BIOL 224 Lab Exam 2 Flashcards
Define plasma membrane
membrane found in all cells that separates the interior of the cell from the outside environmen
define aquaporin
channel proteins facilitating transport of water between cells.
define osmosis
the movement of water from areas of low solute concentration to areas of high solute concentration
define isotonic
solute concentration is equal on both sides
define hypertonic
high solute concentration (water goes out of cell)
define hypotonic
low solute concentration (water goes into cell)
define osmoregulation
the maintenance of constant osmotic pressure in the fluids of an organism by the control of water and salt concentrations.
define hemolysis
when cells explode
define crenation
when cells shrivel up
define osmoregulator
Animals that maintain body solute concentrations different from the environment
define osmoconformer
animals that do not maintain their osmotic concentrations different from the environment
define metanephridia
excretory gland found in invertebrates that lets them pee out excess water
The internal tissues of annelids are hyperosmotic relative to the freshwater soil surroundings. As a result, annelids take in water osmotically and produce hypoosmotic urine to get rid of excess
water. In annelids, excretion and osmoregulation are accomplished by a highly developed organ system called metanephridia
describe how animal cells are affected when osmolality varies
shrink in hypertonic (high solute concentration) and grow in hypotonic
explain features of the plasma membrane in animal cells that underpin its role in
osmosis.
its semipermeable meaning that water can cross through it when solutes or ions cannot
explain the role of osmoregulatory organs in maintaining extracellular fluid
composition in vertebrates
The kidneys are the main osmoregulatory organs in mammalian systems; they function to filter blood and maintain the osmolarity of body fluids at 300 mOsm
Describe the function of aquaporins. Where in the human body are these
membrane proteins found?
found in the plasma membrane –> let water thru
lots in the kidneys
Why is it a bad idea for humans to drink sea water?
Osmotic pressure is also the reason you should not drink seawater if you’re stranded on a lifeboat in the ocean; seawater has a higher osmotic pressure than most of the fluids in your body. You can drink the water, but ingesting it will pull water out of your cells as osmosis works to dilute the seawater.
Describe how osmoregulatory challenges differ between the marine,
freshwater and terrestrial environments for vertebrate animals.
freshwater animals are faced with body weight gains and
losses depending on the osmotic gradient that exists in their environment.
Generally, the large volume of water in the ocean ensures minimal fluctuations
of the osmotic environment and osmoconformers are usually exposed to a relatively stable environment. However, Animals trapped in a tidal pool must be able to adapt to short-term osmotic stress and survive for about 12 hours until the next tide
Terrestrial –> salts have to be consumed
- water must be obtained and preserved within the animal
define alveoli
any of the many tiny air sacs of the lungs which allow for rapid gaseous exchange and increase surface area of the lung
define bronchi
the main airways (bronchi) branch off into smaller and smaller passageways — the smallest, called bronchioles, lead to tiny air sacs (alveoli).
TV
Tidal Volume
amount of air that moves during one breathing cycle
measured peak - trough
IRV
Inspiratory Reserve Volume
additional air one can breath in beyond normal breathing–> also reflects upper maximum of lung volume
measured peak of Tv to peak of forced inspo
ERV
Expiratory reserve volume
additional air able to be exhaled from the lungs
measured trough of tv to trough of forced exhalation
RV
residual volume
amount of air left in lungs that cannot be exhaled
= (vc/ 0.75)-vc
VC
vital capacity
maximum volume of air that can be moved in one breathing cycle
measured peak to trough of forced breath
also measured thru specific formula
BP
breath period
time it takes to do one breath
measured peak - peak of Tv in time
BR
breathing rate
rate of breaths per minute
60sec/ BP
MRV
minute respiratory volume
BR x TV
volume of gas moved in a minute
IC
inspiratory capacity
max volume of air one can inhale
TV + IRV
EC
expiratory capacity
max volume of air one can exhale
TV + ERV
FRC
Functional Residual Capacity
volume remaining in lungs after normal exhalation
= ERV + RV
TLC
Total lung capacity
the absolute max volume of air ones lungs can accommodate
TV + RV + IRV + ERV
VC= 75% TLC
define spirometry
study or measurement of quantity of gas exchanged during lung ventilation
define respiratory center
in the medulla oblongata (brainstem), regulates TV and breathing rate
gets info from various sense receptors
explain physiological changes that occur in respiratory system in response to exercise
TV goes up, ERV and IRV go down (because tv went up and its reserve) and VC should be similar
oxygen is used quicker and Co2 increases in the blood during exercise causing sensory receptors to stimulate respiratory center to tell body to breath faster and harder to expel more CO2
explain the physiological differences associated with lung capacities between men and women.
men = bigger = more tissue = bigger lungs = need more o2 = bigger lung capacity
Why is diffusion an inefficient respiratory strategy for organisms that are more
than a few millimeters thick? Describe why oxygen uptake is more challenging
for animals living in water than for animals living in air.
Larger organisms have a greater need for gas exchange, but have a smaller surface area relative to their volume, making diffusion by itself insufficient for gas exchange.
The concentration of oxygen in water is lower than that of air
Animals including humans that live at higher altitudes do not suffer from
chronic hypoxia and reduced aerobic performance. What physiological
adaptations do they have that make them capable of that?
expansion in the width of the blood vessels (both capillaries and arteries) that carry oxygenated blood to the cells.
greater red blood cell volume and increased concentration of hemoglobin, the oxygen-carrying protein that is the main component of red blood cells.
