HBIO 301 FINAL EXAM QUESTIONS AND ANSWERS
WITH COMPLETE SOLUTIONS GRADED A++
Location and orientation of the heart in the thoracic cavity, mediastinum, and
pericardial cavity
Lies left of midline, between 2nd rib and 5th intercostal space, posterior to sternum, in
the pericardial cavity of the mediastinum (the region between the two pleural cavities,
which also contains the great vessels, thymus, esophagus & trachea).
The heart is surrounded by the pericardial sac, which consists of dense network of
collagen fibers that stabilizes the position of the heart (and major vessels) within the
mediastinum.
Pericardium consists of 2 layers:
- Outer Fibrous Pericardium, consisting of dense connective tissue
- The Serous Pericardium comprised of the
visceral and parietal pericardia. Pericardial fluid (15 - 50 ml) lies between the
layers, acting as a lubricant to reduce friction during contractions.
What is the blood pressure in the pulmonary circulation, in the arterial side of the
systemic circulatory system, at the arteriole side of a capillary, the venule of a
capillary and in veins?
,- Pulmonary circulation: ca. 15 mm Hg
- Arterial side of the systemic circulatory system: ca. 120 - 80 mm Hg
- Arteriole side of a capillary: ca. 35 mm Hg
- Venule of a capillary: ca. 15 - 18 mm
- Veins: ca. 15 - 18 mm
Trace pulmonary and systemic circulation through the heart
Pulmonary circuit: right ventricle → lungs →
left atrium (so the left atrium is receiving oxygen rich blood)
Systemic circuit: left ventricle → body →
right atrium (so the right atrium is receiving oxygen-poor blood)
Arteries = away from heart
Veins = toward heart
Capillaries = exchange vessels in between (gases, nutrients, wastes)
Major structural and functional differences between cardiac muscle and skeletal
muscle
Cardiac muscle cells: typically 1 nuclei, short T-tubules, no triads, mitochondria
abundant, very extensive blood supply, aerobic active metabolism, trigger for
contraction: calcium entry from ECF and calcium release from SR, authorhythmicity of
pacemaker cells generates AP, inclusions: myoglobin, lipids, glycogen.
Skeletal muscle: multi-nucleated, long T-tubules with Triads, mitochondria much less
,abundant, extensive glycogen reserves, aerobic resting metabolism (lipid-based) and
anaerobic active metabolism (breakdown of glycogen), usually sustained contractions,
trigger for contraction: calcium release from SR, activity of somatic motor neuron
generates AP.
Morphological and functional features of all heart valves
Atrioventricular (AV) valves:
- Connect right atrium to rt. ventricle: tricuspid
- Left atrium to lt. ventricle: bicuspid or mitral valve
- Valves facilitate one-way blood flow: atria → ventricles
- Cusps attached to chordae tendineae from papillary muscles on ventricle wall
- Papillary muscles prevent cusps from swinging into atria (everting); during ventricular
contraction pressure closes
valve
Semilunar Valves:
Pulmonary and aortic tricuspid valves
- Prevent back flow from pulmonary trunk and aorta into right & left ventricles,
respectively
- Have no chordae tendineae or muscles
Where does the coronary circulation arise and end and what are the major
coronary blood vessels?
- Heart is <1% body mass but requires 5% of blood circulation for function
- (Arise) Coronary Arteries (lt. & rt.) originate at aortic sinuses and then branch out
, - (End) Cardiac veins return deoxygenated coronary blood into right atrium (coronary
sinus)
- High blood pressure & elastic rebound forces blood through coronary arteries between
ventricular contractions
Right Coronary Artery -- supplies blood to rt. atrium, portions of bothventricles and cells
of sinoatrial (SA) & atrio-ventricular (AV) nodes
- gives rise to marginal arteries (surface of
right ventricle)
- Supplies posterior interventricular
artery
Left Coronary Artery -- supplies
blood to lt. atrium, lt. ventricle and
interventricular septum
- gives rise to circumflex artery and
anterior interventricular artery
Cardiac Veins: small veins drain into great cardiac vein which drains into the coronary
sinus and eventually into the rt. atrium (at base of the inferior vena cava)
During exercise, does the amount of blood in coronary circulation change? If so,
by what mechanism?
