1
00:00:00,300 --> 00:00:10,939
Hello, we are going to talk about the heart, its parts and functions while we are doing a dissection.

2
00:00:10,939 --> 00:00:17,420
First of all, what is a heart?

3
00:00:17,420 --> 00:00:23,420
The heart is a hollow muscular organ that transmits heartbeats.

4
00:00:23,420 --> 00:00:36,530
A heartbeat is a constant movement that pounds blood from the veins to the atriums, into the ventricles and finishing the arteries.

5
00:00:36,530 --> 00:00:40,530
Heart rate is the number of times that the heart beats per minute.

6
00:00:42,530 --> 00:00:46,530
And these are the parts of the heart, the front part

7
00:00:47,530 --> 00:00:50,530
and the back part of the heart

8
00:00:50,530 --> 00:00:57,530
and is divided into the right ventricle and left ventricle.

9
00:00:57,530 --> 00:01:03,289
Now we are going to start the dissecting.

10
00:01:03,289 --> 00:01:09,290
We will insert the scissors in the pulmonary artery.

11
00:01:09,290 --> 00:01:16,290
When we cut it, you can see that the pulmonary artery is connected to the right ventricle.

12
00:01:36,579 --> 00:02:01,099
And now we are going to take out the black part.

13
00:02:01,099 --> 00:02:11,550
And now you can see better how is the right ventricle inside.

14
00:02:11,550 --> 00:02:16,349
And now we are going to do the dissection of the other part of the heart.

15
00:02:16,349 --> 00:02:30,699
We are introducing the tweezers to the left atrium that is connected to the left ventricle.

16
00:02:30,699 --> 00:03:00,819
It's hard to cut this part because it's thicker than the other parts of the heart.

17
00:03:00,819 --> 00:03:09,879
You can see the ligaments and how is the left ventricle inside.

18
00:03:09,879 --> 00:03:13,180
And now I'm going to talk about the blood circuits.

19
00:03:13,180 --> 00:03:18,020
the systemic circuit. The blood starts in the left ventricle and goes through the

20
00:03:18,020 --> 00:03:21,759
heart cell which branches into arterioles and then into capillaries reaching all

21
00:03:21,759 --> 00:03:26,740
the tissues and organs that step the lungs. The blood in the capillaries provides

22
00:03:26,740 --> 00:03:31,060
cells with the nutrients and oxygen and removes waste products and carbon

23
00:03:31,060 --> 00:03:35,620
dioxide. Finally, it returns to the heart going through venules and capillaries.

24
00:03:35,620 --> 00:03:41,919
Then we have the pulmonary circuit that begins in the right ventricle from which

25
00:03:41,919 --> 00:03:47,280
a pulmonary artery start. Around the pulmonary alveoli there is a dense cloud of capillaries

26
00:03:47,280 --> 00:03:53,759
in which glass exchange occurs. The capillaries form into venules which in turn join together

27
00:03:53,759 --> 00:04:01,280
to create four pulmonary veins that reach the left atrium. From the atrium blood goes into the left

28
00:04:01,280 --> 00:04:08,280
ventricle to neutral valve to begin the systemic circuit.