| Whats the role of estrogen and progesterone in the female fetus, puberty, and the menstrual cycle? | Before birth: development of genitalia, puberty- female secondary sexual characteristics, menstrual cycle - change in lining of uterus |
| Functions of cholesterol? | Membrane fluidity regulation, synthesis of vitamin d and steroid hormones |
| Cómo es el diagram of a hepatocyte? | El cosillo de afuera es el portal VENUOLE, lo de adentro es el sinusoid |
| Whats the role of estrogen and progesterone in the female fetus, puberty, and the menstrual cycle? | Before birth: development of genitalia, puberty- female secondary sexual characteristics, menstrual cycle - change in lining of uterus |
| Distinguish between sinusoids and capillaries | Sinusoids have pores, kupffer cell, sinusoids have wider diameter. Although they both transport blood and are thin |
| Describe the direction of blood flow in the heart | deoxygenated blood enters the the right atrium through the inferior or superior vena cava. the tricuspid valve opens and blood flows into right ventricle. Then, the pulmonary semilunar valve opens and blood flows to the pulmonary artery to be oxygenated by the lungs. (everything is happening at the same time, in left and right sides of the heart ah). En el lado izquierdo, blood flows into the left atrium through the pulmonary vein. The mitral av valve opens and blood flows into left ventricle. Then the aortic semilunar valve opens and blood flows out to the rest of the body through the aorta |
| Where is the LUB and where is the DUB? | The lub is in the qrs wave when the sl valves open, and the dub is when the sl valves close |
| Explain what happens en un digram con ECG, ventricular volume, and ventricular/aortic/atrial pressure | (Applies for left and right side, bueno mas right side si se habla del aortic pressure) First P wave is due to atrial systole, there's an increase in atrial pressure as it pushes blood into the ventricles. there is isovolumetric contraction as av valves are closed which explains the straight line in ventricular volume after it increases. ventricular pressure also increases slightly here because blood is rushing inside them. then the SL valves open and blood is pushed out the ventricles. this increases aortic and ventricular pressure, as ventricular volume decreases. This ventricular systole also explains the QRS wave in the ecg. Next, cualquier cosa to explain the aortic pressure, el dicrotic notch causes a decrease in aortic pressure as the blood tries to go back into the ventricles REAL QUICK, causing the SL valve to close and blood going back up the aorta, which again causes an increase in aortic pressure. When the SL valve closes, ventricular volume increases again as the av valve opens instead; with blood passively filling the ventricles again. |
| How is the cardiac cycle controlled? | two nerves in the medulla of the brain stimulate the SA node, the natural pacemaker of the heart. Nerve impulses from the SA node go on to conducting fibers throughout the heart |
| Describe the role of arteries and their structure | They take away blood from the ventricles at high pressures to the rest of the body. They have a narrow lumen to resist high pressures, a rough outer coat to prevent bursting, a thick wall to withstand high pressures with elastic fibers to maintain the pressure and muscle to adjust the lumen |
| Describe the role of capillaries and their structure | Capillaries have permeable walls that take blood to body tissue. They have a thin wall for short diffusion distance, pores in between so plasma and phagocytes can leak out, and a narrow lumen so it can fit in small spaces |
| Describe the role of veins and their structure | Veins collect blood from the body at low pressure to take it to the atria. they have a wide lumen to accommodate the blood flowing in, they have a thin wall because theres no risk of bursting, and they have little to no muscle or elastic fibers in their walls; this allows them to be pressed flat by adjacent muscles so blood can move |
| Special characteristics of cardiac muscle cells? | They have myogenic contractions, theyre unbranched, and they have intercalated discs to perform electric conductions |
| Outline IVF | 1. Woman takes drug daily to stop secretion of FSH LH progesterone and estrogen, this way doctors can control the amount and time of egg production
2. superovulation takes place when FSH & LH are injected
3. eggs are retrieved and fused with thousands of sperm and left to incubate
4. The embryo is implanted into the mother's uterus and a progesterone tablet is given to her |
