Prelim 2_BIO
aldosterone
"salt-retaining hormone" which promotes the retention of Na+ by the kidneys. na+ retention promotes water retention, which promotes a higher blood volume and pressure. Partly responsible for urine concentration
Starling forces
- hydrostatic and oncotic pressures -balance of these forces maintains proper fluid volumes & solute concentrations inside & outside the vasculature -Imbalance of these pressures results in too little or too much fluid in tissues
How is Body Temperature regulated ? A mini problem 4-Regulation of body temperature in homeotherms 1-knowing that, propose a mechanism by which infection could affect body temperature 2-A common symptom of fever is to have chills. Explain when and why these occur. 3-Another common symptom is to have "sweats". Explain when and why these occur. 4-Explain what the consequence of a high-level spinal cord injury would be for a patient who develops an infection
1. An infection causes inflammation which alerts the hypothalamus to increase it's set point, which causes the body to heat. 2. To cool down the body vasoconstricts and uses muscles shivers to thermoregulate and decrease the body temperature. 3. If body heat increases the body will use another cooling mechanism such as sweating and vasodilation, which is a way to lose heat and reduce body temp. 4. Patient with an injury to the nervous system will lose the ability to thermoregulate. Partial poikilothermia: the inability to thermoregulate.
Why is ECF important?
1. Maintain cell structure: ions and hydrostatics pressure 2. Maintain cell function--enzymes and action potential. 3. Vehicle for nutrients. Fluctuation in concentration and volume can be dangerous.
Resistance
1/r4. The radius of blood vessels impacts the hemodynamics. If resistance increases, you need to increase pressure to maintain flow.
mammalian heart
4 chambers: 2 atria and 2 ventricles. Most efficient circulation. Blood flow: vena cava--> right atrium-->tricuspid valve-->right ventricle-->pulmonary valve-->pulmonary artery-->lungs-->pulmonary vein--> left atrium-->mitral valve-->left ventricle-->aortic valve-->aorta-->arterioles-->capillaries-->venules-->glomera
composition of urine
95% water and 5% solutes
Medical practitioners have observed that newborn babies (especially premature babies) could suffer from hypothermia (core body temperature <35 °C) immediately after birth, unless attendants institute appropriate actions hence the use of thermal blankets (similar to the survival blanket used in this investigation) in delivery rooms. Why are these blankets necessary? (Can a newborn baby utilize all the compensatory measures you described in question 2? If not, why not?)
A baby's skeletal muscles are not developed sufficiently to initiate shivering; it's store of white fat is limited so restricted in ability to insulate; newborn's skin is very thin so does not function effectively as an insulating agent; a baby could change it's posture but even at its most compact overall small size still gives it a large SA:V, meaning radiative heat loss is more rapidb. Newborns do have brown fat which generates some heat
Norepinephrine
A neurotransmitter involved in arousal, as well as in learning and mood regulation. from sympathetic nerves binds beta 1 receptor increases [Ca+2]i depolarizes cardiac myocyte => Mb potential closer to threshold
Swabbing subject's forearm with alcohol wipe (heat loss)
Alcohol boils at low temp, heat from body needed to cause vaporization of alcohol, this use/loss of heat registers as lower temp of the body at the point of measurement
Metabolism
All of the chemical reactions that occur within an organism that always promote heat gain. Depends on volume: gain heat by volume.
Evaporation
Always lose heat. When water changes from liquid to gas-called (vaporization heat). Results in cooling the body down. Depends on: 1. Volume of water vaporized 2. Ambient temp at which phase change takes place 3. Humidity of ambient temp. ex. perspiration or sweating Main way to prevent overheating and hyperthermia in organisms.
Countercurrent exchange
An adaptation that limits heat loss by conduction. The arteries and veins are next to each other. So the warm blood from the core is able to warm the colder blood coming back to the core from the extremities. You retain heat closer to the core. Extremities are very cold.
invertebrate
An animal without a backbone, low pressure open circulatory system, pumps are required to get material through narrow appendages. Most organ are submerged in hemolymph. They have narrow veins so lots of resistance, but pumps help get blood through.
What does ADH do to the collecting duct?
Antidiuretic hormone stimulates water reabsorbtion by stimulating insertion of "water channels" or aquaporins into the membranes of kidney tubules. These channels transport solute-free water through tubular cells and back into blood, leading to a decrease in plasma osmolarity and an increase osmolarity of urine
Can excrete uric acid without water why?
Because uric acid is less toxic and requires little water to excrete, but it uses a lot of energy.
cohesion-tension theory
Because water is polarized, water molecules gather together cohesively. When water molecules move out of through evaporation other water molecules will be attracted to the others. And the other water molecules will follow all the way to the root--which acts as a suction. If you put some tension on water or negative pressure. This pressure will bring water through cohesion. Transpiration brings the tension.
Homeotherm endotherm
Benefits: independent, foraging, can keep activity high. Cost: use a lot of energy, but cannot survive in extreme climates.
Distal tubule
Between the loop of Henle and the collecting duct; Selective reabsorption and secretion occur here, most notably to regulate reabsorption of water and sodium
Turtle heart
Blood flow: Right Atrium-> ventricule --> pulmonary trunk--> lungs--> pulmonary vein-->left atrium--left ventricle.
What determines blood flow>
Blood flows from high to low pressure. Potential energy produced by the heart + gravity.
rapid and reduced ejection
Blood is ejected rapidly at first -rapid ejection•Then more slowly under reduced pressure -reduced ejection
What happens to blood pressure and resistance as blood travels from the arteries to the veins?
