Lecture 14: Thorax III - The Heart Flashcards
What is the heart?
The heart is a double muscular
pump; its parts function together
to deliver oxygenated blood to
the tissues of the body
What is the function of the right side of the heart? What type of circulation?
receives poorly oxygenated blood from the body and pumps it to the lungs
Pulmonary circulation
What is the function of the left side of the heart? What type of circulation?
LEFT SIDE OF HEART: receives richly oxygenated blood from the lungs and pumps it to the tissues of the body
Systemic circulation
What is the pericardial sac (pericardium)? What are its 2 layers?
the double-walled membrane that surrounds the heart and the root of the great vessels
- Fibrous pericardium
- Serous pericardium
What is the fibrous pericardium? What does it attach to inferiorly?
▪ FIBROUS PERICARDIUM: tough, fibrous, outer layer that attaches inferiorly to the diaphragm
What is the serous pericardium, and its 2 layers?
▪ SEROUS PERICARDIUM: inner, serous membrane; two layers
-Parietal layer
-Visceral layer
Describe location of the parietal and visceral layers of pericardium.
-Parietal layer: lines internal surface of fibrous pericardium
-Visceral layer: adheres directly to the surface of the hear
What is the pericardial cavity?
▪ PERICARDIAL CAVITY: the potential space between the parietal and visceral layers of serous pericardium
What is inside the pericardial cavity, and its function?
Small amount of serous fluid
Reduces friction as the heart moves in the pericardial sac
What can cause an accumulation of substances in the pericardial cavity?
Injury or pathology
Identify indicated structures
Identify indicated structures
Describe the location and shape of the heart
LOCATION: the heart is located in the middle mediastinum to the left of midline and posterior to the sternum, costal cartilages, and ribs 3-5
SHAPE: the heart is shaped like a pyramid
Describe the location of the apex, and base of the heart
*Apex: directed anteriorly and to the left (primarily left ventricle)
*Base: posterior aspect of the heart (primarily left atrium)
What are the 4 surfaces of the heart, and what anatomical structure they coincide with?
SURFACES:
*Anterior (sternocostal): primarily R ventricle
*Inferior (diaphragmatic): primarily L ventricle
*Left (pulmonary): primarily L ventricle
*Right (pulmonary): primarily R atrium
What are the 4 borders of the heart, and what structures are they composed of?
BORDERS OF THE HEART:
*RIGHT: formed by the R atrium
*INFERIOR: formed primarily by the R ventricle (and some L ventricle)
*LEFT: formed primarily by left ventricle (and some L atrium)
*SUPERIOR: formed by R/L atria and great vessels
Identify indicated structures
What are the 3 sulci of the heart?
- Coronary (atrioventricular) sulcus
- Anterior Interventricular Sulcus
- Posterior Interventricular sulcus
Location of the coronary (atrioventricular) sulcus?
Location of anterior interventricular sulcus
Location of posterior interventricular sulcus?D
What are the 5 great vessels of the heart?
- Superior vena cava
- Inferior vena cava
- Pulmonary trunk
- Pulmonary veins
- Aorta
Function and location of superior vena cava:
type of blood, from which body areas?
returns deoxygenated blood to the R atrium from the head, neck, upper limb, and thorax;
located along superior portion of right border of heart
Function and location of inferior vena cava:
type of blood, from which body areas?
returns deoxygenated blood to the R atrium from the abdomen, pelvis, and lower limb; located along inferior portion of right border of heart
Function and location of pulmonary trunk:
type of blood, divides into…
carries deoxygenated blood from
the right ventricle; located in the superior mediastinum; divides into R/L pulmonary arteries
Function and location of pulmonary veins:
type of blood, from where to where, how many
carry oxygenated blood from the
lungs to the L atrium; typically, two on either side
Identify indicated structures
Identify indicated structures
What are the three sections of the Aorta?
- Ascending aorta
- Arch of aorta
- Descending / thoracic aorta
Funcion of the aorta?
carries oxygenated blood from the left ventricle; branches of the aorta are the blood supply to all tissues in the body
Where is the ascending aorta?
the first portion of the aorta, which extends vertically from the superior portion of the L ventricle
Location and function of the Arch of Aorta
the second portion of the aorta, which arches from right to left; major branches to head, neck, and upper limbs
What three major artery branches diverge from the aortic arch?
