Biology 2017-2018 Name: Noble efforts change lives. Excellence. Tenacity. Community. Reflection.

Option D – Human PhysiologyD.4 – The HeartSkeleton Notes

Syllabus Statement GuidanceD.4.U1 Structure of the cardiac muscle cells allows

propagation of stimuli through the heart wallD.4.U2 Signals from the sinoatrial node that cause

contractions cannot pass directly from atria to ventricles

D.4.U3 There is a delay between the arrival and passing on of a stimulus at the atrioventricular node.

D.4.U4 This delay allows time for atrial systole before the atrioventricular valves close.

D.4.U5 Conducting fibers ensure coordinated contraction of the entire ventricle wall.

D.4.U6 Normal heart sounds are caused by the atrioventricular valves and the semilunar valves closing causing changes in blood flow.

D.4.A1 Use of artificial pacemakers to regulate the heart rate.

D.4.A2 Use of defibrillation to treat life-threatening cardiac conditions.

D.4.A3 Causes and consequences of hypertension and thrombosis.

D.4.S1 Measurement and interpretation of the heart rate under different conditions.

D.4.S2 Interpretation of systolic and diastolic blood pressure measurements.

D.4.S3 Mapping of the cardiac cycle to a normal electrocardiogram (ECG) trace.

D.4.S4 Analysis of epidemiological data relating to the incidence of coronary heart disease.

D.4.NOS Developments in scientific research followed improvements in apparatus or instrumentation: the invention of the stethoscope led to improved knowledge of the workings of the heart.

D.4.NOS – Developments in scientific research followed improvements in apparatus or instrumentation: the invention of the stethoscope led to improved knowledge of the workings of the heart.

1. Who invented the stethoscope?

2. What method was used prior to its invention to listen to a patient’s heartbeat?

D.4.U1 – Structure of the cardiac muscle cells allows propagation of stimuli through the heart wall.

Do this: https://www.khanacademy.org/science/health-and-medicine/circulatory-system/heart-muscle-contraction/v/heart-cells-up-close

3. What are a couple features unique to the cardiac muscle cells?

4. What are the squiggly lines called?

What do the doughnut shaped holes represent?

What are they responsible for? What is their purpose?

5. Provide an example of something that would pass through the hole.

6. How does this relate to depolarization? What is the benefit of having these gap junctions?

7. What is the proper name for the “staples”? What are their roles?

8. Why are muscle cells considered a community of cells?

9. What organelle is abundant? Why?

Muscle fibrils, or myofibrils, are crossed by transverse tubules.

These tubules mark the division of myofibrils into contractile units = sarcomeres

Similarities and differences between Smooth, Cardiac, and Skeletal muscle

Factor Smooth Muscle Cardiac Muscle Skeletal Muscle

Location

Cell Characteristics

Control Action

Other Factors

Similarities: Like skeletal muscle, cardiac muscles are in

appearance

Similar arrangement of ( and )

Differences: CM and than SM

Long period

CM contractions are brief twitches as opposed to long smooth contractions

Gap junctions exist

Cardiac muscle is self excitatory (not under control as compared to SM)

D.4.U2 – Signals from the sinoatrial node that cause contractions cannot pass directly from atria to ventricles

D.4.U5 – Conduction fibers ensure coordinated contraction of the entire ventricle wall.

- (SA) (aka pacemaker) initiates

of cardiac muscle cells.

- AV movement of the electrical signal by nearly sec

- conduct the signal to

the .

D.4.U3 – There is a delay between the arrival and passing on of a stimulus at the atrioventricular node.

D.4.U4 – This delay allows time for atrial systole before the atrioventricular valves close.

Specialization in the AV node

1. and do not conduct as quickly

2. # of in the membranes of AV Node cells

- resting potential

- Prolonged period

3. between cells of AV node

4. More - tissue present

Modification to Pukinje Fibers

1. Relatively

2. (faster conduction)

3. of voltage-gated channels

4. numbers of and stores

= of heart chambers

= of heart chambers

PRACTICE: Complete the table below

D.4.S3 – Mapping of the cardiac cycle to a normal electrocardiogram (ECG) trace.

PRACTICE: Add labels to the image below

PRACTICE: What is similar? What is different? Look at version II (typically on the bottom of the ECG)

Normal Sinus Rhythm

Sinus Tachycardia

Sinus Bradycardia