IHOP Exam 2 UPDATED ACTUAL Exam
Questions and CORRECT Answers
Transport of material - CORRECT ANSWER - gases, nutrients, waste,
communication, defense against pathogens,
temperature homeostasis
Heart is a - CORRECT ANSWER - pump
Atria - CORRECT ANSWER - receives blood returning to heart
Ventricles - CORRECT ANSWER - pump blood out
Left side - CORRECT ANSWER - oxygenated blood
Right side - CORRECT ANSWER - deoxygenated blood
Blood vessels - CORRECT ANSWER - - Veins, arteries, and capillaries
- Pulmonary and systemic circulation
- Portal system joins two capillary beds in series.
Pulmonary circulation - CORRECT ANSWER - from right side (leave right ventricle and
go to lung) (deoxygenated)
Blood - CORRECT ANSWER - cells and plasma
The heart is composed mostly of - CORRECT ANSWER - myocardium (cardiac muscle)
,Which 2 sets of heart valves ensure one-way flow - CORRECT ANSWER -
Atrioventricular valves
Semilunar valves
Atrioventricular valves - CORRECT ANSWER - - Between atria and ventricles
- Tricuspid valve on the right side
- Bicuspid valve, or mitral valve, on the left side
Semilunar valves - CORRECT ANSWER - • Between ventricles and arteries
• Aortic valve
• Pulmonary valve
The heart is encased within . . . - CORRECT ANSWER - the pericardium (a membranous
fluid-filled sac)
During ventricular contraction, the AV valves - CORRECT ANSWER - remain closed to
prevent blood flow backward into the atria.
During ventricular relaxation, the semilunar valves - CORRECT ANSWER - prevent
blood that has entered the arteries from flowing back into the ventricles
Contractile cells - CORRECT ANSWER - Striated fibers organized into sarcomeres
Autorhythmic cells, or pacemakers - CORRECT ANSWER - - Signal for contraction
- Smaller and fewer contractile fibers compared to
contractile cells
Cardiac Muscle - CORRECT ANSWER - Do not have organized sarcomeres
,Myocardial muscle cells are - CORRECT ANSWER - branched, have a single nucleus,
and are attached to each other by specialized junctions known as intercalated disks.
Intercalated disks contain - CORRECT ANSWER - desmosomes that transfer force from
cell to cell, and gap junctions that allow electrical signals to pass rapidly from cell to cell.
Cardiac Muscle versus Skeletal Muscle - CORRECT ANSWER - • Smaller and have
single nucleus per fiber
• Branch and join neighboring cells through
intercalated disks
- Desmosomes allow force to be transferred
- Gap junctions provide electrical connection
• T-tubules are larger and branch
• Sarcoplasmic reticulum is smaller
• Mitochondria occupy one-third of cell volume
Cardiac Muscle Contraction Can Be Graded
Action potential starts with the heart pacemaker cells - CORRECT ANSWER - - Voltage-
gated L-type Ca2+ channels in the cell
membrane open (extra cellular calcium
contributes 10%)
- Ryanodine receptors open in the sarcoplasmic
reticulum (SR)
- Calcium binds to troponin
- Crossbridge cycle as in skeletal muscle
Cardiac Muscle Contraction Can Be Graded - CORRECT ANSWER - • Relaxation:
- Calcium removed from cytoplasm: back into the SR with Ca2+ ATPase and out of the cell
through the
, Na+-Ca2+ exchanger (NC)
• Force generated is proportional to number of active
crossbridges
- Determined by how much calcium is bound to troponin
• Sarcomere length affects force of contraction
Figure 14.9 EC coupling in cardiac muscle - CORRECT ANSWER - 1. Action potential
enters from adjacent cell.
2. Voltage-gated Ca2+ channels open. Ca2+ enters cell.
3. Ca2+ induces Ca2+ release
through ryanodine receptor channels (RyR).
4. Local release causes Ca2+ spark.
5. Summed Ca2+ sparks create a Ca2+ signal.
6. Ca2+ ions bind to troponin to initiate contraction.
7. Relaxation occurs when Ca2+ unbinds from troponin.
8. Ca2+ is pumped back into the sarcoplasmic reticulum for storage.
9. Ca2+ is exchanged with Na+ by the NCX antiporter.
10. Na+gradient is maintained by the Na+-K+-ATPase.
Myocardial Action Potentials - CORRECT ANSWER - Vary
Myocardial contractile cells - CORRECT ANSWER - - Depolarization due to Na+ entry
- Repolarization due to K+ exit
- Long action potential (plateau) due to Ca2+ entry in the cell prevents tetanus
Myocardial autorhythmic cells - CORRECT ANSWER - - Unstable membrane potential
called pacemaker
potential
Questions and CORRECT Answers
Transport of material - CORRECT ANSWER - gases, nutrients, waste,
communication, defense against pathogens,
temperature homeostasis
Heart is a - CORRECT ANSWER - pump
Atria - CORRECT ANSWER - receives blood returning to heart
Ventricles - CORRECT ANSWER - pump blood out
Left side - CORRECT ANSWER - oxygenated blood
Right side - CORRECT ANSWER - deoxygenated blood
Blood vessels - CORRECT ANSWER - - Veins, arteries, and capillaries
- Pulmonary and systemic circulation
- Portal system joins two capillary beds in series.
