ZOO2AP Exam Preparation

a bicarbonate/phosphate buffer

The equilibrium potential for a single ion

lowering the activation energy of a reaction

The net movement of water down its concentration gradient

The cell membrane be permeable to the substance

DsA(dCs/dx) where Ds is the diffusion coefficient; A is the cross sectional area; dCs is the change in concentration of substrate and dx is the membrane thickness

fatty acids with polar heads and non polar tails; cholesterol and proteins

False

True

False

The amount of charge stored by a cell membrane

its solubility in water

Sodium

A decrease in blood pressure away from the homeostatic set point results in a cardiovascular response that re-establishes blood pressure homeostasis

Provide insulation along the axon

No new action potential can be triggered

In all vertebrates other than mammals

The right systemic arch

Aortic arch 6

The gut and associated structures

A rumen or caecum

The pylorus, cardia and fundus

The pectoral limbs

The movement of a solute down its concentration gradient using a transporter or a channel

change in membrane potential

The cytoplasm of the cell is considered to be hypo-osmotic to the extracellular environment

tolerate a narrow range of osmotic environments

The movement of an ion across the cell membrane through a channel

the diastolic pressure + 1/3 pulse pressure

acetyl choline and epinephrine

200mM

Potassium

two artia and a single ventricle

specialized conductive tissues in the heart

Movement of molecule A against its concentration gradient facilitated by the transport of substance B with its concentration gradient.

volatile fatty acids

to secrete neurotransmitter

HR x SV

the distance that an action potential can spread along a nerve cell

Potassium

concentration gradient and electrochemical gradient

no channels are activated in the cell and no ions are moving through the membrane. -90mV

0 because each ion would have an equal chance of going across the membrane and therefore the potential wouldn't lean positive or negative.

Defines the equilibrium potential using all the ions that are permeable to the membrane

originates in the brain stem and lower part of the spinal cord. The division of the autonomic nervous system that restores the body's normal resting state and conserves energy.

increases physiological responses such as heart rate and respiration. responses are not under voluntary control

a division of the peripheral nervous system that regulates involuntary functions; made up of sympathetic and parasympathetic nervous systems

the portion of the vertebrate nervous system consisting of the brain and spinal cord

the section of the nervous system lying outside the brain and spinal cord

Involuntary nerves

Voluntary Nerves

of nerves and nerve impulses, carrying away from CNS

of nerves and nerve impulses, conveying information from organs to CNS

the volume of blood pumped out by a ventricle with each heartbeat (end diastolic volume - end systolic volume)

the amount of blood pumped out by the ventricles in a given period of time

the rate at which the heart beats (beats per minute)

Having teeth that are uniform in form, shape, and function.

a lifetime of generations of teeth, like a conveyor belt. such teeth have a breif life and are simple in design

having second set of teeth that replaces the first

promotes secretion of HCl and growth of both stomach and intestinal mucosa. Formed in pyloric gland area of the stomach.

the amount of enzyme is in excess of the amount of substrate

The affinity of the enzyme for its substrate derived from the half maximum velocity of the reaction

The net movement of water down its concentration gradient

maintain a constant internal osmotic environment using numerous cellular or organ systems

Has two branches0 the parasympathetic and the sympathetic branch

The transfer of energy from one molecule to another is coupled to reduce the overall free energy of the reaction

Sodium

a depolarization event that reaches threshold triggering an action potential

Individual depolarization events separated by time build upon each other resulting in a greater change in membrane potential

The spiracles

Van Hoff's Law

two atria and a single ventricle

teeth that are uniform in structure

Allow swallowing of large prey

The Nernst equation determines the equilibrium potential of an ion using the concentration gradients for that ion. As the ratio of concentration on the outside of the cell and concentration of inside the cell decreases the Nernst potential becomes more negative.

State at which electrical potential across a membrane balances with a concentration gradient of an ion to which that membrane is permeable. There isn't an excess charge or concentration difference between the inside and outside of the membrane.

The arterioles provide resistance since there are so many of them. They allow the pressure to decrease before the blood hits the capillaries although the flow rate remains constant. Poiseuille's Law describes the flow through the vessels.

Determines frequency of contractions in gastrointestinal tract

A distribution ratio describing how the inhaled anesthetic distributes itself between two phases at equilibrium. The solubility of the inhaled anesthetics in blood and tissue is denoted by the partition coefficient

Eion=(RT/Fz)log([ion]out/[ion]in RT/Fz=58mV

dQs/dt=DsA(dCs/dx)

Vm=(RT/Fz)log((Pk[K+]o+PNa[Na+]o+PCl[Cl-]o)/(PK[K+]i+PNa[Na+]i+PCl[Cl-]i)

acetyl choline and acetyl choline

• ΔP = 8•η•L•Q/(π•r4)
• η = coefficient of viscosity
• L = length of pipe
• r = radius of pipe
• Q = flow rate of fluid

Controls secretions in the duodenum and regulates the pH. Also found in the pancreas. Formed in the duodenum.

