1. D.4: The Heart

2. Annotate a correctly drawn, scientific diagram of the human heart. * You should have 13 labels*

3. http://highered.mheducation.com/sites/0072 495855/student_view0/chapter22/animation_ _the_cardiac_cycle__quiz_2_.html

4. Cardiac muscle (myogenic tissue) Striated muscle tissues, similar arrangement of the contractile proteins actin and myosin to skeletal muscle. Due to the involuntary control of cardiac muscle, there are some unique structural features. Cells are Y shaped, joined end to end forming a complex network This structure allows for a wave of depolarization throughout the tissue  Synchronized muscle contraction.

5. Sinoatrial node A collection of uniquely structured cardiac cells that spontaneously initiate action potentials without stimulation from other nerves. Also known as pacemaker of the heart. Purkinje fibres: specialised tissue transmitting impulse from SA node. Systole: contraction of cardiac muscle Diasystole: relaxation of cardiac muscle

6. Atrioventricular node There is a delay of approx. 0.12s between the arrival of the stimulus from the SA node and the initiation of the impulse in the ventricles. The cells in the AV node take longer to become ‘excited’ Smaller diameter & poor conductors Reduced Na+ channels Fewer gap junctions More non-conductive tissue

7. Purkinje fibres Specialized cardiac muscle fibres. Conduct impulse. http://highered.mheducation.co m/sites/0072495855/student_vie w0/chapter22/animation__condu cting_system_of_the_heart.html

8. Analyzing ECG trace Electrocardiogram (ECG/EKG) detect electrical signals produced as the heart contracts. P caused by atrial systole QRS caused by ventricular systole T coincides with ventricular diastole ECG can be used for interval analysis – the time between the beginnings/ends/duration of any point of the heart beat. Analysis of these trends is a useful tool in heart pathology.

9. Defibrillators https://www.youtube.com/watch?v=vsSfUisVD9k https://www.youtube.com/watch?v=BuUUm2waYtw

10. Hypertension & thrombosis Consequences Narrowing arteries Weakening of artery walls either as a result of persistent high pressure or damaged due to plaque deposits Weakened blood vessels in the brain can result in leaking, rupture or formation of blood clots (stroke) Chronic high blood pressure is a common cause of kidney damage in the glomerus Risk factors Family history indicating a genetic predisposition Old age Post menopause women (due to fall in oestrogen levels) for this same reason, men are more at risk Smoking, high salt diet, diet high in saturated fats, Sedentary lifestyle Height has been correlated! Thrombosis = blood clot Myocardial infraction = heart attack (cardiac muscle starved of oxygen) Hypertension = increased pressure on artery walls