Giraffe have unusually high heart rates for their size, at 150 beats per minute. When the animal lowers its head the blood rushes down fairly unopposed and a rete mirabile in the upper neck, with its large cross sectional area, prevents excess blood flow to the brain. When it raises again, the blood vessels constrict and direct blood into the brain so the animal does not faint. The jugular veins contain several (most commonly seven) valves to prevent blood flowing back into the head from the inferior vena cava and right atrium while the head is lowered. Conversely, the blood vessels
The Brain from Planet Arous classic. It has been parodied on American television like the comedy series "Malcolm in the Middle", which uses a segment of "The Brain from Planet Arous" as part of the opening credits. A clip was also used in the opening scene of the comedy film "Ernest Scared Stupid" as part of a collage of horror films. "The Brain from Planet Arous" is also featured in the film "The Butcher Boy" (1997), which is viewed by the main character at his local movie theater. The voice clip: from the film was used in the 1997 Jay Weinland track "Sound Stage Strut"