BISC306 - LAVERTY

BISC 306, GENERAL PHYSIOLOGY

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    Welcome to the BISC 306, General Physiology course page. Here you will find the course syllabus, sample exam, outlines of class notes and specific reading/problem assignments for each semester exam.
 
 

• REVIEW MATERIAL FROM CHAPTERS 1, 2 AND 4
 
Chapter 1: Internal environment, homeostasis, body fluid compartments

Chapter 2: ions, polar molecules (incl hydrogen bonds, water), solutions (incl mol solubility, concentrations, H+ ions and acidity), Organic molecules (know basics of structure of carbohydrates fatty acids, phospholipids and proteins).

Chapter 4: Binding sites (affinity, saturation); regulation of binding (allosteric, covalent); enzymes; regulation of enzyme reactions.
 
 

• SPECIFIC READINGS (NOT COVERED IN CLASS)

 
• Chapter 9: Adaptation (of sensory systems). page 230, Fig 9-3
• Chapter 9: Vesibular system (special sense for balance, movement, acceleration). pages 256-258
• Chapter 10: Growth Hormone ("Summary Example"). pages 283-284, Fig. 10-21

 

 
 
 
 
 

• REVIEW OUTLINE

 

 
 
 

A. Concepts for review

1. ions in solution
2. bioelectricity
3.ligand-protein interactions: allosteric effects; binding properties
B. Biomembranes
1. Composition: phospholipids, proteins (integral and peripheral), carbohydrates
2. hydrophobic properties
3. fluidity: phospholipid factors that influence fluidity
C. Transport Across Membranes
1. simple diffusion through bilayer
Fick's eq
partitioning (partition coef)
2. diffusion through pores or channels (ions) on diffusion of ions (electromotive force)
dual driving forces on diffusion of ions (electromotive force)
properties of channels
selectivity
types of gating mechanisms (ligand, voltage, mechanical)
3. Facilitated Diffusion
cell uptake of glucose through GLUTs
4. Primary active transport: eg Na/K-ATPase
transporter changes affinities for substrates on opposite sides of bilayer
role of ATP in forcing transitions/affinity changes (organizes transporter operation)
5. secondary Active transport: eg, SGLT glucose transporters
role of Na binding & Na gradient in driving active glucose transport
6. Model of epithelial transport: two step, vectorial transport of glucose by intestinal cells
requires asymmetrical distribution of transporter proteins ("polarized cell")
requires tight junctions to restrict movement between cells (compartmentalizes)
D. Endocrine Systems
1. general features
classical glands vs neuroendocrine
types of molecules (proteins, amino acids, steroids)
general aspects of signal systems
cytoplasmic vs surface receptors
receptor up and down-regulation
G-proteins
second messengers
kinase cascades
2. Example of steroid hormone action: aldosterone
aldo secreted from adrenal cortex in response to decreased blood volume...acts of kidney cells to increase Na and water absorption
mechanisms of action: increase protein synthesis of ENaC channel subunits
3. Epinephrine and stress
epi from adrenal medulla acts on liver to increase glycogenolysis (raise blood glucose)
surface receptor (G-protein coupled receptor)
G-protein, adenylate cyclase activation, cAMP as second messenger
protein kinase A activation, kinase cascade (importance??)
4. Cholecystokinin (CCK) and fat digestion:
CCK released from intestinal I cells in presence of fat, CCK acts on pancreas to increase release of lipases into intestinal lumen
CCK surface receptor; G-protein coupled; activation of phospholipase C
PIP2 breakdown into IP3 and DAG, both signaling molecules
IP3 induces release of Ca from ER compartment (ligand gated channel)
DAG activates PKC cascade
5. Insulin and blood glucose regulation
source: pancreatic beta cells
stimulus: high blood glucose (active absorption from intestine)
targets: skeletal muscle and adipose tissue
effect: stimulates insertion of GLUT-4 glucose transporters on target cell membranes; increases cell uptake of glucose and lowers blood glucose


6. Vertebrate Pituitary

structural features: lobes, functional connections to hypothalamus, portal blood vessels
examples of hormones from each lobe
endocrine "heiracrchy" or axes
7. Cortisol and long-term responses to fasting
cortisol from adrenal cortexacts on skeletal muscle to increase gluconeogenesis (raise blood glucose)
hypothalamic control via CRH, into portal blood vessels
activate release of ACTH from anterior lobe
ACTH activates release of cortisol from adrenal cortex
long and short loop feedback regulation of cortisol
 
