Heart and mediastinum Flashcards
The sternal angle is between T___ and T___
T4 and T5
What is the superior boundary of the mediastinum
Thoracic inlet
What is the inferior boundary of the mediastinum
Diaphragm
What is the anterior boundary of the mediastinum
Sternum and costal cartilages
What is the posterior boundary of the mediastinum
Thoracic vertebrae
What is the lateral boundary of the mediastinum
Pleura
What are the cavities in the thoracic cavity
- mediastinum
- pleural cavity
- Pericardial cavity
What are the cavities that make up the abdominopelvic cavity
- Abdominal cavity
- Pelvic cavity
Contents o the superior mediastinum
Great vessels of the heart, thoracic ducts (left), parts of azygos system, Right and left vagus nerves (recurrent laryngeal nerves), pulmonary, esophageal and cardiac autonomic nerve plexuses, thymus, parts of trachea and esophagus
Contents of infero-anterior mediastinum
Fat, lymph tissue, vessels, in small children thymus may extend into this region
Contents of infero-middle mediastinum
The heart and it’s pericardial tissues
Contents of infero-posterior mediastinum
Thoracic aorta, esophagus, pulmonary arteries and veins, azygos system, thoracic duct, sympathetic trunk and thoracic splanchnic nerves
The thoracic splanchnic nerves are in the _____ portion of the mediastinum. They are bilateral and emerge from the ____-
Inferoposterior, emerge from thoracic sympathetic trunks
All three of the thoracic splanchnic nerves (Greater, Lesser, Least) are part of the abdomnopelvic splanchnic nerves and provide _______ to ______
Sympathetic innervation to viscera inferior to the diaphragm
The thoracic splanchnic nerves are all presynaptic that will synapse with _________ in abdomen
Prevertebral ganglia in abdomen
What are the areas of constriction where swallowed foreign objects are most likely to lodge and where a stricture may develop
At the arch of the aorta, left main bronchus, and diaphragm (note that this is the Esophageal hiatus, which is where the diaphragm has an opening for esophagus to pass through)
___ is the center of the cardiovascular system
Heart
____ carry blood away from the heart
arteries
_____ carry blood back to the heart
veins
Arteries and veins entering and leaving the heart are called the
great vessels
The heart ensures the _____ flow of blood through both the heart and the blood vessels
unidirectional
back flow of blood in the heart is prevented by ____ in the heart
valves
The heart acts like ____ independent, side- by-side pumps that work independently but at the same rate. What are they
- 2
- one directs blood to the lungs for gas exchange (pulmonary circulation)
- One that directs blood to body tissues for nutrient delivery (systemic circulation)
The heart develops ____ through alternate cycles of heart wall contraction and relaxation
- blood pressure
____ is essential to push blood through blood vessels to the body tissues for nutrient and waste exchange
Minimum blood pressure
_______ consists of the chambers on the right side of the heart (right atrium and ventricle) as well as the pulmonary arteries and veins
Pulmonary circuit
_____ consists of the chambers on the left side of the heart (left atrium and ventricle), along with all the other named blood vessels
Systemic circuit
Oxygenated blood form the left side of the heart is pumped into the _____, the larges systemic artery in the body, and then into smaller systemic arteries
aorta
Gas exchange in tissues occurs from ____
capillaries
Most veins merge and drain into the __________, which drain blood into the right atrium
superior and inferior venae cavae
The heart weighs about ____ to ___ grams
250 to 350
The heart is located ____ of the body midline posterior to the sternum in the ____ mediastinum
left, middle
The heart is rotated such that its ____ side or border (_________) is located more anteriorly, while its ______ side or border (_______) is located more posteriorly
- Right side or border (right atrium and ventricle)
- Left side or border (left atrium and ventricle)
The posterosuperior surface of the heart, formed primarily by the _____, is called the base
left atrium
The inferior, conical end of the heart is called the ____
apex
The apex projects slightly _____ toward the ______
anterioinferiorly toward the left side of the body
The _____ that enter the left atrium border this base
pulmonary veins
The pericardium has how many layers and what are they
- 3 (visceral, parietal, fibrous)
The heart is contained in a ____, ____ sac held in place within the mediastinum by connective tissue that supports the great vessels’ external walls superior to the heart and diaphragm inferior to it
fibrous, serous
The pericardium functions
restricts heart movements so that it doesn’t bounce and move about in the thoracic cavity, and prevents the heart form overfilling with blood
The outer portion of the pericardium is a tough, dense connective tissue layer called the _____
fibrous pericardium
The fibrous pericardium is attached to both the ___ and ____
sternum and diaphragm
The inner portion of the pericardium is a thin, double-layered serous membrane called the
serous pericardium
The serous pericardium is made up of what two parts
- Parietal layer
- Visceral layer
The parietal pericardium is adhered to the ______. The only potential space with fluid is between the ___ and ____
- Fibrous pericardium
- visceral layer and parietal layer
The heart wall consists of ___ distinctive layers. Which are called?