| Describe the menstrual cycle and its feedback control, as well as the role of the different hormones and steroids during the cycle | The uterus sheds its lining in menstruation. A peak in FSH, which promotes the development of a new follicle, is secreted from the pituitary gland develops the follicles which produce more estrogen. As estrogen increases, it makes follicles more receptive to FSH so estrogen also increases as a result (positive feedback). Estrogen at this point is in charge of repairing and preparing the uterine lining after menstruation. Then when it's peaking, estrogen causes an increase in LH but inhibits FSH, therefore leading to a decrease of estrogen (negative feedback). LH makes the corpus luteum, which secretes progesterone and estrogen, as well as completing the oocyte and digesting the wall of the follicle so it can burst in ovulation (osea, peak en LH causes ovulation). There is a peak in progesterone following ovulation to thicken the endometrium. Then the rise in progesterone and estrogen causes a decrease in LH & FSH (negative feedback because those hormones stimulates those steroids before). Then when estrogen and progesterone levels fall when no embryo is implanted, FSH rises again etc etc |
| which cells secrete insulin and glucagon? | beta pancreatic cells secrete insulin, and stimulate liver to turn glucose into glycogen, whereas alpha pancreatic cells secrete glucagon to do the opposite |
| What is the difference between Type I and Type II diabetes? | Type I is onset during childhood and cannot be changed with dietary changes, se tiene que inyectar insulin. it happens when the immune system kills beta cells. Then Type II is onset during adulthood and is treated with diet changes, happens because target cells become desensitized to insulin |
| How does leptin work? | It binds to leptin receptors in the hypothalamus to inhibit appetite and increases with body mass |
| What is thyroxin for? A deficiency of what hampers its synthesis? | regulating metabolic rate and temperature. deficiency of iodine |
| How does melatonin secretion work? | It is secreted through the pineal gland by the SCN. the SCN does this once the ganglion cells lets it know it's light or dark |
| What is a nerve impulse? | When an action potential travels through one end of an axon to the other |
| How can action potential be reached? | When the axon reached -50mV either through synapses or propagation of nerve impulses |
| From where to where can the dendrites transmit impulses? | brain to spinal chord |
| from where to where can the axon transmit nerve impulses? | toe to spinal chord |
| what is myelin? | it's layers of fatty sheath that form around the axon due to Schwann cells |
| What is saltatory conduction? | It's when nerve impulses jump between the nodes of Ranvier between the myelin sheath. This speeds of nerve impulses |
| how do synapses work? | the nerve impulse reaches the end of the axon. neurotransmitters leave the presynaptic cell through exocytosis and diffuse through the synaptic cleft. they bind to neurotransmitter receptors in the postsynaptic cell, which immediately allows sodium to diffuse in. This creates an action potential. The leftover neurotransmitters are broken down in the synaptic cleft and taken in by vesicles into presynaptic cell |
| What are cholinergic synapses? what does it have to do w insects? | they are synapses using acetylcholine as a transmitter. neonicotinoid pesticides bind to acetylcholine receptors, and cholinesterase cant break them down, so synapses in insects fails |
| What's the sequence of polarization? with mV values | when the axon is polarized it is at -70 mV. then it has to reach a threshold of around -50mV so a sodium channel can let sodium in to depolarize to +30mV. then to repolarize to < -70mV, a potassium channel lets potassium out. finally to hyper polarize, the refractive period occurs with the Na+K+ pump taking the axon back to resting potential at -70mV. |
| List the 3 lines of defense and how they protect the body | 1) Skin: contains sebaceous glands that skin too acidic for most pathogens to grow on it (by fatty and lactic acid)
mucous membrane: pathogens stick to mucous and taken away by cilia, or theyre killed by lysozyme enzyme
2)phagocytes: they break down pathogens through endocytosis using enzymes from lysosomes. non-specific immunity
3) lymphocytes: they make antibodies that bind to specific antigens on antibodies. once they bind, the lymphocyte is activated and it replicates to take down the pathogen. some remain as memory cells |
| how is fibrin made? | platelets or damaged cells release clotting factors, which catalyze prothrombin, which catalyzes thrombin, which catalyzes fibrinogen, which catalyzes fibrin |
| what is a spirometer for? | measuring tidal volume |
| what is emphysema? | when mucus accumulates in the lungs because and alveoli is broken down by protease , due to smoking or air pollution por ejemplo |
| outline the movement of muscles and thoracic volume/pressure and pulmonary pressure during inhalation | 1. external intercostal muscles contract to push ribcage up and out
2. diaphragm moves down
-thoracic volume increases and pressure falls below atmospheric pressure
-lungs take in air until their pressure matches atmospheric pressure |
| outline the movement of muscles and thoracic volume/pressure and pulmonary pressure during exhalation | 1. internal intercostal muscles contract for ribcage to go down and in
2. diaphragm moves up when abdominal muscles contract
-thoracic volume decreases, pressure rises above atmospheric pressure
