BIOL Exam 3

Respiratory System function

supply tissues with oxygen and remove the carbon dioxide from blood

Respiration=

collective processes

Pulmonary Ventilation

what we commonly refer to breathing, simply the movement of air into and out of the lungs

External Respiration

movement of gases between atmospheric air in the lungs and the blood, O2 moves out of the alveolar air and into the blood and joins air in the alveoli

O2—>lungs—>blood

CO2—>blood—>lungs

Gas transport

carbon dioxide and O2 travel in the blood to and from cells, CO2 to lungs and out and O2 in and to tissue

Internal respiration

movement of gases between the blood and the body’s cells, gas exchange with the tissues involves the exit of O2 from the blood into cells while CO2 exits cells to enter the blood

O2—>blood—>cells

CO2—>cells—>blood

respiratory zone

site of gas exchange, soley within the lungs and includes some specialized small air tubes and the alveoli

conducting zone

rigid conduclts allowing movement encompasses the structures from the nose to the smallest air tubes within the lungs and is strictly for ventilation

Vibrissae

nose hairs that trap particles

Nasal Cavity roof

ethmoid/sphenoid

Nasal cavity floor

palatine/maxilla/palate

Conchae

protrude medially, increases surface area, bony ridges on lateral wall

Olfactory mucosa

on superior nasal conchae

contains cells that initiate olfactory sensations

Respiratory Mucosa

lines the rest of the tract

has lysosomes, defensins, mucous glands

if this becomes irritated, your nose runs and it will cause a sneeze

Functions of conchae and mucosa

warm and moisten and filter air= when inhaling

reclaim warmth and moisture during exhale

Paranasal sinuses description

spaces in the bones around the nasal cavity

Paranasal sinuses bones

frontal, sphenoid, ethmoid, and maxillary

Paranasal sinuses functions

lighten skull keep us from head planting

help warm and moisten air

Headache

described as pressure

the drainage areas of the sinuses get filled and blocked with mucus, the air is trapped within and onbsorbed into the bone like a vacuum

Neti Pot

nasal irrigation

Vocal folds

a pair of true vocal cords, primary source of vace production

Vestibular folds

a pair of false vocal cords

Glottis

at the junction of the vocal folds in an opening

Structures used to speak

tongue, top of mouth, exhaling air, lips, shape of oral cavity, teeth, pharynx

Whispering

voice becomes more monotne because you’re not pushing as much air out

What increases the thickness of vocal folds

testosterone

males have longer vocal folds

How do vocal folds move as we speak and don’t speak

wide apart when we don’t and brought together when we are

Valsalva manuever

tuck and suck, bracing abdominal cavity, will cause temporary increase in blood prsessure

babies do this

exhaling against a closed glottis or bearing down as though to defecate

Trachea

also known as the windpipe

Ring of cartilage

more c-shaped

behind the trachea is a muscle called

trachealis muscle

Trachealis muscle

if it contracts it pulls the cartilage muscle together

decreases diameter of trachea which aids in coughing

how we increase the force of a cough

Esophagus

flat like a fire hose

only expands with passage of food or water and will push trachealis muscle sometimes

carina

very last tracheal cartilage, highly embedded with neurons

if particle touches it we cough

Primary bronchi

left and right one

Secondary bronchi

2 on the left and 3 on the right

Tertiary bronchus

8 on the left and 10 on the right

Bronchioles

cuboidal ET, complete layer of smooth muscle and no cartilage

can close off in a asthma attack

blood supply to lungs for oxygenation=

pulmonary arteries

blood supply to lungs for olung tissue nourishment=

bronchial arteries

Respiratory zone order of flow

terminal bronchiole—>respiratory bronchioles—>alveolar ducts

Air-blood barrier

fused walls of alveoli and capillaries

Alveolar walls

Type 1 cells simple squamous ET

permit gas exchange by simple diffusion

Surfactant

produced by type II cells scattered in alveoli

keep alveoli open

disrupts surface tension

Respiratory membrane features

smooth muscle

elastic fibers

alveolar pores help equalize the pressure

macrophages keep clean

Pleural lining

double walled membrane

parietal pleura

lines thoracic cavity

Visceral pleura

lines outside of lungs

Pleural space

in-between with some fluid

Pleurisy

inflammation of lining—>painful

if the pressure in the pleural space is greater than the pressure in the lungs then

the lungs would be squishes/collapsed

so it has to always be negative

Muscles of inspiration pressure goes down

sternocleidomastoid

scalenes

pectoralis major

external intercostals

diaphragm

Muscles of expiration pressure goes up

internal intercostals

abdominal muscles

Quiet breathing

the external intercostal muscles contract elevating the ribs and moving the sternum