Blood pressure is highest in the arteries and decreases as it moves through the capillaries into the veins. It is at it's lowest pressure then. The narrow diameters of the arterioles and capillaries dissipates much of the pressure.
veins
Blood vessels that carry blood back to the heart
Discuss how the heart and pattern of circulation observed in the turtle, squid, and Manducalarva are both similar to and different from those of mammals. Can you relate these differences to the lifestyle of these animals? (You can use Figure 6 as a reference when discussing blood flow through the mammalian heart and to the body.)
Both the turtle and squid have a closed system like mammals and a double circuit plan, although this is accomplished in different ways—the turtle having multiple chambers in its heart while the squid has 3 separate hearts. Unlike the mammal and squid, the turtle can alter the path of blood flow in different circumstances to maximize efficiency (e.g. bypassing the lungs when underwater). The system observed in Manduca is the most different as this is an open system, but there is still a heart to pump circulatory fluid throughout the body. There are other points students could bring up too—the goal is for them to generate a good discussion. Lifestyle—big idea is that there is not one solution to a problem that is the best in all circumstances...both an organism's evolutionary history and lifestyle play roles in the traits we observe in organisms living today. For example, ectotherms do not require as much oxygen as endotherms of equivalent size—having some mixing of oxygen rich and poor blood (as seen in the turtle due to the incomplete septum dividing the ventricle) does not have the same impact as it would in a mammal. Again, there are many points that can be brought up here, good discussion is the goal.
bundle branches
Branches off the Bundle of His that conduct impulses to the left and right ventricles
How do you control temperature?
By controlling the heat exchange. Ex. Fries and potato in the oven at 425 degrees. When you take them out--fries will cool faster than potato because it has more mass to hold in heat.
How to modulate or control body temperature?
By regulating metabolism, radiation, convection, conduction, and evaporation.
Which of the following is not true about heat exchange? A-evaporative cooling works better in the desert than in the tropics B-In countercurrent exchange, heat from warm blood warms returning cold blood to retain heat in the body core C-Metabolism of ectotherms doesn't generate heat D-an arctic whale has up to 50 cm of fat under the skin to insulate internal organs by decreasing conduction
C-Metabolism of ectotherms doesn't generate heat. Although ectotherms don't gain most of their heat through metabolism--they can generate some heat from metabolism.
Under frigid conditions and without the woolen cover describe how your body compensates to maintain a relatively steady body temperature? What are the metabolic requirements in such a situation?
Change posture to reduce surface area—this reduces radiative and convective heat loss; vasoconstriction of superficial vessels to reduce heat loss; involuntary shivering to generate more metabolic heat; CNS slows activity of sweat glands; possibly burning of brown fat; pilerection (hair on skin stand up—"goosebumps"—this decreases convective heat loss by increasing the boundary layer at the skin (our hair is quite sparse so this does not really increase insulation like it does in mammals with more significant hair/fur)b. Typical aerobic metabolism—shivering etc. requires energy but not so much that O2supply can't keep up
A circulatory system has
Circulatory fluid Interconnecting vessels or pipes A muscular pump (heart) It connects the fluids that surrounds cells with the organs that exchange gas, absorb nutrients or excrete waste. They can be open or closed
How to organisms bring nutrients and chemicals to all cells?
Circulatory system
AV node (atrioventricular node)
Conduction relay node between the atria and ventricles. Signal from the SA node travels through the AV node to the ventricles. Creates a delay between the atria and ventricles.
How to decrease surface loss?
Conduction: decrease Thermal conductivity: use fur or insulation strategy to diminish surface loss. Convection: decrease convection coefficient Radiation: decrease emissivity.
arterioles
Control the flow of blood into the capillaries. Main regulation of upstream blood pressure. Called resistance vessels because they can contract and regulate blood flow and pressure.
orthostatic hypotension
Decrease in blood pressure related to positional or postural changes from lying to sitting or standing positions. Change in position makes you a bit dizzy. You suddenly you change the height (gravity). Locally, you change potential energy of the head and you decrease blood pressure in the head.
Why don't diffuse work for larger organisms?
Diffusion is not efficient and cannot distribute molecules and nutrients in a timely fashion. Larger organisms use vascularization for bulk flow to move nutrients and molecules quickly and long distances.
Conduction
Direct transfer of kinetic energy between two objects. Must have physical touch. Energy can be gained or loss. Depends on: 1. The area of contact - how much contact (small or large). 2. Difference in T1 and T2 of both surfaces 3. Thermal conductivity-- how well the surfaces conduct heat. Ex. Heat yourself by hot water bottle that will warm you up. (a way to gain heat). Lizard in the desert that lift feet and tail to limit contact to limit heat exchange and getting excess body temperature.
Doe mentions more frequent urination (polyuria). This strengthens your conclusion that Mr. Doe does indeed suffer from chronic hypertension. Why does this particular symptom help reinforce your diagnosis? Discuss this in light of your understanding of kidney function, as well as hormones involved. Another condition that causes patients to present with polyuria, is uncontrolled diabetes mellitus. Explain what diabetes mellitus is, and how it could lead to increased urination. After checking Mr. Doe's sugar blood levels you find they are normal indicating he does not have diabetes mellitus.
Does it reinforce your diagnosis? Yes, it does. This is basically the same logic that before for swelling. Except this time, the increased hydrostatic pressure occurs in the nephron, especially in Bowman's capsule. This in turn increases primary urine filtration. If this is chronic, the excessive urine formation cannot be compensated by kidney reabsorption and this in turn will increase diuresis. Here this should be an opportunity to discuss hydrostatic pressure and Bowman's capsule.
Behavioral adaptation for ectotherms
Don't thermoregulate, but can still modulate temperature through behavior. Such as physical activity to warm up. Ex. Winter. Or Mosquitos feeding on an animal --blood is warm. Cools off by peeing (evaporative cooling).
