You Were Correct

The giraffe has a complex cardiovascular system, and is unique amongst mammals in having a head that may be up to 3m above its heart. In order to provide its head with sufficient nutrients and oxygen, the giraffe's heart must therefore pump hard enough to overcome the huge hydrostatic pressure generated by the tall column of blood in its neck. This results in the giraffe having extremely high blood pressure (280/180 mm Hg) and a heartbeat of up to 170 beats per minute. Research has revealed that arterial pressure near the giraffe heart is about twice that in humans, to provide more normal blood supply to the brain. Thanks to their huge lungs which can hold 55 litres of air, they are also able to put plenty of oxygen into their blood.

It was previously thought that a giraffe had a really big heart, but recent research has revealed that there isn’t room in the body cavity for this. Instead, the giraffe has a relatively small heart and its power comes from a very strong beat as a result of the incredibly thick walls of the left ventricle.

To protect the giraffe's brain from sudden changes in blood pressure when it lowers its head to drink, it has valves to stop the back-flow of blood and elastic-walled vessels that dilate and constrict to manage flow.

Click here to download our New DYK app for Free for your phone or iPad

Your Stats


76/103 74%
9th September 2020
19th August 2020
5th August 2020
22nd July 2020
8th July 2020
23rd June 2020
10th June 2020
27th May 2020
13th May 2020
29th April 2020
15th April 2020
1st April 2020
18th March 2020
4th March 2020
19th February 2020
5th February 2020
22nd January 2020
8th January 2020
25th December 2019
11th December 2019
27th November 2019
13th November 2019
30th October 2019
16th October 2019
2nd October 2019
18th September 2019
4th September 2019
21st August 2019
7th August 2019
24th July 2019
10th July 2019
26th June 2019
12th June 2019
29th May 2019
15th May 2019
1st May 2019
17th April 2019
3rd April 2019
20th March 2019
6th March 2019
20th February 2019
6th February 2019
24th January 2019
9th January 2019
26th December 2018
12th December 2018
28th November 2018
14th November 2018
31st October 2018
17th October 2018
3rd October 2018
19th September 2018
5th September 2018
22nd August 2018
8th August 2018
25th July 2018
11th July 2018
20th June 2018
6th June 2018
23rd May 2018
9th May 2018
25th April 2018
11th April 2018
28th March 2018
14th March 2018
28th February 2018
4th February 2018
31st January 2018
17th January 2018
3rd January 2018
20th December 2017
6th December 2017
22nd November 2017
8th November 2017
25th October 2017
11th October 2017
20th September 2017
6th September 2017
23rd August 2017
9th August 2017
26th July 2017
12th July 2017
28th June 2017
14th June 2017
31st May 2017
17th May 2017
3rd May 2017
12th April 2017
29th March 2017
15th March 2017
1st March 2017
15th February 2017
1st February 2017
18th January 2017
4th January 2017
21st December 2016
7th December 2016
23rd November 2016
9th November 2016
26th October 2016
12th October 2016
28th September 2016
14th September 2016