Class Notes (836,147)
Canada (509,656)
BIOC34H3 (114)
Lecture

Study+Guide+Question+Answers+2013+Lectures+1+to+12.pdf

15 Pages
141 Views
Unlock Document

Department
Biological Sciences
Course
BIOC34H3
Professor
Stephen Reid
Semester
Winter

Description
1 Answers to Study Guide Questions: Lecture 1-12 (2013) Lecture 1: Electrical Conduction within the Heart Which changes in ionic conductance (permeability) accompany the various phases of the pacemaker potential? 3. 1. 2. 4. a) In zone 1, a decrease in K and an increase in PNa In zone 2, an increase in Ca b) In zone 1, a decrease in K and an increase in PCa In zone 2, an increase in Na c) In zone 3, a large increase inNa : In zone 4, an increase inKP and a decrease inCa d) In zone 3, a large increase inCa: In zone 4, an increase in K and a decrease in PNa e) A and D The action potential that travels along the conduction pathway of the heart moves upward into the ventricles (from the apex of the heart) via the ? a) AVnode b) SAnode c) Purkinje Fibres d) Atrioventricularvalves e) Bundle of His 2 Lecture 2: Cardiac Action Potential and the Electrocardiogram Which changes in ionic conductance (permeability) DO NOT accompany the various phases of the cardiac action potential? a) In zone 0, an increase in PNa b) In zone 1, a decrease in PNa a decrease in P Knd an increase in P Ca c) In zone 2, a decrease in PNa and an increase in PCa d) In zone 3, an increase in P and a decrease in P K Ca e) C and D The P and T waves of the ECG represent and , respectively. a) Ventricular repolarisation and atrial depolarisation. b) Atrial depolarisation and atrial repolarisation. c) Ventricular depolarisation and atrial repolarisation. d) Atrial depolarisation and ventricular repolarisation. e) Atrial depolarisation and ventricular depolarisation. The following ECG trace is representative of what cardiac disorder? a) Atrial flutter. b) Atrial fibrillation. c) Ventricular fibrillation. d) Wandering atrial pacemaker. e) Second degree heart block. 3 Lecture 3: ECGs, Electrical Axis of the Heart and the Cardiac Cycle In order for both of the semilunar valves to be open: a) P (pulmonary artery) < P (right ventricle) and P (aorta) > P (left ventricle) b) P (pulmonary artery) < P (right ventricle) and P (aorta) < P (left ventricle) c) P (right ventricle) = P (aorta) and P (left ventricle) = P (pulmonary artery) d) P (pulmonary artery) > P (right ventricle) and P (aorta) > P (left ventricle) e) P (pulmonary artery) > P (right ventricle) and P (aorta) < P left ventricle During Iso-volumetric contraction of the heart: a) There is an increase in pressure without a change in volume. b) The semilunar valves are closed. c) The AV valves are closed d) A and B e) A, B and C 4 Use the following information and diagrams to calculate the mean electrical axis of the heart. Each division on the leads equals 1. Magnitude of the QRS complex in lead I = 2 Magnitude of the QRS complex in lead II = 5 Magnitude of the QRS complex in lead III = 3 a) Approximately 33° b) Approximately 43° c) Approximately 67° d) Approximately 90° e) Approximately 115° 270 225 315 180 0 135 45 90 270 225 315 180 0 135 45 90 5 Lecture 4: Cardiac Cycle Continued and Regulation of Cardiac Output Cardiac output = ? a) Blood pressure / Total peripheral resistance b) Heart rate X stroke volume c) Heart rate X EDV d) Blood pressure X Total Peripheral Resistance e) A and B Use the following numbers to calculate stroke volume and pulse pressure. Heart rate = 100 beats per minute CO = 1 L/min TPR = 0.1 mmHg min/ml Diastolic pressure = 80 mmHg a) SV = 10 ml; PP = 60 mmHg b) SV = 10 ml/min; PP = 60 mmHg c) SV = 100 ml: PP = 93 mmHg d) SV = 80 ml; PP = 60 mmHg e) SV = 10 ml; PP = 80 mmHg An acetylcholinesterase inhibitor applied to the heart would the heart rate because it would XXXXX the strength of signals. Note, within