Amphibian circulation
Double circulation; two atria and 1 ventricule. Two circuits: 1 to the lung ( to be oxygenated). Other circuit to distribute to the oxygenated blood to the body. Because of 1 ventricle --you send mixed blood. Closed circulatory system.
At the end of marathons, survival blankets like those used in comparison 3 are handed out to finishers. Consider what you have learned in lecture about body temperature and its regulation as well as how these blankets influence heat exchange between the body and the environment. Explain what is happening to a runner's body temperature during a race and what thermoregulatory mechanisms are employed. What changes at the end of the race when the athletestops running and how does this influence body temperature? Why is the survival blanket necessary/how does it help the athlet
During the marathon rates of cellular respiration (ATP-->glucose) and muscle contraction are higher than at rest. Both of these contribute to metabolic heat. This means that during the race, As temp raises above set point the hypothalamus activates cooling mechanisms—sweat glands produce sweat, blood vessels in skin dilate. Your body temp is higher than at rest, but not critically high. b. When you stop racing Hmetabolism decreases—lower rates of respiration and muscle contraction, meaning that body temperature starts to decrease. However, your skin/clothes are likely still wet from sweat meaning you are still losing heat from evaporation (conductive losses also sped up due to higher conductivity of wet vs. dry clothes) further contributing to decreasing body temp. c. Unless the air temp is very warm these factors can cause your body temp to drop too much. As seen in section the survival blanket limits radiative heat loss and therefore helps runners' body temps from dropping too low.
Which of the following would NOT help a homeothermic endotherm, such as a deer, to maintain Tbody as the Tambient decreases without increasing its metabolism ? A. Decrease conductance B. Puff up its fur C. Evaporate sweat D. Curl up into a ball E. Get out of the wind
Evaporate sweat--only increases heat loss.
What causes tension that brings water from root to shoot in Xylem sap?
Evaporation from the leaf through the stromata will pull water from the root. It sucks sap
transpiration
Evaporation of water from the leaves of a plant, makes the water film retreat, high surface of the microfibrils creates tension with water. That tension pulls on xylem sap and pulls it from root to shoot.
Radiation
Exchange of energy through infrared magnetic waves or particles. We can receive or emit radioactive waves as a way of exchanging heat. This depends on: 1. surface area-bigger area can radiate more than smaller. 2. difference in the two surface temperatures (T1-T2) 3. The color of emissivity- different colors will emit more radiation.
How do organisms excrete waste?
Excretory system: kidney
Excretion
Filtration-reabsorption+secretion
valves
Flaps of tissue that open and close to allow the flow of blood in one direction only. The heart's valves are located at the entrances and exits of its chambers.
net filtration pressure
Glomerular hydrostatic-osmostic-bowman's pressure
Fight or flight
Heart rate can be sped up(parasympathetic neural input - acetylcholine)(sympathetic neural input - noradrenaline, norepinephrine)
Heart beat
Hearts of most creatures beat myogenically (muscle generates the rhythm). Rhythm is controlled by the autonomous nervous system
How do homeotherms gain heat?
Heat gain: Basal metabolic rate: most of heat gain Exercise: Shivering: muscles suddenly contract, they use energy and add to the heat. Non-shivering thermogenesis (Brown fat adipose tissue): Heat loss: (can do the opposite to gain heat) Sweat glands for evaporative cooling Radiation: by opening and closing capillaries under the skin surface. Opening capillaries increases radition Arrange hairs at an upright angle.
Finally, discuss how Bumetanide's mode of action can lead to a restoration of normal blood pressure.
Here, the idea is simple too. More diuresis, means more water loss. This could be related to the notion of dehydration, except here you eliminate surplus of water rather than loosing physiological levels. As water from interstitial tissues is connected to the blood, Mr. Doe will also eliminate water retention in interstitial tissues. As a result, the blood volume of Mr Doe will decrease, and the accumulation of extracellular fluids will decrease too. That results in a decrease in blood volume and peripheral resistance, and thus blood pressure.
What happens in the capillaries?
High cross-sectional area-velocity is low. Hydrostatic pressure is low--allows for ion, gases and nutrients to diffuse freely. Fluids can be exchanged by Starling forces.
Hypothermia and hyperthermia regulation
Hmetabolism increases leading to an increase in body temp. Evaporative cooling Body in Homeostasis at set point Hyperthermia Hypothalamus START HERE: Sweat glands activated Vasodilation of capillaries Core temp reduced Imbalance is noted (blood flow)HEAT Messages sent to skin Radiation Negative Feedback Hypothermia Hypothalamus Reduced Radiation STARTHERE Shivering HEATLOSS Vasoconstriction of capillaries Messages sent to skin Core temp raised Negative Feedback Imbalance noted (blood flow)Body in homeostasis at set point
Quotient 10
How we quantify the enzymatic function to the temperature. Describes the sensitivity of an enzyme to the temp. Look at the rate of action of your enzyme at a given temperature and if its
fluid exchange in capillaries
Hydrostatic pressure forces fluid out at arteriole end, but at venule end osmotic pressure forces fluid in
A disease called Kwashiorkor that often affects undernourished children in Africa is due to lack of sufficient protein in the diet. A major symptom is a swollen belly. Given what you know about the two important pressures in the capillary bed and their causes (be sure to name them), how might protein deficiency account for this symptom?
Hydrostatic pressure from (heart beat or vascular recoil) drives plasma and nutrient solutes from the capillaries into the interstitial space at the arterial end of the capillary bed. Waste solutes and plasma are pulled back into the capillaries at the venous end by oncotic pressure due to large proteins in the blood, primarily albumin. If the child has a deficiency of blood proteins, less plasma will be returned to the capillaries and will remain in the interstitial space to create swelling.