Labored breathing

additional muscles contract, causing additional expansion of the thorax

Expiration

diaphragm relaxes and decreasing the superior-inferior dimension of the thoracic cavity

Inspiration

diaphragm contracts and increases the superior-inferior dimension of the thoracic cavity

when in relaxed state the diaphragm is

dome-shaped

when it contracts the diaphragm is

flattened

negative respiratory pressure

less than Patm

postive repiratory pressure

greater than Patm

Intrapulmonary pressure

in alveoli

fluctuates with breathing

always eventually equalizes with Patm

Forces promoting lung collapse

elasticity of lungs and surface tension of alveolar

surfactant

Forces promoting lung expansion

elasticity of chest wall and low intrapleural pressure

pressure in pleural space less than pressure in lungs

Hemothorax

blood in pleural space—>space pressure becomes greater—>lung is going to collapse

Pneumothorax

collapsed lung

atelectasis

pressure differential removed

Dalton’s law

total pressure =sum

Henry’s law

concentration of a gas in a liquid is determined by its partial pressure an it solubility

Diffusion of gases through respiratory membrane depends on

membrane thickness

diffusion coefficent of gas

surface area

partial pressure differences

70% of the air we breathe is

nitrogen

External respiration

driven by pressure gradients

ventilation amount of gas reaching the alveoli

perfusion amount of blood flow circulating by alveoli

ventilation-perfusion coupling

ventilation-perfusion coupling

tightly regulated to maintain efficient gas exchange

Internal respiration

driven by pressure gradients

Factor’s affecting Hb’s affinity for O or what stimulates O2 release

PO2

increased body temp.

decreased pH

increased CO2 partial pressure

increase in BPG

cigarette smoking

if pH goes down then the affinity of hemoglobin

goes down

CO2+H2O—>

H2CO3 ←→H+ + HCO3-

CO2 is picked up in tissues and transported in blood in 3 forms

dissolved in plasma

bound to hemoglobin

bicarbonate ion in plasma (most common)

Oxygen is mainly transported through

hemoglobin

CO2 transports at lungs

bicarbonate ions move into RBCs and bind with hydrogen ions to form carbonic acid

carbonic acid is split by carbonic anhydrase to release carbon dioxide and water

CO2 diffuses from blood to alveoli and out the body

Medulla respiratory center

dorsal groups stimulate diaphragm via phrenic nerve

ventral groups stimulate intercostals and abdominal muscles via intercostal nerves

Pontine respiratory groups

involved with switching between inspiration and expiration

Fetus

7 months earliest fetus can breathe on its own

Autonomous respiration

Lungs filled with fluid

Site of gas exchange

At birth

Respiratory centers activated

Respiratory rate

Childhood development

lungs continue to develop

Respiratory efficiency—-with old age

decreases

Intrapulmonary pressure.

Pressure

inside lung decreases as

lung volume increases

during inspiration;

pressure increases

during expiration

Intrapleural pressure.

Pleural cavity pressure

becomes more negative

as chest wall expands

during inspiration.

Returns to initial value

as chest wall recoils.

Volume of breath

During each breath, the

pressure gradients move

0.5 liter of air into and out

of the lungs.

Homeostatic imbalances that reduce

compliance

– Deformities of thorax

– Ossification of the costal cartilage

– Paralysis of intercostal muscles

Athletic training

– Vital capacity increases slightly; residual volume

decreases slightly

– At maximal exercise, tidal volume and minute

ventilation increases

– Gas exchange between alveoli and blood increases

at maximal exercise

– Alveolar ventilation increases

– Increased cardiovascular efficiency leads to

greater blood flow through the lungs

Effects of Aging

• Vital capacity and maximum minute

ventilation decrease

• Residual volume and dead space increase

• Ability to remove mucus from respiratory

passageways decreases

• Gas exchange across respiratory membrane

is reduced

Apnea

sleep disorder in which breathing repeatedley stops and start, uninterrupted breathing

Hyperventilation

when breathing becomes too fat

Hypercapnia

too much CO2

Hypocapnia

lower than normal CO2

Hypoventilation

increased CO2 low O2

Mechanical & Chemical Stimuli

stretch, osmolarity, presence of substrate in

lumen stimulate receptors

Autonomic reflexes

Intrinsic control

(short reflex)

regulation of digestion Local enteric

nerve plexi

Extrinsic control

long reflex) regulation of digestion by

the central nervous system works

through the local enteric nerve plexi

Local enteric nerve plexi

affect smooth muscle of organ

wall or gland