- 3
- External epicardium
- Middle myocardium
- internal endocardium
The ____ is the outermost heart layer and is also known as the visceral layer of serous pericardium
Epicardium
As we age, more fat is deposited in the _______,and so this layer of the heart becomes thicker and more fatty
epicardium
____ is the middle layer of the heart wall and is composed chiefly of cardiac muscle tissue
myocardium
The ____ is the thickest of the three heart wall layers
myocardium
The internal surface of the heart and external surfaces of the heart valves are covered by a thin endothelium called the _____
endocardium
Between the endocardium and myocardium lies a _____ layer, which is composed of areolar connective tissue
subendocardial layer
___ are thin-walled chambers that are located superiorly
atria
the anterior part of each atrium is wrinkled, flaplike extension called an
auricle
____ receive blood returning to the heart through both circulatory circuits
Atria
____ receives blood from the systemic circuit
right atrium
____ receives blood from the pulmonary circuit
Left atrium
Two large arteries, the ____ and the ___ exit the heart at the basal surface
pulmonary trunk and aorta
The _____ carries blood from the right ventricle into the pulmonary circuit
Pulmonary trunk
The ___ conducts blood from the left ventricle into the systemic circuit
aorta
The atria are separated from the ventricles externally by a relatively deep ______ (or _______) that extends around the circumference of the heart
Coronary sulcus (atrioventricular sulcus)
On both the anterior and posterior surfaces of the heart, the _________ and the ______ are located between the left and right ventricles
Anterior interventricular sulcus and the posterior interventricular sulcus
Anterior interventricular sulcus and the posterior interventricular sulcus extend inferiorly from the ______ toward the heart apex
coronary sulcus
what is in the posterior interventricular sulcus
- posterior interventricular artery
- middle cardiac vein
The _____ heart skeleton is located between the atria and the ventricles, and is formed from dense irregular connective tissue
Fibrous
Functions of fibrous skeleton of the heart
- Separates the atria and ventricles
- Anchors heart valves by forming supportive rings at their attachment points
- provides electrical insulation between atria and ventricles
- insulation ensures that muscle impulses are not spread randomly throughout the heart, and thus prevents all the heart chambers from beating at the same time
- provides a rigid framework for the attachment of cardiac muscle tissue
In the adult heart, the fossa ovalis can be view in the
right atrium
The _____ receives blood from the systemic circuit and the heart muscle itself
right atrium
What 3 major vessels empty into the right atrium
- superior vena cava
- Inferior vena cava
- Coronary sinus
______ drains blood from the head, upper limbs, and superior regions of the trunk
Superior vena cava
______ drains blood from the lower limbs and trunk
inferior vena cava
_______ drains blood from the heart wall
Coronary sinus
The _____ forms a wall between the right and left atria
interatrial septum
The right atrium of an adult has has the fossa ovalis which is remnant of what fetal structure
foramen ovale
The right atrium has ____ muscle
pectinate
Semilunar valves function similarly to the
venous valves
The right atrioventricular (AV) or Tricuspid valve separates
the right atrium from the right ventricle
The right atrioventricular (AV) is also called the
tricuspid valve
The right atrioventricular (AV) valve has _____ triangular flaps
3
The right atrioventricular valve is forced closed when
the right ventricle begins to contract, thus preventing blood back flow into the right atrium
An ______ forms a wall between the right and left ventricles
