Lecture 16: Anatomy of the Thorax and Breathing Flashcards

1
Q

What lines our body’s cavities?

A

serous membranes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are serous membranes?

A

double layer of secretory tissue with fluid between the layers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the two layers of serous membranes and where are they?

A
  • visceral layer on the organ

- parietal layer on the body wall

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are the two serous membranes in the thoracic cavity?

A

pericardium

pleura

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is the mediastinum?

A

where the heart, pericardium and major vessels are found

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Inside the pleural cavities there are the

A

lungs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What bones indicate the boundaries of the thoracic cavity?

  • anterior
  • posterior
  • inferior
  • superior
  • lateral
A
  • anterior: sternum
  • posterior: 12 thoracic vertebrae
  • lateral: ribs
  • superior: base of neck
  • inferior: diaphragm
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is inside the thoracic cavity?

A

the left and right pleural cavity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is inside the pleura?

A

pleural fluid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Where does the visceral pleura sit?

A

On the lung itself

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Where does the parietal pleura sit?

A

against the ribs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the purpose of the pleural fluid?

A

to create frictionless movement so the lungs don’t get damaged when they expand and rub against the ribs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Breathing is driven by

A

pressure changes within the thoracic cavity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Inspiration causes the volume to _____ and the pressure to ________

A

increase

decrease

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Expiration causes the volume to _____ and the pressure to ________

A

decrease

increase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is Boyle’s Law

A

P = 1/V

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Pressure is measured by

A

the number of collisions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

How does the number of collisions affect the pressure?

A

the increased number of collisions, the higher the pressure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Air moves to the ____ pressure space

A

lower

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

By changing the volume fo the thorax, we can change the

A

pressure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

In between breathing, there is no

A

pressure gradient

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Describe the flow of air when breathing in and why

A

When breathing in, the volume of the thoracic cavity increases so pressure decreases so air flows in

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Describe the flow of air when breathing out and why

A

When breathing out, the volume of the thoracic cavity decreases so pressure increases so air flows out

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

How do the ribs attach to the costocartilage?

A

Via costochondral joints

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What type of joint are costochondral joints?

A

Cartilaginous joints

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What is the name of the joints attaching the sternum to the ribs?

A

sternocostal joints

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Are sternocostal joints cartilaginous or synovial?

A

The first one is cartilginous and the others are synovial

28
Q

What is the name of the joints that attach the cartilages of neighbouring ribs?

A

interchondral joints

29
Q

What type of joint are interchondral joints?

A

synovial

30
Q

How do the ribs articulate with the vertebrae?

A

through costotransverse and costovertebral joints

31
Q

Where are the costotransverse joints?

A

between the rib and the transverse process of vertebrae

32
Q

Where are the costovertebral joints?

A

between the ribs and the body of the vertebrae

33
Q

What sort of joints are costotransverse and costovertebral joints?

A

synovial joints

34
Q

What is used to change the volume of the ribcage?

A

respiratory muscles

35
Q

What are the primary inspiratory muscles?

A

disphragm

intercostals

36
Q

When are the accessory structures active?

A

Only when they are needed

37
Q

Where are the intercostal muscles?

A

In between the ribs

38
Q

What sort of muscle is the diagragm?

A

skeletal muscle

39
Q

What shape is the diaphragm when it is relaxed?

A

dome shaped

40
Q

What shape is the diaphragm when it is contracted?

A

it is flat

41
Q

How does the diaphragm affect the inflow of air?

A

Contraction of the diaphragm flattens it and expands the thoracic cavity. This means the pressure decreases so air flows in

42
Q

Where do the intercostal muscles attach?

A

diagonally between neighbouring ribs

43
Q

What are the two layers of the intercostal muscles?

A
  1. external intercostals

2. internal intercostals

44
Q

What happens when external intercostal muscles contract?

A

It pulls the ribcage upwards to increase the depth of the cavity

45
Q

External and internal intercostal muscles run in

A

opposite directions

46
Q

What happens when internal intercostal muscles contract?

A

it pulls the ribcage down and inwards

47
Q

Which intercostal muscles are used for inspiration?

A

external

48
Q

Which intercostal muscles are used for expiration?

A

internal

49
Q

What is quiet breathing?

A

everyday breathing without thinking about it

50
Q

What is forced breathing?

A

Doing exercise, needing more air in and out

51
Q

Which intercostals are only involved in forced expiration?

A

internal intercostals

52
Q

What are the functions of the accessory muscles?

A
  • increase cavity volume for forced inspiration

- decrease cavity volume for forced expiration

53
Q

What happens during quiet inspiration with regards to the diaphragm and the intercostal ribs?

A

the diaphragm contracts and it flattens which enables air to enter
the external intercostal ribs lift the ribs upwards

54
Q

What happens during forced inspiration with regards to the diaphragm and the intercostal ribs? Is there anything else that is used?

A
  • the diaphragm contracts and it flattens which enables air to enter
  • the external intercostal ribs lift the ribs upwards
  • the accessory muscles contract to further expand the thoracic cavity
55
Q

What happens during quiet expiration with regards to the diaphragm and the intercostal ribs?

A
  • it is a passive process
  • the diaphragm relaxes and becomes dome shaped
  • the external intercostals relax so the ribs are no longer raised
56
Q

What happens during forced expiration with regards to the diaphragm and the intercostal ribs? Is there anything else that is used?

A
  • the diaphragm relaxes and becomes dome shaped
  • the external intercostals relax so the ribs are no longer raised
  • the internal intercostals contract to depress ribs
  • accessory structures contract to further decrease the cavity volume
57
Q

Lung tissue is very ______ and is always trying to _____

A

elastic

recoil to a smaller shape

58
Q

Why do we need the lungs to expand?

A

Because otherwise we would not get the pressure difference

59
Q

What is the role of the pleura with regards to expanding the lungs?

A

It makes the lungs stick to the thoracic wall so when walls do, the lungs do to

60
Q

Lungs expand during

A

inspiration

61
Q

Lungs decrease during

A

expiration

62
Q

The pleural fluid forms a

A

fluid bond with the lungs

63
Q

What is the significance of the fluid bond?

A

When the thoracic wall expands, the lungs is pulled with it

64
Q

How does airflow relate to the lungs?

A

When the ribcage expands, the lungs go with it which increases the volume which decreases the pressure and means that air flows in

65
Q

What are the anatomical features of the thoracic cavity?

A

Bones, joints and muscles form the thoracic wall

Inside the cavity there is the mediastinum, plus the lungs within a double layer of pleura

66
Q

How does the anatomical features change the thoracic volume?

A

Inspiration: diaphragm and external intercostals contract. Accessory muscles contract for forced breathing

Expiration: diaphragm relaxes. Internal intercostals and accessory muscles contract for forced breathing

67
Q

How does our anatomy facilitate breathing?

A

Muscles move bones at joints to increase and decrease pressure for inspiration and to decrease volume and increase pressure for expiration. Pleural fluid adheres lungs to thoracic wall to ensure lungs expand and recoil as the cavity volume changes.