Lecture 15:Aortic Arches/veins Flashcards
Describe the basic arrangement of the 6 pairs of aortic arches in the generalized vertebrate and relate to the dorsal and ventral aorta
Aortic arches form during embryonic development…this development pattern is relatively unchanged in fishes but considerably modified in tetrapods.
6 pairs of aortic arches connect the paired dorsal aorta to the ventral aorta.
Describe the comparative anatomy of the aortic arch pattern in shark and r/t gills
1st aortic arch is lost.
Afferent/efferent spiraculars carry blood to/from gills [spiracles]
Afferent/efferent spiraculars carry blood to first pair of gills[spiracles]-pseudobranch
Arteries off efferent aortic arches: hypobranchials and external carotid.
The reduced first gill arch of a shark because the 1st gill arch is lost.
is oxygenating already oxygenated blood
Pseudobranch
Describe the changes in the aortic arch pattern and the specialization asso. W/ lungs.
Pulmonary artery develops from arch VI
Arches III and IV lose their capillary beds.
Describe the aortic pattern in tetrapods, including the fate of all 6 pairs of arches.
- 1st and 2nd pairs of aortic arches form, then degenerate.
- 3rd pair form internal and common carotids.
- fourth pair=form paired aortic arches.
- 5th pair degenerate.
- 6th pair=asso. W/ pulmonary system.
External carotids are cranial extensions of the paired:
Ventral aortae cranial to the 3rd arches
Describe and compare the aortic arch pattern in birds and note the fate do the 6 pairs of arches.
Arch pairs: I, II, V, and LEFT aortic arch IV are lost.
Right aortic arch IV becomes the systemic arch
Loss of ductus caroticus and ductus venosus
Describe and compare the aortic arch pattern in mammals and note the fate do the 6 pairs of arches.
1st and second pairs of aortic arches form then degenerate.
3rd pair form internal carotids.
R 4th arch forms R subclavian.
L 4th arch forms aortic arch.
5th degenerate[barely form]
6th pair asso. W/ pulmonary system.
Common carotids are derived from:
the ventral aortae btw the 3rd and 4th aortic arches
List the 3 groups of aortic branches and give examples of each group
Dorsal intersegmentals: cervical, thoracic (intercostal), lumbar intersegmentals, subclavians, iliac arteries
Ventral intersegmentals: vitelline vessels, allantoic vessels
Lateral intersegmentals: mesonephric, adrenal, renal, and gonadal arteries
Describe the pattern of arteries that supply the brain (circle of willis)
The anterior and posterior communicating arteries branch off of the internal carotid artery
Supplies blood to the brain and surrounding structures.
Describe the general venous pattern in vertebrates and the formation of the inferior vena cava
All blood from the head is shunted to the R and drained into the R cardinal vein-superior vena cava.
Inferior vena cava is built as a patchwork quilt asymmetrically from remnants of: vitelline vein, subcardinals, Supracardinals, iliacs
Define portal system and list 3 types of portal systems in vertebrates
“A system of veins that carries blood toward the heart but ends in a capillary bed in an organ other than the heart”
-hepatic portal, renal portal, and hypophyseal portal system
Describe the development and functions of the hepatic portal system
Hepatic portal systems carry oxygen-poor but nutrient-rich blood from GI to the liver via hepatic portal vein.
This is different than the hepatic veins.
From the L vitelline vein =makes hepatic portal vein
Describe the development and functions of the Renal portal system
The postcardinal veins form capillary connections w/ the kidney.
This is a way of making the kidney circulation more efficient by only allowing blood to return from the posterior part of the body into a capillary plexus in each kidney.
