Structure and Function II Exam 4

what are the primary functions of the respiratory system

-gas exchange

-communication (you need air to talk)

- olfaction (smell-nose)

- acid-base balance (Co2)

how many lobes does the right lung have? names of the lobes? what fissures seperate them?

3; upper lobe, middle lobe, lower lobe; horizontal fissure (separates superior and middle), oblique fissure (separates middle and inferior)

how many lobes does the left lung have? names of the lobes? what fissure seperates them?

2; upper lobe, lower lobe; oblique fissure

how many segments does the right lung have? left lung?

10; 8

what is the difference between the conducting and respiratory zone?

conducting zone (nose to bronchioles) is airflow only, respiratory zone (alveoli) is gas exchange

what is the pathway of air? (starting at nose)

nasal cavity

pharynx

larynx

trachea

primary bronchi

secondary (lobar) bronchi

tertiary (segmental) bronchi

bronchioles

terminal bronchioles

alveoli (where respiratory zone starts)

where is the site of airflow resistance?

bronchioles, where SNS stimulates bronchodilation and PSNS stimulates bronchoconstriction

the _______ is the specialized tissue responsible for detecting odors and initating the sense of smell

olfactory epithelium

what is the pharynx?

muscular funnel extending about 13 cm from the nose to larynx

what are the 3 regions of the pharynx? what does each region do?

1) nasopharynx: (distal to posterior nasal aperture and above the soft palate) it receives auditory tubes and houses pharyngeal tonsil. the inhaled air turns 90 degrees downward as it passes her (relatively large particles cannot make the turn, so they stick to the mucus near the tonsil. this region passes AIR ONLY. is lines with pseudo stratified columnar epithelium.

2) oropharynx: (space between posterior margin of soft palate and epiglottis)

3) laryngopharynx: (posterior to larynx)

2/3 play a role in swallowing and speech. those regions pass air, food, and drink. they are stratified squamous epithelium.

what is the larynx?

a cartilaginous chamber about 4cm long and its primary function is to keep food and drink out of the airway and it evolved to also help sounds production- phonation. (why this is also called the voice box)

what is the epiglottis? what does it do?

the superior opening of the larynx, it is a "flap." at rest it is vertical. during swallowing, extrinsic muscles pull the larynx upward and tongue pushes epiglottis downward, thus closing the airway and directing food and drink into the esophagus.

t/f in infants, the larynx is higher in the throat, creating a continuous airway from nasal cavity to larynx to allow infants to breath while swallowing. the epiglottis deflects milk away from the airway. By 2 years old, the tongue becomes more muscular and descends the larynx lower.

true

it is possible to breath while swallowing

no (after the age of 2)

The larynx is composes of 9 cartilages. Name and describe them.

- the first 3 are solitary/ large

1) epiglottic cartilage: most superior, spoon-shaped supportive plate in epiglottis

2) thyroid cartilage: largest, shield-like shape, covers anterior and lateral larynx

3) cricoid cartilage: ring-like

- the remaining cartilages are smaller and occur in pairs

4/5) two arytenoid cartilages: little horns

6/7) two corniculate cartilages: attached to top of arytenoid cartilages

8/9) two cuneiform cartilages: supports soft tissues between arytenoids and epiglottis

what is the adams apple?

the anterior peak of the thyroid cartilage called the "laryngeal prominence". testosterone stimulates its growth (why it is larger in males than females)

what 2 cartilages of the larynx are the box of the "voicebox"

thyroid cartilage and cricoid cartilage

what cartilages of the larynx funciton in speech

the 2 arytenoid cartilages and the 2 corniculate cartilages

there are 4 fibrous ligaments of the larynx that bind the cartilages and form a suspension system for the upper airway. name and describe them

- first 2 are extrinsic ligaments

1) thyrohoid ligament: suspends larynx from hyoid bone

2) cricotracheal ligament: suspends trachea from cricoid cartilage

3) vestibular ligaments: supports superior vestibular folds (play no role in speech, but close larynx during swallowing)

4) vocal ligaments: inferior vocal cords (folds) produce sound when air passes between them and contain the vocal ligaments

what is the glottis? (part of larynx)

vocal cords and the opening between them

what are the muscles of the larynx walls

- superficial extrinsic muscles connect the larynx to hyoid bone and elevate larynx during swallowing (also called infrahyoid group)

