Assertion: giraffe | /r/CapableOf | lower its head
Facets:
value: to drink
type: PURPOSE
value: to eat
type: PURPOSE
value: to the ground
type: TRANSITIVE-OBJECT
value: to the water
type: TRANSITIVE-OBJECT
value: suddenly
type: MANNER
value: to eat water
type: PURPOSE
value: in order to prevent blackouts
type: PURPOSE
value: to the river
type: TRANSITIVE-OBJECT
value: to pool
type: TRANSITIVE-OBJECT
Source sentences:
text: Thick-walled arteries in the neck have extra valves to counteract gravity when the head is up; when the giraffe lowers its head to the ground, special vessels at the base of the brain control blood pressure.
text: Their neck veins contain valves and a network of tiny veins to constrict blood flow to their brain when they lower their head to drink in order to prevent blackouts.
text: They spend almost all of their time grazing among, tall branches for herbs, vines, flowers and fruits, but will lower their heads and graze off the ground if something is tempting enough.
text: Its heart can be over two feet long and is engineered with a network of bypasses and anti-pooling valves that allow the giraffe to raise and lower its 500-pound (227 kg) neck and head without fainting.
text: The giraffe has adapted to this by having a special valve in its artery that stops blood from flowing to the brain when it lowers its head.
text: But when the giraffe lowers its head to eat or drink, the blood rushing down at such high pressure would cause the blood vessels to burst.
text: But when the giraffe lowers its head to eat or drink, the blood rushing down at such high pressure would cause the blood vessels to burst.
text: The giraffe has special valves to protect its brain and keep it from blacking out when it lowers its head to drink; they both constrict and release blood flow.
text: The giraffe has adapted to this by having a special valve in its artery that stops blood from flowing to the brain when it lowers its head.
text: In this way, when the giraffe lowers its head, the external carotid artery fills with blood, and prevents the excessive flow of this to the admirable reticulum; at the same time, the jugular vein prevents blood flow through a series of valves arranged along this vessel.
text: It spreads its front legs awkwardly so it can lower its head to the river or pool.
text: Additionally, the jugular veins contain a series of one-way valves that prevent excess blood flow to the brain when the giraffe lowers its head to drink.
text: Additionally, the jugular veins contain a series of one-way valves that prevent excess blood flow to the brain when the giraffe lowers its head to drink.
text: In the upper neck, a complex pressure-regulation system called the rete miribale prevents excess blood flow to the brain when the giraffe lowers its head to drink.
text: Something that puzzled people for a long time was why the giraffe did not burst the blood vessels in its head when it suddenly lowered its head to the ground, and why, when it suddenly lifted up its head again, it did not get giddy.
text: The giraffe has a large heart to allow it to raise and lower its head without fainting.
text: In the upper neck Giraffes have a complex pressure regulation system that prevents excess blood flow to the brain when the Giraffe lowers its head to drink.
text: For instance, they have the highest known blood pressure but, interestingly enough, the blood pressure to the brain drops when the giraffe lowers its head.
text: When it lowers its head, all that high pressure blood would likely rush downhill (further assisted by gravity) and blow out the delicate blood vessels in the brain and eyes
text: However, its anatomy also prevents that the brain gets too much blood when they giraffe lowers its head to eat or drink water.
text: When the giraffe lowers its head to drink, it gets no circulation of blood to the brain.
text: Because of its long neck, one would expect blood to rush to the brain of a giraffe when it lowers its head to drink, or to drain away from the brain when the head is lifted back up.
text: Their upper neck has a special regulation system that prevents excess blood flow to the brain when giraffe lower their head to drink.
text: a lot so they can lower their heads to the water.