Thermogenin
In BAT--a protein that uncouples the electron transport chain in oxidative phosphorylation so the mitochondria produces heat not ATP
When subjected to hyperthermic conditions explain how the principles of Convection and Conduction could be employed to regain a core temperature set point between 36.5 and 37.5°C.
In hyperthermic conditions, the body has excess heat to get rid of. Conduction can be used to lose heat, e.g. with an ice pack or soaking in cool water (but convection comes in here as well). Convective heat loss can come from sitting in a cool stream or under a cold shower. Convective heat loss can also come from fanning oneself if the air temperature is less than Tb. If the air temperature is great that Tb, there could still be some evaporative cooling associated with fanning, but there would be no convective cooling.
How to modulate radiation by skin?
Increase blood flow to the surface. You vasodilation--open capillaries under the skin. Increase heat exchange by bringing warm blood to the skin. Vasoconstrict--prevent blood from reaching the skin. Decrease blood flow to surface and heat loss by radiation and keep heat in the core.
T1 (Q10)
Is the temperature of the reaction rate at which R1 is measured. (T1 < T2)
T2 (Q10)
Is the temperature of the reaction rate at which R2 is measured (T2 > T1)
In 2018, the Boston Marathon was run in pretty extreme conditions—temperatures ranging between 38-46 oF, head winds of 5-10mph with gusts over 25mph, and a persistent heavy rain. According to reports in the Boston Globe and the Boston Athletic Association's website, of entrants who actually started the race, 95.8% of them finished the race with 10.3% of runners needing medical treatment throughout the course. Looking at just the elite field, 45% finished the race with 54.4% needing medical treatment throughout the course. Given what you have learned about thermoregulation in both lecture and section, is it reasonable to suggest that thermoregulation contributed to this difference between elite runners and the rest of the field? If so, explain. (Note, the average BMI for elite male marathoners was 19.42 in 2011 as reported in a study in the Journal of Sports Sciences.)
It is safe to assume that the BMI of your average elite marathoner is lower than that of your average recreational/amateur runner. This means the SA:Vol of the elite runners is greater than that of the amateur runners and therefore they dissipate heat at a faster rate (metabolic heat generated by volume, heat lost across body surface.) While this is always true, under these weather conditions of both cold and wet, it could be that the elite runners were more prone to hypothermia as they lost heat more quickly and metabolic heat could not keep up with this loss (despite the heat generated by metabolism and muscle contraction.). It is possible this contributed to the % finishing stats this year, although likely a number of factors were at play.
If the pressure in the veins is low how does blood move from the veins?
It requires valve to prevent blood back flow and muscle pumps (such as breathing) to move the blood back to the heart.
How does the heart produce pressure?
Left ventricle contracting. Two pressures: systole (bigger number) and diastole (smaller number).
Phloem
Living vascular tissue that carries sugar and organic substances (food)throughout a plant. Movement is bi-directional. From source to sink.
Insulation strategy
Manipulating thermal conductivity by increasing the distance from the cold environment and the organs. ex. Sea lion.
Kleibar's law
Metabolic rate is grossly proportional to body mass. Smaller animals use more energy per kg of tissue because they lose more heat due to high surface areas. They have a higher metabolic rate, O2 delivery rate, heart rate, and blood volume. Bigger animals consume less energy because they lose less heat per kg of tissue due to less surface area.
Collecting duct
Most osmoregulation occurs here. It is in the same concentrated gradient as loop of henle, but is regulated by a hormone. Most responsible of concentrated urine does this by a hormone--vasopressin or adh that promotes water reabsorption.
Fick's law
Net diffusion flux goes from a high to a low concentrated area that is proportional to the concentration gradient. The further away you are from the source, the concentration decreases. Thus, the slope is flatter. Bigger the slope closer to the source= higher flux. Equation: J = -D [change in C] / [change in X] J= flux C= concentration X= distance
brown adipose tissue
Non-shivering thermogenesis. UCP-1: create heat withought shivering. UCP- goes into the mitochondria and acts as an uncoupler by dissipating atp prodution and the proton gradient which produces heat. Brown adipose tissue are filled with mitochondria--ATP generated. When proton gradient goes through UCP, energy is released as heat and not ATP. It increases fatty acid oxidation to compensate for respiration inefficiency. (In the head of babies--because they're small and at risk for losing heat. Some remaining in adults around spine and clavicle.)
Animal vascular system
Only uses positive pressure. They use a pump.
Why don't plant have pumps?
Plants have very low energy demands
Q10 formula
Q10 = R1t + 10 degrees/R2t
flow rate formula
Q= delta P/ Resistance. flow rate is how much liquid goes through the pipes.
R1 (Q10)
R1 is the measured reaction rate at T1 (T1 < T2)
R2 (Q10)
R2 is the measured reaction rate at T2 (T2 > T1)
vasodilation
Relaxation of the smooth muscles of the arteriole blood vessels, producing dilation. Caused by O2, high Co2, heat. Thermoregulate: to cool off or lose heat.
How do organisms exchange gas
Respiratory system
Kidney
Responsible for excretion. Takes in blood (filtrate), reclaims valuable solutes, reabsorb water, secrete and eliminates urea by limiting the loss of ions and water.
Repolarization
Return of the cell to resting state, caused by reentry of K+ into the cell while sodium exits the cell. Diastole.
Electrical transmission of the heart
SA node-->AV node-->bundle branches and then contraction of ventricles.