-lungs keep exhaling until pressure in falls back to atmospheric pressure |
| What makes the alveolus fit for gas exchange? | It is permeable to o2 and co2 for gas exchange, it has a large surface area, it is moist for o2 to dissolve, and it has a thin wall for short diffusion distance |
| Talk about the three components of the alveolus and their purpose | Capillaries: have a low o2 and high co2 concentration, gas exchange occurs
type I pneumocyte: has a thin wall for short diffusion distance
type II pneumocyte: releases a surfactant to reduce surface tension in the alveolus; to prevent sides from sticking together. AND they keep the alveolus moist |
| With what enzyme are carbon compounds broken down in the small intestine? what are the products? | AA (endopeptidase)= shorter peptides
lipids (lipase) = fatty acids and glycerol
amylose (amylase) = maltose |
| What happens to undigested amylose and amylopectin in the small intestine? | maltose gets broken down by maltase, and dextrins by dextrine |
| whats the structure of the small intestine in order? | villi, mucosa, submucosa, longitudinal muscle, circular muscle. the two muscles contract so food can mix with enzymes |
| why is HDL good? | because it carries cholesterol from the body to the liver for removal, opposite of LDL |
| what is jaundice? | accumulation of bilirubin in plasma due to problems in the liver, gallbladder, or bile duct |
| What do epithelial cells parietal and chief cells secrete respectively? | Acid and pepsinogen (for hydrolysis of polypeptides) |
| What part does an artificial pacemaker stimulate? | the right ventricle |
| what is a defibrillator for? | Regulating the chaotic fibrillation of the ventricles |
| 5 functions of liver? | 1. detoxification of waste when it converts ammonia into urea
2. turning cholesterol to bile salts: speeds up digestion of lipids in small intestine
3. regulation and storage of nutrients: stores glucose as glycogen if needed, and converts glycogen into glucose if needed. stores vitamin a and d
4. breaking down erythrocytes: they INGEST THE RBC in phagocytosis and separate the heme (iron to make more RBC in bone marrow and bilirubin to be excreted in bile) and globin (protein/fatty acid) groups
5. production of plasma proteins: 90% of proteins in blood plasma are made by liver |
| what is vitamin c deficiency called? what is vitamin c needed for? | it's called scurvy, and vit c is needed to synthesize collagen fibers |
| what is vitamin d deficiency called and what does it cause? can vitamin d be synthesized? | osteomalacia and can cause rickets in children. it can be synthesized but only in UV light, so the liver stores it for winter |
| How does cholera happen? | The bacterium Vibrio cholera causes an infection. The toxin released by the bacteria binds to intestinal cells, where it is brought into the intestinal cells through endocytosis. The toxin then triggers the release of Cl- and HCO3- ions from the cell into the intestine. Therefore, water leaves the intestinal cells due to osmosis (they follow the region of higher solute concentration) and the cells become dehydrated. Due to excess water in the intestine there is watery diarrhea. To replace the water loss, water is drawn from the blood into the cells, but this can lead to serious dehydration of the individual and lead to death. |
| Why is cholesterol not the sole factor affecting CHD rates? | - genetic factos influence cholesterol levels
-positive correlation between saturated fat intake + cholesterol increases CHD
-liver also produced cholesterol |
| What is PKU? | Excess of phenylalanine, no enzyme to convert it to tyrosine |
| How are epithelial cells adapted for absorption? (and where are they found?) | (vili are the tiny projections that cover each fold of the ileum) Each epithelial cell covering the villus attached to surrounding cells to form tight junctions. This allows most materials to pass into the blood vessels that line the villi. The cell surface membrane on the intestinal lumen side has extensions called microvilli. The collection of microvilli on the intestinal side of the epithelial cells is called the brush border. The function of the brush border is to increase the surface area for absorption. Relatively high amounts of ATP are required to drive active transport processes. Thus epithelial cells have large numbers of mitochondria. Pinocytic vesicles are often present in large numbers due to absorption of some foods by endocytosis. The surface facing the lumen of the intestine is referred to as the apical surface and the surface facing the blood vessels is referred to as the basal surface. These surfaces have different types of proteins involved in material transport. |
| How is gastrin secreted? | The brain sends signals to endocrine system when food is in the stomach so that it secretes gastrin through the vagus nerve. gastrin secretes more acid and pepsinogen, but is kept in check by secretin and somatostatin |
| How does blood reach the liver? | hepatic portal vein takes deoxygenated blood away from hepatocytes, while the hepatic artery supplies it with oxygen rich blood. the vein and the artery divide into vessels called sinusoids which are in very close contact with the hepatocytes |
