Heart anatomy Flashcards
What is the heart
4 chambered fibromuscular pump
What is the size of the heart
Size of an adult fist
Where is the heart located
Mediastinum
How many and what are the external features/surfaces of the heart
- Diaphragmatic surface
- Posterior (Base) surface
- Sternocostal (Anterior) surface
- Right pulmonary surface
- Left pulmonary surface
What are the cusps of the valves in the right ventricle
Pulmonary valve which has 3 cusps - Anterior semilunar, Right semilunar, Left semilunar
Tricuspid valve which has 3 cusps - Septal, Anterior, Posterior
Where are the atrioventricular and semilunar cardiac valves located
Atrioventricular and aorto-pulmonary pathway of blood flow
What is the problem that could arise from valve incompetency
Blood backflow which leads to heart failure over time
What happens in a cardiac failure
Hypertrophied heart
- Diastolic heart failure due to filling problem
- Left ventricle unable to relax normally resulting in fluid backing up into lungs
- Diastolic failure leads to problems with heart relaxation and filling with blood
Dilated heart
- Systolic heart failure due to pumping problem
- inability of heart to contract enough to provide blood flow forward
- problems with contraction and blood ejection
What is the other name of bicuspid valve
Mitral valve
What does each cusp contain
Core of connective tissue and endothelial covering
What are the 3 apex of the heart
Clinical apex, true anatomical apex, radiological apex`
Which pericardium is pain sensitive
Fibrous and Parietal Serous pericardium. Both are innervated by Phrenic nerve
What are the supporting ligaments of the heart
Vertebropericardial ligaments, Superior sternopericardial ligament, Sternopericardial ligament, Phrenicopericardial ligament
What is the difference between pulmonary and systemic circulation
Pulmonary circulation is from heart to lungs
Systemic circulation is from heart to body
Explain the process of blood flow
- O2 rich blood from left atria moves into left ventricles and then to aorta
- O2 rich blood flows from aorta to the systemic capillaries and gas exchanges occurs
- O2 poor blood flows back into heart via inferior and superior vena cava to right atria and then to right ventricle
- Blood flows from right ventricle to pulmonary trunk and then to pulmonary arteries to lungs
- Gas exchange occurs at pulmonary capillaries
- O2 rich blood flows through pulmonary veins to left atrium
what makes the posterior surface (base)
Left atrium + Right atrium + Proximal part of great veins
What makes the sternocostal (anterior) surface
Right atrium, Right ventricle, Left ventricle
What makes the diaphragmatic surface
Left and Right ventricle
What is the significance of transverse pericardial sinus
Allows surgeon to isolate the pulmonary trunk and ascending aorta and apply a temporary ligature or clamp. This allows surgeons to stop or divert the circulation of blood in these arteries while performing cardiac surgery, such as coronary artery bypass grafting.