Problem: increase in osmolarity or hypernatremic
Sensor: osmoreceptor in hypothalamus hypertonic dehydration-high electrolytes. Problem for cells, shrinkage... True dehydration leads to intracellular thirst Response: hypothalamus thirst center triggers thirst.
Wrapping subject's upper body with a survival blanket (heat loss)
Similar to woolen material, but more efficient—better at reducing radiative heat loss and reducing convective loss
Fish circulation
Single circulation; atrium to ventricle to gills (oxygenated) to body then back to atrium. Lots of work for the ventricule-size limit on what type of organism can use this system. Closed circulatory system.
Microcirculation
Small blood vessels, including arterioles, capillaries, and venules
Open circulatory system
Such as in insects--all cells and organs have access to hemolymph.
surface to volume ratio
Surface area per unit of volume ( SA:V or SA/V ). SA is squared. V is cubed. Organisms gain heat by volume due to metabolism and lose heat by surface area. A bigger organism will have more volume, but less surface area, which means they will lose heat less. A smaller organism will have more surface area, but less volume--which means they will lose heat easier.
Systole vs. diastole
Systolic pressure is the pressure exerted when the ventricle contracts. Diastolic pressure is only the recoil of arteries vs the actual heart pressurizing blood.
Heat Exchange equation
Tbody = Tambient + Hmetabolism +/- Hradiation +/- Hconvection +/- Hconduction - Evaporation
How do the valves keep blood flowing monodirectionally during relaxation?
The atrial valves open and the pulmonary/aortic valves close under vascular pressure. This prevents backflow from the arteries into the ventricles.
Find the four valves in the heart again. How do the valves between the chambers differ from those between the ventricles and the aorta and pulmonary artery? Discuss how each functions.
The atrioventricular (AV) valves are located between each atrium and ventricle (tricuspid between the right atrium & ventricle, bicuspid between the left atrium & ventricle) and are anchored by strong fibers—visible in the dissection. The semilunar valves are located at the exits of the heart—where the aorta leaves the left ventricle & where the pulmonary artery leaves the right ventricle, and don't have the same anchoring fibers. Contraction of the ventricles causes the AV valves to close (preventing backflow into the atria) while causing the semilunar valves to open; the semilunar valves are closed while ventricles are relaxed preventing significant backflow.
vasoconstriction
The contraction of arterial smooth muscle. Caused by low O2, CO2, cold, vasopressin. Thermoregulate: to keep warm.
You ask Mr. Doe to regularly monitor his blood pressure and finally conclude that he suffers from chronic hypertension. You decide to treat Mr. Doe with Bumetanide which is a class of drug called a loop diuretic. The mode of action of Bumetanide is to inhibit Na+ pumps that act in the ascending loop of the nephron in the kidney. How might this help restore normal blood pressure in Mr. Doe?
The gradient of salt is vertical and that is key to reabsorb water. The trick is to understand that urine does a U turn and therefore faces first an ascending gradient, then a descending gradient of salt. That + the impermeability to water in the ascending loop allows water reabsorption. How is the gradient established? => Countercurrent multiplication: the vertical gradient is created and maintained continuously by the combination of urine flow and salt reabsorption in the ascending loop. One important thing to understand is therefore that salt reabsorption is important for reabsorbing salt (yes, it's deep, I know...) but ALSO to create the gradient of Salt that allows the loop of Henle to reabsorb water.
how do molecules move without circulation?
The move by diffusion, but slowly and only efficient in short distances. Size and circulation matter. Smaller cells can use diffusion to move molecules. An elephant will need a circulatory system.
oncotic pressure
The osmotic pressure in the blood vessels due only to plasma proteins (primarily albumin) --> causes water to rush back into capillaries at end. Pressure increases as progresses through capillaries.
sinoatrial node
The pacemaker of the heart, located in the right atrium.
depolarization
The process during the action potential when sodium is rushing into the cell causing the interior to become more positive. Contraction during systole.
convective heat transfer coefficient
The rate of heat transfer between a solid surface and a fluid per unit surface area per unit temperature difference.
Heat
The total energy that a substance possesses by virtual of the sum of random motion of it's atoms and molecules.
Convection
The transfer of heat by mass flow of liquid, air. It will remove or bring heat to contact. You can gain or lose heat, but convection is generally a way to lose heat and results in cooling aka Convective Cooling Depends on area: 1. Area 2. Difference of temperature (t1 (ambient) and t2). 3. Rate of flow ex. Using a fan to cool down Taking a shower
nephron
The tubular excretory unit of the vertebrate kidney.
podocytes
These cells form a porous membrane surrounding the endothelial cells of the glomerulus. Only allows ions and water into bowman's capsule.
Explain why it is important for arteries to have greater elasticity than veins.
This is because the blood in the arteries is passing through with a higher pressure than in veins. The thick, elastic walls of arteries accommodate that pressure
The open circulatory system observed in the Manduca is inefficient at moving materials around the body. How then is this system still able to work for this organism (and other insects)?
This system is very inefficient in moving nutrients around the body. However, gas exchange is mediated by a separate system of spiracles and tracheae, and blood sugar levels are much higher than in mammals. Finally, insects are relatively small. When they move, the incompressible (it's aqueous) blood is squeezed and sloshed to different parts inside the body as muscle groups contract. Thus, tissues get the nutrients they need and the system works, albeit inefficiently, to solve the problem common to all large metazoans.
How does pressure work in the Phloem system?
