Zoo-Lab (Sem-1) - Exercise 24: The Circulatory System

blood circulatory system

transports digested food from the digestive tract to the different parts of the body

heart

the pumping organ

blood vessels

arteries; veins; capillaries

blood

the medium for transport and contained in the vessels

ventricles; auricles; conus arteriosus

external parts of the heart

ventricles

viewed externally; a conical posterior portion of the heart; pale in color and hard because of its thick wall

auricles

viewed externally; the anterior expanded thin-walled, cark, and softer parts of the heart; divided into right and left side

conus arteriosus

(in frogs) viewed externally; a swollen and pale structure located dorsal to the right auricle and obliquely across the ventral surface of the latter; usually embedded with fats which are yellowish in color

interauricular septum

(in frogs) viewed internally; membranous partition between the right and left auricular cavities or chambers

sino-auricular opening

(in frogs) viewed internally; single big opening on the dorsal surface of the right auricle; opening of the sinus venosus to the right auricle

pulno-auricular opening

(in frogs) viewed internally; a small opening on the dorsal surface of the left auricle; the entrance of the pulmonary vein into the left auricle

right auricle

(in frogs) which side is the bigger auricle?

right auricle

(in frogs) receives a bigger volume of deoxygenated blood from different parts of the body

left auricle

(in frogs) receives a smaller volume of oxygenated blood from the lungs

ventricular cavity/chamber

(in frogs) viewed internally; a single cavity in the ventricle and this extended into its thick wall by numerous pockets (the ventricular pockets)

auriculo-ventricular (AV) opening

(in frogs) viewed internally; a single opening of the right and left auricles into the ventricle

auriculo-ventricular (AV) valve

(in frogs) viewed internally; the structure that guards the AV opening; prevents the backflow of the blood from the ventricle to the auricles when the former contracts

chordate tendinae

(in frogs) viewed internally; fiber-like structures that anchor the AV valve to the muscular wall of the ventricle

semilunar valve

(in frogs) viewed internally; a small and half-moon-shaped valve at the entrance of the ventricle to the conus arteriosus; can be seen only in good dissection under a stereomicroscope; prevents the backflow of blood from the conus arteriosus to the ventricle after the blood leaves the latter

spiral-valve/s-shaped blood

(in frogs) viewed internally; inside the conus arteriosus; directs the oxygenated and the deoxygenated blood from the ventricle into their proper arteries