• –Muscle cells – produce force and movement
• –Nerve cells – electrical signaling
• –Epithelial cells – secrete and absorb ions & molecules
• –Connective tissue cells – connect, anchor, support

Change in variable being regulated results in responses tending to push the variable in the opposite direction to the original change (inhibitory). E.g. If you are in a room and the room gets hotter, the body will sweat to cool itself. E.g. Aircon senses that the room is getting hotter, and turns on and sends out cooler air to lower room temperature

Initial change sets of a sequence of events that increases the disturbance even further (stimulatory). E.g. When you do something and it feels good so you keep doing it.

• Receptor - receives a message that tells something about the environment
• Afferent pathway
• Integrating centre - processes the message (e.g. the brain)
• Efferent pathway - may be multiple
• Effector- provides the response to the message that helps to modify the response to the stimulus

• Lipids:
• Phospholipids
• Glycolipids
• Cholesterol
• Proteins:
• Channels
• Pumps
• Enzymes

Provide a barrier to the movement of substances between the cell and the extracellular environment or between intracellular compartments. No cell wall like in plants, cell membrane only.

Hydrophilic polar head and hydrophobic non-polar tail made of glycerol and fatty acids.

Aggregates formed by lipids due to their hydrophobic and hydrophilic regions.

True

Laterally, flex and rotate, and flip across layers

• Cholesterol - rigid molecule which decreases fluidity
• Unsaturated carbon chains - increase fluidity
• Distribution of different types of lipids is not uniform in the cell

dQS/dt = DSA (dCS/dx)

• C_S= concentration of substrate (S)
• x = thickness of membrane
• A = cross sectional area
• D_S = diffusion coefficient
• β_S= partition coefficient

The rate of diffusion of a substance over a given time

• Diffusion coefficient (Ds) – just a number for the measurement of the diffusion of the substance, based on such things as size and shape of the molecules
• Area (A) – area of the membrane, or the compartment that is being diffused across.
• (dCs/dx) – change in the concentration of a substance across a certain distance of a membrane (x). X differs to A because a is more 3d, as diffusion may occur in multiple directions.
• Bs – the partition coefficient – defining the solubility of the substance, it is the ration of the concentration of the lipid bilayer divided by the concentration of the aqueous environment.

Fick’s Law defines quantitatively the ease with which substance can permeate a membrane

Through pores, ion gated channels, ligand gated channels and stretch activated channels.

Pore opens to allow movement of ions, H2O and small molecules, which move down concentration or electrical gradient. No energy is required, other than the thermal energy inherent to all atoms above absolute zero. Rate is purely a function of the concentration gradient. The steeper the gradient, the higher the rate of influx.

A change in membrane potential, such as negative Vm outside (inside) the cell would make the channel open (close). They are selective in which molecules they will let in to repel molecules of the same change, and attract molecules of different charge.

Ligand-gated channels are switched on by some other molecule (molecule A), that when it attaches to a particular site on that channel it opens, and a suitable molecule B can move through the channel.

When the membrane is stretch the channel opens

molecules attach to receptor on outside, receptor flips around and molecule falls off inside

molecule attach to receptor on outside, receptor turns around and molecule falls off inside

facilitated/coupled transport – as a molecule is going in, another molecule is going out

Activity of Na+/K+ pump maintains the distribution of high IC potassium and low IC sodium relative to their EC concentrations. Net transfer of positive charge to outside of cell

Energy source is an electrochemical gradient. Movement of an ion down its EC gradient coupled to the transport of another molecule (e.g. glucose, a/a) E.g. Na+ would move from outside (with higher concentration) to inside (with lower concentration), down the gradient. Another molecule piggybacks on the movement of Na+ to get inside the cell as well.

Solute moves in same direction as ion in secondary active transport

Solute moves in opposite direction to ion in secondary active transport.

Regions of the plasma membrane fold into the cell, forming small pockets that pinch off to form IC vesicles enclosing a small volume of ECF

Membrane-bound vesicles in the cytoplasm fuse with the plasma membrane and release their contents to the outside of the cell

The net movement of water across a semi- permeable barrier that is permeant to water but impermeant to solutes

Extracellular environment more dilute or exerts a lower osmotic pressure

Extracellular environment more concentrated or exerts a higher osmotic pressure

Does not cause a change in cell volume

Causes cells to shrink

Causes cells to swell

Tolerate a wide range of osmotic concentration in the extracellular environment. They can be osmoregulators (maintain constant internal milieu with consumption of ATP) or osmoconformers (can vary the concentration of impermeant molecules).

Tolerate only a narrow range of osmotic concentration in the extracellular environment.

The potential that builds up across a cell membrane that counterbalances the desire for diffusion down a concentration gradient.

• Donnan Equilibrium is defined by a reciprocal distribution of the anion and cation:
• [K+]i  =  [Cl-]o
• [K+]o      [Cl-]i
• Arises because of the need for electroneutrality; cations and anions cross in pairs; at equilibrium the rate of diffusion of KCl is equal in both directions.