| Explain why it is important for nervous and hormonal mechanisms to control the secretion of digestive juices. | Two main reasons contribute to the significance of control secretion of digestive juices. The first is that, given the natural gaps between an animal’s meal and the next, gastric juices aren’t actively secreted all the time. Otherwise, it would not be possible to conserve energy between meals. Secondly, when an animal’s fight or flight response is activated, they need energy from the digestive process to invest in muscle use. |
| Describe the role of acid conditions in the process of digestion. | Acid conditions allow the denaturation of proteins, so that the amino acid chain can be exposed and hydrolyzed by pepsin. It also breaks apart the extracellular matrix that holds cells together in tissues. Moreover, acid conditions convert inactive pepsinogen secreted by chief cells into pepsin AND it helps to control pathogens in ingested blood |
| What are other reasons to include fiber in one's diet other than to prevent constipation? | Asides from preventing constipation, fibre can help prevent mupltiple diseases of the large intestine, such as bowel cancer, hemorrhoids, and appendicitis. Moreover, by increasing the bulk of material in the stomach and intestines, there is less desire to eat and therefore less risk of obesity. Absorption of sugars may also be slowed down, so risk of developing Type II diabetes is reduced |
| Describe the process of egestion of materials that are not absorbed and give two examples. | Cellulose and lignin are examples of dietary fiber that exists the body as feces. Dietary fiber, unabsorbed water and excretory products are released as feces. Water comes from the mouth/stomach/small intestine, and the excretory products could include bilirubin from the breakdown of red blood cells |
| How much energy to change temperature of water? | 4.2J of heat energy are needed to change temperature of water by 1 degree |
| How are exocrine secretory cells (acinus) structured? What do they do? | Extensive ER for enzyme synthesis, lots of mitochondria for protein synthesis, and secretory granules. They secrete digestive juices to food in the alimentary canal |
| What are the layers of the gastrointestinal tract? | Mucosa, submucosa, longitudinal and circular muscle, serosa |
| Describe how stomach acid secretion can be reduced by proton pump inhibitor drugs to treat heartburn due to “acid reflux”. | The corrosive acid of the stomach can sometimes irritate the esophagus when the circular muscle at the top of the stomach, which stops stomach fluid from doing this, malfunctions. This is called acid reflux and causes heartburn. The proton pump called H+, K+ -ATPase is the proton pump responsible for the acidic environment of the stomach. So to inhibit the protein pump, proton pump inhibitors or PPIs are prescribed. They bind to a single pump, so the effect on the entire acid production system is not permanent; given the pumps are constantly recycled and replaced. |
| Outline the function of the stomach in food digestion | Produces hydrochloric acid to denature proteins and break up cells (It also kills pathogens pero for digestion specifically),hydrochloric acid also activates pepsinogen to break down proteins. it CHURNS food for mechanical digestion |
| State a pathogenic bacterium that can cause stomach ulcers | H. pylori |
| Functions of bile? | It helps to break down fat into fatty acids |
| Sepa identify parts of the circulation within the liver (distinguish between central vein and venuole) | Kupffer cells tambien ahi metidos adentro, hepatocytes lining todo el sinusoid y la branch of hepatic artery un poco ahi |
| What happens to the nitrogen in the CHON of amino acids? | It is converted from ammonia into urea in the liver |
| How are triglycerides transported from the small intestine to hepatocytes | Triglycerides are transported in chylomicrons (biggest lipoprotein droplet or VLDL) |
| Explain the reason for dual blood supply to the liver | The hepatic artery carries oxygen rich blood to liver tissue, whereas hepatic portal vein carries nutrient rich deoxygenated blood from small intestine |
| Distinguish between sinusoids and capillaries | Sinusoids have pores, kupffer cell, sinusoids have wider diameter. Although they both transport blood and are thin |
| Cómo es el diagram of a hepatocyte? | El cosillo de afuera es el portal VENUOLE, lo de adentro es el sinusoid |
| Functions of cholesterol? | Membrane fluidity regulation, synthesis of vitamin d and steroid hormones |
| Where is bile made and stored? | Made in liver, stored in gallbladder |
| When do the different stages of the menstrual cycle take place? | 1) follicular phase termina en day 14 con ovulation, y luego empieza el luteal phase |
| Whats the role of estrogen and progesterone in the female fetus, puberty, and the menstrual cycle? | Before birth: development of genitalia, puberty- female secondary sexual characteristics, menstrual cycle - change in lining of uterus |