E. Neuronal communication systems
1. morphological characteristics of nerve cells (dendrites, soma, axons, axon terminal, synapses)
2. cellular neurophysiology
recordings of membrane PD from non-excitable vs excitable cells
characteristics of action potentials (APs)
all or none (pre-programmed behavior, amplitude, time course)
threshold or trigger level
overshoot
frequency coding of stimulus strength
refractory period
Equilibrium potentials and Nernst eq. (know how to predict changes in resting membrane PDs with change in ion concentrations
resting membrane PD (steady state) vs potassium equilibrium potential (Ek)
Ionic basis of AP
cell depolarizes, overshoots and moves towards ENa
changes in Na and K conductances
inward vs outward currents
voltage gated Na and K channels (m, h and n gates)
Hodgkin positive feedback cycle of Na channel opening
relative kinetics of different gates accounts for time course of AP
refractory periods:
inactivation state---absolute refractory period
K channels open, residual outward current---relative refractory
spike initiating zone (axon hillock) region of highest Na channel density
3. propagation of Aps along cell membrane
patch to patch spread of current (within cytoplasm)
each "patch" fires a new AP as Na channels enter Hodgkin cycle (self-regenerative)
Myelin: allows for saltatory condction (node to node), increased conduction velocity
4. Overall organization of nervous system
central vs peripheral
sensory (afferent) vs motor (efferent)
peripheral efferent somatic vs autonomic
monosynaptic reflexes (kneee jerk reflex)
5. Synapses
overall (generalized) structual organization (eg neuromuscular junction)
presynaptic structures vs postsynaptic
presynaptic synapses
role of presynaptic calcium channels
neurotransmitters
postsynaptic electrical responses (ligand gated channels)
EPSPs (and EPPs)--excitatory, inward currents)
IPSPs--inhibitory (outward currents)
convergence of post-synaptic currents at spike initiating zone
summation and integration (analog to digital conversion)
temporal summation
spatial summation
6. The auditory sense neuronal pathway
structure of Organ of Corti of inner ear
basilar and tectorial membranes: mechanotransduction (mechanically-gated channels)
hair cell : role of stereocilia, receptor potential, release of neurotransmitter
1st order sensory neuron: generator potentials, APs initiated in SIZ
APs conducted to CNS

A. Text Readings: Pay particular attention to the following figures and pages (covered in class).

• Figs. 15-4, 15-11, 15-19, 15-23, 15-36
• Pages 470-471 (inspiration); 475-477 (lung volumes); 483-489 (transport of O2 and CO2 in blood); 490-495 (control of respiration)

• Figs. 16-2, 16-3, 16-5,16-12,16-14,16-18,16-20,16-22, 16-30, 16-31, 16-32
• Pages 512-513 (glomerular filtration); 513-516 (reabsorption and secretion); 516-517 (renal clearance--of inulin); 521-522 (sodium and water reabsorption); 523-525 (urine concentration); 526-529 (control of sodium reabsorption); 531-532 (renal water regulation --including sweating as summary example); 545-547 (bicarbonate handling) 547 (acidosis and alkalosis)

• Figs 18-4, 18-5,18-7, 18-10
• Pages 597-599 (post-absorptive state); 600-603 (insulin)

B. Review Questions: an aid to reviewing material (not all inclusive)

• What specialized features of the lung alveoli allow for efficient gas exchange with the blood?
• What is the function of type II alveolar cells?
• If dissolved oxygen amounts to 0.3 ml/100ml blood, but total O2 is 20 ml/100 ml, where is the rest of the O2?
• What is the major structural difference between hemoglobin and myoglobin? Which has a higher affinity for O2?
• How do the structural features of hemoglobin relate to its O2 binding kinetics?
• What are some important features of the Hb-O2 binding curve (dissociation curve)? What is the P50?
• What happens with Hb-O2 binding/release when blood encounters tissue areas that are more active, metabolically, than usual?
• How does the Bohr effect contribute to O2 delivery to active tissue? Overall, what 3 mechanisms enhance O2 delivery to metabolically active tissue?
• What happens to Hb-O2 kinetics when you hyperventilate? Why? What happens when you move to high altitude? How are these questions related to each other?
• What are the various forms of CO2 found in blood? What is the major form?
• How is HCO3 formed? Where is it formed? Where does it end up?
• What features of red blood cells (RBCs) are important in the above process?
• Describe the chemical reaction for CO2 hydration/dehydration. How does this relate to the Henderson-Hasselbalch equation?
• What are three different functions of hemoglobin in RBCs?
• Why is CO2 regulated in the blood? What does CO2 represent? (in terms of acid base balance)

