Thursday 29 November 2012

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

Wednesday 28 November 2012

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

Thursday 22 November 2012

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).

Homework 1



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

Thursday 15 November 2012

Kerboodle activities

1. asbestos webquest

2. causes of disease quiz

3. movement in & out of cells quiz

4. lung disease quiz

Thursday 8 November 2012

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

Monday 5 November 2012

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