Circulatory system 🗸 Flashcards
Circulatory system
made of the cardiovasular system, and lymphatic system
Cardiovascular system
made of the arterial system, the heart and the venous system
Pulmonary circulation
from the right of the heart
to the lungs
to the left side if the heart
Systemic circulation
from the left side of the heart
to the capillary beds of tissues and organs
to the right side of the heart
Epicardium
most outer layer of the heart, visceral serous pericardium
Myocardium
middle layer of the heart, cardiac muscle layer
Endocardium
the inner layer of the heart, continuous with the endothelium of the blood vessels connecting with the heart
The four cardiac valves
pulmonary valve
tricuspid valve
mitral (bicuspid) valve
aortic valve
Pulmonary valve
at the entrance to the pulmonary artery
Tricuspid valve
between the right atrium and ventricle
Mitral (Bicuspid) valve
going into the left atrium from the pulmonary vein
Aortic valve
between the left ventricle and atrium
The conduction system of the heart
Initiates and propagates rhythmic depolarisation, which results in rhythmic cardiac muscle contractions
First step of Conduction system
electrical impulse starts at the sinoatrial (SA) node
Second step of Conduction system
Impulse travels down the atrioventricular (AV) septum to the AV node
third step of conduction system
impulse travels down the left and right bundles of the interventricular septum
fourth step of conduction system
impulse spreads out to the myocardium through the conductive fibres and the ventricles contract
Outer layer if blood vessels
tunica adventitia, connective tissues
middle layer of blood vessels
tunica media, elastic fibres and smooth muscles
inner layer of blood vessels
tunica intima, endothelium
Sympathetic tone
a background low level of contractions from the smooth muscles in arterioles
Anastomoses
arteries connect to each other without a capillary network
Anastomoses provide an alternative route, why?
To supple cells that are distal to an arterial occlusion (end of an artery)
What are alternative routes by anastomoses called?
Collateral
End artery
the only arterial blood supply for an area of the body
Infarction
The irreversible cell death due to hypoxia (lack of oxygen) caused by the loss of arterial blood being supplied to the area
Why does infarction happy
Untreated occlusion of an end artery
Where do the left and right coronary arteries of the aorta supply blood to?
The heart muscle
Where do the arch branches of the aorta supply blood to?
The upper limbs and head
Where does the descending aorta supply blood to?
the thorax and abdomen
What does the abdominal aorta branch into within the abdomen?
Iliac arteries that supply blood to the pelvis and lower limbs
Where are the coronary arteries?
At the bottom of the ascending aorta, on the right of the heart
What two types of artery branch of the arch of the aorta?
The subclavian artery and the common carotid artery
How does venous blood return to the heart?
Venous valves
skeletal muscle oumpx
accompanying veins
What are the four structures of the venous system?
Superficial veins
deep veins
hepatic portal venous system
systemic venous system
Superficial veins
smaller, run within he superficial fascia, drain into deep veins
deep veins
larger, run to the deep fascia in cavities, often in neurovascular bundles
Hepatic portal venous system
Drains venous blood from GI Tract and associated veins to clean
Systemic venous system
drains all venous blood into the vena cavae
What do lymphatic capillaries collect?
tissue fluid called lymph
Where does lymph travel to in order to drain into the body
The thoracic duct and lymphatic duct
lymph from superficial lymphatics goes?
to the deep lymphatics
lymph from the right lymphatic duct goes to?
the right venous angle
lymph from the thoracic duct (left) goes to?
the left venous angle
