Phys 335- unit 1 Learning objectives

Use figure 6.23 to explain why action potentials normally propagate in only one direction along axons.

All voltage gated sodium ions along the way are already opened or inactivated (think of burned black powder ash trail) *** The propagation of the action potential from the axon hillock region to the axon- terminal end is typically one way because the absolute refractory period follows along in the "wake" of the moving action potential

Draw a generic neuron and label the dendrites, cell body, axon hillock, axon, and axon terminals.

(***Cells of nervous system are NEURONS) 1. dendrites: receive info 2. Cell body = soma 3. Axon hillock: produce signal (other names= initial segment, trigger zone) 4. Axon: outgoing signal, carries AWAY from cell body 5. Axon terminals: accepts signal and sends along

Use figure 1.1 and list the four basic tissue and cell types.

-epithelial cell- epithelial tissue -connective tissue- connective tissue -neuron-nervous tissue -muscle cell- muscle tissue

List our four general types of carrier-mediated transport. Using figure 4.10, discuss the principle features of the four general types of carrier-mediated transport. What do they have in common and what makes them unique?

1. Facilitated diffusion - uses a transporter to move solute 2. primary active transport - direct use of ATP (PUMP) (creates the electrochemical gradiant that secondary uses).. 3 Na+ out and 2 K+ into cell 3. secondary active transport - the use of the stored energy of an electrochemical gradient across a membrane to move the ion and second solute across the plasma membrane 4. Channel-mediated diffusion - Vm- Eion as energy source; molecules using pathway= Na+ K+ Ca2+; moving high to low concentration

Using figure 6.4, discuss the locations and general functions of afferent neurons, efferent neurons, and interneurons. Table 6.1 will help you with this objective.

1. PNS Afferent neurons activity "affects" what will happen next into the CNS 2. CNS Interneurons enable communication between sensory or motor neurons 3. PNS Efferent neurons "effecting" change: movement, secretion, projecting out of the CNS

Using figure 6.32b, illustrate the local current flow that underlies an IPSP.

9. net effect is either: Hyperpolarization (if K+ or Cl-) OR Inhibits Further Depolarizations (Cl-) those cells without active Cl- pumps **local current is going AWAY from axon hillock

Draw figure 7.20 and describe in detail the ascending pathway taken by pain and temperature signals versus the ascending pathway carrying body movement, limb position, fine touch, and pressure information.

A. Anterolateral neuron (afferent neuron from pain or temperature receptor) 1. anterolateral column of spinal cord 2. axon crosses over WITHIN SPINAL CORD and ascends on the opposite side hemisphere 3. goes into thalamus, 2nd interneuron sends information into somatosensory cortex 3 neurons: 1 sensory afferent and 2 interneurons B. Dorsal column system (afferent neuron for limb position, fine touch, body movement) 1. cell body in dorsal root ganglion 2. central process continues to brain stem 3. first synapse onto internuron, where crossing over happens to other hemi 4. Synapse carries to sensory cortec Signal crosses over at brainstem to thalamus 3 nerons: 1 sensory afferent neuron 2 interneurons

Draw figure 7.6 and discuss the importance of both size and density of receptive fields on acuity. Use two-point discrimination tests as illustrative examples.

Acuity: the precision of localizing stimulus **size and density of receptive fields matters in the ability of the acuity -the bigger the receptor field of a single sensory unit, the LESS ACCURATE / LESS ACUITY you have

Describe what is meant by sensory stimulus transduction and define an adequate stimulus.

Adequate stimulus- What the receptor typically responds to, what it is most sensitive to Pressure for photoreceptors on eye is NOT THE ADEQUATE stimulus because you have to push hard to get a response

1 Use figure 1.1 and list the four levels of organization in the human body, from smallest to largest.

Cell__tissue__organ__organ system

Sketch figure 6.38 and identify the forebrain (and its parts), the brainstem (and its parts), and the cerebellum.

Forebrain: -Cerebrum -frontal lobe -Parietal lobe -occipital lobe -temporal lobe -Diencephalon -Thalamus: relay station, distribute signals up and down spinal cord -Hypothalamus: master control system (homeostasis) Brainstem: (life support) -Midbrain -Pons Medulla oblogata Cerebellum

Draw, label, and discuss figure 6.15 to demonstrate your understanding of a graded potential.

Graded potential: the amount of chemical stimulus gives you different amounts of polarization (membrane change is proportionate to the intensity of the stimulus) ; no threshold or refractory period unlike action potential

Using figure 6.8, describe how a resting membrane potential (Vm) is measured and what a "typical" Vm is for neurons

In real cells Vm = -70 mV (relative permeability determines which ion dominates in determination the RMP) Vm- Eion = the enthusiasm to move (membrane potential- equilibrium potential= actional potential)

Why are plasma membranes described as Fluid Mosaics?

Lots of motion and momentary gaps between hydrophilic heads and phobic tails... solutes are penetrating Hydrophilic substances are non penetrating

Explain and differentiate action potential propagation in unmyelinated versus myelinated neurons. Use figure 6.24 to define and illustrate "salutatory conduction".

Myelinated neurons: produced by oligo in CNS and Schwann in PNS ; voltage gated Na+ channels are clumped at nodes, where action potential happens so AP can jump from node to node -MUST FASTER BC YOU'RE SKIPPING GROUP TO GROUP (think page reading... pgs 3, 5, 9) (myelination for when you need speed, like motor neurons) "Salutatory conduction"= action potential jumps from node to node as they propagate along a myelinated neurons Unmyelinated neurons: voltage gated Na+ channels are throughout (slower, used in digestion regulation, no rush)

Using figure 6.40, identify and discuss the brain's limbic system.

thalamus- relay center hippocampus- learning and memory hypothalamus- appetities, unconcious control

Using table 4.3, define and differentiate between solutions described as: isotonic, hypertonic, hypotonic, isosmotic, hypoosmotic, hyperosmotic.

