Physiology Final

What are the 3 fluid compartments of the body?

• ICF

• Interstitial fluid

• Plasma

Define homeostasis.

maintenance of the internal environment in a narrow range

What is the difference between intrinsic and extrinsic regulation?

• Intrinsic : local

• Extrinsic : a system regulated from outside the organ

Whats the difference between a feedback and feed-forward response?

• Feedback is a response after a change has been detected

• Feedforward is a response in anticipation of a change.

Whats the difference between a negative and positive feedback system?

• Negative is when the response is opposite of the original change

• Positive is when the response is in the same direction as the original change

What are the 3 components to all negative feedback systems?

• Sensor

• Control Center

• Effector

What are the 3 components of a membrane?

• Lipids

• Proteins

• Carbohydrates

What does it mean for a molecule to be amphipathic?

• has polar and non-polar parts

How is a phospholipid amphipathic?

• has a polar head and non-polar tail

What are the 2 functions of cholestrol in the plasma membrane?

• Stability

• Fluidity

What are the 3 specialized types of cell junctions?

• Desmosomes

• Tight Junctions

• Gap Junctions

What are the 3 methods of membrane transport?

• Simple diffusion

• Facilitated transport

• Vesicular transport

According to Fick’s Law, what are the 3 factors that increase diffusion rate and the 2 factors that decrease diffusion rate?

Increases diffusion rate :

• Concentration

• Surface Area

• Permeability

Decreases diffusion rate :

• Size

• Distance

If a red blood cell (300 mosm) is placed in a hypotonic solution (100 mosm), which way would water go? What would happen to the cell would it grow or shrink?

Into the cell; it would grow

What are the characteristics of molecules that need to be transported by facilitated transport?

• Polar

• Small

What are the 2 types of carrier-mediated transport?

• Symport

• Cotransport

Compare and contrast facilitated diffusion and active transport.

• Compare - Both use carriers

• Contrast - Active Transport requires energy and Facilitated Diffusion does not

What are the 2 types of vesicular transport?

• Endocytosis

• Exocytosis

What side the membrane can sodium and potassium be found in a resting cell?

Sodium outside and Potassium inside.

Which way does sodium and potassium want to go according to their concentration gradient?

• Sodium wants to go into the cell

• Potassium wants to go out of the cell

At vRest, which direction does sodium want to go based on its electrical potential? Potassium?

• Sodium wants to go into the cell

• Potassium wants to go into the cell

If the Vm was +40 mV, which direction would sodium want to go based on its electrical potential? Potassium?

• Sodium wants to go out of the cell

• Potassium wants to go out of the cell

What are the 2 reasons that the membrane potential at rest is negative (-)?

The sodium/potassium pump moves more sodium out than it transports potassium in AND the potassium leak channels are more permeable than the sodium leak channels.

What 2 systems do we use to communicate to the body?

• Nervous

• Endocrine

Describe the 2 types of Vm changes.

• Depolarization : the Vm becomes less negative

• Hyperpolarization : the Vm becomes more negative

If a positive ion moved from the outside of the cell to the inside of the cell at Vrest what kind of change would this make in the Vm?

Depolarization

If the membrane potential went from -70mV to -50mV, what kind of change has taken place?

Depolarization

If Vrest becomes less negative, what would you call that kind of response?

Depolarization

What determines how big of a change a graded potential will have?

the size of the stimulus

How do you change the permeability of an ion to the plasma membrane?

By opening or closing gated ion channels

What ion is moving across the membrane during the upshoot and which way is it moving?

Sodium moves into the cell

What ion is moving across the membrane during the downshoot and which way is it moving?

Potassium moves out of the cell.

What is the function of the refractory period?

To prevent action potentials from going back up an axon

What are the 2 types of refractory periods?

• absolute

• relative

What is the difference between contiguous conduction and saltatory?

