Lecture 2: respiratory pump

Question 1

Diaphram

Answer 1

Dome shaped
when relaxed: pushes into thorax
Contraction: flattens
Expands lower rib cage by lifting up on the ribs by attachment to the costal arch
PRIMARY INSPIRATORY MUSCLE
INNERVATED by PHRENIC NERVE

Question 2

External intercostal muscles are oriented to?

Answer 2

lift ribs (during inspiration)

Question 3

Internal intercostal muscles are oriented to?

Answer 3

depress the ribs (during expiration)

Question 4

T/f: Raising ribs decreases circumference of the chest

Answer 4

FALSE: it increases the circumference

Question 5

Abdominals

Answer 5

muscles of expiration (primary); used for forceful exhale; active contraction pushed diaphragm into thorax passively

Question 6

Volume of thorax is increased by?

Answer 6

Flattening of diaphragm and lifting of ribs , pressure of chamber decreases and air is sucked in

Question 7

Pump

Answer 7

respiratory muscle; expands chamber volume by creating negative pressure

Question 8

Parietal and visceral pleura are separated by?

Answer 8

thin layer of plural fluid

Question 9

pleural pressure

Answer 9

negative pressure in this fluid created by opposite forces of the chest wall/ tendency to spring outward, pulling the lung out at its rest position and the lung wants to collapse

Question 10

Pnemothorax

Answer 10

hole made in the chest, causing lung to collapse and the chest wall to expand (each going in respective rest position); lungs don’t move; no ventilation

Question 11

Alveolar Pressure

Answer 11

P(subA) Pressure difference between atmosphere and alveoli; at rest it is equal to atmospheric pressure;lung expansion makes it more negative