Exam # 3 Study Guide Lectures: 19-26Lecture 19 (March 16)Homeostasis vs. EquilibriumWhat is the difference between homeostasis and equilibrium? What are negative feedback loops?Homeostasis is the tendency to keep processes (ex: in our body) at a maintained healthy state. Body temperature, blood pressure, and sodium content in bodily fluid in our bodies must maintain homeostasis. Although our bodies fluctuate levels, there are high and low limits our bodies ideally remain in. Energy must be put into a system if our systems are outside of the set point range. The set point is in between the high and low levels of the set point range (ex: 98.6 degree body temperature. Equilibrium differs between homeostasis because objects in equilibrium are in balance without the input of energy. Negative feedback loops are a means of maintaining homeostasis. It is not a synonym for homeostasis. They compensate for a loss in homeostasis. An example of a negative feedback loop is a thermostat. Rooms have a set point. When a stimulus occurs (ex: decrease in room temperature), the sensor (thermostat) will turn the heater on. The response is that heating starts, and the room temperature increases to reach the set point of the room temperature. Whatever set the change in motion, the negative feedback loop will spit out the reverse of the initial stimulus.Lecture 20 (March 18)Homeostatic Regulation of Blood PressureHow is blood pressure regulated?The sensor during the homeostatic regulation of blood pressure is the baroreceptor. It does not make a decision, it just reports a change. The integrating center is the vasomotor center, cardioacceleratory center, and cardioinhibitory center. Decisions are made here: if blood pressure is too high, it needs to be lowered. If blood pressure is too low, it must be increased. The response is an attempt to bring blood pressure into an ideal blood pressure range. Nerves transmit action potentials to send a signal. The vasomotor center will signal blood vessels to dilate or constrict to decrease and increase blood pressure, respectively. More action potentials will cause the constriction of blood vessels, less will cause them to dilate. More action potentials to the cardioinhibitory center will cause the heart to slow down, and less will cause it to speed up. More action potentials to the cardioacceleratory cener will cause the heart to speed up, and less will cause it to slow down. Both centers are active all the time.Lecture 22 (March 22)Review of Homeostasis (worksheet), Intro to ReproductionIn-class worksheet on homeostasis example. What are the basics of reproduction?BIOL 240W 1st EditionCara drinks a large amount of fluid, and as all of the water is absorbed into her blood stream, her bloodpressure begins to rise (stimulus). As a result, Baroreceptors (sensor) will stretch and then generatemore action potentials per second. These actions potentials travel to the integration centers.Baroreceptors are located in the chest (aorta) and neck (corroded artery). The vasomotor center(integration center) will generate fewer action potentials per second. This will cause the blood vessels(target) to dilate. The effect will be that blood pressure will decrease (response). The cardioinhibitorycenter (integration center) will generate more action potentials per second. This will cause the heart(target) rate to slow down. The effect will be that blood pressure will decrease (response). Thecardioacceleratory (integration center) center will generate fewer action potentials per second. This willcause the heart (target) rate to slow down. The effect will be that blood. pressure will decrease(response). Integration centers are located in the brain. This is a negative feedback loop.Sexual reproduction produces haploid gametes through meiosis; males undergo spermatogenesis andfemale undergo oogenesis. Gametes come together to form a haploid zygote. Reproduction occurs toincrease the total number of offspring over generations. Asexual reproduction occurs through fission(parent splits into two individuals), fragmentation (body is fragmented and regenerated from missingparts), budding (new, smaller individuals arise from existing ones), and parthenogenesis (an egg isdeveloped without fertilization). Asexual reproduction preserves genes and is beneficial in stableenvironments.Lecture 23 (March 25)Fertilization and the Human Reproductive SystemWhat are the fertilization strategies? What are the basics of the male reproductive system?Hermaphrodites can produce male and female gametes. It does not mean they possess both male and female genitalia. They can undergo self-fertilization or sexual reproduction. Sex reversal means organisms can change their gender. Hormones cause the development of reproductive parts of the opposite gender (ex: guppies). There is more than one way to make a zygote. An internal strategy occurs when the male deposits sperm in or near the reproductive tract. Fertilization takes place inside the female. Thisoffers protection from a hostile external environment. There must be cooperation between the male and female. In these cases, there are fewer gametes with a high chance of zygote survival. The zygote is protected from water loss by several membranes. Laid eggs are protected by shells, and zygotes possess placenta and the parent possesses mammary glands (milk). Humans utilize the internal strategy.The external strategy occurs when the male fertilizes the egg outside of the female’s body. Synchronous behavior occurs when the male is sensitive to chemical cues from the female and attempts to deposit sperm soon after eggs are available. Asynchronous behavior occurs when the male courts the female, resulting in the release of eggs from the female. Many gametes are produced in external fertilization, and zygotes have a lower survival rate. An example of an organism that undergoes external fertilization is a frog. Both processes involve pheromones.Males contain sperm cells that are made in the testes (gonads). Testes are held inside a sac called the scrotum. Mature sperm cells are transported to the epididymis. During ejaculation, the sperm cells travel through the vas deferens, pass near the seminal vesicle, enter the ejaculatory duct and then the urethra. Semen are composed of 10% sperm cells in salt water, 60%