Human Physiology Review Guide Chapters 10-17 PDF

Introduction to Human Physiology Review for Chapters 10-17 This sheet is designed as a study aid for you, which you may or may not use at your discretion. These pages overview basic concepts and ideas in the form of questions. If you choose to use this guide, you read through your notes carefully s...

Introduction to Human Physiology Review for Chapters 10-17 This sheet is designed as a study aid for you, which you may or may not use at your discretion. These pages overview basic concepts and ideas in the form of questions. If you choose to use this guide, you read through your notes carefully several times before attempting to answer these questions--use it as an opportunity to test your knowledge on these topics before the exam, not as the sole basis of your studies. I have attempted to be as inclusive of the material we have covered (in topics), but your notes are your best source of information for the exam. Chapter 10 Define transduce. - Change environmental info into action potentials What initiates membrane potential change? transducer What is a modality? Each type responds to particular info What are the two types of neural receptors? Are they myelinated? - Naked (free) receptors o Light touch o Unmyelinated - Complex neural receptors o Encased in connective tissue o Myelinated o Deep touch What type of information do nonneural receptors receive? - Olfaction - Gustation - Vision - Hearing and balance Define: Adequate stimulus The form of energy to which a receptor is most responsible 1|Page  Threshold Minimum stimulus Receptor potential Change in sensory receptor membrane potential Receptive field Physical area where stimuli activates neuron What are the four major groups of receptors? - Chemoreceptors - Mechanoreceptors - Thermoreceptors - Photoreceptors What does it mean when we say "receptive field size determines sensitivity"? - More sensitive areas have smaller receptive fields - Less sensitive areas have larger receptive fields Know that sensory information travels to the brain via ascending pathways or cranial nerves. - Spinal cord to brain= ascending pathways - Directly to the brainstem via cranial nerves What are perceptual thresholds and habituation? - Perceptual threshold o Stimulus level to be aware of sensation - Habituation o Decreased perception through inhibitory modulation Understand that neurons determine the sensory modality and where they terminate. Be able to put together pieces of this chapter (sensory) and the previous chapter (brain) to discuss where perceived information is sent in the brain (e.g., does it travel through the thalamus or not). All sensory info goes through the thalamus except olfaction How does lateral inhibition help us distinguish a stimulus (see lecture figure)? What does this do with primary, secondary, and tertiary neurons? - The cell that is stimulated produces more outputs and depolarizes the next neuron - It also inhibits the cells around it so we can decipher where the signal is coming from 2|Page How is the intensity of a stimulus coded by the number of receptors activated and frequency (see lecture figure)? How do moderate and longer (and stronger) stimuli vary in duration and amplitude? How does this change the frequency of action potentials and level of neurotransmitter release? - The intensity of the stimulus depends on the number of receptors activated or the frequency at which they are activated. - ????? Explain how tonic and phasic receptors adapt to a continuous stimulus. - Tonic o Sends signals as long as a signal is present o Adapt slowly - Phasic o Adapt quickly o Sends a burst of activity and the adapt o smell Trace the pathways for somatic sensation from the receptor to the somatosensory cortex (e.g., primary, secondary, and tertiary neurons) - Primary neuron synapses in the medulla o proprioception and fine touch - Primary neuron synapses in the spinal cord o Nociception and coarse touch - Secondary neuron synapses in the thalamus - Tertiary neurons project to the somatosensory cortex What are nociceptors? Where are they located? - Neurons with free nerve endings - Found in skin, joints, muscles, bones, viscera What is meant by the phrase "pain is subjective perception"? - Fast pain is sharp and localized - Slow pain is dull and more diffuse How is fast and slow pain different (in sensation and fibers)? - Fast pain is A delta fibers o sharp - Slow pain is C fibers o dull 3|Page What are examples that each of the following respond to: Mechanical Pinching, cutting Thermal Extreme heat or cold Chemical Acids, capsaicin What is referred pain? - Poorly localized pain perceptions from visceral or somatic pain - Converge on a single ascending tract Describe pain modulation (e.g., study the lecture figures). How are each of the following involved in pain perception and when pain is absent: Slow pain C fiber Stops inhibition of the pathway if strong enough Inhibitory interneuron Will suppress the pain pathway of input from C fiber is absent Explain the gate control theory. How do Aβ fibers interact with C fibers? Moreover, how