- deeper intrinsic muscles: control vocal cords by pulling on the corniculate and arytenoid cartilages

t/f in adult males, vocal cords are longer and thicker, vibrate slower, produce lower pitches sounds.

true

what is the loudness of words determined by

the force of air passing between the vocal cords

t/f vocal cords do not actually produce words as we know them, but the noise

true

what is the trachea?

the "windpipe" it is a rigid tube 12cm long/ 1 cm in diameter that is anterior to esophagus. it is supported by 16-20 c-shaped rings to hyaline cartilage to reinforce the trachea and keep it from collapsing during inhalation. the gaps in the cartilages are to give room for the esophagous to expand as food passes by. the inner lining has mucus-secreting goblet cells and cilia

the trachea has C-shaped rings of _____ on the anterior side and _____ of the posterior side

cartilage; smooth muscle

what is the smooth muscle of the trachea

trachealis: contracts and relaxes to adjust air flow

what is the mucocilary escalator?

in the trachea, mucus traps inhaled particles and the upward beating of the cilia drives the mucus covered debris towards the pharynx to be swallowed

the end of the trachea is at the sternum, and forks into what?

L and R main bronchi (the lowest c-cartilage of the trachea is called carina and it directs airflow to the main bronchi's)

each lung has a "slit" called the ____ where the lung receives the main bronchus, blood vessels lymphatics, nerves

hilum

t/f the right lung is shorter than the left because the liver rises higher on the right and the left lung is narrower because the heart tilts left

true

which bronchial tree is wider and more vertical, causing inhaled foreign objects to get lodged in this side more often

right

from the fork in the trachea that makes the main bronchus, the right main bronchus has ____ branches and the left has _____

3 (one to supply each lobe), 2 (again one to supply each lobe)

after the main bronchus, in both lungs the _____ bronchi branch into the _____ bronchi

lobar (secondary); segmental (teritary) (there are 10 in R, 8 in L to supply each lung segment)

t/f each segmental bronchi in the lung ventilates a functinally independent unit of lung tissue called _________

bronchopulmonary segment

all bronchi are lined with ____, and all divisions of bronchial tree have ____ tissue

cilia; elastic

what are bronchioles? describe them.

smaller branches of the bronchi. the portion of lung ventilated by one bronchiole is called a pulmonary lobule. each bronchiole divides into 50-80 terminal bronchioles that have cilia. each terminal bronchiole has 2+ smaller respiratory bronchioles which have alveoli. each respiratory bronchiole divided into 2-10 passages called alveolar ducts which also have alveoli.

What does the pulmonary artery serve? bronchial arteries?

Pulmonary: follows the bronchial tree and alveoli

bronchial: bronchi and bronchioles (NOT ALVEOLI)

why does the heart (RV) send blood to the lungs?

to oxygenate blood

why do inhaled drugs work so fast?

every alveolus has its own blood supply (capillary), so the drug can diffuse very quickly into the blood stream

what is the respiratory membrane? what makes up the respiratory membrane?

all structures that o2/co2 has to diffuse through during gas exchange; type I alveolar cells, basement membrane, endothelial cells

t/f in every alveolus there is a macrophage to eat things that should not be there

true

although not part of the respiratory membrane, alveoli also have type II alveoli cells, what is the purpose of them

to secrete surfactant, which is a substance that is inside each alveolus to reduce surface tension and reduce tendency of lungs to collapse during expiration

what is the hydrostatic pressure (blood pressure) of the pulmonary capillaries? the COP? if that net filtration or reabsorption

HP: 10mmHg (out)

COP: 25 mmHg (in)

net 15 mmHg (in): net reabsorption (needed to keep fluid out of the lungs)

t/f in the lungs there is more extensive lymphatic drainage than any other organ?

true (to prevent fluid accumulation)

the parietal pleura is attached to ______. why is that important?

thoracic wall

- lungs inflate simultaneously

- required for the negative pressure of the intraplureal cavity

what is pleurisy?

an inflammation of the pleura (thin layers of tissue that form the pleural sac around the lungs). When the pleura become inflamed, they rub against each other, causing sharp chest pain that worsens during breathing, coughing, or sneezing. It can be caused by infection (like pneumonia), autoimmune conditions, or other lungs diseases.

