Organs separated by sacs like produce
The tract is divided into an upper and a lower respiratory tract.
The upper tract includes the nose, nasal cavities, sinuses, pharynx and the part of the larynx above the vocal folds.
The lower tract includes the lower part of the larynx, the trachea, bronchi, bronchioles and the alveoli.
Gas exchange takes place in alveoli
The first bronchi to branch from the trachea are the right and left main bronchi.
The alveoli are the dead end terminals of the "tree
any air that enters them has to exit via the same route
Not all the air in the lungs can be expelled during maximally forced exhalation.
This is the residual volume of about 1.0-1.5 liters which cannot be measured by spirometry.
Parasympathetic system causes bronchoconstriction
Sympathetic nervous system causes bronchodilation
Contractile Cells
Intercalated discs
Intercalated discs
Heart
Chambers, Pacemaker, Rhythm
Chambers, Pacemaker, Rhythm
Sinoatrial Node
Pacemaker, Rhythm
Pacemaker, Rhythm
1
8
10
8
8
4
5
4
13
10
13
0
9
4
7
14
7
0
18
0
1
4
7
5
5
10
8
4
17
8
4
12
3
4
2
18
12
22
6
4
3
21
4
5
26
15
24
4
7
31
5
6
7
3
5
4
3
1
2
1
2
2
4
2
1
3
18
15
18
3
3
1
2
2
1
3
3
1
7
8
3
1
1
2
2
1
14
21
18
2
7
4
5
5
4
4
4
4
5
6
6
6
5
4
4
1
1
1
4
11
4
4
3
6
4
9
5
3
9
4
3
5
7
5
2
2
10
3
6
5
3
5
2
6
2
4
4
2
2
9
8
8
11
2
8
2
6
4
2
8
2
8
7
5
3
3
2
3
8
5
4
5
3
13
9
4
3
2
5
3
3
2
8
4
6
2
2
2
3
6
5
10
2
3
14
0
22
0
8
4
5
4
6
8
6
0
1
1
12
0
6
4
1
4
0
0
10
8
6
10
7
1
30
30
30
35
30
30
30
35
30
30
30
23
30
30
30
23
25
0
0
0
25
0
0
0
Organs separated by sacs like produce