatic capillaries, if not the lymph vessel flaps close preventing lymph back flow. Lymph fluid will rejoin the blood in the subclavian veins completing the cycle.
B. Transport of Proteins and Large Glycerides The small intestines have lymph capillaries called lacteals, fat gets absorbed there. Fat is transported in the lymph system to the subclavian veins, and then liver, because it is too large for capillaries. Fat and plasma proteins are transported via the lymph.
C. Return of Materials to the Blood Water, proteins, ions and fats are returned to the blood at the subclavian veins.
2. Composition of Lymph (Similarity to Blood Plasma; Substances Transported) The same as interstitial fluid to begin with, but picks up lymphocytes and proteins as it flows through lymph nodes. Transports metastatic cancer cells, returns protein and interstitial fluid to circulation, brings fat from the digestive system to the blood.
The name lymph came from the roman god of fresh water Lympha. Lymph is the same as blood plasma, but without plasma proteins, which are too large to go through the capillaries pores. No red blood cells or platelets either.
3. Source of Lymph (Diffusion from Capillaries by Differential Pressure) Blood plasma from capillaries leaks out (since there are fenestrations/openings), becoming lymph. The lower pressure of the lymph and higher pressure of the capillary drives the diffusion. The path is blood, to interstitial fluid, to lymph, back to blood.
4. Lymph Nodes (Activation of Lymphocytes) Lymph nodes contain lymphocytes that are activated when foreign antigens enter the lymph node, this causes proliferation (chemical release), antibody production and cytokine release.
Bone marrow pluripotent stem cells form either 1) myeloid precursors (end up as phagocytes, basophils or eosinophils) or 2) lymphoid precursors (end up as lymphocytes). The myeloid stem cells make red blood cells, megakaryocytes (form platelets), monocytes (become macrophages and dendritic cells) or polymorphonuclear leukocytes (eosinophils, basophils and neutrophils) and mast cells. While lymphoid stem cells, form T cells, B cells and natural killer cells.
T-lymphocytes (from the Thymus), cytotoxic T cells kill infected cells via apoptosis, and helper T cells signal for macrophages, T and B cells, both recognize antigens on infected cells.
B-lymphocytes (from the Bone Marrow) plasma cells (secrete antibody when exposed to antigen), and memory cells (waiting for the same antigen to attack again in the future).
Natural killer cells (increased count as a result of massage) kill cancer/abnormal cells.
Phagocytes (macrophages, dendritic cells and neutrophils) eat foreign invaders, clean debris and dead cells .
Macrophages and dendritic cellspresentantigens.
Eosinophils kill multicellular parasites.
Basophils fight ticks (and other ectoparasites) and help regulate T cells, as well as being involved with allergic inflammation.
Mast cells are also involved with allergies, they are the attacker in rheumatoid arthritis and multiple sclerosis, the benefit of mast cells is they activate the bodies immune response when under bacterial attack.
A. Macrophages, Neutrophils, Mast Cells, Natural Killer Cells, Dendritic Cells (Innate/Nonspecific Immunity) The mast cells cause inflammation and alert the body to attack, the neutrophils kill invaders, the macrophages and dendritic cells both kill and present antigens of invaders (for T and B lymphocytes to memorize).
B. T Lymphocytes (Specific Immunity) The T lymphocytes recognize antigens, cytotoxic T cells kill the invading cells via apoptosis, helper T cells call for back up by signaling for macrophages, T and B cells to come kill the invading cells.
C. B Lymphocytes, Plasma Cells (Specific Immunity) The B lymphocytes alert the immune system using antibodies. Plasma cells secrete antibodies when exposed to an antigen.
Day 16:
2. Tissues The main tissues associated with the immune system are the thymus tissues (T cell mature), the bone marrow (B cells mature), the lymph nodes and the spleen tissues.
A. Bone Marrow Blood cells are made in the bone marrow, B lymphocytes mature here (thus the name).
B. Spleen The spleen removes old red blood cells from circulation, also removes platelets allows white blood cells to hang out and grow. The fetal spleen makes blood cells. Removes bad stuff from the blood.
C. Thymus T cells mature in the thymus (thus the name).
D. Lymph Nodes White blood cells also hang out here (can't always hang out in the spleen). The lymph nodes are like blind canyons, trapping pathogens for the white blood cells to kill. When the white blood cells of the body notice antigens, they signal the immunological alert.
3. Basic Aspects of Innate Immunity and Inflammatory Response Innate immunity means non-specific immunity. The first time a pathogen enters the body it only has innate immunity and inflammation to kill the pathogen. The next time it knows the tricks, habits and appearance of the pathogen and the body will have specific immunity as well as innate immunity and inflammatory response.
Skin is part of innate immunity; the thick oily kerainized outer layer is like a rain jacket, the bacteria and friends (flora) that live on our skin keep other stuff from having room to live there.
Mucus membranes are part of innate immunity; the mucus traps pathogens physically preventing them from moving like a fly trap, cilia they "bounces" the pathogen out of the body.
White blood cells (the phagocytes anyways) are part of innate immunity; the swallow and kill pathogens, like snakes.
Natural killer cells are part of the innate immunity; I'm not going to explain what they do the pathogens...
Antimicrobial proteins: lyse (slice up) bacteria, interfere with virus replication, and complement (punch a hole in) pathogen membranes. In summary if attached by a bacteria, a virus and a fungus, the antimicrobial proteins slice up the bacteria, pierce the fungus and cock block the virus.
Fever and Inflammation are part of innate immunity; heat helps white blood cells function better, inflammation causes more white blood cells to go to the site of infection by sending out chemical signals and making capillaries more permeable.
Antigens and antibodies are used for specific immunity, also called adaptive immunity.
Antigen presenting cells kill invaders then display their antigen on their surface, like a warrior displaying a decapitated head on a spike.
Antigens are recognized by T and B cells. The cyctotoxic T cells see the antigen and go kill the invaders with that antigen.
Helper T cells call for help when they see an antigen. They call macrophages, cytotoxic T and B cells.
B cells produce antibodies, which not only make pathogens easier to find but also, kill pathogen by putting holes in their membranes (complement activation), making them easier to eat (opsonization) and making pathogens unable to sick to a host cell (neutralization) keeping them in circulation where white blood cells are hunting them.
5. Structure of Antibody Molecule Antibodies are Y shaped (contain two light chains and 2 heavy chains linked together by disulfide bonds, the tips of the fork (called the hypervariable region) bind to a specific antigen.
6. Mechanism of Stimulation by Antigen; Antigen Presentation The mechanism of stimulation by antigen varies based on if the pathogen is extracellular or intracellular. An extacellular pathogen will be eaten by a macrophage, pieces of it get displayed on the surface of the macrophage, helper T cells call the alarm when they see the pieces, allowing the macrophages to destroy the pathogen and B cells to make antibodies that can also destroy the pathogen. An intracellular pathogen invades a host cell, pieces of the pathogen end up on the cell membrane, cytotoxic T cells recognize the pieces (antigens) and cause the infected cell to self-destruct.