"Tonicity:" considered to predict the cell volume change (refer to learning obj. 48)

1 Per figures 3.5 and 3.6, draw a typical plasma membrane and its molecular components.

(refer to obj 19 for pic)

Using figure 4.20, draw and describe the processes of endocytosis and exocytosis.

***Both require ATP, many require membrane proteins Endocytosis: movement into a cell Exocytosis: movement out of a cell (ex= neurotransmitters)

Using both words and sketches, define "binding affinity" and clearly distinguish between high, intermediate, and low binding affinity sites.

***Different affinity possible between receptors and ligands (high, intermediate, and low affinity binding sites) Saturation binding curve relates ligand concentration and percent saturation; shows how well the receptors and ligands associate

Functionally and chemically distinguish between integral and peripheral membrane proteins.

***Distinguished by how the protein is disassociated from the membrane Integral- have substantial interaction with fatty lipids, have to destroy the plasma membrane with a detergent in order to get to protein out of membrane Peripheral- to extract it, you change the conditions of the fluid (ex= pH change )

Identify 5 types of neuronal glial cells, where they are found, and what function(s) they perform.

***Glial cells support the function of neurons. 4 types: 1. Astrocyte cells: manipulate, regulate, maintain the ECF conditions; important for the formation of the **blood brain barrier** 2. Ependymal cells: line fluid filled cavities; produce cerebral spinal fluid 3. Microglia cells: act as scavengers, debris removers 4. Oligodendrocyte: produce myelin (in CNS, but made by 5. Schwann cells in the PNS)

Define the term "nerve". As in figure 6.42, list the five regions of the spinal cord from top to bottom, state how many spinal nerves are associated with each, and explain what information is carried by spinal nerves.

***Nerve is a bundle of axons (can have both afferent and efferent characteristics) (-Cervical-8, thoracic-12, lumbar-5, sacral-5, CO-1 )

1 Define homeostasis with words and draw the conceptual loop we developed in lecture.

***Refers to the dynamic mechanisms that detect and respond to deviations in physiological variables from the set point values by imitating effector responses that restore the variables to the optimal physiological range Homeostasis- cellsà tissuesà organsà organ systemsà alter and manipulate the extracellular fluid conditions which bathes and mantainsà cells (LOOP)

Describe neuromodulators; what is their general mechanism of action?

***another way to modulate the strength of a synapse -activate 2nd messengers at non-synaptic receptors (usually metabotropic receptors) -can interact with receptors on either presynaptic or postsynaptic cells to modify effectiveness of the synapse at transmitting a signal **neurotrasnmitters are involved in rapid communication, whereas neuromodulators tend to be associated with slower events such as learning, development, and motivational states

Using figure 7.21, describe the Sensory Homunculus/Somatotopic Map and explain the significance of the different sizes of body parts in the map.

***sensory homunculus: Termination areas for ascending labeled lines 1. Area size 2. Grouping

Using figure 4.16, explain the principle of osmosis.

***special case of diffusion; diffusion of water towards more solutes - water CAN cross most cell membranes due to channels called aquaporins - BEFORE diffusion: the partition between the compartments is permeable to water only -AFTER diffusion... equilibrium has developed, movement of water and solute has equalized concentrations

Using figure 3.32, describe and depict both allosteric modulation and covalent modulation of receptors. What changes in both types of regulation? How does the change occur?

***used to help ligand and receptors work, to have affinity Allosteric modulation- modulator protein changes shape of binding site; need a friend to convince receptor protein that the ligand can work Covalent modulation- need ENZYME driven change (kinase, phosphorylate proteins by taking ATP phosphate and transfer to OH group... drives receptor to change shape) to cause high AFFINITY (Phosphatases TAKE phosphate group away to undo what kinase did)

Draw figure 5.4 and discuss the properties and steps that a hydrophobic signaling molecule typically utilizes.

**are membrane- penetrating messengers usually bind to intracellular receptors and then alter gene transcription and protein synthesis **typically have a slow effect because they are inducing the synthesis of new proteins

Draw figure 5.10 and describe the steps of the PLC-PKC signal transduction cascade. 2nd cascade to know

**in end, Ca2+ (and DAG) ACTIVATES PROTEIN KINASE C 1. First messenger to Receptor 2. G protein 3. Phospholipase C releases head group 4. IP3 Head group released into cell, finds ionotrpic receptor on smooth ER 5. Calcium released and activates kinase 6. Active protein kinase C 7. Protein PO4 allows cell response

Using figure 4.19 explain what would happen to the volume of a cell dunked into a solution that is: isotonic, hypertonic, and hypotonic.

**water (the ECF)moves to where there is more solute, whether its in or out or no change Isotonic: no movement, no change in cell volume bc same volume in and out of cell Hypertonic: Cell shrinks, water moves to where there is more solute (Ex: 400 NP outside cell, 300 NP inside cell, water moves out shrinking cells) Hypotonic: Cell swells, water moves into cell (Ex: 300 NP inside cells, 200 outside, water moves in)

Using figure 4.11, draw and describe primary active transport. Then describe the molecular details of the Na+/K+-ATPase pump as it is working.

- ***Requires energy input, usually ATP - move solute against a concentration gradient (creates and maintains) - transport protein PERFORMS the hydrolysis of ATP

Using figure 4.9 and your lecture notes, discuss two experiments that measure solute flux rates and reveal the difference in saturation behavior between diffusion and carrier-mediated transport.