What is the significance of pericardium with relation to pericardiocentesis
Pericardiocentesis is a procedure done to remove fluid that has built up in the sac around the heart (pericardium). It’s done using a needle and small catheter to drain excess fluid. If not, heart is unable to pump blood enough and effectively
Why should atrioventricular and semilunar valves remain competent always
Leads to blood backflow and heart failure
Where are atrioventricular cardiac valves located
Located at opening of atria into ventricles
Where are the semilunar cardiac valves located
Located at opening of ventricles into aorta and pulmonary trunk
What is the difference between atrioventricular and semilunar cardiac valves
Closure of valves is active in atrioventricular valves whereas semilunar cardiac valves are passive
What is the function of papillary muscles
Works with chordae tendineae to prevent inversion or prolapse of valves on systole
What is the function of chordae tendineae
Works with papillary muscles to prevent inversion or prolapse of valves on systole
What is the purpose of trabeculae carneae
Prevents high pressure blood flowing in from forming bubbles and suction could occur which impairs heart’s ability to pump efficiently
What are the components of left ventricle
Mitral/bicuspid valve
- anterior and posterior cusp
Papillary muscles
- anterior and posterior
Chordae tendineae
Coronary sinus
What are the components of left atrium
Pulmonary veins
Valves of foramen ovale
Mitral/Bicuspid valve
What are the components of right ventricle
Tricuspid valve
- Anterior, Septal, Posterior
Chordae Tendineae
Papillary muscles
- Anterior, septal Posterior
Trabeculae carneae
Conus arteriosus
septomarginal trabecula
Pulmonary valve
- Anterior, Right, Left semilunar
Pulmonary trunk
Arch of aorta
What is the function of conus arteriosus
Transports deoxygenated blood from right ventricle to pulmonary trunk and onto lungs
What is the function of septomarginal trabecula
AKA Moderator band
Does not attach to the tricuspid valve, but acts as part of the electrical conduction pathway of the heart
Significance of foramen ovale
Significant in fetal circulation
What are the components of Right Atrium
Superior and Inferior vena cava
Valve of inferior vena cava
Oval fossa
Limbus of oval fossa
fossa ovalis
Valve and opening of coronary sinus
Crista terminalis
Musculi pectinati
What is the function of crista terminalis
discrete bundle of atrial myocardium that conducts impulses generated by the SA node to the atrioventricular (AV) junction
What is the function of musculi pectinati
Acts as a Right atrium volume reserve during adverse loading conditions
Explain the covering layers of the heart
Outside to inside
- Fibrous pericardium
- Parietal layer of serous pericardium
- Pericardial cavity
- Visceral layer of serous pericardium
- Myocardium
- Endocardium
What is the pericardial cavity filled with and how many mL
Pericardial fluid
15 - 50 mL
What is the treatment methods for Ischemic Heart Disease
Coronary artery bypass grafting
Balloon angioplasty and stents
What makes the posterior (base) orientation of the heart
Left atrium, proximal parts of great veins, and right atrium
What makes the diaphragmatic orientation of the heart
Right and left ventricle
What makes the sternocostal (anterior) orientation of the heart
Left ventricle, right ventricle and right atrium
What is the significance of Transverse pericardial sinus
Allows surgeon to isolate pulmonary trunk and ascending aorta
Use these to stop/divert blood circulation in arteries while performing cardiac surgery
Coronary arteries of heart
Right coronary artery
Right marginal branch of right coronary artery
Left coronary artery
Sino-atrial nodal branch of left coronary artery
Posterior interventricular branch of circumflex branch of left coronary artery
Left circumflex artery (Circumflex branch of left coronary artery)
Left anterior interventricular artery (Anterior interventricular branch of left coronary artery)
Diagonal branch of anterior interventricular branch
Coronary veins
Great cardiac vein
Anterior interventricular vein
Posterior cardiac vein
coronary sinus
Middle cardiac vein
Small cardiac vein
Right marginal veins
Anterior veins of right ventricle
What are capillaries lacking compared to veins and arteries
No elastic tissue, smooth muscle, fibrous tissue
What are blood arteries and the disadvantages of them
They are end arteries which means if compromised, the muscles supplied by that vein/artery is affected
Describe cardiac cells
Cross striations and connected by intercalated discs and connects one myocyte with another
Difference between ventilation and respiration
Ventilation is gas movement whereas respiration is the exchange of gases
What is the role of upper respiratory tract and lower respiratory tract
Upper respiratory tract - Ventilation
Lower respiratory tract - Ventilation & Respiration
What separates the nose from mouth (nasopharynx from oropharynx)
Soft palate
Oropharynx is in between what pathways
Air and food pathways
What is the significance of the pharynx
Separates food and air pathways
How do you see the opening of larynx
Laryngoscopy
What is the significance of larynx
Prevent asphyxiation (choking; primary function) and voice production (secondary function)
What is the function of goblet cells
Produce mucus
What is the function of ciliated cells
Move mucus to esophagus via pharynx
What is the function of mucus
Traps dust and moisture incoming air to become more humid
Why is warming the incoming air necessary for breathing
Cold air will cause the muscles to contact which makes it difficult to breathe. Bringing the temperature to body temperature reduces the muscle contraction and minimize air resistance
What happens to prevent food particles from entering the nasopharynx from the oropharynx during the act of swallowing?
