Body Fluids And Circulation Flashcards
Blood flows strictly through
Blood vessels.
Blood vessels in our body are
Arteries and veins.
Layers present in the blood vessels.
- Tunica intima - innermost
- Tunica media
- Tunica externa - outermost
Tunica Indica constitutes of
Squamous endothelium.
tunica media constitutes____?
Smooth muscle and elastic fibres
Tunica externa is made up of
Fibrous connective tissue with collagen fibre.
Which layer of the blood vessels is comparatively thinner in veins ?
Tunica media.
Blood pumped by right ventricle enters ____?
Pulmonary artery.
Blood pumped by the left ventricle pumps blood into
Aorta.
The human circulatory system is also called
The blood vascular system.
The human circulatory system consists of ?
- Muscular chambered heart
- A network blood vessels
- Blood
Location of heart
Situated in the thoracic cavity, between the 2 lungs, slightly tilted to left.
Heart is protected by
Double walled membranous bag called pericardium.
The pericardium encloses ___?
Pericardial fluid.
Heart has 4 chambers. Name them.
Upper two - atria ( small)
Lower two - ventricle ( larger)
What separates the left and right atria ?
Inter atrial septum ( thin)
What separates the left and right ventricles ?
Inter ventricular septum ( thick )
The atrium and ventricle of the same side are separated by
Atrio ventricular septum.
The opening between the right atrium and the right ventricle is guarded by
Tricuspid valve
The opening between the left atrium and the left ventricle is guarded by ?
Bicuspid or mitral valve.
The openings of right and left ventricles are provided with ?
Semilunar valves
Function of valves in the heart ?
Blood flow in one direction.
Direction of blood flow in the heart .
From atria to ventricles
From ventricles to artery or aorta.
The heart is entirely made of
Cardiac muscles
A specialised cardiac musculature is distributed in the heart which is called?
Nodal tissue.
Most of the nodal tissue is present in ?
Right atrium
The nodal tissue present in the right upper corner of atrium is ?
Sino atrial node (SAN)
Atrio ventricular node AVN is found in ?
Lower left corner of right atrium, close to atrio ventricular septum.
Path of the nodal fibres.
- AV bundles continue from AVN
- Passes through AV septa
- Emerges on top of IV septum
- divides into left and right
The branches of Av bundles give rise to minute fibres called ?
Purkinje fibres.
The nodal musculature is auto excitable. Explain.
It has the ability to generate action potential without external stimuli.
Maximum no. Of action potentials that can be generated by the SAN
70 to 75 per minute.
The SAN is called the pacemaker. Why ?
It is responsible for initiating and maintaining the rhythm contractile activity of the heart.
When the heart is in a relaxed state , the four chambers are in
Joint diastole.
Blood that flows into the left ventricle is from ?
The pulmonary veins
(Veins not artery idiot)
The blood that flows in the right ventricle is from
Vena cava
Which valves are open and closed When blood flows into the ventricles
Open - tricuspid amd biscupid
Closed - semilunar valves
After the blood flows into the ventricles through the atrium, what action takes place ?
Atrial systole.