- Diffusion: process does not saturate (flux rate only limited by concentration gradient) - Carrier Mediated: processes saturate (number of available carriers places an upper limit on the flux rate, curve will flatten) Application: diabetes; insulin= higher amount, but only have so many transporters in kidneys, whatever remains ends up in urine

List organelles and functions

- Membranes (surround organelles and cells) - Nucleus- (Genomic DNA) - Ribosomes- (Protein synthesis) - Endoplasmic reticulum- (Protein synthesis and calcium dynamics) - Golgi apparatus (sorting modifying, directing secreted proteins) - Mitochondria- (ATP synthesis) - Lysosomes (digestion/ break apart) - Cytoskeleton (strux/ funx)

List the three types of events that regulate the gating of ion channels.

- Selective for certain ions - Gated by chemical, electrical, or mechanical events

1 State four functions of a plasma membrane (see Table 3.1).

- Selective permeability (passage of substances) - Receptors (detect 4 chemical messengers) - Link adjacent cells together by membrane junctions (esp desmosomes and gap junctions) - Anchor cells to the extracellular matrix)

Using figure 4.8, draw and describe facilitated diffusion. (of large, hydrophilic solutes)

- diffuse down gradient (high to low)à move in direction predicted by the concentration gradient - in active transport, energy source required to move materials -USES TRANSPORTER to move solute

Using figure 6.14, define and discuss what is implied by depolarization, overshoot, repolarization, and hyperpolarization.

-70 mV= rest Going towards zero from -70 mV: depolarizing Going past zero into positive membrane potentials: overshoot Return towards rest from positive or negative value: repolarization Go below -70 mV: hyperpolarization

1 Write the three bullet points that define and describe positive feedback loops.

-Cause a rapid change in a variable (very few found in us) -Increase or reinforce the change of a variable -They require a terminating event to break the loop (otherwise they keep going)

Using figure 6.44, define dual innervation as it pertains the ANS and give some examples. Then detail the functional anatomy of both parasympathetic and sympathetic motor neurons, including their cell body locations, lengths of pre and post ganglionic neurons, locations of ganglia, and how neurotransmitters are released from varicosities not axon terminals.

-Dual intervention of parasympathetic and sympathetic is the typical pattern Lengths of pre and post ganglionic neurons are opposite of each other Locations: Pre- cranial sacral ; post- thoracal lumbar

Using figure 6.9, reproduce the talking points that summarize our starting point of the membrane potential concept

-ECF and ICF have balanced charges; tiny number of ions along the membrane cause the membrane potential -Membrane potential changes only when current flows across the membrane (Na K Cl Ca are the biggest ions involved)

1 Define feed forward regulation. How is it different than negative feedback control? Describe some examples of when this occurs in the body.

-Feed forward limits the amount of change; it does not prevent change... it ensures that the change is not too large Occurs before negative feedback Examples: skin temp receptors anticipates core temp change that will occur when entering new environments ; blood pressure and respiration alterations when anticipating physical activity

Using figure 4.13, draw and describe secondary active transport. Then describe what cotransport (aka symport) and counter-transport (aka antiport) indicate. Use figure 4.14 to draw examples of each.

-Movement against a concentration gradient -***Energy provided by another molecule's concentration gradient (often times it is the Na gradient that comes from the primary pump) -ATOP not hydrolyzed by transport protein -if the second solute is moving in same direction of its Na+ ion gradient= COTRANSPORT -If second solute and Na+ ion move in opposite directions: COUNTERTRASNPORT ***Driven by Na+

Explain the difference between molarity (moles per liter) and osmolarity (osmoles per liter).

-Osmolarity: total solute concentration / liter of water -a solution that is 1 mol/ L NaCl has an osmolarity of 2 osmoles/L -a solution that is 1 mole/L glucose has an osmolarity of 1 osmole/L -1 mol/L CaCl2 has osmolarity of 3 mol/L ***1 osmol = 1 mol of solute particles ; it is useful to have a concentration terms that refers to the total concentration of the solute particles in a solution, regardless of their chemical composition

Explain what it means to say that one branch of the autonomic system is discrete, and one is generalized; state the identity of each.

-Parasympathetic is discrete (long preganglionic axon) -Sympathetic is generalized (divergence in ganglion)

103 Reproduce table 6.6 and add the talking points from lecture. (neurotrasnmitters/ neuromodulators)

. Ach= excitatory (nicotinic and muscarinic receptors) à it is the receptor or ion channel that determines whether an IPSP OR EPSP develops; but some 2. Biogenic Amines A. Catecholamines (derivatives of tyrosine) 1. Dopamines 2. Norephinephrine 3. Epinephrine B. Serotonin C. Histamine 3. Amino Acids A. Excitatory amino acids (GLUTAMATE is classic) B. Inhibitory amino acids (GABA and GLYCINE are classic) 4. Neuropeptide (Opioids, oxytocin, substance P = NT in pain) 5. Gases (nitric oxide... relaxes smooth muscle, vasodilation) 6. Purines (adenosine and ATP...effect on smooth muscle depends on R type, can have differing types)

Using figure 6.27 as a guide, list the presynaptic events involved in neurotransmitter release at chemical synapses.

1. A.P. Propogates to terminal 2. Ca 2+ channels open (voltage gated) 3. Ca2+ activates vesivle exocytosis- trigger synaptotagmin and SNARE proteins to induce membrane fusion and neurotransmitter release 4. Neurotransmitter diffuses across tiny gap (15nm)

Reproduce figure 7.19 and describe how pain pathways are modulated by higher neuronal centers, various therapies, and drugs such as morphine and NSAIDs.

1. Analgesia (aspirin) blocks synthesis of prostaglandins (COX enzyme inhibitor) ... could still be making the arachidonic acis, but no longer converting it 2. Novacaine, lidocaine: block Na chs, NO AP'S 3a. Pre: opiate receptors block transmission of pain at synapse (PRE-SYNAPTIC INHIBITION EX)

1 Build table 1.2 and discuss the five important generalizations about homeostatic control systems.

1. Control mechanisms try to balance input/ output 2. Negative feedback is always towards the typical expected value 3. There are a range of values, not a single value 4. Set points can be re-set up or down Conflicts arise!