Translocation is done by companion cells that are able to take stored sugar and load it into phloem. Sugar is built in the leaf and transported and loaded (this is an active process) in phloem. Because you increase concentration of sugar, water will diffuse by osmosis to higher concentration-inside of the phloem. Then you have an uptake of water. You increase pressure around the source. Once you unload the sugar, water will flow out of phloem. The pressure gradient generates bulk flow.
plant vascular system
Two types of vascular transportation system: phloem and xylem. Use both negative and positive pressure to generate movement in the pipes.
Pouseuille's Law
Velocity depends on this law. Flux is proportional to the the delta in pressure (from high to low pressure) and other parameters, [ radius of pipe, viscosity of liquid length of the pipes]. The other parameters are the inverse of resistance. Q= delta P/ Resistance
Define the conditions under which Evaporative Cooling will be the major mechanism used to maintain homeostasis in core body temperature.
When Ta is hotter than the Tb set point and relative humidity of the air is dry, evaporative cooling will be very effective at bringing Tb back down to the set point
what opens the NA+ voltage gate?
When a neighboring cell depolarizes it opens the voltage gate eventually it reaches a threshold and K+ voltage gate opens and the cell repolarizes.
How do the valves keep blood flowing monodirectionally during ventricular contraction?
When the ventricle contracts, the atria valves close under pressure, which prevents back flow from ventricles into the atria and the aortic/pulmonary valves open.
vessel elements
Wide, short tubes that, along with tracheoids, make up the xylem. They have perforated plates at the end. Only found in angiosperms. They transport water fast and require constant tension to maintain water cohesion.
Will temp increase or decrease with: Wrapping subject's forearm with woolen material
Woolen material provides insulation, temporarily prevents several mechanisms of heat exchange: no forced or free convective heat loss, reduced radiative heat loss. There is some conductive heat loss (material touching skin), but wool has low thermal conductivity, only inner surface gains heat and quickly equilibrates w/ skin
During the screen, you notice that Mr. Doe has swollen ankles and legs (suggesting there is edema).Do you think this is an argument for or against hypertension? Using your knowledge of microcapillaries and fluid movements, explain what will happen to fluid exchange when blood pressure varies, and how that can explain the swelling you observed.
Yes, this is an argument for hypertension. If Mr. Doe has high blood pressure, that means he has increased hydrostatic pressure in all capillary systems. Fluid exits capillaries due to hydrostatic pressure and is reabsorbed due to constant oncotic pressure. It could be a good idea to reexplain that oncotic pressure is just osmotic pressure, when osmosis is dominated by circulating proteins as a main driver. Due to increased blood pressure, fluid is pushed out of the capillary sector and accumulates in interstitial fluids. With time, Mr. Doe starts to accumulate more fluid in this extracellular compartment, which translates into swelling. This is called edema.
how do animals thermoregulate?
You need to limit heat loss and most of heat loss is due to surface area.
If you have sepsis or anaphylactic shock what will happen?
You will faint. all Arterioles vasodilates, blood pressure goes down and you can't bring blood to all the tissues and you have shock and you faint, resistance is down. Blood is suddenly going all places in all tissues and you lose the pressure.
salty food can lead to elevated tension and maybe hypertension
Your plasma will have high osmotic pressureyou will be dehydratedand therefore drink more water (thus increasing plasma volume in ECF)kidney will decrease its function to retain water (thus increasing plasma volume) The heart will try to compensate for the decrease in blood volume and pressure to maintain cardiac output by vasoconstricting blood vessels, increasing resistance and Possible increase in blood pressure => could aggravate hypertension!
Circulation
a liquid that carries molecules and nutrients. Blood for animals. Insects use hemolymph. Plants use sap.
temperature coefficient (Q10)
a measure of how much the rate of a reaction increases with a 10 °C temperature increase.
sympathetic nervous system
a set of nerves that prepares the body for action in challenging or threatening situations
Consider the different thermoregulatory adaptations discussed in lecture. Which of these is comparison 4 (alcohol wipe) best modeling? Explain how this adaptation contributes to thermoregulation, the mechanism(s) of heat exchange involved, and how it is modeled by the alcohol wipe. Can you provide an example of such an adaptation in both an endotherm and an ectotherm?
a. Evaporative cooling (evaporation)b. Phase change from liquid-->gas requires energy (heat of vaporization). This energy is removed from the object it is leaving. This mechanism is used to cool the body down when the body temp rises too high above the set point. c. When the alcohol evaporates from your arm, it is absorbing the heat required for the phase change from your skin, thus resulting in a cooler temperature. d. Mammals (endotherms) sweat. Desert cicadas (ectotherms) have sweat pores through which excess sap (food) from plants is exuded. Mosquito (ectotherm) retains fluid drop by abdomen while feeding (blood meal).
Flux (aka flow rate)
amount of liquid flowing through the pipe.
Ectotherm
an animal whose body temperature varies with the temperature of its surroundings. They do not thermoregulate.
Phloem sap
an aqueous solution that is high in sucrose; travels from a sugar source (from the leaves) to a sugar sink (any cell in the plant that needs to consume sugar). Can be bi-directional because cells all over will need sugar.
sugar sink
an organ that is a net consumer or storer of sugar.
Sugar source
an organ that is a net producer of sugar, such as mature leaves
ADH
antidiuretic hormone (vasopressin) that promotes more concentrated urine. Promotes retaining water.
capillaries
any of the fine branching blood vessels that form a network between the arterioles and venules.
heterotherms
are endotherms that choose when to thermoregulate. Ex. bats who do not thermoregulate while sleeping, but thermoregulate when they're active.
16% of blood is in the
arteries. It is also where the pressure is. That's where the blood is sent to perfuse all tissues.
Arterioles and Venules
arterioles are the smallest artery in the body the artery divides into arterioles before the capillaries. venules are the smallest veins in the body.