Vm = Vin-Vout

a measure of the total sum of charge that has accumulated across the cell membrane

Refers to the movement of charge - in this case the movement of ions across a cell membrane. This requires the presence of channels. Thus the conductance of a membrane is a measure of its permeability. Ohms Law 1=G x deltaVm where I is the ionic current (amps)

Defines the degree of hindrance to the movement of charge. In this case the ease with which ions move through a channel

The concentration gradient

Action potentials are essentially brief electrical signals. They are important for signaling in many cells. They allow the spread of information over long distances as well as locally. They are typically generated from the activity of voltage-gated ion channels

Skeletal muscle, skin and derivatives

Visceral organs - involuntary tissues. These nerves are specialised - form the autonomic nervous system.

Spinal nerves and cranial nerves

Cervical, thoracic, lumber and sacral.

• Dorsal column = somatic and visceral neurons (cell bodies)
• Ventral column = visceral and somatic motor neurons (cell bodies)
• Gray commissures = cross over point of nerve fibres
• Dorsal and Ventral funiculus = axons running towards or away from brain
• Lateral funiculus = mixed directions

• heart - pump
• arteries - resistance vessels
• capillaries - tissue perfusion vessels
• veins - compliant vessels and fluid stores
• accessory organs: skeletal muscles       additional pumps

• High pressure
• Fast blood return
• Distribution of blood to tissues can be regulated
• Blood is separated from interstitial fluids

• Low pressure
• Slow blood/fluid return
• Difficult to regulate blood flow
• Blood/fluids directly feed cells

Cardiac output multiplied by resistance at arterioles (total peripheral resistance)

• Arteries are thicker with low compliance
• Capillaries are very thin with no compliance
• Veins are thin, elastic and very compliant.

Cell behaviour in a solution (i.e. shrink or swell) within a particular concentration of non-permeating solutes.

The net movement of water across a semipermeable barrier

The total amount of solute (mol/kg) per unit volume (L)

The total amount of solute (mM/M) per unit volume (L)

No net change in the cell because the total number of nonpermeable particles is equal on both sides of the cell.

The cell will swell because the total number of non permeable particles is greater in the cell so water will move into the cell

The cell will shrink because the total number of non-permeating particles is greater in the extracellular fluid so water moves out of the cell.

Negative feedback

Na+ channel and K+ channel

• The rate of influx of a molecule or ion displays saturation kinetics
• Directly requires energy in the form of ATP
• Transport of molecules against a concentration gradient
• Generally highly selective for a given molecule/ion

The rate of influx of a molecule or ion is directly proportional to the concentration gradient, molecules move down their concentration gradient, generally highly selective for a given molecule/ion, no energy is required.

The cell membrane is selectively permeable to certain solutes.

A state of electrochemical equilibrium that is achieved because two fluid filled compartments are separated by a semipermeable membrane that is permeable to only some of the ions present.

Adaptations to the environment (e.g. drought tolerance)

Origins of a physiological trait (character reconstruction, cladistics)

Considers 'function' in all animals (subsets human physiology, avain physiology)

Emphasises mechanisms (firefly example)

For such a large number of problems there will be some animal of choice, or a few such animals, on which it can be most conveniently studied.

Animals that allow their internal environment to vary when their external environment changes. Known as ectotherms, which are poikilothermic.

Animals that hold their internal environment constant despite changes to their external environment. Known as endotherms,  which are homothermic.

Transporters and pumps

The Na+/K+ pump establishes the concentration gradient for Na+ and K+ in nearly all cells. The pump transports 3 Na+ ions out of a cell for every 2 K+ ions into a cell. The pump uses ATP to do this because it is pumping ions against their gradient. The Na+/K+ pump is sometimes described as an action potential pump because of the difference in net charge pumped out of the cell.

The concentration gradient is being dissipated. The electrical gradient is being developed.

What the effect of an ion, with a given concentration gradient, that is permeable to a cell membrane, will have on the membrane potential that arises when ions move down their electrochemical gradients. The membrane potential at which the ions stop moving is the potential at which the ion is in electrochemical equilibrium, or to put it another way, its equilibrium potential.

Whenever ion conc out= ion conc in because the concentration gradient is eliminated and thus the principle driving force is lost and as a consequence no potential is established.

Local response is related to an insufficient depolarisation that leads to a failure in exciting enough Na+ channels to active that they are able to continue to depolarise a cell so as to further active more Na+ channels.

Oesophagus, crop, liver, proventriculus, gizzard, pancreas, intestine, cloaca

The bit the tongue of birds rests in, like their beak

Temporary storage of good so birds can gorge. Large diameter for whole foodstuffs.

Glandular stomach, secretion of mucous HCl and digestive enzymes, and enzymatic breakdown of food.

Teeth equivalent, used for grinding/breaking up food. Functions through muscular contractions.

U shaped loop, site of digestion and absorption.

Water and electrolyte absorption

Site of fermentation, digestion and absorption - enzymatic breakdown of cellulose.

Receives waste from digestive, urinary and reproductive systems.

• Liver - bile production
• Pancreas - digestive enzymes to small intestine to aid acid neutralisation