Elevation of soft palate
Where does the lower respiratory tract starts to trachea
C6 (Cricoid cartilage) to T4 (Sternal angle)
What is the smooth muscle found in trachea
Trachealis
Where does the tracheal bifurcation occur
Sternal angle in between IV and V vertebrae
Which bronchus would food go into when someone starts choking
Right bronchus
Why is the right bronchi wider than left bronchi
Right bronchi is already forming other bronchi generations
Arch of aorta and heart push the left lung to the side
Why is cancer at bronchi dangerous
It can spread to spine which results in back pain and possible malignancy
When is a bronchus considered a bronchiole
Lack of cartilage
What are the different generations of the bronchus to alveoli
1st - 11th Generation is Bronchi
12th - 14th generation is bronchiole
15th - 23rd generation is respiratory bronchiole to alveoli
What are the differences between bronchus and bronchiole
Cartilage
- Bronchus has hyaline cartilage plates, bronchioles do not
Cell epithelium
- Bronchus has respiratory epithelium, bronchioles have low columnar ciliated epithelium
Cells
- Bronchus has goblet cells and submucous glands, Bronchioles has sparse goblet cells and submucous glands
Both have smooth muscle deep to epithelium
Which lung is longer
Left lung
Which lung is larger and why
Right lung because left lung space taken up by heart
Which structure does not cast any impression on mediastinal surface of lungs
Pulmonary trunk
What is necessary for alveoli to conduct gas diffusion
Moist air/Water
Where is the xiphoid process
Tip of the sternum
What is the sternal angle also called
Manubriosternal joint
When diaphragm contracts, what does it do?
Descend
What is the purpose of the diaphragm
To create negative pressure for air to come in
Which ribs are floating ribs
Ribs 11 and 12
Which ribs do not connect to the sternum directly but are connected to another rib by cartilage
Ribs 8 - 10 connect to Rib 7 by cartilage
What does each lung contain
1x Principal bronchus
1x Pulmonary artery
2x pulmonary veins
Bunch of bronchial vessels, nerves and lymphatics
Where does the acinus/acini begin
15th - 23rd generation
Why is lingula called as such
Because it looks like a tongue
Where is the lowest point of pleural fluid
Costodiaphragmatic recess
What is the distribution of the surface area of Type I and II cells in alveoli
90% of surface area is Type I and 10% of surface area is Type II
What helps to give bronchus its rigid structure
Cartilage
What is the difference between trachea and bronchus in terms of their cartilage plates
Trachea has C-shaped cartilage plates whereas bronchus has broken cartilage plates
What is the purpose of elastic tissue in the context of lungs
It is stretched to keep bronchiole airway open even where there is no hyaline cartilage
Why is the pleural cavity important
With the help of pleural fluid, it reduces friction which could lead to alveoli collapse and ensure a negative intrapleural pressure
Which part of the sternum is the most fragile
Sternal angle
What are the 2 joints between the ribs and vertebrae
Costovertebral joint and Costotransverse joint
What does each rib connect to at the vertebrae
Demifacet
What makes the innermost layer of intercostal muscles
Transversus thoracis, Innermost intercostal, Subcostalis
Which muscles are the most active in forced expiration
Transversus thoracis, innermost intercostal and subcostalis
Which ribs are considered atypical
Ribs 1, 11 and 12
Where does Rib 2 articulate with sternum
Articular demifacets of sternal angle (manubriosternal joint)
What are lobar bronchi
First Bronchi branching out from left and right bronchi
What are the 3 dimensions for respiration
Increased Anterior - Posterior diameter
Increased Transverse diameter
Increased vertical diameter
Why is the lung having bronchopulmonary segments is advantageous
If one love needs to be removed, it can be without compromising the entire lung. However, the amount of air that can be taken in is reduced but still remains functional