Draw figure 5.6 and describe the steps of the PKA signal transduction cascade. Then draw figure 5.9 and provide some example targets/responses to activated PKA.

1. Hydrophilic receptor (metabotropic receptor= connected to cascade) 2. G protein connected metabotropic receptor to an effector 3. Stimulates adenylyl cyclase 4. Convert ATP into cAMP (second messenger) 5. Activates protein kinase (pKa) 6. Phosphorylated proteins give rise to cells response (refer to figure 5.6 for pic explanation)

Explain why postsynaptic potentials are brief using four talking points.

1. Neurotransmitter rapidly binds and unbinds 2. Neurotransmitter reuptake into presynaptic terminal and or 3. Neurotransmitter diffusion away from the synapse and or 4. Enzymatic destruction of neurotransmitter (and re-uptake of products)

List two factors that influence the propagation velocity of action potentials along neurons.

1. One way (WHY? High density of voltage gated sodium channels) 2. Myelination increases velocity propagation (called saltatory conduction) 3. velocity increases with axon diameter (less resistance in cytoplasm with larger diameter)

Draw an example graph that illustrates summation of graded potentials.

1. Proportional to size of stimulus 2. Decrease with distance from stimulus site 3. Can be depolarization or hyperpolarization's 4. Can summate with each other 5. are short distance signals that rely only on local flow of ionic currents 6. (aka called generator potentials, sensory receptor potentials in chap 6)

Using figure 6.13, summarize in 3 steps how a resting membrane develops, beginning from a state where there is no membrane potential.

1. Pump sets up the Na+/ K+ concentration gradient and thus sets up the Eions 2. At first, more K+ diffuses; creates charge difference ; RMPà -70 (ex large K+ leak thru leak channels, small Na+ leak thus not Ek nor Ena) OHMS LAW 3. Na+ and K+ then both move at the resting steady state, not an equilibrium because ATP is required to keep fluxes equal (stable resting potential is achieved)

Draw figure 7.2 and demonstrate how sensory receptor potentials are graded while action potentials arising from them are not. Describe what happens to receptor potentials and action potentials as the intensity of stimulation of a sensory unit increases.

1. Sub 2. Supra (if action potential propogating, NT released into CNS) 3. Supra (bigger graded potential, more frequent pulse of action potentials NOT BIGGER ACTION POTENTIALS as it is, AP's are not graded)

List four properties that distinguish action potentials.

1. are "all or none" like a gun, fire or not fire 2. are not graded by stimulus size (ECF conditions influence appearance/ characteristics) 3. can NOT SUMMATE due to refractory period (absolute and relative refractory period) 4. do NOT decrease with distance, they propogate over long distances, large local currents ... very opposite than graded potentials

1 Use figure 1.9 to discuss the mechanisms of body core temperature regulation via negative feedback.

1. decreased body temp 2. receptors (temp sensitive neurons) 3. afferent pathway (nerves towards CNS) 4. integrating center (compare to set point of 98.6 degrees F) 5. efferent pathway (nerves exiting brain) 6. effectors (skeletal and smooth muscle contraction, decrease of bloow flow) 7. shivering response

As in figure 6.34, describe eight ways that synaptic transmission can be altered by drugs and diseases.

1. increase leakage of NT from vesicle to cytoplasm, exposing it to enzyme breakdown 2. increase transmitter release into cleft 3. block trasnmitter release 4. inhibit transmitter synthesis 5. block transmitter reutake 6. block cleft or intracellular enzymes that metabolize transmitter 7. bind to receptor on postsynaptic membrane to block (antagonist) or mimic (agonist) transmitter action

Draw figure 5.12 and describe the steps of the PLA2-ARA signal transduction cascade. 3rd cascade to know

1. receptor ligand complex as always 2. membrane phospholipidà arachidonic acid through phospholipase A2 enzyme that uniquely targets the second fatty acid tail (which is arachidonic acid) 3. arachidonic acid is hydrophobic and can go out of or into cell; if arachidonic acid is released and encounters cyclic acids, it produces prostaglandins (important for PAIN); arachidonic acid can counter lipogeneses pathway outside of cell, produce leukotrienes (important for allergic/ inflammatory reactions)

Draw and label figure 6.19. Using the seven talking points, describe an action potential and state how they are different from graded potentials.

1. steady resting membrane potential is near Ek, Pk+ > PNa+ due to leaky K+ channels 2. local membrane brought to threshold voltage due to depolarizing stimulus 3. (rising action of graph) current through opening voltage-gated Na+ channels rapidly depolarizes the membrane, causes more Na+ channels to open 4. (peak of graph) inactivation of Na+ channels AND delayed opening of K+ channels HALT DEPOLARIZATION 5. Outward current through open voltage gated K+ channels reploarizes the membrane BACK TO NEGATIVE potential 6. (dip in graph) Persistent current through slowly closing voltage-gated K+ channels HYPERPOLARIZES membrane towards Ek, Na+ channels return from inactivated state to CLOSED state 7. closure of voltage gated K+ channels returns the membrane potential to its resting value

Describe and illustrate the calcium-dependent exocytosis of neurotransmitter via the SNARES and fusion pores.

5. Ca2+ binds synaptotagmin, causing SNARE complex to draw vesicle to plasma membrane (calcium must bind to the synaptotagmin protein for exocytosis)

List the postsynaptic events that underlie inhibitory postsynaptic potentials (IPSPs).

