Osmoregulation in Animals

Osmoregulation

• Osmosis is vital for animals and affects every cell.
• Osmoregulatory systems maintain extracellular fluid composition and minimize osmosis-induced changes in cell volume.
• Plasma membrane forms a hydrophobic barrier that restricts solute movement, but allows water to move freely through osmosis.
• Osmosis is the only way of water to move in or out of cells, depending on solute concentration gradient.
• Water moves from areas of low solute to high solute concentration, and influenced by solutes and their interactions.
• Osmoregulatory systems involve active transport of ions across epithelial surfaces, with water following the ion gradient via osmosis.
• Osmoregulatory animals maintain different body solute concentrations from their environment, for example, freshwater fish that are hyperosmotic to it.
• Osmoconformers do not maintain different osmotic concentrations from their environment, for example, some marine animals.
• Isotonic condition has equal solute concentration inside and outside the cell.
• Hypotonic solution has lower osmolarity.
• Hypertonic solution with higher osmolarity.
• Osmolality measures of the concentration of all chemical particles in fluid.
• Animals in aquatic environments have semipermeable membranes.
• Hemolysis is the rupturing of red blood cells and the release of hemoglobin into surrounding fluid.
• Crenation, when applied to cells, describes the formation of abnormal notched surfaces due to water loss through osmosis.
• Red blood cells undergo crenation in response to ionic changes or membrane abnormalities and disrupt ability to maintain an isotonic state via echinocytes and acanthocytes shapes.
• Cells are usually in an isotonic solution within the body, indicating the same solute and water concentration inside and outside.
• Metanephridia are excretory glands found in some invertebrates.

Experiment #1: Osmoregulation in Annelid Worms

• Four known concentrations of seawater were used.
• Worms were weighed before and after being in the solutions for 30 minutes.
• Osmotic change was measured.
• Percent of initial mass indicated worm response relative to seawater percentage.
• Original seawater concentration is 1000 mOsm.
• Earthworm internal solute concentration is 250-400 mOsm.
• Worm weight decreases placed in 50% = 500 mOsm due to higher external solute concentration and water movement out into hypertonic solution.
• Worm weight increases placed in 5% = 50 mOsm due to higher internal solute concentration and water movement into the cell.

Lab #5: Osmoregulation Experiment #2: Osmotic Effects on Animal Cells

• Red blood cells in plasma are in an isotonic solution.
• Red blood cells are incubated in unknown solution 1 and appear larger and rounder due to water moving into the cell in a hypotonic solution, causing them to swell.
• Red blood cells are incubated in unknown solution 2; cells appear smaller. They are placed in a hypertonic solution, causing water to move out and cells to shrink (crenulation).
• Very hypotonic solutions cause cell lysis.
• Red blood cell solution is relative to the cell.
• 40 dashes equal 100 micrometers; cell diameter can be used to determine what kind of solution it is.

Human Respiratory System Physiology

• Pulmonary ventilation involves air inflow and outflow between atmosphere and alveoli.
• Pulmonary ventilation is determined via spirometry.
• Spirometry recordings are measurements to diagnose asthma and other lung conditions.
• Diffusion is sufficient for gas exchange in small animals.
• Large animals use the lungs and gills to increase the surface area for gaseous exchanges.
• Actively metabolizing cells require oxygen and waste CO2 removal.
• Lungs increase the surface area for gaseous exchange.
• Human respiratory system includes tubes branching into alveoli.
• Air entering/leaving lungs provides information on respiratory physiology.
• Volume recorder measures air volume in different categories during lung ventilation.
• The respiratory system includes a series of tubules and branches.
• Bronchi are the main airways branching into smaller bronchioles which lead to alveoli that rely on simple diffusion.
• Alveoli are clusters of membranous air sacs, with a thin membrane for short diffusion distance.
• Total surface area is same as a tennis court.
• Diffusion factors are respiratory surface area, diffusion distance, and concentration gradient.
• Air is moved through low O2 and high CO2 into lungs and pulmonary ventilation for high O2 and low CO2 in alveolar air to ensure a high concentration gradient.
• Tidal volume (TV) measures of air moving in/out of lungs during breathing cycle.
• Inspiratory reserve volume is additional air breathed in after.
• Expiratory reserve volume is additional air breathed out after normal expiration.
• Residual volume (RV) is air not exhaled with lower O2 and CO2, but mixes fresh air and facilitates gas diffusion in capillaries.
• Vital Capacity is maximum air volume exchanged during breathing.
  • VC Male = (.025H in cm) – (.022A) – 3.60.
  • VC Female = (.041H in cm) – (.0180A) – 2.69
• Peripheral chemoreceptors detect blood pH, O2, and CO2 levels.
• Stretch receptors provide sensory that modulates the respiratory center neurons.
• Spirometer is a volume recorder measuring air exchanged during lung ventilation.
• Spirometry test measures air breathed in/out of lungs.
• The respiratory center modulates TV and breathing adjustments.