Interventricular septum
The internal wall surface of the right ventricle has 3 cone-shaped muscular projections called _______, which anchor ____
papillary muscles, which anchor chord tendineae
functions of chord tendineae
attache to the cusp of the AV valves and prevent everting and flipping into the atrium when contracting
At its superior end the right ventricle it narrows into a smooth-walled, conical region called the _____
conus arteriosus
The _____ marks the end of the right ventricle and the entrance into the pulmonary trunk
pulmonary semilunar valve
Pulmonary trunk divides into ____ and ____
right and left pulmonary arteries, which carry deoxygenated blood to the lungs
located within the walls of both ventricles immediately before the connection of the ventricle to the pulmonary trunk and aorta
Semilunar valves
Each semilunar valve is composed of
three thin, rocketlike semilunar cusps
Smooth posterior wall of the _______ contains openings for approximately four pulmonary veins
left atrium
The left atrium has some ____ muscles along its anterior wall as well as an _____
pectinate, auricle
The left atrioventricular (AV) valve is also called the
bicuspid or mitral valve
what is the largest of the four chambers of the heart
the left ventricle
The left ventricle is typically _____ times thicker than the right ventricular wall
3 times thicker
Trabeculae carneae in the ____ ventricle are more prominent
left
in the left ventricle ___ large papillary muscles attache to the chordae tendineae that help support the left AV valve
2 (note that this is different than the right which has 3 but this makes sense because the right AV valve is a tricuspid and the left AV Valve is bicuspid)
At the superior end of the ventricular cavity, the _______ marks the end of the left ventricle and the entrance into the aorta
aortic semilunar valve
The heart is innervated by the
autonomic nervous system
Innervation of the heart consists of both _____ and ___ components. Referred to as the ____ or _____
Sympathetic and parasympathetic (cardiac or coronary plexus)
_____ innervation increases the rate and the force of heart contractions
Sympathetic innervation
______ innervation decreases heart rate, but tends to have no effect on force of contractions, expect in special circumstances
parasympathetic
left and right coronary arteries travel in the ______ of the heart to supply the heart wall (note these are the only branches of the ascending aorta)
Coronary sulcus (atrioventricular groove)
the openings for the left and right coronary arteries are located immediately _____ to the aortic semilunar valve
superior
The right coronary artery typically branches into the
- marginal artery (supplies the right border of the heart)
- Posterior interventricular artery (supplies both the left and right ventricles)
The marginal artery supplies
the right border of the heart
The posterior interventricular artery supplies
both the left and right ventricles
The left coronary artery typically branches into
- Anterior interventricular artery (also called the left anterior descending artery (LAD)
- Circumflex artery
The anterior interventricular artery ( or LAD) supplies
the anterior surface of both ventricles and most of the interventricular septum
The circumflex artery supplies
the left atrium and ventricle
Cardiomyopathy
- a condition in which a ventricle has become enlarged thickened and/or stiffened. As a result, the heart’s ability to pump is reduced. Two types of cardiomyopathy include: Dilated cardiomyopathy and hypertrophic cardiomyopathy
_____ is a procedure in which a catheter is inserted with a tiny balloon that presses the plaque blockage against the artery so that blood may flow more freely through the vessel. A ___ is then inserted to keep the vessel pathway open and the blood flowing
Angioplasty, stent