Heart & Circulatory System

Heart (1): structuremade of cardiac musclesurrounded by the

pericardium (Herzbeutel)coronary arteries supply

the heart muscle2 sides - La-rve (!) each side consists of 2

chambers: an atrium and a ventricle

heart valves prevent back flow during contraction

Valves of the heart

Atrio-ventricular valves

(Segelklappen)

Mitralklappe (I)Tricuspidalklappe(C)

Between atrium and ventricle

Semilunar valves

(Taschenklappen)

Aortenklappe (K)Pulmonalklappe (E)

Where blood exits (=leaves) the heart

11 Herzscheidewand

Die Herzteile

1 Hohlvene (vena cava)

2 rechte Herzvorkammer

3 rechte Herzkammer

4 Aorta

5 Lungenarterie6 Lungenvene

7 Taschenklappe8 linke Herzvorkammer

9 Segelklappe

10 linke Herzkammer

Heart(2): Activity

Atria and ventricles always contract alternately: Systole:

period when atrium relaxes & ventricles contract

Diastole: period whenatrium contracts & ventricles relax

Stethoscope: to hear the heart beats

http://pediatriccardiology.uchicago.edu/PP/heart_murmur.htm

Atrium

Ventricle

Heart (3): Activity

The cardiac pacemaker

Control of the heartbeat electrical impulses are sent

from the SA (sinoatrial) node (“Sinusknoten”) and AV-node (=Vorhofknoten) and.

through the autonomic

nervous system

(sympathetic NS/

parasympathetic NS )

These impulses first cause the atria to contract and then they cause the ventricles to contract. They control and coordinate the beating exactly. The cardiac pacemaker sends

out electrical impulses.

“Heartfacts”

An adult’s heart beats about 70 times a minute. That means when you are 70 years old your heart would have beaten 3 billion times.

It has the power of about 580 PS a day and weighs about 350 g.

It pumps about 5 litres of blood a minute.

The blood needs about 1 minute to circulate through the body.

Types of blood vessels (1)

Arteries (sg. artery):Take blood away from the heart, their walls are muscular and elastic (blood pulses through them with high pressure).Arteriosclerosis can lead to an infarct.

main artery: aorta

capillariesartery vein

arteriole venu

le

tissue fluid

tissuecells

capillary wall

O2 glucose CO2 wastes

Types of blood vessels (2)Veins (sg. vein):Blood flows back to the heart, the walls are thin and not muscular.They have valves to prevent backflow of blood. This is also done by the arteries which are next to them (a. & v. are mostly grouped together), sometimes through the contraction of striated muscles („Muskelpumpe“)main vein: vena cava (Hohlvene)

Capillaries (sg. capillary):

„Haargefäße“ , can only be seen under a microscope (diameter about 8/1000 mm),

their functions are the exchange of materials (through diffusion) between blood and cells and the regulation of body temperature.

Valves allow bloodto go forward...

…but notbackward

valveopen

musclescontracted

valveclosed

valveopen

musclesrelaxed

valveclosed

Varicose veinsVaricose veins arise when there are weaknesses in the vein walls

Der Blutkreislauf (2)

1 Kopfvene2 Lungenkapillaren3 Lungenarterie

4 rechte Herzvorkammer5 Hohlvene6 rechte Herzkammer7 Beinvene8 Kopfkapillaren9 Kopfarterie

10 Lungenvene11 linke Herzvorkammer12 Körperarterie13 Herzklappen14 linke Herzkammer15 Leberkapillaren16 Darmkapillaren17 Beinarterie18 Muskelkapillaren

Circulatory System (1)

The Heart pumps the blood through a double circulatory system.

The “journey of the blood”: systemic circulation (Körperkreislauf): blood

from left ventricle > aorta > arteries > capillaries > exchange with cells > veins > vena cava > right atrium

pulmonary circulation (Lungenkreislauf): blood from right ventricle >deoxygenated blood over pulmonary artery > lungs > becomes oxygenated > oxygenated blood pulmonary vein > left atrium

Circulatory System (2) The blood flows

permanently through blood vessels, which are more than 1000 kilometres long.

About 13% of the blood is always in the pulmonary circulatory, about 15% in arteries & 59% in veins of the systemic circulation. 5% in capillaries and about 9% in the heart.

hepatic portal vein brings blood with nutrients from the digestive system to the liver.

Der embryonale Blutkreislauf

Der embryonale Kreislauf besitzt „Kurzschlussver-bindungen“: das Foramen ovale und den Ver-bindungsgang zwischen Lungen- und Hauptschlag-ader. Beide sorgen dafür, dass die noch nicht entfaltete Lunge umgangen werden kann.

Blood vessels

Terminology

What is an artery? What is a vein? What is deoxygenated blood?

(=“venöses Blut”) What is oxygenated blood?

(=arterielles Blut”) Gibt es Venen mit arteriellem Blut

und Arterien mit venösem? (=Are there veins with deoxygenated blood and arteries with oxygenated blood?)

On which side of the heart is the blood oxygenated/deoxygenated?

Each organ has its own blood supply

it depends on: their need for oxygen their amount of

supporting blood vessels

their function

Individual Organs require different amounts of blood

Blood Pressure (Blutdruck) Blood pressure – the pressure,

the blood exerts on the wall of the actual blood vessels – and is measured is measured in terms of millimeters of mercury (mmHg).Example- 140/90 mm Hg. Both values are used in BP assessment however it is the lower number which is more important.

The normal range for the upper figure is 100 plus the individual‘s age(however this does not apply to the elderly where it is usually higher!).

The upper figure is the systolic and the lower figure is the diastolic value.

High and Low Blood Pressure

Low Blood Pressure (Hypotension)Is not always a cause for concern nor does it always cause problems. Usually symptoms include: Dizziness, Reduced appetite, Morning listlessness, Sleep disturbances, Cold shivers, etc.Low blood pressure is usually not life threatening, and among the elderly there exists the possibility of collapse during a dizzy spell.High Blood Pressure (Hypertension)When The upper value is above 160 and the lower value is above 95, then this indicates elevated blood pressure.If the BP is elevated over a longer period of time, there is the risk of damage to various organs including: Vascular disease, Eyes -, Kidneys - and Heart disease, and leading possibly to a Cerebral hemorrhage.

The Electrocardiogram (ECG) With an ECG electrical activity in

the heart is measured. This isindicated as curves or spikes.

By measuring blood flow, it can determine whether there has been previous damage to the heart muscle from heart attacks or from inflammation, and whether blood flow is adequate

For an exact diagnosis a Stress – ECG (Belastungs-EKG) needs to be performed (Ergometer).

The P-spike indicates stimulation in the frontal chamber. QRS- spike indicates stimulation over all the chambers. And the T- curve indicates the decrease in overall electrical stimulation.

The heart lung machine

Herz und Lunge im Verbund

Quellen

Timm, Michael: „Gesundheit in Frage und Antwort“, Midena- Verlag, Augsburg 1997

Natur und Wissen3: „Der Mensch“, Bertelsmann international, München 1984

de Bernabe, Dr. E. G., „Schülerwissen aktuell“, Tosa- Verlag, Wien 1998

Brenner, Klaus- Ulrich: „Der Körper des Menschen“, Weltbild- Verlag, Augsburg 1996

www.mallig.de Atlas der Anatomie, Buch und Zeit Verlagsgesellschaft,

Köln 1990 Unger, Hödl, Kalnoky u.a., „Biologie und Ökologie“ Band II

WB, Trauner Verlag, Linz 1997 Animationen: http://www.le.ac.uk/pathology/teach/va/titlpag1.html