Lung Volumes and Capacities

• Exercise: Heart and lungs act together with oxygen requirements in tissues.
• Lungs provide oxygen and remove carbon dioxide.
• Heart pumps oxygen to muscles.
• Breathing increases from 15 to 40–60 times/minute to meet extra oxygen demand for 100 litres.
• Circulation speeds up to take oxygen to muscles to increase CO2 production.
• Breathing rate (breaths/minute) equals 60 sec/minute divided by mean breath period (sec/breath).
• Minute Respiratory volume equals tidal volume * breathing rate
• Inspiratory Capacity (IC) = TV + IRV, Expiratory Capacity (EC) = TV + ERV
• Functional Residual Capacity (FRC) = ERV + RV , Total Lung Capacity (TLC) = TV + RV + IRV + ERV
• During exercise, ventilation can increase from 5–6 to >100 litre min-1.
• Ventilation and oxygen consumption increase linearly with work rate.
• Male and female lung volume differences are based on body size.
• Males have larger sizes, meaning larger thoracic cavity.
• Diffusion is inefficient for organisms over millimeters thick; there are more challenges taking oxygen living in water than air.
• Surface area-to-volume ratio of the animal decreases when living on land.
• Diffusion rate depends on surface area.
• Large organisms have a greater need for gas exchange, but have less surface area.
• When the size of an animal increases, the distance between the animal's surface and its internal surfaces also increases.
• Diffusion itself is too slow for gas exchange for most organisms.
• Animals at high altitudes do not suffer chronic hypoxia and reduced aerobic performance.
• Smoking damages alveoli, affecting gas exchange: smokers have different spirometry functional capacities.
• Resting volumes are taken; person exercises and then returns
• Adjust the amount of air to meet metabolic demand.
• CO2 is increased when exercising.
• Frequency of breath and tidal volume increases.
• CO2 increases during exercise, the body increase ventilation.
• The ERV has a hard line because the residual volumne maintains the aveoli

Human Circulatory System Physiology

• Cardiac cycle in vertebrates involves sequential contraction of atria and ventricles.
• Electrocardiogram (ECG) measures and interpretation is critical for clinical diagnosis of heart conditions.
• Hearts rhythmical contraction sequence is triggered by potentials conducted throughout the heart.
• Body fluids conduct electricity and electrical activity.
• Blood ejected from heart distributed via arterial system.
• The aerial system functions as pressure revisor with blood flow related to pressure difference.
• Heart function is increased with centralized blood pressure, but ANS controls smooth muscles in artery walls.
• Vasoconstriction increases centralized blood pressure.
• Vasodilation decreases centralized blood pressure.
• Autonomic nervous system effects on arterial system alter blood distribution.
• Aspects of heart activity can be modified b autonomic nervous system.
• Nervous system input adjusts cardiac function for body tissues demands.
• Contraction rate and myocardial contractility can be changed. Increased heart rate lowers time between beats, reducing time to complete a depolarization/repolarization cycle.
• Nerves from both the sympathetic division releases norepinephrine.
• Parasympathetic vagus nerves release acetylcholine as neurotransmitter
• Any change in heart rate can change altering arterial blood pressure, especially in central vessels like the aorta.
• Vasodilation and heart rate affect blood pressure elsewhere; feedback loops work within the autonomic nervous system at the same time .
• Baroreceptor reflex ensure central arterial blood pressure is maintained at a level appropriate for metabolic activities.
• The diving reflex is involved in blood flow to limbs, gut and skin and delivers blood to the heart and brain while reducing oxygen and air.
• Myocardium carries this sequence that triggers the contraction of the sequence.
• The measurements should be taken with the P and T wave and the OTR.
• The activity that happens in the actria and ventircles, and activvity within the cariac conduction

Experiment 1: ECG

• Electrical activity of heart can be viewed by waveforms such as, P, Q, R, S ,AND T.
• P wave is atrial depolarization
• Q, R, S represents the ventricular depolarization
• T wave shows the ventricular repolarization
• the order if events starts eith depolarization of aatrial contraction

Lab #7: Human Circulatory System Physiology

Exp 1: Effects of Exercise on the ECG and Peripheral Circulation

• Resting, exercising and recovering heart activity and pulse amplitude is observed.
• P-P interval provides heart rate.
• pulse represents vasoconstriction and vasodilation in peripheral circulation which is the blood flow to fingertip.
• Vasodilation and vasoconstriction is measured.
• The body shunts blood when needed.
• Blood is redistributed to lungs and cells with vasoconstriction causing a decrease in pulse.
• Body can send blood back to fingertip during the recovery phase.
• Increased blood goes to the skin because heat has to be released from the warm blood.
• SNS,PNS, and norepiniphine are involved and result in high heart rate if active.

Experiment 2: Human Circulatory System Physiology

• There is an increase in PNS activity.
• body conserves O2 when face is placed ungerwater
• vasoconstriction triggers pns
• heart rate decreases
• vasodilation happens

Metabolic Rate Lab

• Metabolism is the sum of chemical reactions in an organism by obtaining metabolic rate.
• Temperature, diet, age, calories, and activity level can affect this rate.
• Energy maintenance from steady carb, fats, protein supply; oxygen and an organic molecule react to create CO2 and energy
• Exchange is measured by producing unit time and gas.
• Measure heat exchange through before/after chambers using water .
• Endotherms use basal metabolic rate.
• Lower mass has lower metabolic rate, larger mass create more tissue and energy indicative

Experiment 2: Metabolic Rate

• Minimum metabolism of fasting animals occurs at temperature.
• Glycolysis changes due to being dependednt.
• Chemical reactions affect.
• Temperature quotient will remain stable when maintained for these temperatures
• enzyme activity increases
• Typical Q10 is 2, that represents an exponential increase
• Temperature changes cause different interactions