Download 6.2 Blood continued

Double circulatory system
Review video
https://www.youtube.com/w
atch?v=9fxm85Fy4sQ
Blood flowing to and from
the lungs
Blood flowing to and from all
other organs in the body.
Including, heart muscles.
Capillaries of
head and arms
Superior
vena cava
Aorta
Pulmonary
artery
Circulation of
Blood through the
Body
Pulmonary
Capillaries of vein
right lungs
Capillaries
of left lung
Inferior
vena cava
Capillaries of
abdominal organs
and legs
Draw and label a diagram of the heart. Include the
following labels:
Aorta
Semi lunar (aortic) valve
Left ventricle
Atrioventricular (mitral) valve
Left atrium
Pulmonary vein
Vena cava
Right atrium
Atrioventricular (tricuspid) valve
Right ventricle
Semi lunar (pulmonary) valve
Pulmonary artery
Septum

The Heart

The heart is a double pump:
1. The right side of the heart pumps
blood to the lungs
2. The left side of the heart pumps blood
to the rest of the body.
The Heart
 The walls of the heart are composed of
cardiac muscle.
 Contraction of cardiac muscle is
myogenic.
 Myogenic means that it can contract on
its own it does not need to be
stimulated by a nerve.
The Heart
 The heart is enclosed in a protective sac
of tissue.
 In the walls of the heart, two layers of
tissue form around a thick layer of
muscle.
 Contractions of the layer of muscle
pump blood.
The Heart – Coronary
arteries
– There are many
capillaries in the
muscular wall of the
heart.
 These are called the
coronary arteries.
The Heart – Coronary arteries
 The function of the coronary arteries
are listed below:
 Bring nutrients to heart muscle
 Bring oxygen for aerobic cell
respiration, which provides heart
tissue with energy necessary for heart
contraction.
 Remove waste products (CO2) from
heart muscle
HTTP://WWW.KSCIENCE.CO.UK/ANIMATIO
NS/BLOOD_SYSTEM.SWF
HTTP://WWW.GWC.MARICOPA.EDU/CLASS/BI
O202/CYBERHEART/ANTHRT.HTM
Causes and consequences of occlusion (blockage) of the
coronary artery.
Development of fatty tissue (aka atheroma) in the artery wall
next to the endothelium.
Risk factors include:
- High concentration of low density lipoproteins in the
blood, consumption of trans fats (damage endothelium,
chronic high blood pressure due to smoking/stress
- Chronic high blood glucose concentration (diabetes, poor
diet), infection of the artery wall (Chlamydia pneumoniae),
Control of
heart rate
Cardiac muscle contracts and relaxes spontaneously – myogenic muscle
contraction
Sinoatrial node (SA) in the right atrium. Natural pacemaker, ‘sends out’
electrical signals every 0.8 sec. Contracts both atria.
Atrioventricular node (AV) also in the right atrium. Receives signal, sends
a second signal 0.1 sec. later. Contracts ventricles.
The medulla area in the brainstem, sends signals to the SA, via the cranial
nerve to alter the heart rate depending on body conditions. E.g. exercise.
Intent and consequences…
Ethical decisions often faced by doctors who
are asked by a patients family to withdraw
treatment to ‘ease a patients suffering’, this
can result in the death of the patient.
Euthanasia is illegal in many countries, but
should we always prolong life if we can…
these are important questions which cannot
always be answered easily.
http://highered.mheducation.com/sites/0072495855/
student_view0/chapter22/animation__the_cardiac_cy
cle__quiz_2_.html
http://library.med.utah.edu/kw/pharm/hyper_heart1
.html
http://www.austincc.edu/apreview/NursingAnimation
s/cardiac_cycle.swf
Aka adrenaline
Hormone, produced by the adrenal
glands. Causes an increase in the
heart rate – fight or flight hormone.