2nd Midterm Exam: Comparative Anatomy, Spring 2002

  1. What is the evolutionary fate of the sinus venosus?
  2. It becomes the atrio-ventricular node in mammals.
  3. It becomes the left atrium in mammals.
  4. It becomes the right atrium in birds.
  5. It forms the foramen of Panizzi in crocodilians.
  6. It becomes the sino-atrial node in mammals.
  1. The Foramen of Panizzi:
  2. Enables the shunting of blood in lizards and snakes.
  3. Establishes the resting heart rate in crocodilians.
  4. Is the source for ‘fight or flight’ hormones in reptiles.
  5. Enables the shunting of blood in crocodilians.
  6. Functions with the Pineal Eye to regulate skin emmisivity.
  1. What is the function of the Conus Arteriosus?

  1. It separates O2 rich from O2 poor blood.

  1. It restricts the flow of blood thus increasing blood pressure.
  2. It evens out the surges in blood pressure when the blood leaves the heart.
  3. It shunts blood to facilitate thermoregulation in reptiles.
  4. It reduces osmotic pressure within the ventricle.
  1. What is the primary problem associated with the mixing of O2 rich and O2 poor blood?
  2. Saturation of epithelial tissue with CO2.
  3. A reduction in the concentration gradient for O2 andCO2 across the membrane separating the alveoli of the lung from the capillaries of the lung.
  4. It increases the osmotic concentration of the blood, reducing the efficiency of the glomerulus.
  5. It results in the slow death of heart muscle.
  1. How do lizards manage to minimize the mixing of O2 rich and O2 poor blood? (circle all that apply).
  2. The ventricle is partially divided by a septum.
  3. The Conus Arteriosus has a spiral valve to direct the flow of fluid.
  4. Blood flow through the heart is non-synchronous and turbulent.
  5. Blood flow through the heart is synchronous and laminar.
  6. The Sinus Venosus directs the flow of blood to the appropriate atrium.
  7. Atrial contraction is iniatiated symmetrically.
  8. Atrial contraction is initiated asymmetrically.
  1. In terms of engineering (design efficiency), which of the following circulatory systems is best?

  1. Fish
  2. Frogs
  3. Lizards
  4. Mammals
  5. Birds
  6. Crocodilians

  1. Label the diagrams below with the following: A) Fish, B) Frog, C) Lizard, D) Mammal.
  1. What is the problem associated with portal systems?
  2. They transport toxins between portions of the body.
  3. They result in low pressure.
  4. They produce excessive amounts of lymph.
  5. They have a tendency to retain lymph.
  1. What is the definition of a portal system?
  2. A circulatory component bounded on both sides by capillary beds.
  3. A circulatory component feeding more than one type of tissue.
  4. Any low-pressure circulatory component.
  5. A circulatory component carrying venous blood, at low pressure, through vessels containing 1-way valves.
  1. With regard to portal systems, what is the general trend in vertebrates as we make the transition from fish, to amphibians, to reptiles, to mammals?
  1. With regard to the number of lymph hearts, what is the general trend in vertebrates for the same organisms listed above?
  1. With regard to lymph ostia, what is the general trend in vertebrates for the same organisms listed above?
  1. T / F The breast muscle of the turkey is Red Muscle.
  1. T / F The sacrospinalis muscles of the human back are Tonic Muscles.
  1. T / F The muscles of the small instestines are Visceral Muscles.
  1. T / F The extrinsic eye muscles are Smooth Muscles.
  1. T / F The Biceps Femoris is Somatic Muscle.
  1. T / F The muscle tissue surrounding the dorsal aorta is Cardiac Muscle.
  1. Label the diagram below with the following terms. Use the letter associated with each term. A) Sarcomere, B) Fascicle, C) Myofibril, D) Epimysium, E) Perimysium, F) Endomysium, G) Intercalated disks, H) Microfilaments, I) Tendons, J) Aponeuroses, K) Fascia. Please note: not all terms will be used.


  1. Explain why some muscle/lever systems use multiple origins/insertions for the muscles, even though the bones can move only through a single arc or plane (eg. Biceps or Triceps and the radius/ulna).
  2. Having 2 or more muscles with different origins or insertions acting on the same lever system spreads out the maximum tension portion of the tension/length curve.
  3. Having 2 or more muscles with different origins or insertions acting on the same lever system narrows the maximum tension portion of the tension/length curve, resulting in a stronger system.
  4. Having 2 or more muscles insures that at least one muscle will function, even when another muscle is injured or fatigued.
  5. Having 2 or more muscles with different origins or insertions acting on the same lever system reduces the maximum tension on the joint.
  6. The advantage of pinnate muscles is that
  7. They minimize physiological cross-sectional area while maximizing morphological cross-sectional area.
  8. They produce large amounts of tension over short distances.
  9. They produce moderate tension over long distances.
  10. They maximize physiological cross-sectional area and morphological cross-sectional area.
  1. How does the pectoral girdle musculature of a cat differ from that of a lizard?
  1. The strength of a muscle (the maximal tension produced by the muscle) is dependent on
  2. The length of the muscle.
  3. The total volume of glycogen in the muscle.
  4. The length of individual muscle fibers.
  5. The cross-sectional area of the muscle.
  1. For the lever systems (pelvic girdle and femur) diagramed below, draw a high speed muscle on (A), and a low speed muscle on (B).

AB

  1. What is the difference between branchiomeric and hypobranchial muscle?
  1. What is the difference between epaxial and hypaxial muscle?
  1. Why does the pectoral girdle musculature of a cat differ from that of a salamander? Please provide specific reasons, not just a general statement about the fact that they are different. I am looking for a functional-morphology answer.
  1. Consider the diagram below. Circle all the statements that are true for this diagram.
  2. The curve of passive tension represents the force required to stretch a relaxed muscle.
  3. The total tension curve is the force measured from an active muscle at various lengths.
  4. The difference between the resting and total tension curves is the active tension curve.

  5. The difference between the resting and total tension curves represents only the force of the active contractile components of the muscle.
  1. In general, the gut retention times of arboreal folivores are
  2. Equivalent to those of terrestrial carnivores.
  3. Roughly equal to those of all other mammals.
  4. Less than those of carnivores.
  5. Greater than those of carnivores.
  1. Which of the following are probably adaptations to an herbivorous diet? (circle all that apply)
  2. Presence of a reticulated colon.
  3. Presence of a ceacum.
  4. Presence of polyphyodont dentition.
  5. Long gut retention times.
  6. A short gastrointestinal tract.
  7. A segmented stomach.
  8. Extremely rapid peristalsis.
  1. What is the primary difficulty of herbivory?
  2. Plant material lacks some key vitamins and minerals.
  3. Plant material is abrasive, and erodes the teeth.
  4. Plant material containing cellulose is impossible for vertebrates to digest.
  5. Herbivory requires large size, and large animals are subject to high predation levels.
  1. T / F Reptiles, amphibians, and fishes lack lips and cheeks.
  1. T / F In mammals, teeth are restricted to the premaxilla, maxilla and dentary.
  1. What is the significance of the secondary palate?
  2. It enables an animal to breathe and eat at the same time, and thus maintain a high metabolic rate.
  3. It enables animals to prevent food items from entering the respiratory system.
  4. It permits refinement of the olfactory senses, since they are no longer inundated with material from the oral cavity.
  5. It provides a surface for the insertion of palatal teeth.
  1. Essay Explain in detail how the Panda (a member of the order Carnivora, and truly a bear) is able to persist on a diet of bamboo leaves.