6. Neurotransmitter binds to receptor 7. Ligand-gated channels open (chemical gating) 8. EITHER K+ flux out or Cl- flux in ***Cl- is inhibitory... Cl- reduces any excitatory action, reduces AP probability of occuring

List the postsynaptic events that underlie excitatory postsynaptic potentials (EPSPs).

6. Neurotransmitter binds to receptor 7. Ligand-gated channels open (chemical gating) -iontropic R 8. Cations flow through (mainly Na+ or Ca2+) ***this is excitatory synapse, so need to depolarize the post synaptic membrane

Using figure 6.32a, illustrate the local current flow that underlies an EPSP.

9. Net effect is depolarization (a tiny EPSP)... An exitatory postsynaptic potential. a graded potential that makes an AP more likely. (peak in graph) **local current flow (+) away from site on inside

Write the equation that applies Fick's Law of diffusion to biological membranes.

A quantitation of diffusion - accounts for movements, permeability, molecular surface area, molecular weight, concentration gradient across membrane

Using figure 7.15, make a list of five different skin receptors and their properties.

A. Meissner's corpuscle- B. Merkel's corpuscle- C. Free neuron ending-

Reproduce table 6.4 to ensure your understanding of differences between graded potentials and action potentials

AP: -all or none -cant be summed -has threshold -has refractory period -conducted without decrement... deploarization is amplified to a constant value at each point along the membrane -duration is constant -is only deploarization -intitiated by graded potential -mechanism depends on voltage-gated ion channels GP: -Amplitude varies with size of stimuli -can be summed -has no threshold -amplitude decreases with distance (not decremental) -duration varies with initiating conditions -can be depolarization or hyperpolarization -initiated by environmental stimulus (receptor) by NT (synapse) or spontaneously -mechanism depends on ligand-gated ion channels or other chemical/ physical changes

Define the absolute and relative refractory periods. Then sketch figure 6.22 to describe an experiment you could use to determine those periods.

Absolute refractory period: does not matter the strength of stimuli, you are not getting a response... either all voltage gated Na+ channels are either open already or not active Relative refractory period: if you wait a bit of time and give another stimulus but its stronger, you get an action potential... for action potential, Na+ conductance > K+ conductance ***Reasons for larger stimulus requirement: 1. few closed sodium channels 2. Open potassium channels (must oppose the repolarization)

Differentiate between adaptation and acclimation

Adaptation: inherited c characteristic that favors survival; in environment ... VS. Acclimation: changed functioning/ performance of existing system; effectiveness of homeostatic control system can be enhanced by prolonged exposure to specific environment Ex: in high altitudes, you're acclimating not adapting; they revert to status once at low altitude

Using table 5.1, describe the difference between an agonist versus an antagonist.

Antagonist: binds receptor, prevent subsequent events of ligand (antihistamine ex) Agonist: binds receptor, triggers subsequent events of ligand (decongestant ex)

Draw figure 5.5 and discuss the properties and steps that a hydrophilic signaling molecule typically utilizes. Also define what an ionotropic receptor is.

Bind to extracellular receptors and then EITHER 1. alter the shape of ion channels (IONOTROPIC RECEPTOR) 2. initiate second messenger cascades **typically have a fast effect because they modify proteins

1 Use figure 1.10 to define and distinguish between four types of chemical messengers.

CHEMICAL MESSENGERS: -Autocrine- acts on same cell that secreted the substance -Paracrine- targets cells in close proximity to the site of release of paracrine substance -Neuron- neuron or muscle cell in close proximity to site of neurotransmitter release -Horomone secreting gland cell- target cells in one or more distant places in the body

Causation vs. Correlation

Causation: if dependent variable is altered due to a change in independent variable Correlation: if a third variable causes changes in both the independent and dependent variable so it looks like there is a causation

Using figure 6.37, identify and discuss both the functional and the anatomical divisions of the nervous system

Central Nervous system: brain and spinal cord Peripheral nervous system: everything else... 2 divisions à -afferent division- (AT, TOWARDS CNS)- Somatic sensory (touch, feel) ; visceral sensory (internal organs) ; special sensory (vision, smell, taste) -efferent division- (EXIT, AWAY FROM CNS)- Somatic motor (sk movements, usually conscious) ; autonomic motor (sympathetic fight or flight, parasympathetic rest and digest, enteric gut wall nervous system) pg 139 textbook

Using figure 6.5, draw and define a synapse, a presynaptic neuron, a neurotransmitter, and a postsynaptic neuron.

Chemical synapses: neurons communicate here, Neurotransmitter: chemicals are released by presynaptic neurons at axon terminals and act on postsynaptic neurons Presynaptic: TOWARDS synapse Postsynaptic: AWAY from synapse

1 What are a few examples of positive feedback in the human body?

Childbirth: Smooth muscle of uterus contracts, myometrium is squeezed to stretch cervix open; hypothalamus secretes oxytocin to jam baby into cervix more

1 State the chemical function of cholesterol in the plasma membrane.

Cholesterol helps keep fatty acid tails together; but fatty acid tails can get too close together and form a solid (so cholesterol needs to be just right)

Use Table 1.1 and list the body's organ systems. For each system include the major organs or tissues and the primary function(s) of the system

Circulatory- transport blood throughout body Digestive- digestion and absorption of nutrients and water; elimation of wastes Endocrine- regulation and coordination of many activities in the body, including growth, metabolism, reproduction, etc. Immune- defense against pathogens Integumentary- protection against injury Lymphatic- collection of extracellular fluid for return to blood; participation in immune defenses; absorption of fats from digestive system Musculoskeletal- support, protection, movement of body; production of blood cells Nervous- regulation and coordination of many activities in the body; detection and responses to internal and external envrionments Reproductive - Respiratory- exchange of carbon dioxide and oxygen; regulation of hydrogen ion concentration in the body fluids Urinary- regulation of plasma composition through controlled excretion of ions, water, and organic wastes

Using figure 6.25, define and illustrate convergence and divergence with regard to neuronal pathways. Explain the functional significance of each neuronal arrangement.