Coronary blood flow may ↑ 9x during vigorous activity (exercise)
WITH COMPLETE SOLUTIONS GRADED A++
Location and orientation of the heart in the thoracic cavity, mediastinum, and
pericardial cavity
Lies left of midline, between 2nd rib and 5th intercostal space, posterior to sternum, in
the pericardial cavity of the mediastinum (the region between the two pleural cavities,
which also contains the great vessels, thymus, esophagus & trachea).
The heart is surrounded by the pericardial sac, which consists of dense network of
collagen fibers that stabilizes the position of the heart (and major vessels) within the
mediastinum.
Pericardium consists of 2 layers:
- Outer Fibrous Pericardium, consisting of dense connective tissue
- The Serous Pericardium comprised of the
visceral and parietal pericardia. Pericardial fluid (15 - 50 ml) lies between the
layers, acting as a lubricant to reduce friction during contractions.
What is the blood pressure in the pulmonary circulation, in the arterial side of the
systemic circulatory system, at the arteriole side of a capillary, the venule of a
capillary and in veins?
,- Pulmonary circulation: ca. 15 mm Hg
- Arterial side of the systemic circulatory system: ca. 120 - 80 mm Hg
- Arteriole side of a capillary: ca. 35 mm Hg
- Venule of a capillary: ca. 15 - 18 mm
- Veins: ca. 15 - 18 mm
Trace pulmonary and systemic circulation through the heart
Pulmonary circuit: right ventricle → lungs →
left atrium (so the left atrium is receiving oxygen rich blood)
Systemic circuit: left ventricle → body →
right atrium (so the right atrium is receiving oxygen-poor blood)
Arteries = away from heart
Veins = toward heart
Capillaries = exchange vessels in between (gases, nutrients, wastes)
Major structural and functional differences between cardiac muscle and skeletal
muscle
Cardiac muscle cells: typically 1 nuclei, short T-tubules, no triads, mitochondria
abundant, very extensive blood supply, aerobic active metabolism, trigger for
contraction: calcium entry from ECF and calcium release from SR, authorhythmicity of
pacemaker cells generates AP, inclusions: myoglobin, lipids, glycogen.
Skeletal muscle: multi-nucleated, long T-tubules with Triads, mitochondria much less
,abundant, extensive glycogen reserves, aerobic resting metabolism (lipid-based) and
anaerobic active metabolism (breakdown of glycogen), usually sustained contractions,
trigger for contraction: calcium release from SR, activity of somatic motor neuron
generates AP.
Morphological and functional features of all heart valves
Atrioventricular (AV) valves:
- Connect right atrium to rt. ventricle: tricuspid
- Left atrium to lt. ventricle: bicuspid or mitral valve
- Valves facilitate one-way blood flow: atria → ventricles
- Cusps attached to chordae tendineae from papillary muscles on ventricle wall
- Papillary muscles prevent cusps from swinging into atria (everting); during ventricular
contraction pressure closes
valve
Semilunar Valves:
Pulmonary and aortic tricuspid valves
- Prevent back flow from pulmonary trunk and aorta into right & left ventricles,
respectively
- Have no chordae tendineae or muscles
Where does the coronary circulation arise and end and what are the major
coronary blood vessels?
- Heart is <1% body mass but requires 5% of blood circulation for function
- (Arise) Coronary Arteries (lt. & rt.) originate at aortic sinuses and then branch out
, - (End) Cardiac veins return deoxygenated coronary blood into right atrium (coronary
sinus)
- High blood pressure & elastic rebound forces blood through coronary arteries between
ventricular contractions
Right Coronary Artery -- supplies blood to rt. atrium, portions of bothventricles and cells
of sinoatrial (SA) & atrio-ventricular (AV) nodes
- gives rise to marginal arteries (surface of
right ventricle)
- Supplies posterior interventricular
artery
Left Coronary Artery -- supplies
blood to lt. atrium, lt. ventricle and
interventricular septum
- gives rise to circumflex artery and
anterior interventricular artery
Cardiac Veins: small veins drain into great cardiac vein which drains into the coronary
sinus and eventually into the rt. atrium (at base of the inferior vena cava)
During exercise, does the amount of blood in coronary circulation change? If so,
by what mechanism?
Coronary blood flow may ↑ 9x during vigorous activity (exercise)
