Chapter 12 Part 3 Flashcards
Describe basic anatomy of bird and mammal hearts
Both:
o Ascending aorta
o Left and right atrium
o Left and right ventricle
Describe differences of bird and mammal hearts
Birds:
o Thicker walls between chambers
o Tend to have larger hearts than mammals (relative to body size and mass)
o Tend to pump more blood per unit time than mammalian hearts
Mammals:
o Smaller, thin pieces within chambers to split into sections
Ventral aorta
carries deoxygenated blood from heart to 4th arch on bottom of arches
Aortic arches
blood vessels associated with each gill or brachial arch
6 in total, varies from group to group in arches lost and arches kept, as well as arches modified to become something else
associated each with brachial arch
Dorsal aortae (anterior)
paired with arches and carries oxygenated blood across top of arches
Dorsal aortae (posterior)
singular thick tube that carries oxygenated blood
Afferent branchial arteries
o Afferent vessels: heart to gills
Pretrematic and posttrematic branches:
anterior and posterior halves of each collecting loop
Efferent branchial arteries
Efferent vessels: gills to body
Where do the four aortic arches come from?
ventral aorta; service gills associated with five pharyngeal slits
Pharyngeal gill slits in sturgeons
the first pharyngeal slit persists as a small spiracle
Pharyngeal in most fish
absent in the adult - The first aortic arch is lost along with this first slit
How many functional gills do teleosts have?
four (pairs)
Describe gills in Australian lungfish
o 1st pharyngeal slit reduced to a spiracle, associated aortic arch (I) also reduced
o ln the Australian lungfish (Neoceratodus): the remaining five pharyngeal slits open to fully functional gills supplied by four aortic arches (III–VI)
Describe gills in African lungfish
o 1st pharyngeal slit reduced to a spiracle, associated aortic arch (I) also reduced
o In the African lungfish (Protopterus) functional gills reduced further:
▪ 3rd and 4th gills are absent entirely, their aortic arches (III–IV) (above)
▪ 5 & 6 present and functional as gills
Describe gills in general in all lungfish
o 1st pharyngeal slit reduced to a spiracle, associated aortic arch (I) also reduced
o In all lungfishes, the efferent vessel of the most posterior aortic arch (VI) gives rise to the pulmonary artery but maintains its connection to the dorsal aorta via the short ductus arteriosus
In tetrapods, what is the fate of the first, second, and fifth aortic arches?
all lost in adulthood in tetrapods
How many external gills do most larval salamanders have? Which aortic arches are they derived from?
o First two aortic arches (I, II) disappear early in development
o Most larval salamanders:
▪ Next three aortic arches (III–V) carry external gills
▪ Arch VI sprouts the pulmonary artery to the developing lung
▪ External gills are lost following the larva’s transformation into the adult, but the aortic arches are retained as major systemic vessels
Describe gills in adult salamander
▪ Section of ventral aorta between arches III and IV becomes the common carotid artery
▪ Arches IV, V constitute major systemic vessels that join the dorsal aorta
▪ Arch VI: joins the dorsal aorta - forming the ductus arteriosus and the pulmonary artery; Pulmonary loop, maintains D.A. connection
What is the carotid duct?
o In larval amphibians (salamanders), lost in adult stages
o Carotid duct: Closes at metamorphosis; Forces the carotids to fill with blood from a derivative of the ventral aorta
Ductus arteriosus
This is a fetal blood vessel that connects the pulmonary artery to the aorta, allowing blood to bypass the non-functioning fetal lungs and flow directly into the systemic circulation.
Which vessels are derived from the ventral aorta in amniotes?
The ventral aorta in amniotes gives rise to the aortic arches, which form major arteries such as the carotid arteries, subclavian arteries, and parts of the aorta.
Which systemic arch persists in birds? Mammals?
Aortic/systemic arches III, IV, and VI