does this change the perception of pain? - AB fibers synapse on inhibitory interneurons and increase inhibition - Integrated response from AB and C fibers DECREASE the perception of pain Do not worry about the section on analgesic drugs. Chapter 11 Understand the division and functions of the efferent peripheral nervous system. How many neurons does each use to reach its target? - Somatic motor neurons o Control skeletal muscle o One neuron - Autonomic neurons o Uses 2 neurons o Controls: § Smooth muscle § Cardiac muscle 4|Page  § Glands § Adipose tissue Describe the two subdivisions of the autonomic division and how they can be distinguished anatomically and by their activity under certain situations. How do autonomic reflexes support homeostasis, and which part of the brain controls these activities? - Sympathetic o Fight or flight - Parasympathetic o Rest and digest What autonomic reflexes are directed by the medulla? Which is directed by the hypothalamus? - Medulla o Cardiovascular o Pulmonary o Urinary o Reproductive o Digestive - Hypothalamus o Temperature o Satiety o Thirst Antagonistic control is the hallmark of the ANS, but what are some examples of how the two divisions are complementary or cooperative? - Complementary o Sympathetic and parasympathetic both produce saliva - Cooperative o Urination Describe the two-neuron efferent path in the autonomic nervous system, including the roles of preganglionic and postganglionic neurons. Where are the ganglia in each located? And how is their location related to their target and effect? (see Figure 11.5) - Preganglionic neuron o Cell body in brain or spinal cord o Extends to the autonomic ganglion - Postganglionic neuron o Cell body in autonomic ganglion o Extends to target tissue 5|Page The vagus nerve (CN X) carries most parasympathetic fibers. What does it innervate? - Heart - Lungs - Esophagus - Stomach - Pancreases - Liver - Small intestine - Upper ½ of large intestine What neurotransmitters are released by sympathetic and parasympathetic preganglionics and postganglionics? Discuss the role of cholinergic and adrenergic synapses. - Sympathetic o Adrenergic synapse o Preganglionic § Ach o Postganglionic § NOR - Parasympathetic o Cholinergic synapse o Preganglionic § Ach o Postganglionic § Ach What is the importance of varicosities and synapses en passant? - Varicosities are unusual synapses - Synapses en passant o Release NT along length of the axon Where is ACh used as a neurotransmitter? What are the two types of cholinergic receptor subtypes? What stimulates and blocks each? - All motor neuron synapses - All preganglionic - Parasympathetic postganglionic - Cholinergic receptors o Nicotinic § Stimulated by nicotine § Blocked by curare o Muscarinic § Stimulated by muscarine § Blocked by atropine 6|Page How do nicotinic ACh receptors excite postsynaptic membranes (i.e., when bound to the receptor, what moves across the membrane)? What type of effect do muscarinic receptors produce? What ions move across the cell when they are inhibited or excited? - Nicotinic o Ach binds to ligand gated channel and allows NA to flow in which depolarizes the cell - Muscarinic o Produces parasympathetic nerve endings o NA or Ca and K Where would you find adrenergic receptors? How does adrenergic stimulation vary among different tissues? - Using the examples in the lecture (from the table), can you compare the roles of the sympathetic and parasympathetic nervous systems? - Chapter 12 What is the sarcoplasm? What is the sarcolemma? What are Transverse Tubules? What type of channels do Transverse Tubules have? - Sarcoplasm o Has typical organelles plus contractile proteins - Sarcolemma o Plasma membrane - Transverse tubules o Extend deep into the cell o Have voltage-sensitive calcium channels What are Myofibrils? Can you order muscle fibers, myofilaments, and myofibrils from largest to smallest? - Bundles of myofilaments enclosed in sarcoplasmic reticulum - Largest o Myosin - Smallest o actin 7|Page What is the sarcoplasmic reticulum? What are Terminal Cisternae? What are their functions? What is a Triad? What types of pumps are in the sarcoplasmic reticulum? - Sarcoplasmic reticulum o Contains calcium pumps that import calcium - Terminal cisternae o Blind sacs of sarcoplasmic reticulum § Serve as calcium reservoirs - Triad o 2 cisternae with T Tubule in between What are myofilaments? What are thick filaments? Thin filaments? Which of those (thick or thin) would you find myosin-binding sites, tropomyosin and troponin? Which of these are regulatory proteins? - Myofilaments o Contractile proteins with myofibrils - Thick filaments o Consists of bundles of many myosin protein molecules - Thin filaments o Twisted strands of actin § Myosin binding site § Tropomyosin and Troponin Regulatory proteins What is a sarcomere? What are Z-disks? Can you identify and define A-bands and I-bands? Which gets smaller with contraction? Where is the H-zone? Where would you find the thick and thin filaments in the areas above? What is the M-line? - Sarcomere o Myofilaments arranged in repeating units - Z-disk o