- Brachiocephalic trunk
- L Common Carotid Artery
- L Subclavian Artery
What 2 arteries arise from the brachiocephalic trunk?
- R Common Carotid
- R Subclavian
Destination of blood in R and L common carotid?
to the right side of the head / neck
to the left side of head / neck
Bloodflow in L and R subclavian artery
To left upper limb and right upper limb
Location and fuction of descending / thoracic aorta
the third portion of the aorta,
which courses through thoracic cavity; supplies thoracic wall
(continuous with abdominal aorta
Identify the indicated structures
Right Atrium:
1. Border
2. Blood flow
- Forms right border of the heart
- Receives deoxygenated blood from superior and inferior vena cava
What is the right auricle?
an ear-like muscular pouch that projects from the right atrium
What muscles and septum is present in right atrium?
Pectinate muscles and the interatrial septum
What is the interatrial septum?
Muscular wall separating the R atrium from the L atrium
What is the fossa ovalis?
Adult remnant of a fetal shunt (i.e., the foramen ovale) that connected the right and left atria
Right Ventricle:
1. Which surface
2. Border
3. Blood supply (which valve)
4. Delivers blood to (which valve)
- Forms most of the anterior surface of the heart (and some inferior surface)
- Forms most of inferior border
- Receives deoxygenated blood from the right atrium (atrioventricular / tricuspid valve)
- Delivers deoxygenated blood to pulmonary trunk (via pulmonary semilunar valve)
What muscular structures (2) and septum are present in right ventricle?
- Trabeculae Carneae
- Septomarginal trabeula (moderator band)
- Interventricular Septum
What are the trabeulae carneae and interventricular septum?
- trabeulae carneae - irregular muscular elevations in interior wall of right ventricle
- Interventricular septum - partition between left and right ventricles
What is the septomarginal trabeula?
The moderator band: a muscular bundle extending from the interventricular septum to the papillary muscles
the septomarginal trabecula is an important part of the heart’s conducting system)
What are the indicated structures of the right atrium?
What are the indicated structures of the right ventricle?
Left Atrium:
1. Surface
2. Blood flow
- Forms most of the base (posterior surface)
of the heart - Receives oxygenated blood from the lungs via the pulmonary veins
What is the left auricle, and what does it contain?
- Left auricle: an ear-like muscular pouch extending from the left atrium (contains pectinate muscles)
- Internal walls include a smooth-walled portion and a muscular part (i.e., the left auricle) made up of pectinate muscles
Left Ventricle:
1. Surfaces
2. Borders
3. Blood flow (which valve)
4. Delivers blood to (which valve)
- Forms most left surface of the heart and some of the inferior surface
- Forms the left border of the heart and the apex
- Receives oxygenated blood from the L atrium (via atrioventricular / bicuspid valve)
- Delivers blood to Aorta (via aortic semilunar valve)
What covers the interior walls of the left ventricle?
Trabeculae Carneae (2-3 times thicker than R ventricle)
Identify indicated structures
What are the 2 main classes of valves in the heart?
- Atrioventricular (AV) valves: separate the atria from the respective ventricles
- Semilunar Valves: located at the origins of the aorta and pulmonary trunk
What is another name for the right AV valve?
How many valve cusps?
Right AV (Tricuspid) valve: located in the orifice between the R atrium and the R ventricle
contains three valve cusps
Another name for left AV valve?
How many valve cusps?
Left AV (Bicuspid) valve: located in the orifice between the L atrium and the L ventricle
contains two valve cusps
What are the chordae tendinae, and their function?
Tendinous cords that attach to the valve cusps and to the papillary muscles (see below)
With papillary muscles, prevent prolapse of the valve cusps into atrium
What are papillary muscles?
conical projections from the interventricular wall; the chordae
tendinae (see below) attach to the apices of the papillary muscles
Explain how chordae tendinae work together with papillary muscles to prevent valve prolapse.
