Avian and Reptile Anatomy- Norwood

Question 1

describe avian thoracic and cervical vertebrae (5)

Answer 1

1. between 5-10 thoracic vertebrae
2. starts with the first vertebrae that has a rib attaching to the sternum (keel: where sternal muscles attach)
3. ribs all connected to help inflate lungs
4. larger keel for larger muscle attachment for flight muscles
5. have much more cervical vertebrae than mammals

Question 2

describe avian lungs (2)

Answer 2

1. unidirectional air flow due to air sacs
2. bones are pneumatized (air filled) to increase the air capacity for lungs to add even more oxygen to blood providing energy for flight

Question 3

what is the avian organ for vocalization? where is it?

Answer 3

syrinx; located right as trachea bifurcates

Question 4

how many ribs can a snake skeleton have?

Answer 4

up to 500

Question 5

what are chelonians? what is their sternum?

Answer 5

turtles and tortoises; carapace is sternum

Question 6

describe reptile lungs (3)

Answer 6

1. squamata/honey comb
2. in some species of snake, left lung is reduced or absent
3. turtles regulate their buoyancy by adjusting residual lung volume to counteract their negatively buoyant shells

Question 7

how many heart chambers do ALL mammals have?

Answer 7

4

Question 8

give the circuits and chambers of fish, frog, turtle/lizard, crocodile, bird, and mammal hearts

Answer 8

fish: 1 circuit, 2 chambers
frogs: 2 circuits, 3 chambers
turtles/lizards: 2 circuits, 5 chambers
crocodiles, birds, mammals: 2 circuits, 4 chambers

Question 9

what is one difference between bird cardiovascular system and mammals?

Answer 9

birds have larger hearts and pump more blood per unit time than mammals relative to body size and mass

Question 10

describe variations of the reptile heart (4)

Answer 10

1. most reptiles have 3 (2 atria, 1 ventricle) chambered hearts (except crocodiles-4 chambers)
2. these modifications mean that reptiles are much less susceptible adverse effects of hypoxia and changes in blood pH
3. 2 atria and 1 ventricle causes mixing of oxygenated and deoxygenated blood
4. blood can be shunted from left to right and right to left, this helps with diving and holding breath for long periods of time