• What happens to plasma HCO3  levels during metabolic acidosis? What is one common form of metabolic acidosis?
• What is the compensation for metabolic acidosis? How does the body know to carry out this compensation? What detectors are involved? What is this compensation trying to accomlish in the short term? (in terms of the henderson-Hasselbalch eq)
• What would cause respiratory alkalosis? What would be the compensation for this? (ie how would it be corrected)
• How do we manage to take a breath (inspiration)? What muscles are involved? What is the importance of the pleural membranes?
• Which is more effective, rapid shallow breathing or slower, deeper breathing? Why? How is this quantified (ie, what lung measure would best show tthis effect?)
• Why is "reverse active hyperemia" important?
• What kinds of sensors contribute to regulation of respiration? Where do you find chemosensors? What do they respond to? Where does this sensory information go?
• Is the chemosensor response to elevated pCO2 appropriate? ie, what is the final effect of this stimulation?

• Define the processes of filtration, reabsorption and secretion.
• What is meant by the term "filtration fraction?"
• What are renal pyramids? Renal calyces?
• What are podocytes? Where are they found? What is their importance?
• What specific features of the glomerulus/renal filtration system enhance the ability to filter blood into urine?
• Caculate the GFR, given inulin concentrations in the urine = 200 mM; in plasma = 2 mM and urine flow rate of 1 ml/min. What are the final units of this calculation?
• In which nephron segments would you find the following: isosmotic reabsorption; dilution of urine; aldosterone receptors; ADH receptors; ammonia production; low water permeability; high water permeability; SGLTs
• What is the importance of carbonic anhydrase in the proximal convoluted tubule? What role does the Na+/H+ exchanger play? What is the significance of proximal tubule cellular uptake of the amino acid glutamine?
• Under what conditions would you expect to find increased numbers of ENaC sodium channels and where would you see this increase?
• How does aldosterone enhance K+ secretion?
• How does the kidney restore new HCO3 ions to the blood to replace those used in blood buffering of acids?
• What is meant by the "single effect"? Where does this take place?
• Why is the loop of Henle referred to as a "countercurrent multiplier"?
• What is the source of ADH? What stimulates its release? What is the specific target cell response?
• Explain the role of each of the following in a reflex response to sweating: hypothalamuc; macula densa; JG cells; collecting duct; adrenal cortex.

• What happens during the absorptive state in the liver? In adipose tissue? In skeletal muscle?
• What hormone mediates these responses?
• What three kinds of responses protect blood glucose during the post-absorptive state? Why is this important?
• What is the process of gluconeogenesis? Where does it occur? (multiple answers)? What substrates can be used?
• What is meant by "glucose sparing"?
• Describe the mechanism of insulin release from source cells. What are these source cells and where are they located?
• What basic problems may lead to the condition of diabetes mellitus?

A.    Text Readings: pay particular attention to the following figures and pages (covered in class):

• Figs 11-5, 11-16
• Pages 300-301 (cross bridge cycle), 310-311 (summation), 314-316 (fiber types)

• Figs 14-25, 14-33, 14-40, 14-46, 14-50, 14-55 &59 (hemorrhage)
• Pages 392-393 (cardiac APs and SA node), 396-399 (cardiac cycle), 402 (Frank-Starling), 410-414 (arterioles), 420-422 (bulk flow across capillaries), 428-432 (arterial pressure regulation), 441 (upright posture)

B.    The following study questions are designed only to aid you in reviewing the material. Use each question to make sure
          you  understand not only the specific answer, but peripheral issues that would be related to that question.

• What are some similarities and differences between skeletal muscle and cardiac muscle? between skeletal muscle and smooth muscle?
• describe the observed changes in sarcomere banding pattern (A, I, H) during a muscle cell contraction. How did early muscle physiologists interpret these observations? (mechanism for contraction)
• What is the role for troponin/tropomyosin on the thin filaments?
• How does ATP participate in the myosin cross-bridge cycle? What is rigor mortis and what is its cause?
• What events occur between the time that an action potential reaches the terminus of a motor neuron and the beginning of a muscle cell contraction?
• What role does Ca++ play in excitation-contraction coupling? Where does this Ca++ come from? (and how?)
• What are two ways that we can control whole muscle tension? What is a motor unit?
• How do our muscles "know" how much tension to generate in order to respond to a given load or to apply a given force?
• Why is the maximal twitch tension less than the total tension that can be generated by a muscle?
• What are some major differences between the various skeletal muscle fiber types?