Bernouli's Principle
as the velocity of a fluid increases, the pressure exerted by the fluid decreases. Total energy is the sum of Potential energy of pressure + Kinetic energy (trivial) + gravity.
P wave
atrial depolarization
pacemaker cells
autorhythmic cells. are modified muscle cells that act more like neurons and can initiate the cardiac cycle.
Excretion requires a tubular shape
because it is a progressive refining filtrate produces urine.
laminar flow
blood flows in parallel layers through a vessel and the flow of the blood will differ at the center than at the periphery. There is more friction at the periphery. the closer you get to the center the less friction you have and the higher the speed.
Quiescent period:
blood flows in ventricles(ventricular diastole)
capillary arborization
branching of capillaries--velocity will decrease.
arteries
bring blood away from the heart
What does the transpiration do for the trees?
brings minerals and nutrients to all parts of the tree and helps to cool down the trees.
Vascular system
bulk flow. 1. Circulation 2. Pipes- moves liquid through these and the movement is due to pressure gradient. Pressure must be high at one end and low at the other end and the liquid will move from high pressure to low pressure and the liquid will move much faster than diffusion. 3. Requires a plumbing system and source of pressure
cardiomyocytes
cardiac muscle cells. Connected by porous junctures. Action potential in 1 cell generate action potential in neighboring cells. Spreads throughout heart.
vascular tone of arterioles
controls how much blood can reach a specific tissue and determines blood pressure. the degree of contraction-changes the perfusion (how much blood can reach a specific tissue) of tissue. Increase vascular tone, decrease radius, increase resistance, increase pressure in upstream.
Dipole
created by equal but opposite charges that are separated by a short distance
action potential
depolarization followed by repolarization. One cell stimulates the next cell.
how to calculate a mean arterial pressure:
diastole pressure +1/3 of pulse pressure.
pulse pressure
difference between systolic and diastolic pressure 120/70 = 50 pulse pressure.
regional heterothermy
different parts of the body have different temperatures. It allows them to keep the core temp more stable. Ex. polar bear that has cold feet.
Hormonal regulation in the kidney is done
distal tubule and collecting duct will modulate by physiological status. Depending on state of dehydration, you will modulate the activity of distal tubule and collecting duct, therefore regulate volume and concentration of ECF.
systemic capillaries
distributes gases and nutrients in the body
Reptile circulatory system
double circulation; very similar to amphibians except for crocodilians and except they have some separation between the circuits so the blood doesn't mix. Closed circulatory system.
tracheids
elongated cells in the xylem of vascular plants that serve in the transport of water and mineral salts. They evolve from one cell and are found in all plants. Do not have perforated plates. The cells are dead (without a nucleus) are thin and hollow and allow for the transport of water & minerals. They have a primary wall (cellulose) and a secondary wall (lignin). Have a high surface to volume area due to the pits and can hold water against gravity by adhesion during transport unlike vessel elements.
Fish in salt water
faces dessication, water loss by osmosis, actively secrete NACI, high osmolarity environment, secrete a small amount of water, concentrated urine.
bowman's capsule
filtrate is generated from blood.
Velocity
flow/cross-sectional area. Q/cross-sectional area. It's the speed.
Atrial systole
forces more blood in ventricles.(still ventricular diastole)
sieve tube elements
found in phloem; stacked end to end; have holes so materials can get in and out of the phloem. Living cells that have no nucleus at maturity
Acetylcholine
from vagus nerve allows K+ to flow out,hyperpolarizes cardiac myocyte => leak takes longer to reach threshold. (parasympathetic)
Systemic circuit
goes throughout the body and back to distribute the O2to all organs of the body, as well as remove wastes.
cardiac output
heart rate x stroke volume
What determines blood flow through the heart?
hemodynamics.
hypertension
high blood pressure. Over 120/80
vertebrates
high pressure closed system.
How is body temperature regulated?
hypothalamus Body temp increases--activate cooling mechanisms: sweating and vasodilation to increase radiation. If you increase evaporation, you increase radiation. Body goes back to set point. Body temp decreases--sensed by hypothalamus triggers heating feedback loop (shivering-metabolic heat, vasoconstriction--diminish radiation).
thick ascending limb
impermeable to water, active Na+K+ transport
Athropod circulatory system
in multicellular animals some kind of pump is central to the transport of nutrients and oxygen, as well as the removal of wastes. In some relatively small multicellular animals, such as arthropods, nutrients and wastes simply slosh around in a low pressure, open body cavity, and pumps are used primarily to move material through narrow appendages because their resistance to flow is too great for the low-pressure system. The system arthropods use works, but it is inefficient and may be one evolutionary constraint that keeps them from getting really big.
edema
increased hydrostatic pressure causes edema because it increases fluid in the interstitial space.
diuresis
increased output or excretion of diluted urine. Water reabsorption.
Next, discuss how a Na+ transporter inhibitor will affect the function of the nephron, and discuss the impact of Bumetanide on diuresis.
inhibiting Na+ reabsorption will decrease Na+ gradients, and therefore allow less water to be reabsorbed. The key concept here is that to increase diuresis, you decrease salt reabsorption, showing how both are linked.
hypothalamus
internal set point or temperature that it monitors. When the body temp is lower or higher than the set point will trigger a feed back loop to maintain homeostasis.
systole
left ventricle contracting and expulsing blood with high pressure into the aorta. The semi-lunar valve opens. Aorta stores pressure and expands.