Pulmonary circulation - CORRECT ANSWER - from right side (leave right ventricle and
go to lung) (deoxygenated)
Blood - CORRECT ANSWER - cells and plasma
The heart is composed mostly of - CORRECT ANSWER - myocardium (cardiac muscle)
,Which 2 sets of heart valves ensure one-way flow - CORRECT ANSWER -
Atrioventricular valves
Semilunar valves
Atrioventricular valves - CORRECT ANSWER - - Between atria and ventricles
- Tricuspid valve on the right side
- Bicuspid valve, or mitral valve, on the left side
Semilunar valves - CORRECT ANSWER - • Between ventricles and arteries
• Aortic valve
• Pulmonary valve
The heart is encased within . . . - CORRECT ANSWER - the pericardium (a membranous
fluid-filled sac)
During ventricular contraction, the AV valves - CORRECT ANSWER - remain closed to
prevent blood flow backward into the atria.
During ventricular relaxation, the semilunar valves - CORRECT ANSWER - prevent
blood that has entered the arteries from flowing back into the ventricles
Contractile cells - CORRECT ANSWER - Striated fibers organized into sarcomeres
Autorhythmic cells, or pacemakers - CORRECT ANSWER - - Signal for contraction
- Smaller and fewer contractile fibers compared to
contractile cells
Cardiac Muscle - CORRECT ANSWER - Do not have organized sarcomeres
,Myocardial muscle cells are - CORRECT ANSWER - branched, have a single nucleus,
and are attached to each other by specialized junctions known as intercalated disks.
Intercalated disks contain - CORRECT ANSWER - desmosomes that transfer force from
cell to cell, and gap junctions that allow electrical signals to pass rapidly from cell to cell.
Cardiac Muscle versus Skeletal Muscle - CORRECT ANSWER - • Smaller and have
single nucleus per fiber
• Branch and join neighboring cells through
intercalated disks
- Desmosomes allow force to be transferred
- Gap junctions provide electrical connection
• T-tubules are larger and branch
• Sarcoplasmic reticulum is smaller
• Mitochondria occupy one-third of cell volume
Cardiac Muscle Contraction Can Be Graded
Action potential starts with the heart pacemaker cells - CORRECT ANSWER - - Voltage-
gated L-type Ca2+ channels in the cell
membrane open (extra cellular calcium
contributes 10%)
- Ryanodine receptors open in the sarcoplasmic
reticulum (SR)
- Calcium binds to troponin
- Crossbridge cycle as in skeletal muscle
Cardiac Muscle Contraction Can Be Graded - CORRECT ANSWER - • Relaxation:
- Calcium removed from cytoplasm: back into the SR with Ca2+ ATPase and out of the cell
through the
, Na+-Ca2+ exchanger (NC)
• Force generated is proportional to number of active
crossbridges
- Determined by how much calcium is bound to troponin
• Sarcomere length affects force of contraction
Figure 14.9 EC coupling in cardiac muscle - CORRECT ANSWER - 1. Action potential
enters from adjacent cell.
2. Voltage-gated Ca2+ channels open. Ca2+ enters cell.
3. Ca2+ induces Ca2+ release
through ryanodine receptor channels (RyR).
4. Local release causes Ca2+ spark.
5. Summed Ca2+ sparks create a Ca2+ signal.
6. Ca2+ ions bind to troponin to initiate contraction.
7. Relaxation occurs when Ca2+ unbinds from troponin.
8. Ca2+ is pumped back into the sarcoplasmic reticulum for storage.
9. Ca2+ is exchanged with Na+ by the NCX antiporter.
10. Na+gradient is maintained by the Na+-K+-ATPase.
Myocardial Action Potentials - CORRECT ANSWER - Vary
Myocardial contractile cells - CORRECT ANSWER - - Depolarization due to Na+ entry
- Repolarization due to K+ exit
- Long action potential (plateau) due to Ca2+ entry in the cell prevents tetanus
Myocardial autorhythmic cells - CORRECT ANSWER - - Unstable membrane potential
called pacemaker
potential