Convergence: a lot of neurons create one effect Divergence: multiple action potentials created from one summation of graded potentials

Using figure 7.17 as an example, define a referred pain and describe the mechanism that causes this phenomena.

Convergence: both sensory afferent processes end up on the same interneuron Ex: heart attack, feel pain in left arm due to referred pain à

Explain how the terms negative feedback and positive feedback relate to the function of voltage gated Na+ and K+ channels during a typical neuronal action potential.

Depolarization is what opens each channelà positive feedback: each channel has increased flow of na+ into the cell, depolarization of membrane, opening of voltage gated Na+ channels Negative feedback: K+ channels represent 1. depolarization of membrane by na+ influx, opening of voltage gated k= channels, increased pK, increased flow of k+ out of cell, repolarization of membrane potential

Calculate the equilibrium potential of potassium and sodium ions using the Nernst equation.

Eion= 61/ z x log (conc ECF / conc ICF)

Reproduce the diagram we developed in class that explains the concept of an electrochemical gradient and how its components affect the movement of an ion through a cell membrane.

Electrochemical gradient describes how both the concentration and membrane charge affects ions Direction and magnitude of ion fluxes across the membranes depend on both the concentration difference and the electrical difference (the membrane potential)- combined are the electrochemical gradient across the membrane

1 Draw a simplified body plan as we did in lecture. Differentiate between the external and internal environments. Include all the talking points presented during lecture.

External and internal are separated by an epithelial layer External: continuous, surroundings to external skin, air in lungs, food in stomach and intestines, urine in bladder; cells have no direct exchange with external environment Internal: where most of cells are in contact with; interstitial fluid and plasma are extracellular fluid, plasma is fluid around blood cells, interstitial fluid is fluid around all other cells

Similar to figure 6.41, draw and label a cross-section of the spinal cord. Highlight the functional relationships and flow of neural signaling in afferent and efferent neurons.

Gray matter inside (cell bodies) White matter outside (myelinated axons) Dorsal root is afferent Ventral root is efferent

Using figure 6.39, describe gray and white matter and discuss their functions in the brain.

Gray matter: outer layer= cortex (cell bodies); makes up the lobes outer layers White matter: axons -commissures and tracts= axons and myelin -nuceli= functional clusters of cell bodies

Explain why intracellular fluid and extracellular fluid Na+ and K+ concentrations are different, and state the typical values found in each compartment (utilize Table 6.2).

ICF: Conc maintained by Na+/K+/ATPase Pumps Na+: 15 K+: 150 ECF: Conc maintained by Kidneys Na+: 145 K+:5

State the typical concentrations of Na+ and K+ in the intracellular and extracellular fluid. Explain what is responsible for maintaining the extracellular concentrations and what is responsible for maintaining the intracellular concentrations.

Intracellular: Na 15 mM K 150 mM ***Maintained by pump Extracellular: Na 145 mM K 5 mM ***Maintained by your kidneys (MORE NA IN more K out)

Reproduce figures 7.9 and 7.10 to explain what lateral inhibition is and why it enhances acuity.

Lateral inhibition enhances acuity; you can tell exactly where the tip of pencil is because of AP frequency difference. Axon collaterals 1 and 2 excite interneurons, which are inhibitory on A and C (=axoaxonic inhibition)

1 Describe what is meant by a "membrane leaflet". Are the lipid components the same in each?

Leaflet- layer; phospholipids are not the same (refer to obj 21 for pic)

Using figure 3.29, define and depict a receptor and a ligand.

Ligand- any molecule or ion that binds to a protein by either electrical attraction or hydrophobic forces Receptor- binding site for ligand

Using figure 6.36, explain the neurophysiology and significance of long-term potentiation.

Long term potentiation: mechanism of learning and memory (strengthening a synapse!) 1. changes to pre 2. Glutamate release 3. Glutamate binds to both channels 4. Na+ entry depolarizes cell 5. Depolarization drives Mg2+ ion out of pore 6. Ca2+ entry activates second-messenger systems 7. Long lasting increase in glutamates receptors and sensitivity

Using potassium and sodium ions as examples, explain the concept of an equilibrium potential. Write the Nernst equation and discuss what it tells you.

Membrane potential at which two fluxes become equal in magnitude but opposite in direction is called the equilibrium potential Example 1: If there is a membrane permeable only to K+, leaves A- behind, attracts K+ to come back in Example 2: membrane only permeable to Na+, allows Na+ down concentration gradient into cell and brings positive charge into cell, develops tendency for Na+ to be kicked out

Draw and label figure 7.16 to discuss the neuronal pathway carrying pain sensation to the brain, including the neurotransmitters involved and the brain regions where synapses occur.

Naked axon endings responding to intense deformation, tissue damage, intense stimuli of many types (polymodal) e.g. chemical ligands released with tissue damage like histamine, cytokines, and protsoglandins ***also respond to damaging temps and mechanical sheering forces Nociceptorsà afferent pain fiber (PNS) à central process projects into CNSà release either substance P or Glutamate (both excitatory) excite anterolateral pathà somatosensory cortex

1 Use figure 1.8 to show how the five components of a negative feedback system sense and respond to a deviation from normal.

Negative feedback always wants you to get BACK TO NORMAL, SET POINT (OPPOSES CHANGE): 1. Regulated variable changes value, deviates from normal range 2. detection at receptor 3. often nerves, horomones through afferent pathway (at/ towards the brain) 4. integrating center, comparing to set point 5. nerves / horomones through efferent pathway (exiting brain ) 6. effector (tissues, organs, systems or behaviors) 7. response (opposes intial change, back towards set point = negative feedback)

From table 6.8, discuss the functions served by cranial nerves II, IX, X, and XI.

