CHD development images

CHD development

1. LDLs enter the artery wall
2.macrophages phagotise the LDLs & form foam cells
3.accumulation of foam cells forms fatty streaks
4.fatty streaks are surrounded by fibrous tissue to form a fibrous cap - the build up is now a plaque
5. the artery wall stretches to accomodate the plaque & to ensure the volume of the artery lumen is maintained
6. eventually the plaque build up starts to restrict the lumen & reduce blood flow
7. the reduced size of the lumen increases the pressure of the blood flow
8. the plaque ruptures, releasing the fatty, fibrous & calcium deposits into the lumen
9. this rupture can result in thrombosis (i.e. the formation of a blood clot)
10. the blot clot further restricts the blood flow to the heart muscle (if athersclerosis is occuring in the coronary arteries).

CHD risk factors

Cardiac cycle & control of CC images

exam question & markscheme on control of the cardiac cycle

 

(a)

The cardiac cycle is controlled by the sinoatrial node (SAN) and the atrioventricular node (AVN). Describe how.

(5)

markscheme:

(a) 

1.SAN initiates heartbeat / acts as a pacemaker / myogenic;

Q Must be in context

2.(SAN) sends wave of electrical activity / impulses (across atria)
causing atrial contraction;

Reject: signals / electronic / messages / nerve impulses once only

3.AVN delays (electrical activity / impulses);

Neutral: reference to non-conducting tissue delaying impulses instead of the AVN

4.(Allowing) atria to empty before ventricles contract / ventricles
to fill before they contract;

5.(AVN) sends wave of electrical activity / impulses down
Bundle of His / Purkinje fibres;

6.(Causing) ventricles to contract (from base up) / ventricular
systole;  5 max

Pressure changes in the cardiac cycle

Heart image

Homework 2

Write the journey of a red blood cell though the heart- the sequence of blood vessels and chambers. Use all the keywords and parts of the heart structure in your answer. Can do it as a flow diagram with animations, a storyboard or as written prose (story/ poem/ narrative).

Email: rti@cheney.oxon.sch.uk

Homework 1

http://www.bhf.org.uk/heart-health/how-your-heart-works/know-your-heart.aspx

British heart foundation interactive

Go to this website- do the interactive videos & quizzes

There is a certificate at the end for completing all the activities!

When on this site click start & your are just there to explore

Kerboodle activities

1. asbestos webquest

2. causes of disease quiz

3. movement in & out of cells quiz

4. lung disease quiz

assessment objectives

Progress test Tuesday 13th Nov

There will be a mini progress test on the lipids topic on Tuesday

It is not very long so don't panic. We will mark it in the lesson & if there is time you will get to look through your lung disease booklets.

Ms Timms

Kerboodle homework

www.kerboodle.com

look at the mechanism of breathing animation- make notes to support the work in class

Print out the alveolar gas exchange exam questions & complete for next Tuesday 13th November