Isotonic dehydration or hypovolemia
loss of fluid without changing ECF concentration. Decrease in blood volume. Decrease in volume triggers high blood pressure. Sensor: baroreceptorProblem for organ systems, low pressure...Hypovolemia leads to extracellular thirst
Fish in Fresh water
low osmalarity, actively pump in salt, water gain by osmosis, salt loss by diffusion, dilute urine.
urea
major nitrogenous waste excreted in urine. Lose some water to eliminate the waste. Water loss from ECF.
companion cells
make up phloem vessels, along with sieve tube elements that transport sugar.
Temperature
measure of speed of the random motions of the atoms or molecules
Closed circuit
net flow of blood will be constant, but velocity can vary.
Protein and nucleic acids create what type of waste
nitrogenious waste: ammonia, urea, uric acid -->toxicity decreases. Ammonia is most toxic.
Squid circulatory
no chambered heart. Closed system. branchial heart-->regulating circulation between the gills and heart. Branchial hearts R&L--> systemic heart-->gills to be oxygenated No mixing of oxygenated blood with deoxgygenated blood. inveterbrate.
Rest of heart
parasympathetic neural input - acetylcholine)(norepinephrine)the heart rate can be slowed down or digest
ascending limb
permeable to NaCl, not water (wall is thicker) salt diffuses out.
descending limb
permeable to water but not solutes
arteriole smooth muscles
pre-capillary sphincters surround arterioles they are able to change the diameter (by contracting or relaxing. to maintain blood flow, which impacts how much blood can flow.
Glomerular colloid osmotic pressure (GCOP) is created by __________.
pressure from proteins that bring fluid back into circulation
Mean Arteriole Pressure (MAP)
pressure that propels blood to tissues.
heart
pumps blood; 4 chambers: R&L Atrium: thin-walled; collects blood and pumps into the ventricle R&L Ventricle: thick wall; main pump that pumps blood into circulation
glomerular hydrostatic pressure
pushing filtrate into the bowman's capsule.
Proximal tubule
reabsorption of ions, water, and nutrients. Volume of filtrate decrease, iso-osmotic--water and salt reabsorbed--Na+K+ pump.
Diastole
relaxation of the left ventricle, and it refills with blood. The semi lunar valve closes. Pressure is maintained by the elastic recoils.
ureter
sends blood to the bladder
Prukinje fibers
small neuro fibers that conduct impulse through ventricles and trigger ventricular contraction
Polarization
sodium is high outside the cell and K+ is high in the cell which creates an action potential.
Poikelotherm
source of heat is derived from the environment, but they do not regulate their body temperature.
Thermoregulating ectotherms
source of heat is from the environment, but behavioral thermoregulate
Homeotherms
source of heat is metabolism and they're able to regulate their body temp. Ex. Humans
Non-regulating endotherm
source of heat is metabolism, but doesn't regulate their body temperature. Ex. naked mole rat.
Endotherm
source of heat mostly comes from metabolism
Lignin
substance in vascular plants that makes cell walls rigid and lines the cells wall (not uniformly) which causes pit and allow water to stick.
closed circulatory system
system in which blood is contained within a network of blood vessels
Gigantotherm
the ability of an extremely large animal to maintain a constant and relatively high body temperature due to its low surface/volume ratio. Even gigantic ectotherms can keep their body temp high almost like endotherms. Size becomes a major determinate of thermoregulation-b/c it dictates s:V ratio and how much gain and loss you face.
parasympathetic nervous system
the division of the autonomic nervous system that calms the body, conserving its energy
Extracellular fluid (ECF)
the interstitial fluid, blood plasma, and other body fluids. It's electrolytes and non electrolytes. Main electrolytes are sodium and chloride.
The emissivity of an object is determined by
the measure of an object's ability to emit infrared energy. Emitted energy indicates the temperature of the object.
blood pressure
the pressure that blood exerts in all directions, including against the walls of the vessel.
hydrostatic pressure
the pressure within a blood vessel that tends to push water out of the vessel. the pressure decreases as it progresses through the capillaries.
Pulmonary circuit
the pulmonary circuit, goes to the lungs and back to remove CO2 and take on O2.
peripheral resistance
the resistance of the arteries to blood flow. As the arteries constrict, the resistance increases and as they dilate, resistance decreases.Blood pressure depends on peripheral resistance. Peripheral resistance is the same during both diastole and systole. Therefore, blood pressure is elevated for both values.
Hemodynamics
the science of the blood flow through the circulation
Water vapor diffuses or evaporates in plants through where?
the stroma.
Innervation
the supply of nerves to a specific body part. The heart is innervated by vagal and sympathetic fibers. The right vagus nerve primarily innervates the SA node, whereas the left vagus innervates the AV node
When osmorepeceptors in the hypothalamus sense dehydration
they release the hormone ADH
lung capillaries
tiny blood vessels surrounding lung tissue through which gases pass into and out of the blood
iso-osmotic
two solutions having the same osmolarity: glomeluar and proximal filtrate are isoosmotic.
counter current multiplication
using NA+K+ pump to create a concentration gradient to create a concentrated urine. 1. single effect: Na+K+ pump into interstitial space creates gradient 2. Flow of new filtrate becomes more concentrated as it's pushed to the bottom b/c as it progresses through descending limb where the interstitial space is more concentrated, water diffuses out by osmosis. Creates a vertical and horizontal gradient.
Xylem (wood)
vascular tissue that is unidirectional and carries water upward from the roots to every part of a plant. Transports water and minerals. Made up of dead cells: tracheids and vessel elements
What regulates microcirculatory flow?
vasoconstriction and vasodilation
Blood capacity and volume is located
veins. 70% of blood is in the veins. Called Blood capacitance.
QRS wave
ventricular depolarization
T wave
ventricular repolarization
Left stroke volume
volume after diastole: larger number (120) volume after systole: smaller (70) The difference is the stroke volume = (50)
