The Cardiovascular System

CHAPTER 8

Where is the heart located?

• Centrally in the chest

– Surrounded by lungs, protected by ribs

– Between 3rd-7th ribs in ________ animals and 2nd-6th ribs in _________ animals

– Lies in the _____________ (interpleural space), which is the space between the pleural covering of the right and left lungs.

• Trachea, esophagus, and other vascular structures are also found here

Orientation of the heart

• Bottom of the heart is shifted to the left of the chest

• ________ - the bottom of the heart where the left ventricle comes to a point

• ________ - the top of the heart where major blood vessels enter and exit

Composition of the Heart Wall

Outer layer of the heart is called the _________________.

-The pericardium consists of an outer fibrous pericardium and an inner serous pericardium.

•FIBROUS pericardium– loosely attaches to the diaphragm.

• The SEROUS pericardium consists of two layers:

*The __________ pericardial layer is adhered to the fibrous pericardium.

*The __________ pericardial layer lies on the surface of the heart and is also known as the epicardium.

Between the two layers of the serous pericardium is the pericardial space.

This is a fluid filled cavity that ________________ the two layers which allows the heart to smoothly expand and contract.

• Beneath the epicardium is the ______cardium, the thickest layer of the heart tissue.

• The inner surface of the heart that lines its chambers is the ______cardium.

External anatomy of the heart: Chambers

• Auricles- (left and right) ear-shaped chambers located at the base. They are identified by knowing which ventricle they lie above.

• ________ ventricle - long and narrow, thick-walled, makes up the apex of heart

• ________ ventricle - broader surface area, thinner walls

• The borders of the ventricles contain interventricular sulci, which are grooves of fat and blood vessels that are part of ____________ circulation of heart.

Vessels and chambers that contain DEOXYGENATED

blood

•The _______ _________ (cranial and caudal) empty deoxygenated blood into the RIGHT ATRIUM

•The Pulmonary _________ (left and right) emerge from the RIGHT VENTRICLE as the pulmonary trunk

– Quickly divides into right and left

pulmonary arteries traveling to each lung

Vessels and chambers that contain OXYGENATED

blood

• The Pulmonary _________ (left and right) return oxygenated blood to the LEFT ATRIUM

• The _________ is the largest artery in the body – The walls of the aorta are the

thickest of any blood vessel– The aorta emerges from the LEFT

VENTRICLE and delivers oxygenated blood to the body.

Internal Structures of the Heart

Atrioventricular Valves:

-Right Atrioventricular Valve (aka Right AV valve/Tricuspid Valve) separates the right

atrium from the right ventricle

-has ___ flaps/leaflets

-Left Atrioventricular Valve (aka Left AV Valve/Mitral Valve/Bicuspid Valve) separates

the left atrium from the left ventricle

-has ___ flaps/leaflets

These valves open and close simultaneously!

The AV valves are attached to _________ __________, which prevent the flaps from bending back into the atria.

_____________ muscles connect the chordae tendinae to the interventricular septum

The _____________ band is a band of tissue present in the right ventricle.

-not attached to flaps of tricuspid valve-provides additional structural support to the wall of the right

ventricle

Semilunar valves:

-Aortic valve

-Pulmonary/pulmonic valve

Both valves are made of ____ leaflets. The aortic valve leads to the aorta and the pulmonary/pulmonic valve leads to the

pulmonary trunk.

These valves open and close simultaneously!

Can you label the chambers and valves?