work together to ensure that cells receive the oxygen and nutrients they need for cellular respiration and function, while efficiently removing waste products like carbondioxide
RESPIRATORY SYSTEM
an organ system responsible for the respiration, the process of obtaining oxygen from the external environment and eliminating carbondioxide.
Chondrichthyes - Comparative Anatomy Vertebrate Circulatory System
Sinus venosus receives blood & fills by suction when ventricle contracts, enlarging pericardial cavity
Osteichthyes - Comparative Anatomy Vertebrate Circulatory System
Heart structure similar to cartilaginous fishes
Presence of a bulbus arteriosus instead of a conus arteriosus
Most teleosts are "cold-blooded" likely due to this heart structure
Lungfish - Comparative Anatomy Vertebrate Circulatory System
Modifications enable separation of oxygenated blood from lungs and deoxygenated blood from elsewhere.
Formation of a spiral valve
Spiral valve alternately blocks & unblocks entrances to left and right pulmonary arches, sending unoxygenated blood to the skin & lungs.
Shortening of ventral aorta helps ensure oxygenated & unoxygenated blood remains separate in the heart, moving directly into appropriate vessels
Reptiles - Comparative Anatomy Vertebrate Circulatory System
Lizards have a muscular septum partially dividing the ventricle.
When the ventricle contracts, opening in septum closes, momentarily dividing ventricle into two separate chambers.
Left half of ventricle pumps oxygenated blood (from left atrium) to body.
Right half pumps deoxygenated blood (from right atrium) to lungs.
Atria empty into
Single ventricle
Ventricle
Divided into narrow chambers to reduce mixing of blood
Amniotes - Comparative Anatomy Vertebrate Circulatory System
Heart consists of 2 atria & 2 ventricles, with a sinus venosus except in adult birds & mammals.
Complete interatrial septum. and interventricular septum found only in crocodilians, birds, & mammals
Aves + Mammals - Comparative Anatomy Vertebrate Circulatory System
4 chambers in the heart
Complete septum with no mixing of blood
Pulmonary for gas exchange with the environment
Systemic for gas exchange (and all other exchange needs) of the rest of the body
Complete interventricular septum + division of ventral aorta into 2 trunks
1. Pulmonary trunk takes blood to the lungs
2. Aortic trunk takes blood to the rest of the body
Result of modifications: All blood returning to right side of heart goes to the lungs; blood returning from lungs to the left side of heart goes to systemic circulation
Arterial Channel - supply most tissues with oxygenated blood (but carry deoxygenated blood to respiratory organs)
Basic Pattern of Arterial Channel:
the ventral aorta emerges from the heart and passes beneath pharynx
the dorsal aorta emerges to the body and passes above digestive tract
6 pairs of aortic arches connects the dorsal and ventral aortas
Fishes - Aortic Arch
Ventral aorta extends forward below the pharynx & connects developing aortic arches. The first pair of arches develop first.
Segments of the first pair are lost & remaining sections become different pseudo branchial arteries.
Arches 2 - 6 become occluded
dorsal segments = efferent branchial arteries
ventral segments = afferent branchial arteries
Capillary beds develop within nine demi branches
Tetrapods Aortic Arch
embryos have 6 pairs of aortic arches
but the 1st & 2nd arches are temporary & not found in adults
the 3rd aortic arches & the paired dorsal aortas anterior to arch 3 are called the internal carotid arteries
the 4th aortic arches are called the systemic arches
the 5th aortic arch is usually lost
the pulmonary arteries branch off the 6th arches & supplyblood to the lungs
FISHES
Respiratory Organ - Gills
Heart - 2 chambered
Type of Circulation - Single circulation
AMPHIBIANS
Respiratory Organ - Cutaneous Respiration and Lungs
Heart - 3 chambered
Type of Circulation - Double circulation (Pulmonary and Systemic)
AMPHIBIANS
Respiratory Organ - Cutaneous Respiration and Lungs
Heart - 3 chambered
Type of Circulation - Double circulation (Pulmonary and Systemic)
REPTILES
Respiratory Organ - Lungs and Other Accessory Breathing Organs
Heart - "5 chambered heart"
Type of Circulation - Double circulation (Pulmonary and Systemic)
BIRDS
Respiratory Organ - Lungs and Air sacs (undirectional)
Heart - 4 chambered
Type of Circulation - Double circulation (Pulmonary and Systemic)
MAMMALS
Respiratory Organ - Lungs (bidirectional)
Heart - 4 chambered
Type of Circulation - Double circulation (Pulmonary and Systemic)