resp system

two components of the respiratory tract

upper and lower resp tract

components of the URT

nasal/oral cavity

pharynx

larynx

trachea

components of the LRT

bronchi

bronchioles

alveoli

characteristics of the resp tract (3)

wet, hairy, supported by cartilage

how is the resp tract wet + what does it do

mucus; traps foreign particles

how is the resp tract hairy + what does it do

lined with cilia; moves foreign particles out of tract

function of resp tract being supported by cartilage

strong, flexible connective tissue (forming rings) that gives structure to the tract and prevents it from collapsing

functionf of nasal cavity (3)

- cleans air (nostrils have tiny hairs)

- warm air (epithelial cell/turbinate bones lined w capillaries)

- moistens air (turbinate bones lined w thin membrane that secretes mucus)

nose turbinate

thin bones that increase SA and allow air to reach more warmed, moist surfaces in noise

result sin cleaner/warmer air reaching lungs

larynx

aka voice box has vocal cords

the passage of air in the larynx causes cords to

vibrate and produce sound

shortened cords cause

higher pitch

longer cords produce

lower pitch

male vocal cords grow during \______ causing the voice to \______

puberty; deepen

laryngitis

inflammation of vocal cords

laryngitis is caused by

infection (usually viral)

smoking

regurgitation of stomach acid when vomiting

overuse of vocal cords

vocal cord nodules

nodules that arise due to excessive use/constant straining of voice

trachea maintains its rigidity bc of

cartilage rings

trachea is lined with these two cells

goblet and epithelial cells

goblet cells

produce mucus which traps foreign particles

epithelial cells

ciliated -- brush mucus w foreign particles upward thru tract

sneezing and coughing helps expel \______

mucus + other inhaled particles

the trachea branches into two

bronchi

the bronchi are the beginning of

the LRT

each bronchus leads to a

diff lung

bronchi are reinforced with

cartilage

each lung is divided into

lobes

the right lung has \____ lobes

three

the left lung has \____ lobes

two (to accommodate the heart)

pleura

flexible membrane around the lungs

functions of the pleura (2)

- protects the lung/lines thoracic cavity

- allows lung to expand/contract when breathing

bronchi branch into smaller tubes known as

bronchioles

alveolus/alveoli

spherical hollow cavities (air sacs) surrounded by capillaries

alveoli create large SA for

gas exchange

alveoli/capillaries have walls that are only \_____________ to allow for rapid diffusion of gases

single cell layer

lung surfactant functions (2)

- helps lower surface tension in airways + keeps alveoli open

- has immune proteins defending vs. bacteria/viruses/infectious agents

oxygen and co2 are exchanged at the \____ \_____ of the alveoli in lungs and at \______ \______

in surface; body cells

gases are exchanged by \______ along a concentration gradient

diffusion

concentration gradient

diff in concentration and gases diffuse from high to low concentration

co2 \_____ the blood vessel into the \_______

leaves; alveolus

oxygen goes into the

blood vessel

o2 in inhaled air will go to

o2 in capillaries in lungs

o2 in capillaries near body cells will go to

o2 in body cells

external respiration

exchange of gases bet air and blood

occurs in lungs

o2 diffuses from alveoli to

capillaries

co2 diffuses from capillaries to

alveoli

internal respiration

exchange of gases bet blood and cells of surrounding tissue

occurs in body tissues

o2 diffuses from capillaries to

tissues

co2 diffuses from tissue to

capillaries

breathing consists of

inhalation and exhalation

inspiration

aka inhalation

taking air into lungs

expiration

aka exhalation

removing air from lungs

respiratory muscles

diaphragm and intercostals

diaphragm

dome-shaped sheet of muscle that separates thoracic and abdominal cavities

intercostal muscles

muscles of ribcage

external intercostals

outer surface of ribcage that pulls ribs up

internal intercostals

inner surface of ribcage that pulls ribs down

the diaphragm contracts during

inhalation

the diaphragm relaxes during

exhalation

the ribcage expands as

rib muscles contract

the ribcage gets smaller as

rib muscles relax

mechanics of inhalation

diaphragm contracts/flattens

external intercostals contract and internal ones relax

ribcage moves up and out

lung vol increases

mechanics of exhalation

diaphragm relaxes and returns to dome shape

external intercostals relax and internal ones contract

ribcage moves down

lung volume decreases

thoracic cavity

contains heart and lungs

how do we know when to inspirate

resp centre in brain stem sends signal that causes diaphragm/intercostal muscles to contract

how does feedback work in breathing

stretch receptors in lungs send signals to brain that indicate lungs expanded

how do we know when to expirate

brain stops signalling muscles causing them to relax

breathing is under (voluntary/involuntary) control

involuntary / autonomic

can someone override signals and consciously control breathing?

yes but temporarily

frequency of ventilation

\# of breaths in a given amt of time

normal resp rate

16-20 breaths/min

increase in cellular activity will cause an increase in

cellular respiration

(more co2 will be produced)

co2 forms \______ \___ in the blood which causes a (higher/lower) blood pH

carbonic acid; lower

receptors in brain recognize the pH decrease (carbonic acid) so they

- signals to diaphragm/intercostal muscles to contract more rapidly and forcefully

- increased breathing rate and vol of inhalation

- signals increased heart rate