Smoking causes damage to the alveoli in the lung. How does that affect gas
exchange in human body? If you conduct spirometry measurements between
smokers and non-smokers, what differences in the functional capacity of lungs would you likely to observe?
the chemicals in smoke destroy the tiny air sacs, or alveoli, in the lungs that allow oxygen exchange.
people who don’t smoke can breathe better duh
define myocardium
muscular tissue of the heart
define brady/tachycardia
bradycardia –> slow HR less than 60bp
tachycardia –> fast HR 100+ bpm
define myogenic/ neurogenic
controlled by heart / nerves respectively
define systole/ diastole
Diastole is when the heart muscle relaxes.
When the heart relaxes, the chambers of the heart fill with blood, and a person’s blood pressure decreases.
Systole is when the heart muscle contracts.
When the heart contracts, it pushes the blood out of the heart and into the large blood vessels of the circulatory system. From here, the blood goes to all of the organs and tissues of the body.
define baroreceptor
mechanoreceptors located in blood vessels near the heart that provide the brain with information pertaining to blood volume and pressure
triggered by diving reflex when body pulls all blood to heart and brain in panic mode
define baroreflex
maintain blood pressure at nearly constant levels. The baroreflex provides a rapid negative feedback loop in which an elevated blood pressure causes the heart rate to decrease.
worked with vagus nerve in psymp ns to slow heart and release ach
define depolarzation/repolariaztion
depolarization –> movement of an area to a more positive value via ions
repolarization –> cells become more negative
explain the physiology that underlies the response of the heart and peripheral
components of the circulatory system to exercise
during exercise the sympathetic NS is more active, and the nerves that innervate the pacemaker cells release norepi to make cells beat faster and increase heart rate, because body needs more oxygenated blood to fuel tissues as it gets used at a faster rate
pulse amplitude decreases as a result of this, blood needs to go to lungs and legs
explain the physiology of the heart and peripheral components of the circulatory
system that are associated with the diving response.
when your face hits the water the cold and pressure stimulate the trigeminal nerve and puts your body into survival mode, where your body tries to conserve blood for the head and heart, causing rapid vasoconstriction causing a change in pressure stimulating barorecpetors and triggering parasympathetic NS to release ACH via vagus nerve in heart to make cells beat slower to conserve oxygen to the areas that need it
Describe the electrical conduction pathway that is responsible for initiating
a heart contraction cycle, starting with the heart’s pacemaker.
sinoatrial node (SA node) causes atrial depolarization (contracts, P wave), goes through the bundle of HIS, bundle fibers and purkinje fibers to atrioventricular (AV) node (QRS complex, but a little later) causing ventricular depolarization, then ventricle repolarizes (T wave)
Describe the effects of the autonomic nervous system on the ECG and
overall heart activity.
when the sympathetic ns is more active, heart rate quickens and is shorter distance between pulses on ecg
opposite for parasymp
define glycolysis
the breakdown of glucose by enzymes, releasing energy and pyruvic acid.
part of cellular respiration
define cellular respiration
a series of chemical reactions that break down glucose to produce ATP, which may be used as energy
process by which biological fuels are oxidised in the presence of an inorganic electron acceptor such as oxygen to produce large amounts of energy, to drive the bulk production of ATP.
define indirect calorimetry
Indirect calorimetry (IC), which measures oxygen consumption and carbon dioxide production, provides an assessment of energy expenditure/ or heat produced
define metabolism
sum of all chemical reactions
define cata/anabolism
catabolism –> breakdown reactions
anabolism –> buildup reactions
define metabolic rate
energy expenditure / unit time
higher with weight
but lighter have higher/weight
define standard metabolic rate
fasting minimum rate of metabolism at a given external temperature of not mammals as their metabolic rate is largely determined by the temperature of their environment
define basal metabolic rate
fasting minimum rate of metabolism in animals
explain the physiology that underlies CO2 production
CO2 is a byproduct of cellular respiration converted from the oxygen we inhale and is exhaled out of the body as waste
explain the physiology that underlies mass specific metabolic rate.
smaller animals have higher metabolic rates
may be due to smaller surface to volume ratio means more heat is lost meaning they have to generate it more rapidly
Explain the difference between SMR/BMR (Standard/basal metabolic rate)
and MMR (maximum metabolic rate). What is aerobic scope (also called
aerobic metabolic scope)? Why does the aerobic scope of ectothermic
animals decline as temperature rises?
(MMR) is typically used to represent the maximum rate of aerobic metabolism of an animal –> not just at rest
Aerobic scope represents an animal’s capacity to increase its aerobic metabolic rate above maintenance levels (i.e. the difference between standard (SMR) and maximum (MMR) metabolic rates).
metabolism increases with temp, so they cannot increase metabolic rate as much as it is already increasing
Explain why many endotherms can also be characterized as heterotherms or
poikilotherms? What is the difference between a temporal and a regional
heterotherm? Describe the physiological benefits of temporal and regional
heterothermy.
pikilotherm –> an organism that cannot regulate its body temperature except by behavioral means such as basking or burrowing.
Heterotherm –:> physiological term for animals that vary between self-regulating their body temperature, and allowing the surrounding environment to affect it.
Regional heterothermy describes organisms that are able to maintain different temperature zones in different regions of the body.
Penguins and many arctic birds use these exchangers to keep their feet at roughly the same temperature as the surrounding ice which prevents the birds from getting stuck to ice sheets!
Temporal heterothermy refers to animals that are poikilothermic or homoeothermic for a portion of the day, or year. Often, body temperature and metabolic rate are elevated only during activity. When resting, these animals reduce their metabolisms drastically, which results in their body temperature dropping to that of the surrounding environment. This makes them homoeothermic when active, and poikilothermic when at rest. Bats and hummingbirds go into what is known as torpor and bears hibernate. Both are examples of heterothermy; where the internal temperature of the animal drops during specific periods of time, usually when food is scarce.