Optic, (afferent, eyes) glossopharyngeal (both, swallowling), vagus (both, pharynx, larynx, thorax, abdomen) accessory (efferent, neck)

Using figure 4.18, describe what will occur when there are different concentrations of non-penetrating solutes on two sides of a membrane that is permeable to water.

Osmotic pressure is proportional to the solute concentration; you need osmotic pressure in order to oppose water from moving into a compartment

Using figure 4.18, explain what osmotic pressure represents and why it is proportional to the amount of non-penetrating solutes.

Osmotic pressure: is proportional to the solute concentration; it is the pressure that would have to be applied to stop water from moving into a compartment

Discuss and distinguish the functions of somatic, visceral, and special sensory neurons, and give examples of what is detected by each.

PNSà Afferent divisionà àsomatic sensory: touch, pressure, pain àvisceral sensory: not conscious monitor and process; blood pressure, O2 levels, etc. àspecial sensory: vision, hearing, taste, smell (desentisize, focus) PNSà Efferent divisionà àsomatic motor (to skeletal muscles); à autonomic motor (to smooth muscle, GI tract, heart, glands, usually not conscious control) -ends in a ganglion (grouping of cell bodies in PNS) -Has two-neuron chain between CNS and effector organ -Innervates smooth and cardiac muscle, glands, GI neurons, BUT NOT SKELETAL -Can be either excitatory or inhibitory à Parasympathetic division = rest and digest à Sympathetic = fight or flight

1 Define and distinguish between Physiology, Anatomy, and Pathophysiology.

Physiology- how the body functions, how it works, it's mechanisms Anatomy- structures, its parts, because function follows form Pathophysiology- disease mechanisms or processes, what is occurring often aids our understanding of "typical" physiology

1 Using figure 1.3, draw and label a diagram that illustrates the major fluid compartments of the body. With labels for each compartment, indicate the volumes in an average-sized person.

Plasma- 3 L Interstitial Fluid- 11 L Intracellular fluid-

Use figure 6.26b to sketch chemical synaptic transmission that occurs axo-dendritic, axo-somatic, and axo-axonic. For all three, label pre and post-synaptic membranes, the synaptic cleft, the vesicles with neurotransmitter before exocytosis, and the net diffusion of neurotransmitter across the cleft.

Pre to postsynaptic (important regulatory feature) communicating synapses Axo -denditic Axo -somatic Axo -axonic (vital for presynaptic inhibition / facilitation to occur)

Reproduce table 6.5 which summarizes the factors that determine synaptic strength.

Presynaptic factors: -axon terminal membrane potential -axon terminal Ca2+ -axo-axonix synapses -certain drugs and diseases, which act via the above mechanisms Postsynaptic factors: past history of membrane (exitation or inhibition) -effects of other neurotrasmitters or neuromodulators acting on postsynaptic neuron -enzymatic destruction of neurotransmitter -neurotransmitter reuptake

Compare/contrast the major characteristics of pathways by which substances cross membranes (i.e. the characteristics shown in Table 4.2 and exemplified in figure 4.15).

Primary active transport- use ATP directly secondary active transport- use ion gradients directly facilitated diffusion- uses transport protein channel mediated- use of ion channels / vm-eion (membrane potential - equilibrium potential of ion)

Use figure 7.3 to distinguish the response and function of rapidly-adapting receptors versus slowly-adapting receptors; state an alternate term for each type.

Rapidly adapting (phasic receptor)- stimulus application, stimulus removal (putting pants on example, only get information when you put pants on and off) BODILY EXAMPLE: Messeiner's corpuscle: rapidly adapting mechanoreceptor, touch and pressure Slowly adapting (tonic) receptor- continual response, slowly adapting receptor along backside of torso that is receiving pressure from chair while sitting (examples= blood pressure, posture) BODILY EXAMPLE: Merkel's corpuscle- slowly adapting mechanoreceptor, touch and pressure

List the major properties that determine the function of an ion channel.

Require integral transmembrane Must be hydrophilic environment for ion

Draw and discuss figure 6.16 to illustrate key characteristics of graded potentials.

Resting membrane potential is starting reference point Depolarization stimulus makes action potential more likely (EXITATORY) Hyperpolarization of stimulus makes action potential less likely (INHIBITORY) ***size of graded potential depends on the stimulus strength, proportional, decay rapidly with distance ("decremental")***

State the main role of the nervous system in maintaining homeostasis

Role in homeostasis: control system that receives info about internal (ECF) and external environment, integrates it, and directs activities of cells throughout the body to maintain homeostasis

Describe the interactions between positively and negatively charged particles, and how those interactions are changed depending on the amount of charge and distance of separation. Utilize figure 6.7 for this learning objective.

Separated charges have the potential to do work (in millivolts mV) Phospholipid bilayers have the ability to separate charge; has a high electrical resistance and acts as a capacitor... at rest the membrane potential is NEGATIVE (inside with tespect to outside) ***ALL CELLS HAVE A POTENTIAL DIFFERENCE ACROSS THEIR PLASMA MEMBRANE (in millivolts mV)

1 Explain the concept of a "set point" in physiology and discuss an example of when a set point might change.

Set point can be reset, can go up or down ; blood pressure set point might change

Using a combination of figures 4.1, 4.2 and 4.3, define and differentiate between simple diffusion, net diffusion, and an equilibrium state.

Simple diffusion- Random movement, has no direction Net diffusion- when there is a direction of movement (high concentration to low concentration, not found at equilibrium) Equilibrium state- equal flux in both directions Net flux accounts for solute movements in both directions

Use figure 7.5 to illustrate and define a sensory unit. Demonstrate how stimulus intensity impacts the afferent action potential frequency.

