Lecture 52 - Avian Anatomy Part. 2

Question 1

the nares of some parrots are surrounded by

Answer 1

cere

Question 2

what is the choana

Answer 2

opening in hard palate

Question 3

describe the periorbital sinuses

Answer 3

soft tissue lateral borders around the nasal cavity and connects to the cervicocephalic air sac

Question 4

T/F: operculum are within the nostril

Answer 4

TRUE

Question 5

rupture of the cervicocephalic diverticula causes

Answer 5

periorbital emphysema

Question 6

describe the trachea of birds

Answer 6

• long with no epiglottis
• complete tracheal rings
• increased dead space

Question 7

what is the syrinx? why is it important?

Answer 7

bifurcation of trachea to the 2 primary bronchi which acts as the site of sound production and fungal granulomas

Question 8

T/F: the lungs of a bird resemble those of small animals with distinct lobes, pleural space, and free in the thoracic cavity

Answer 8

FALSE
1. no lobes
2. no pleural space
3. affixed to ribs

Question 9

ostia

Answer 9

connection to air sacs

Question 10

primary bronchi travel to where

Answer 10

caudal air sacs

Question 11

describe the flow of air once it enters the bird

Answer 11

1. primary bronchi
2. caudal air sacs
3. secondary bronchi
4. parabronchi
5. air capillaries

Question 12

where does gas exchange occur

Answer 12

air capillaries

Question 13

T/F: birds do not have alveoli

Answer 13

TRUE

Question 14

when will birds struggle to breathe

Answer 14

when pressure is placed on keel

Question 15

T/F: breathing is active

Answer 15

TRUE

Question 16

why do birds have the most efficient gas exchange among air-breathing vertebrates

Answer 16

1. less ventilation to achieve the same oxygenation
2. continuous unidirectional airflow
3. counter-current exchange
4. small diameter of terminal airways

Question 17

describe the anatomy of air sacs

Answer 17

• thin membranous structures
• connected to lungs and pneumatic bones
• 9 air sacs

Question 18

describe the 4 part breathing cycle

Answer 18

1. inhale - trachea and/primary bronchus to caudal air sacs
2. exhale - caudal air sacs to lungs with gas exchange
3. inhale - lungs to cranial air sacs
4. exhale - cranial air sac to trachea and expelled

Question 19

T/F: inhalation and expiration cycles happen independently

Answer 19

FALSE

Question 20

air sac cannula

Answer 20

obstruction in the respiratory tract cranial to the lungs

Question 21

what is unique about the right AV valve in birds

Answer 21

no chordae tendinae

Question 22

birds have a ____ QRS. why?

Answer 22

negative; ventricular depolarization starts subepicardially

Question 23

Compared to mammals, birds have:

increased or decreased heart rate relative to body mass

Answer 23

increased

Question 24

Compared to mammals, birds have:

increased or decreased heart size

Answer 24

increased

Question 25

Compared to mammals, birds have: increased or decreased stroke volume and cardiac output

Answer 25

increased

Question 26

where are the kidneys located

Answer 26

renal fossa of synsacrum

Question 27

each kidney is comprised what divisions

Answer 27

1. cranial 2. middle 3. caudal

Question 28

T/F: nerves from the sacral and lumber plexus pass THROUGH the kidneys

Answer 28

TRUE

Question 29

T/F: there is a distinct cortex and medulla of avian kidneys

Answer 29

FALSE

Question 30

the medullary cone contains

Answer 30

loops of henle and collecting ducts

Question 31

how do avian kidneys compensate for their poor concentrating ability?

Answer 31

post renal modifications of urine - lower GI tract and cloaca resorption - nasal salt glands uricotelic - uric acid secretion requires little water but more energy/proteins

Question 32

female reproductive organs are found on the ____ side of the body

Answer 32

left

Question 33

the ____ can be surgically removed but the ____ cannot

Answer 33

oviduct; ovarian follicles

Question 34

T/F: testes can increase in size during breeding season

Answer 34

TRUE

Question 35

describe the avian brain

Answer 35

no neocortex, gyri, nd sulci with large venous sinus

Question 36

instead of the cauda equina, what is in the lumbosacral spinal cord

Answer 36

glycogen body

Question 37

the globes are supported by

Answer 37

scleral ossicles

Question 38

the retina are _____ and have ____

Answer 38

avascular; pectin

Question 39

T/F: tapetum lucidum is present in most birds

Answer 39

FALSE

Question 40

complete decussation of optic nerve fibers at optic chiasm results in

Answer 40

no consensual PLR

Question 41

instead of lymph nodes, the lymphoid organs are

Answer 41

thymus and bursa of fabricius