• Contiguous - the AP spreads to every section of the axon

• Saltatory - the AP skips some part of the axon that are myelinated which leads to faster AP conduction

List all the ion channels important for an AP.

• NA+/K+ pump

• Na+ and K+ leak channels

• VG Na+ channels

• VG K+ channels

Why can an axon have an action potential but a dendrite cannot?

the only part of the cell that has VG channels

What is the primary difference between an EPSP and IPSP?

EPSP - results in a depolarization

IPSP - results in a hyperpolarization

What is temporal summation?

Summation that results from 2 presynaptic AP coming from the same cell but one after the other in close time succession

What is spatial summation ?

summation that results from 2 presynaptic AP coming from different cells at the same time.

Give an example, using human communication, how a person may communicate in a way similar to AUTOCRINE signaling in a cell.

Talking to yourself

Give an example, using human communication, how a person may communicate in a way similar to PARACRINE signaling in a cell.

Overhearing a conversation in the bathroom

Give an example, using human communication, how a person may communicate in a way similar to ENDOCRINE signaling in a cell.

seeing a instagram post “anyone can see”

What is a 2nd messenger ?

An intracellular signaling molecule that can bring about cellular change.

How is G protein activated?

When a ligand binds to a receptor the GDP attached to the G-protein falls off and GTP binds to the G-protein

What does adenylyl cyclase (AC) do?

Converts ATP to cAMP

What does kinase do?

Adds phosphate groups to cellular molecules

What does Phospholipase C (PLC) do?

Converts to IP3 and DAG

What are the 2 divisions of the efferent PNS?

• Autonomic

• Somatic

What are the 2 divisions of the ANS?

• Sympathetic

• Parasympathetic

What are targets for the ANS ?

• Cardiac Muscle

• Smooth Muscle

• Glands

What is the target for the SNS?

Skeletal Muscle

What neurotransmitter is released from the preganglionic parsympathetic neurons?

ACh

What neurotransmitter is released from the postganglionic sympathetic neurons?

NE

What are the 2 types of cholinergic receptors?

• Muscarinic

• Nicotinic

What are the 2 types of adrenergic receptors?

• Alpha

• Beta

Describe the thick filament of skeletal muscle (including the functions of the tail and head).

Contains a tail that functions to stabilize the thick filaments and a head that contains an area for acting, binding, and breaking down ATP.

List the 3 parts of the thin filament of skeletal muscle.

• Actin

• Troponin

• Tropomyosin

What is the role of calcium in skeletal muscle contractions?

Binds to troponin, troponin then removes tropomyosin from the myosin binding site.

How does muscle shortening occur and what do you call this theory?

The sliding filament mechanism where the thin and thick filament slide past each other.

Where does Ca++ come from in a skeletal muscle?

SR

How did Ca++ get out of the SR in the Skeletal Muscle?

An AP activated the DHP receptor which then opened the ryanodine channel on the SR membrane.

List the 3 phases of the cross-bridge cycle?

• binding

• power stroke

• detachment

List the 3 roles of ATP in Skeletal Muscle?

• Detach actin from myosin

• Energize/cock the myosin head

• Pump calcium back into the SR

What 3 things have to happen to allow skeletal muscle relaxation?

• Break down ACh with AChe

• Remove calcium from the cytoplasm

• Tropomyosin has to cover the binding site

What is a muscle twitch?

A single muscle response in a single muscle fiber as a result of a single action potential.

Define the following terms : Motor unit, motor unit recruitment, and asynchronous recruitment

Motor unit : a motor neuron and all the fibers it innervates

MU recruitment : the number of MU’s activated for a specific activity

Asynchronous recruitment : when the MU’s alternate to slow down the speed of fatigue

List the 4 factors that affect the tension a muscle can generate.

• size of fiber

• length-tension relationship

• frequency of stimulation

• fatigue

What is the difference between twitch summation and tetany?