Single sensory unit is all of the peripheral terminals (process, body, central process, all of the projections in the CNS. It Is the afferent neuron) Stimulus intensity increases, the action potential frequency to the central nervous system increases ***SUMMATING GRADED POTENTIALS, but overcoming relative refractory period of AP (being able to touch a hot tea)

1 Define functional unit as used in human physiology.

Smallest piece of the organ, smallest you can break it down

Reproduce figure 6.46 and discuss the various neurotransmitters released, the neurotransmitter receptors, and the target tissues. What is the difference between a neurohormone and a neurotransmitter?

Somatic NS: Ach binds to a nicotinic Ach receptor on skeletal muscle Autonomic NS (parasympathetic division): 1. N-AChR (ionotropic) 2. M-AChR (metabotropic) Autonomic NS (sympathetic division) ***does not release Ach onto the effector ; releases norepinephrine (NE) and epinephrine (Epi) ***Adrenergic receptors receive the NE and Epi Epinephrine (Neurohormone) comes out of adrenal medulla -Neurohormone is released from neuronal cells and gets into bloodstream to reach rest of body -Neurotransmitter not into bloodstream, only signals from nerve fiber to nerve fiber

128 Using figure 7.13, explain the concept of "labeled lines" with regard to sensory neural pathways.

Stimulus location: labeled lines terminate in cortex regions of the brain dedicated to each body area and modality Sensation: sensory information reaches cortex via labeled line Perception: awareness and meaning at association area (INTERPRETS SENSATION)

Use figure 6.21 to illustrate and define subthreshold, threshold, and suprathreshold stimuli.

Subthreshold: do not get to potential Threshold: get you to -55 mV action potential Suprathreshold: get you stronger than threshold

Explain the difference in relationship between Vm and ECl- for cells with chloride pumps and cells without chloride pumps.

TYPE 1: Ecl= Vm = -70 (what it wants to be is what it is) ... Nernst potential at equilibrium is the same as RMP (-70 mV) NO OVERT CHANGE OBSERVED; when chloride channel opens you're already at equilibrium TYPE 2: (chloride pump) Vm not equal to Eion (when chloride channels opened up, there is an enthusiasm to move and an overt change observed)

Using figure 6.31, explain synaptic integration and define both temporal and spatial summation.

Temporal- one input only Spatial- 2 or more presynaptic inputs summating

1 Discuss the main factor that determines the selective permeability of lipid bilayers. Identify and describe substances that are permeable, substances that are not permeable, and explain how substances that are not permeable are in fact able to cross living cell membranes.

Think: more permeable= more diffusion, bigger SA= more diffusion, Bigger substance= slower diffusion, bigger concentration gradient= slower diffusion

Draw and label figure 6.26a of an electrical synapse. Describe their construction, their properties, and their functional significance. List some body locations where they occur.

Very rapid, found in local CNS networks between glial cells/ cardiac/ smooth muscle tissues

First, using your lecture notes, reproduce our derivation of Ohm's Law that we will use in human physiology. Second, use figure 6.12 to apply Ohm's Law, to apply electrochemical gradients, and to explain how net ion movement across a membrane is determined.

Voltage ion -Iion= gion- conductance ion- x (Vm- Eion enthusiasm to move)

Given that lipid bilayers are not very permeable to water, explain how water is able to permeate cell membranes in physiologically relevant amounts.

Volume of compartments has to change! It is the presence of a membrane permeable to solute that leads to the volume changes associated with osmosis - Osm= # solutes ------------------ Vol water

Draw and label figure 6.18 to illustrate the conformations of the voltage-gated Na+ channels and voltage-gated K+ channels that underlie the typical neuronal action potential.

When voltage gated Na+ channels are rapidly opened, the become inactivated (FAST) When voltage gated K+ channels are opened, they become depolarized (very slow process SLOW... stoners, called after-hyperpolarization when it goes BLOW -70 mV bc voltage gated K+ channels stayed open for too long bc too slow to close ) ***Depolarization is what opens both channels, what drives them back to the conformation is repolarization

Use figure 7.1 to describe two types of sensory receptors.

a. Receptor membrane- (Integral membrane protein) b. Receptor cell difference is on modality (stimulus, transduction, receptor potentials)

1 Reproduce figure 3.4 and differentiate between the cytoplasm and cytosol of a cell.

a. cytoplasm: everything between plasma membrane and nucelus (yes, organelles and their fluid) b. cytosol: just the fluid bound by the plasma membrane. NOT ORGANELLES NOR their fluid

1 Using figure 1.4 and blood glucose levels, explain the essence of homeostasis.

blood gluclose increases, levels return to their set point via homeostasis

Reproduce table 6.3 to ensure your understanding and proper usage of membrane potential terms.

graded potentials (potential change of variable amplitude and duration conducted decrementally (according to distance))LEAD TO action potentials (all or none depolarization) membrane potentials= the voltage difference between the inside and outside of the cell equilibrium potential= the voltage difference across a membrane that produces a flux of a given ion species that is equal but opposite to the flux due to concentration gradient of that same ion resting membrane potential = the steady potential of an unstimulated cell

Draw figure 6.33 and define both presynaptic inhibition and presynaptic facilitation.

presynaptic inhibition - decreases NT release from PreB to PostC thus it can inhibit BOTH exhibitory and inhibitory synapses presynaptic facilitation- increase neurotransmitter release from PreB to PostC thus can facilitate BOTH excitatory and inhibitory synapses(advisor to monarchy)

Use figure 5.8 to discuss the amplification principle of signaling cascades.

single molecule of first messenger results in 1 million final products (kinda like divergence)