Delineation - A band o Thick filaments overlapping thin filaments - I band o Only thin filaments - H zone o Central portion of A zone - M line o Middle of H zone What is a motor unit? What is the definition of small and large motor units? Which produces a large amount of force, and which is for precise control? - 8|Page What are the three parts of the neuromuscular junction? - Synaptic knob, synaptic cleft, motor end plate What is the synaptic knob? What is in synaptic vesicles? What is the function of the calcium pumps at the synaptic knob? What happens when the voltage-gated channels open (when triggered by actional potential)? o Expanded tip of motor neuron axon o Neurotransmitters o Establish Ca gradient o Ca flows into the cell Where is the motor end plate? What is its function? o Sarcolemma o Has Ach receptors What is the synaptic cleft? What two structures of the neuromuscular junction does it separate? o Narrow fluid-filled space o Separates synaptic knob from motor end plate What is the voltage of the resting membrane potential of muscles? What establishes the RMP? - -90 mV - Leak channels What are the three physiological steps of muscle contraction? Describe the events of the 1st physiological step. o What triggers calcium entry at the synaptic knob? § Nerve signal from the axon o What happens to the calcium? § Diffuses into the knob o Where is ACh released from? And how? Where does Ach bind? § Released from synaptic knob § Through exocytosis § Binds to the motor end plate Describe the events of the 2nd physiological step. o What is an EPP? How is ACh involved here? What ion diffuses into the cell here? § End plate potential\ § Ach binds to receptor which open the gated channels § Na+ diffuses o What is an Action Potential? Can you describe depolarization and repolarization? Which channels are opening to help the EPP reach the threshold? § o What voltage does depolarization reach? What ion is involved? § +30 mV § Na+ o When the cell repolarizes, what is its voltage? What is a refractory period? § -90 mV 9|Page  o As the action potential travels down the sarcolemma, where does it go to stimulate calcium release (i.e., released internally from where into the sarcoplasm)? § T tubules Describe the events of the 3rd physiological step. o The calcium from the above step moves into the sarcoplasm; what does it attach to? § Troponin o What role does calcium have in crossbridge cycling? § It triggers the cycling o Can you describe the four steps of cross-bridge cycling? § Crossbridge formation § Power stroke § Release of myosin head § Reset myosin head o What happens to the H-zone and I-Band during crossbridge cycling? § They narrow Chapter 14 Which side (e.g., left or right) of the heart has oxygenated blood? And which has deoxygenated blood? - Oxygenated blood o Left side - Deoxygenated o Right side What is the name of the vessel carrying oxygenated blood out of the heart (to the systemic circuit)? What vessel carries blood away from the heart to the lungs? Is It oxygenated? - Ascending aorta - Pulmonary artery o Deoxygenated What is the difference between the autorhythmic and contractile cells of the heart? - Autorhythmic cells o Pacemakers o Signal for contraction - Contractile cells o Striated fibers organized into sarcomeres Can you explain the actional potentials of myocardial contractile cells? What ion(s) causes depolarization, plateau, and repolarization? - Depolarization- Na 10 | P a g e  - Plateau – Ca+ inflow - Repolarization- k+ outflow What is the function of the plateau? o Sustains refractory period o Prevents tetanus Can you compare the refractory periods in skeletal muscle and myocardial contractile muscle? o Can you describe the action potential in an autorhythmic cell? What ion(s) causes depolarization and repolarization? o What is a pacemaker potential? § Unstable membrane potential § In beats per minute, what is the approximate heart rate set by each pacemaker cell (e.g., SA node, AV node, etc.)? SA- 70 bpm AV – 50 bpm Purkinje fibers- 25-40 bpm What is the pathway of conduction through the heart (i.e., sequence of pacemaker cells)? o SA- AV- Bundle of His- Purkinje fibers Can you label an EKG with P, QRS, and T? What does each EKG event represent? Why can we not observe the change in voltage due to atrial repolarization? o Due to the position of the heart’s electrical activity and limitations of the EKG leads What are some physical symptoms of cardiac arrhythmias? Lightheadedness, irregular heartbeat Chest palpitations What is a heart block? Impaired conduction Define and ID on an EKG: § 3rd degree AV Node Block § Atrial fibrillation § Ventricular fibrillation What is defibrillation? Why is it used? § It is used to electrically reset the heart § How do you recognize ischemic disease (e.g., myocardial infarction) on an EKG? Longer s-t complex How does parasympathetic control decrease heart rate (i.e., receptor and ion permeability)? - hyperpolarization How does sympathetic control increase heart rate (i.e., receptors and ion permeability)? - More rapid depolarization 11 | P a g e Make sure you can identify the seven