• The mammalian heart independently pumps blood through two separate but interconnected circuits, which are....
• What is the function of the atrio-ventricular heart valves? When would you find them open? Closed?
• What is the importance of the aortic and pulmonary semilunar valves? When would you find them open/closed?  What accounts for the "heart sounds" (lub-dub)?
• List several unusual properties of cardiac muscle cells.
• What is a pacemaker potential? How does it arise? How is it modulated? What is the role and source of Ca++ in cardiac muscle cell action potentials? Two unusual channels found in types of cardiac muscle cells are...
• What are two important features of the Atrio-ventricular (A-V) node of the heart?
• What does the QRS complex of an ECG recording represent? Why is its form (time course) so different from the P wave?
• How does the sympathetic NS affect stroke volume?
• Why does aortic pressure fall so much less steeply than ventricular pressure during diastole?
• What is the significance of end diastolic volume? What is the major determinant of end diastolic volume?
• Heart rate slows in response to stimulation of the .....nerve. This nerve is a major part of the .....nervous system.
• What effect does heart rate have on cardiac output?
• Why does standing upright reduce cardiac output? How can one compensate for this effect?

• What are the major structural and functional properties of large arteries? Of arterioles? Of veins? Of capillaries?
• A generalized arteriolar vasoconstriction woud have what effect on mean arterial pressure (MAP)?
• How would increased sympathetic NS activity, acting on alpha receptors, affect arteriolar radius? Arteriolar smooth muscle beta receptors are activated primarily by....This activation results in....
• How does skeletal muscle tissue get increased local blood flow during exercise? What factors mediate increased local blood flow during tissue injury or trauma?
• Where are the primary blood pressure sensors located? How would an increase in the firing rate in sensory neurons from these receptors affect  outgoing sympathetic NS activity?
• How does the kiney participate in control of blood pressure?
• What is the source of atrial natriuretic factor (ANF)? What does it do?
• List several cardiovasular responses to hemorrhage.
• What are two major actions of angiotensin?
• Would cardiac output rise or fall with a decrease in baroreceptor firing rate?
• How do changes in blood volume cause changes in blood pressure?
• The major mechanism for the exchange of blood gases (O2 and CO2)across capillaries is...
• What forces determine the net direction of bulk fluid movement across capillaries? How would changes in plasma protein concentrations affect capillary bulk fluid movements? Where would you expect to find capillaries with high Kf values?
• What is the role of the lymphatic system in control of body fluid volumes?

CATALOG DESCRIPTION: Principles underlying function of organisms at the organ, tissue and cellular levels. The major areas covered will be membrane function, neurophysiology, skeletal muscle, endocrine systems, cardiovascular function, respiration, osmoregulation and ion balance, acid base balance, metabolism, and digestive systems. A comparative approach will be used. This is a 4 credit course with required laboratory.

PREREQUISITES: 2 semesters of biology and 2 semesters of chemistry

CLASSES: Mon, Wed, Fri, 9:05-9:55; 130 Smith

OBJECTIVE: To gain an understanding of the basic physical, chemical and biological principles involved in the interactions of cells and organ systems in a complex organism.

TEXT: Vander, Sherman and Luciano; Human Physiology, The Mechanisms of Body Function, McGraw Hill, 8th ed, 2001

Text reading is extremely important; material from readings will be on the exams, whether covered in class or not.

INSTRUCTOR: Dr. Gary Laverty 313 Wolf Hall, 831-8180;  laverty@udel.edu

Office Hours: Mon (1:00-2:00), Tues (9:30-10:30), Thurs (2:00-3) Or by appointment (walk-ins usually welcome)

COURSE WEBPAGE: http://www.udel.edu/Biology/laverty/306home.html

GRADES: There will be three hour-long tests given during the semester and a fourth, cumulative final exam given during final exam week. The format of all exams will be a combination of multiple choice and short answer (including sketches, etc). Exams will cover the material from the lectures and from text readings assigned for each examination period. Occasional problems or short readings may also be assigned to supplement specific areas. Generally, lectures will emphasize the most important points covered in the readings. The final grades will use a plus and minus letter grading scheme. Grades will be based on a point total of 400 points as follows

                                                     three hour exams@ 100 points each ............300

    final exam @ 100 points ............................100
 
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TOTAL ..................       400

DATES         TOPICS                                             CHAPTER/PAGES

Old Test #1