Chapter 22: Heart System (lecture) Flashcards
features of the heart
-move the blood with needed circulation
-heart beats 75 times/min
what are the two parallel pumps?
-pulmonary circulation
-systemic circulation
what occurs in the pulmonary circulation?
takes blood to the lungs and then back to the heart
what occurs in the systemic circulation?
takes blood from the heart and to the rest of the body
basic pattern of blood flow
1) right side of heart (deoxygenated blood)
2) lungs (gas exchange)
3) left side of heart (oxygenated blood)
4) systemic cells (gas exchange)
where is the heart located?
-left of the body midline posterior to the sternum in the mediastinum
-sitting on diaphragm
-slightly rotated
effects of the heart being slightly rotated
-its right side/ right border is located more anteriorly
-its left side/ left border is located more posteriorly
parts of the heart
-base
-right border
-left border
-superior border
-inferior border
-apex
what is the posterosuperior surface (flat side) of the heart called?
base
what is the posterosuperior surface of the heart formed by?
left atrium
what do the great vessels and superior vena cava form?
superior border
what are the great vessels?
-aorta
-pulmonary trunk
-pulmonary arteries
what is the inferior, comical end of the heart known as?
apex
what is the apex of the heart formed by?
left ventricle (points to the left side)
what is the inferior border formed by?
right ventricle
what is the pericardium?
-a fibrous sac and serous lining
-where the heart is contained in
function of the pericardium
-restricts the heart’s movements so that it doesn’t bounce and move about in the thoracic cavity
-prevents the heart from overfilling with blood
what two parts is the pericardium composed of?
-fibrous pericardium (outer portion)
-serous pericardium (inner portion)
tissue of the fibrous pericardium
-tough, dense connective tissue layer
-attached inferiorly to the diaphragm and superiorly to the base of the great vessels
tissue of serous pericardium
thin, double-layered serous membrane
what is the serous pericardium subdivided into?
-parietal layer: liner inner surface of fibrous pericardium
-visceral layer: covers the outside of the heart (outermost layer of the heart itself)
what is the pericardial cavity?
-thin space between the parietal and visceral layers of the serous pericardium
-potential space with a thin lining of serous fluid
how does the serous fluid benefit the pericardial cavity?
lubricates the serous membranes and decrease friction when the heart beats
layers of the heart
-epicardium (outermost layer)
-myocardium
-endocardium
what is the epicardium composed of?
-serous membrane
-made up of areolar connective tissue
what is another name for the visceral pericardium?
epicardium
characteristics of the myocardium and what type of tissue does it have?
-middle layer of the heart wall
-composed of cardiac muscle tissue
-thickest of the three layers
characteristics of endocardium and what type of tissue is it made of?
-internal surface of the heart chambers
-composed of simple squamous epithelium (to keep the blood from leaking out)
chambers of the heart
-atria (left & right)
-ventricles (left & right)
-great vessels
-valves
location and function of atria
-location: the left and right atria are thin-walled chambers located superiorly
-function: receive blood returning to the heart through both circulations
where does the right atrium receive blood? where does the left atrium receive blood?
-right atrium: receives blood from the systemic circulation
-left atrium: receives blood from the pulmonary circulation
location and function of ventricles
-location: the left and right ventricles are located in the inferior chambers
-function: force blood into the great vessels of the heart
what two large arteries exit the heart at its superior border?
-pulmonary trunk (comes from the right ventricle)
-ascending aorta (comes from the left ventricle)
what keeps the blood flowing in the correct direction (one-way flow) in the heart?
several valves in the heart
parts of the atrial walls
-posterior wall (smooth)
-anterior wall (muscular ridges)
-interatrial septum
characteristics and function of the atrial walls
-much thinner than the ventricles
-send blood into the ventricles next door
function of the posterior wall
-prime ventricles: make sure ventricles fill completely before they contract
parts of the anterior wall
-pectinate muscle: muscular ridgeswhat is (found in both left and right atrium)
-auricle: small flap on top of heart
what is the interatrial septum?
forms a thin wall between the left and right atria
parts of the interatrial septum
-fossa ovalis: oval depression that occupies former location of foramen ovale
-foramen ovale: remant of fetal structure, which shunted blood from the right atrium, to the left atrium, during fetal life
veins leading to right atrium
-superior vena cava
-inferior vena cava
-coronary sinus
function of superior vena cava
drains blood from the head, neck, upper limbs, and superior regions of the trunk
function of the inferior vena cava
drains blood from the lower limbs, abdomen, trunk, inferior thorax
function of the coronary sinus
drains blood from the heart wall
veins leading to the left atrium
right (2) and left (2) pulmonary veins
ventricular walls & vessels
-trabeculae carneae
-papillary muscles
interventricular septum