EKGs given in class. Can you determine the heart rate? o Can you determine whether it exhibits an arrhythmia? o Key to EKG's (in order of appearance in notes) Asystole (flatline) = no rate, minimal electrical activity Sinus bradycardia = 40 bpm (pattern normal, just below average) Atrial fibrillation = 100 bpm (atrial pattern irregular, rate at high end of the range) Cannot see distinct P waves (rate of atrial contraction is too rapid) First-degree AV Node Block – 60 bpm (pattern normal, rate normal, but exhibits a delayed – long period of time – between atrial depolarization (i.e., P-wave) and ventricular depolarization (i.e., QRS complex) Sinus tachycardia – 140 bpm (pattern normal, rate above normal range) Normal Sinus Rhythm - 70 bpm (pattern normal, rate normal) Ventricular fibrillation – Cannot calculate the rate (pattern abnormal, electrical activity uncoordinated); i.e., ventricles quivering – a sign of a dying heart Chapter 15 What vessels control blood flow into the capillaries (see Figure 15.1)? - Arterioles Remember, these are partially responsible for resistance in the circulatory system. Where does the exchange of O2 and CO2 occur in the circulatory system? o In the lungs What is pulse pressure? How is it calculated? - Measure of pressure wave produced by ventricular contraction - = systolic pressure- diastolic pressure How is blood returned from areas distal to the heart (e.g., lower limbs)? - Valves, skeletal muscle pump, and respiratory pump What is Mean arterial pressure (MAP), and how is it calculated? - Represents driving pressure - MAP= DP+1/3 (SP-DP) What is the normal MAP range? High MAP? Low MAP? § Normal 70-100 mmHg § High Anything above 100 § Low 12 | P a g e  Anything below 70 What can high MAP lead to? Increase risk of? § Blood clots § Heart muscle damage § Heart attack, kidney failure, and heart failure How can low MAP cause tissue damage? What are examples of conditions associated with low MAP? § Tissue damage § Stroke, sepsis, internal bleeding What are Korotkoff sounds? How do you use them to determine blood pressure? What is a healthy blood pressure (i.e., systolic/diastolic)? - Sounds you hear to take blood pressure - The first sound is systolic pressure - The last sound is diastolic pressure - 120/80 What is MAP determined by? If given an example with changing resistance or cardiac output, can you determine if blood pressure increases or decreases? - MAP ---- CO x R (arterioles) - Increase in cardiac output will increase blood pressure - Increase in resistance will increase blood pressure How would each of these impact blood pressure: Add or loss of fluid § Add would increase § Loss would decrease Vasoconstriction or vasodilation § Vasoconstriction would increase § Vasodilation would decrease Sympathetic stimulation of the heart § Sympathetic stimulation will increase blood pressure by increasing cardiac output How does norepinephrine release (higher or lower) impact arteriolar diameter? - More norepinephrine causes blood vessels to constrict How does epinephrine impact arteriolar diameter? - Binds to a receptors to vasoconstrict - Binds to b2 receptors to vasodilate 13 | P a g e Where is the cardiovascular control center? - Medulla Where are the baroceptors located? What are they measuring? § They are pressure receptors § They are in carotid bodies and aortic bodies What is orthostatic hypotension? - Decrease in blood pressure due to postural change What are its symptoms? § Lightheadedness § Dizziness Study Figure 15.15. Do not memorize the figure but aim to understand how a change in a variable (e.g., TPR) impacts MAP, what detects the change, and how CO would respond to the initial change in TPR. Think through this problem as if TPR increases and again as if TPR decreases. What are examples of non-controllable and controllable factors of cardiovascular disease (CVD)? - Age, sex, family history Atherosclerosis is the formation of plaques in arteries that eventually cause CVD. Know that it starts as an inflammatory response. What type of cholesterol is considered healthy and lethal? § High-density lipoprotein cholesterol Healthy § Low-density lipoprotein cholesterol Lethal Although we covered Figure 15.21 in the lecture (i.e., the development of atherosclerotic plaques), do not worry about answering questions about it. Knowing that plaques are an inflammatory response associated with risk factors (i.e., controllable and uncontrollable) is enough for this class. What is the difference between primary and secondary hypertension? How is hypertension associated with relative risk of CVD (e.g., what does Figure 15.22 show)? - Primary hypertension o 90% of cases o Has no clear cause than hereditary o Cardiac output is normal (usually) § Increased peripheral resistance - Secondary hypertension o 10% of cases o Due to an underlying pathology 14 | P a g e What are three ways to treat hypertension? And how does each impact blood pressure? - Diuretics - Beta blocking drugs - ACE inhibitors Chapter 16 What percentage of 'whole blood' comprises plasma, 'buffy' coat, and red blood cells? - Plasma – 55% - Buffy coat-