- Contraction of ventricles causes contraction of the papillary muscles
- Contraction puts tension on the chordae tendinae, which puts tension on chordae tendinae
- This prevents prolapse of valve cusps and backflow of blood
What are the 2 semilunar valves and their locations?
How many cusps?
- Pulmonary (semilunar) valve
Located at the origin of the
pulmonary trunk where it
exists the R ventricle - Aortic (semilunar) valve
Located at the origin of
the aorta where it exits
the L ventricle
Each semilunar valve each consists of three valve cusps that are concave superiorly
Identify indicated structures
Define coronary arteries. Branches of which artery?
branches of the ascending aorta that comprise the blood supply to the cardiac muscle
Both of the coronary arteries branch from the ascending aorta just superior to the aortic (semilunar) valves (see below)
Location of right coronary artery. What does it supply blood to? (3)
Right coronary artery: arises on the right side of the ascending aorta
supplies blood to the:
a. Right atrium
b. Majority of the right ventricle
c. Inferior (diaphragmatic) surface of the left ventricle
Which sulcus does the R coronary artery follow?
Courses in the atrioventricular (coronary sulcus)
Name 4 major arteries the R coronary branches into.
- Sino-atrial nodal branch
- Right marginal branch
- Atrio-ventricular nodal branch
- Posterior interventricular (posterior descending) artery
What supplies blood to the sinoatrial node, and where?
Right Coronary Artery - Near its origin, the right coronary artery gives off the sinu-atrial (SA) nodal
branch, which supplies the SA node
What is the second branch given off by the right coronary artery?
What does this branch supply?
gives off the right marginal branch, which supplies the right border of the heart
What artery supplies blood to the atrio-ventricular node? What artery does it branch from?
atrio-ventricular (AV) nodal branch
Branches from R coronary artery
Where is the posterior interventricular (posterior descending) artery located?
What artery does it branch from?
Courses inferiorly in the posterior interventricular sulcus.
Branches from R coronary artery.
What is the origin of the left coronary artery? What 3 structures does it supply blood to?
arises on the left side of the ascending aorta; typically supplies blood to the:
a. Left atrium
b. Majority of the left ventricle
c. Part of the right ventricle
Where is the left coronary artery located?
Courses between the left auricle and the pulmonary trunk (in the coronary sulcus)
What 2 major arteries does the L coronary branch into?
Anterior interventricular (left anterior descending) artery
Circumflex artery
Which sulcus is the anterior interventricular artery located in?
courses
inferiorly in the anterior interventricular sulcus
Describe location / trace course of the circumflex artery.
continues in the coronary sulcus to the left border of the heart and then to posterior surface of the heart
What is the coronary sinus, its location and where it drains?
Coronary sinus: the main venous channel of the heart; courses in the posterior aspect of the coronary sulcus and drains into the right atrium
What are the 3 main tributaries of the coronary sinus?
- Great cardiac vein
- Middle cardiac vein
- Small cardiac vein
Trace the course of the great cardiac vein:
1. Origin
2. Course
3. Where does it drain
- originates in the anterior interventricular sulcus
- courses with the anterior interventricular artery
- drains into the coronary sinus on the left side
Middle cardiac vein:
1. Origin
2. Course
3. Drains into
- originates in the posterior interventricular sulcus
- course with the posterior interventricular artery
- drains
into the coronary sinus on the right side
Small Cardiac Vein:
1. Origin
2. Drains into
- originates on the right side of the inferior (diaphragmatic) surface of the heart
- Drains into coronary sinus on the right side
Describe blood flow through the heart
Which of the following vessels courses with the anterior interventricular artery?
A. Coronary sinus
B. Great cardiac vein
C. Middle cardiac vein
D. Pulmonary vein
E. Small cardiac vein
B
Which of the following statements about the chordae tendinae is correct?
A. The chordae tendinae help open the atrioventricular valves
B. The chordae tendinae help open the semilunar valves
C. The chordae tendinae prevent regurgitation of blood into the atria
D. The chordae tendinae prevent regurgitation of blood into the ventricles
E. The chordae tendinae are attached to the valve cusps of the semilunar valves
C
Identify the indicated structures