the synaptic cleft, acetylcholinesterase breaks down acetylcholine into choline and acetyl-CoA a) Decrease…decrease…parasympathetic. b) Decrease…increase…parasympathetic. c) Decrease…decrease…sympathetic. d) Increase…decrease…parasympathetic. e) Increase…increase…sympathetic 6 Lecture 5: Regulation of Stroke Volume How many of the following factors would lead to an increase in EDV? a)1, b)2, c)3, d)4, e)5 Factor 1: An increase in heart rate. Factor 2: Sinus tachycardia. Factor 3: Increased pre-load. Factor 4: Diaphragmatic contraction. Factor 5: Decreased vagal tone to the heart. Which of the following would not lead to an increase in stroke volume? a) An increase in ventricular contractility. b) Increased venous return. c) An increase in aortic pressure. d) Expiration. e) Two of the above would not lead to an increase in stroke volume. Sympathetic stimulation of the heart causes the Starling Curve to shift up due to a(n) increase in ventricular contractility resulting from a(n) increase in calcium in cardiac myocytes. a) Downwards; increase in ventricular contractility; increase in [Ca ]i in cardiac myocytes. b) Upwards; decrease in ventricular contractility; increase in [Ca ]i in cardiac myocytes. ++ c) Upwards; increase in ventricular contractility; increase in [Ca ]i ++ cardiac myocytes. d) Downwards; decrease in ventricular contractility; decrease in [Ca ]i i++cardiac myocytes. e) Upwards; increase in ventricular contractility; increased rate of Ca sequestering in the sarcoplasmic reticulum 7 Lecture 6: Regulation of Stroke Volume and Blood Flow Cardiac output cannot increase indefinitely due to increases in HR because SV decreases due to a decrease in filling time . This can be countered by sympathetic stimulation . a) Heart rate; stroke volume; ventricular contractility; sympathetic stimulation. b) Heart rate; stroke volume; filling time; sympathetic stimulation. c) Stroke volume; heart rate; filling time; parasympathetic stimulation. d) Stroke volume; heart rate; ventricular contractility; sympathetic stimulation. e) Heart rate; EDV; filling time; parasympathetic stimulation. Veins have a large compliance and are often referred to as volume reservoirs. One of the important functional consequences of this is: a) During circulatory shock, blood is retained in the lower pressure venous reservoir therefore preventing blood loss that would occur under high arterial pressure. b) During exercise, ESV and cardiac output can be increased rapidly. c) During exercise, cardiac output to the gut can be rapidly reduced. d) During exercise, stroke volume and cardiac output can be increased rapidly. e) During haemorrhage, EDV can be increased rapidly. Note, the question above wasn’t covered in lecture this year. Which of the following factors would be expected to have a greater influence on blood flow through a vessel in a developing infant compared to an adult? a) Haematocrit and foetal versus adult haemoglobin. b) Blood vessel length. c) The pressure gradient from the start of the vessel to the end of the vessel. d) Vesselradius. e) Plasma protein content. 8 Lecture 7: Blood Flow Which of the following statements below identifies an advantage of a circulatory system that is arranged in parallel? a) Each organ receives incompletely oxygenated blood. b) Blood flow can be regulated to individual organs. c) The system becomes more compliant. d) The system becomes more resistive. e) Blood flow and blood oxygenation become uncoupled. According to Poiseuille’s Law, which of the following factors would be expected to increase blood flow through a vessel? a) Increasing the radius of the vessel. b) Increasing the blood vessel length.
More Less

Related notes for BIOC34H3

Log In


OR

Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


OR

By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.


Submit