• Summation : is when 2 or more twitch’s add together to make a stronger contraction

• Tetany : is when the muscle is stimulated at such a high frequency that you get a maximum contraction

What are the 3 sources of ATP renewal in the muscle cell?

• Creatine phosphate

• oxidative phosphorylation

• glycolysis

List 3 examples of muscular fatigue in skeletal muscle.

• increase of inorganic phosphate

• increase in lactic acid

• decrease in energy reserves

Compare and contrast skeletal and smooth muscle’s thin filament.

• Skeletal : troponin, tropomyosin and actin

• Smooth : tropomyosin and actin, no troponin

Describe how smooth muscle is activated by calcium.

Calcium binds to Calmodulin , Activates myosin kinase , Adds a phosphate to the myosin head , myosin head forms crossbridge

What is the difference between multi-unit and single-unit smooth muscle activation?

• MU - neurogenic

• SU - myogenic connected w gap junctions

muscle table

List the 2 types of cells of cardiac muscle

• Autorhythmic

• Contractile

What is unique about the contractile cardiac muscle cell’s AP and what causes this?

It has a plateau produced by calcium

The plateau of contractile cardiac muscle cell results in a long refractory period. Why is this significant?

It prevents Summation

What is systole and diastole in the cardiac cycle?

• Systole - when the heart is contracting

• Diastole - when the heart is relaxing

What ECG component corresponds w the beginning of the ventricle systole?

QRS Complex

What causes blood to flow from one heart chamber to the next?

Pressure gradient

What is an isovolumetric period of the cardiac cycle?

When the pressure of the ventricle is higher than the atrium but lower than the ventricle, so no blood enters or leaves the ventricle.

What is the stroke volume and how would you calculate it?

Amount of blood pumped out of the ventricle each cardiac cycle

• EDV - ERV

What is cardiac output and how would you calculate it?

Amount of blood pumped by heart each minute

• HR x SV

List the 2 extrinsic systems that effect heart rate adn what changes do they cause?

• PNS : decrease HR

• SNS : Increase HR

How do we intrinsically and extrinsically regulate stroke volume?

Intrinsically - Venous Return and Length - tension relationship in sarcomeres

Extrinsically - SNS and adrenal medulla

What variables determine blood flow rate?

• Pressure Gradient

• Resistance

List the 3 variables determine resistance of a vessel and identify which one has the most influence on resistance?

• Radius of vessel ( most influence)

• length

• blood viscosity

What is the function of arteries besides transporting blood?

Pressure Reservoir

What are the 2 functions of arterioles besides transporting blood?

Cardiac output distribution and blood pressure

What is the function of capillaries besides transporting blood?

Exchange

What is the function of veins besides transporting blood?

Blood reservoir

Define systolic pressure, diastolic pressure, pulse pressure, and mean arterial pressure?

• Systolic pressure : max pressure on vessel wall

• Diastolic pressure : min pressure on vessel wall

• Pulse pressure : the difference between systolic and diastolic

• MAP : the average pressure on the vessel walls

List the 2 types of changes that arterioles make to alter resistance and bloood flow?

• vasoconstriction

• vasodialation

List 3 intrinsic factors that regulate arterioles and state which one is the most influential.

• Local metabolic changes (most important)

• Temperature

• Myogenic stretch response

List 3 extrinsic factors that regulate arterioles and state which one is the most influential

• SNS (most important)

• adrenal medulla

• vasopressin

Why is blood velocity is the slowest in the capillaries?

Greatest surface area

What is the purpose of a metarteriole?

To allow blood to return to the venous system and bypass capillaries that are closed off

List the forces that control filtration and reabsorption at a capillary and indicate which one’s favor filtration and which ones oppose filtration.

• Hp and Oi : favor filtration

• Hi and Op : favor reabsorption (oppose filtration)

List 3 functions of the lymphatic system.

• Return excess filtration to the vascular system

• return filtered proteins to the vascular system

• aids the immune system

• transport fats in the digestive system