Map Lecture Exam Ii Resp

Front 1

What is Intrapleural Pressure (Pip)

Back 1

pressure in space between parietal & visceral pleura (also fluctuates with breathing) (~ slight vacuum)
• Should be ~ −4 mm Hg at rest
** remains below atmospheric pressure (Patm) throughout respiratory cycle

Front 2

Pressure Relationships

Back 2

• Intra-alveolar pressure and intrapleural pressure fluctuate with the phases of breathing
• Intra-alveolar pressure always eventually equalizes itself with atmospheric pressure

Front 3

What is lung collapse?

Back 3

caused by equalization of intrapleural pressure with intra-alveolar pressure
• without negative intrapleural pressure → lungs recoil and collapse

Front 4

pneumothorax

Back 4

air enters intrapleural space

Front 5

Gas exchange in the lungs occurs because of partial pressure differences...

Concentration gradient causes:

Back 5

• O₂ to enter blood
• CO₂ to leave blood

Front 6

Gas exchange at the tissues occurs because of partial pressure differences...

Concentration gradient causes:

Back 6

• O₂ to enter tissues
• CO₂ to enter blood

Front 7

Control of Respiration involves neurons in the:

Back 7

medulla and pons

Front 8

Control of Respiration in the medulla .....

Back 8

sets respiratory rhythm

Front 9

Control of Respiration in the pons .....

Back 9

influences and modifies activity of medullary neurons

Front 10

What are the two respiratory groups of the Medullary Respiratory Centers?

Back 10

Ventral Respiratory Group & Dorsal Respiratory Group

Front 11

Ventral Respiratory Group (VRG)

Back 11

• Rhythm generating
• Integrative center
• Excites "quiet" inspiratory muscles & sets normal respiratory rate & rhythm
• Inspiratory neurons (2 seconds)
• signal contraction of diaphragm & external intercostals
• Expiratory neurons (3 seconds)
• output stops, inspiration ceases
• passive expiration

Front 12

Dorsal Respiratory Group (DRG)

Back 12

• Integrates input from:
• Peripheral Stretch receptors
• Peripheral chemoreceptors

to modify rhythms generated by VRG

Front 13

Pons Respiratory Center

Back 13

• influences & modifies activity of medullary respiratory center
• "smooths out" inspiration and expiration transitions
• e.g. modifies breathing rhythm set by VRG during vocalization, sleep & exercise
• DRG & pons respiratory centers receive info from peripheral receptors & higher brain centers

Front 14

DRG & pons respiratory centers receive info from _____ & _____

Back 14

DRG & pons respiratory centers receive info from peripheral receptors & higher brain centers

Front 15

Breathing rate

Back 15

determined by how long inspiratory center is active (breaths per minute)

Front 16

Breathing depth

Back 16

more stimulation → more motor units excited → greater force of breath

Front 17

Factors that include breathing rate & depth are:

Back 17

• Chemical****
• CO₂
• O₂
• pH
• Reflexes
• Higher Brain Centers
• Exercise
• Pain, emotional stimuli

Front 18

Chemoreceptos

Back 18

sensors that respond to chemical flucuations

Front 19

What are the two chemoreceptors?

Back 19

central chemoreceptors & peripheral chemoreceptors

Front 20

What are the two locations of the chemoreceptors?

Back 20

• central chemoreceptors - medulla
• peripheral chemoreceptors - aortic arch & carotid arteries

Front 21

Factors influencing breathing rate and depth: PCO₂

Back 21

• CO₂ - most potent and closely controlled chemical
• Mediated mainly be central chemoreceptors detecting rising CO₂

Front 22

Hyperventilation

Back 22

increased depth and rate of breathing
• Quickly flushes CO₂ from blood
• Occurs in response to high CO₂
➤ Though a rise in CO₂ act as original status → control of breathing is actually regulated by H+ concentration in the brain

Front 23

Hypoventilation

Back 23

slow and shallow breathing due to abnormally low PCO₂ levels
• Apnea (breathing cessation) - may occur until PCO₂ levels rise

Front 24

Apnea (breathing cessation)

Back 24

may occur until PCO₂ levels rise

Front 25

Peripheral chemoreceptors

Back 25

in aortic bodies & carotid bodies
• Sensitive to O₂ changes (and CO₂)
• Usually only respond to large changes in O₂ (vs very sensitive CO₂ receptors)
• ok because we have large O₂ reservoir bound to Hb
• drop in pH results in an increase in respiratory and breathing rate

Front 26

Factors influencing breathing rate and depth: arterial pH

Back 26

central chemoreceptors and peripheral chemoreceptors

Front 27

Central chemoreceptors

Back 27

insignificantly affected by H+ from arterial blood
• little H+ diffuses from blood into CSF

Front 28

CO₂ and H+ are _____ → but they are distinct stimuli

Back 28

• Drop in pH may reflect an increase in CO₂ but...
• Can reflect other acid accumulation (e.g. lactic acid)

Front 29

Body compensates for low pH by eliminating _____ by increasing breathing & respiratory rate.

Back 29

CO₂

Front 30

Body compensates for low pH by eliminating CO₂ by increasing breathing & respiratory rate.

Why does this make sense?

Back 30

CO₂ + H₂O ⇋ H₂CO₃ ⇋ H+ + HCO₃-

Front 31

Inflation reflex (Hering-Breuer reflex)

Back 31

stretch receptors in airways respond to changes in lung volume
• lungs stretched during inspiration
• send signal to control center to inhibit inspiration

• lungs recoil during expiration
• send signal to control center to stimulate inspiration

Thought to be a protective response (to prevent excessive stretching of lungs)

Front 32

Pulmonary irritant reflex

Back 32

irritating physical/chemical stimuli in nasal cavity, larynx, and bronchial tree
• stimulate cough in trachea or bronchi
• stimulate sneeze in nasal cavity

Front 33

Factors influencing breathing rate and depth

Back 33

enter here

Front 34

What structures make up the conducting zone of the respiratory system and what is the conducting zones purpose?

Back 34

- Structures: Pharynx, Larynx, trachea, and the brachail tree.

- Function: To conduct air into and out of the lungs. Also, serves to condition the air.

Front 35

What structures make up the respiratory zone and what is their purpose?

Back 35

- Structures: Alveoli and respiratory branchiols

-Function: gas exchange

Front 36

What is the Bronchial tree? How are bronchioles different from bronchi?

Back 36

- Highly branched tubes of the lungs/respiratory system. As these tubes become smaller they lose cartilaginous support and gain more smooth muscle proportionally.

- Bronchi: larger tubes w/ cartilaginous support

- Bronchioles: Smaller tubes w/o cartilaginous support

Front 37

Alveoli

Back 37

- spherical air filled structures at the end of the bronchial tree in clusters called alveolar sacs. Very compliant. Covered w/ pulmonary capillaries.

- Type I alveolar cells: Make up the walls of the aveoli.

- Type II alveolar cells: Not a part of the walls of the aveoli. Secrete surfactant.

Front 38

Respiratory membrane

Back 38

- Barrier to gas exchange in the lungs. Comprised of the Type 1 alveolar cells, endothelial cells of the capillaries, and the basement membrane that holds them together.

Front 39

Parietal pleura

Back 39

Membrane inside of the ribs

Front 40

Visceral Pluera

Back 40

Membrane on the outside of the lungs

Front 41

Intrapleural space

Back 41

the area in between the parietal and visceral pluerae.

Front 42

Pleural Fluid

Back 42

Fills the intrapleural space