What is pleural effusion?

the accumulation of excess fluid in the pleural cavity (between visceral and parietal pleura). This can make it hard to breathe and cause chest discomfort. It's often due to heart failure, infections, malignancies, or trauma.

what is hemopneumothroax?

the presence of both air and blood in the pleural cavity. this condition usually results from trauma, or may occur after lung surgery. it can lead to lung collapse and breathing difficulty.

What is a pneumothorax?

"collapsed lung" it is the presence of air in the pleural cavity. air leaks into the space between the parietal and visceral pleura (pleural cavity), causing the lung to collapse partially or completely. it may occur spontaneously, from lung disease, or form trauma. symptoms include sudden chest pain and shortness of breath.

what is atelectasis

partial or complete collapse of the lung or section (lobe) of a lung. it happens when tiny air sacs (alveoli) within the lung become deflated. causes include blockage of airways, pressure on the lungs from outside, or lack of surfactant. it reduces oxygen exchange and can lead to respiratory distress.

what is ventilation

airflow into or out of the lungs; breathing. (NOT gas exchange)

what are the 2 phases on ventilation

1. Inspiration (inhale)

2. Expiration (exhale)

Describe Boyle's Law

P=1/V

- if volume increases, pressure decreases

- if volume decreases, pressure increases

- muscles change volume (size of lungs), which changes pressure, which causes airflow

- remember air flows from high pressure to low pressure

- you compare atmospheric pressure to intrapulmonary pressure to find the net airflow

assuming atmospheric pressure is 0mmHg. also remember that the intrapleural pressure must be negative for lungs to not collapse. in between breaths, what is the intrapulmonary pressure? what is net airflow? Do the same for when someone has inhaled. Now when they have exhaled

- intrapulmonary pressure is 0mmHg, net airflow 0 (no airflow)

- intrapulmonary pressure is -1mmHg, net airflow is - so into the lungs

- intrapulmonary pressure is 1mmHg, net airflow is + so out of the lungs

respiratory muscles causes _____ in thoracic volume which causes ______ in ________ thoracic cavity/ lungs which causes ____ to flow into or out of lungs

changes; changes; pressure; air

during inspiration, what muscles contract? this causes an INCREASE OR DECREASE in volume, which causes an INCREASE OR DECREASE in pressure. which way does air flow

external intercostals contract which raise the ribcage, the diaphragm contacts which moves it downward; increase; decrease; higher pressured atmosphere to lower pressure lungs

during expiration what muscles contract? this causes an INCREASE OR DECREASE in volume, which causes an INCREASE OR DECREASE in pressure. which way does air flow

external intercostals relax (during quiet breathing) or internal intercostal muscles contact (during forceful breathing, also used abs) both make ribcage drop and the diaphragm relaxes moving it up; decreases; increases; higher pressured lungs to lower pressured atmosphere

what is Ohm's law? using that, describe bronchodilation abd bronchoconstriction

F=ΔP/R (f is airflow, ΔP is difference is atm vs intrapul pressure, R is resistance)

- dilation: R is down, so airflow is up

- constriction: R is up, so airflow is down

Pulmonary compliance is a measure of the lung's ability to stretch and expand during breathing. What are some things that affect that

stiffness can be due to scarring and fibrosis. Surfactant can help increase compliance.

what nerve innervated the diaphragm and causes breathing

phrenic nerve

purpose of pulmonary circuit

to oxygenate the blood and get rid of CO2

purpose of systemic circuit

to deliver O2 to the tissues and pick up CO2

what is pulmonary gas exchange

diffusion of gases between alveoli and pulmonary capillaries

what is tissue (systemic) gas exchange

diffusion of gases between cells and tissue capillaries

what type of diffusion is gas exchange

simple diffusion

for pulmonary gas exchange; what are the pressures are o2 and co2 in the alveoli and pulmonary capillaries (blood). Is that loading or unloading

in the alveoli PO2= 104, PCO2= 40

in the blood PO2= 40, PCO2= 45

O2 loading (oxygen from lungs to blood)

CO2 unloading (carbon dioxide from blood to lungs)

for tissue (systemic); what are the pressures are o2 and co2 in the tissue and tissue capillaries (blood). Is that loading or unloading

in the tissue PO2= 40, PCO2= 45

in the blood PO2= 100, PCO2= 40

O2 unloading (oxygen from blood to tissue)

CO2 loading (carbon dioxide from tissue to blood)

efficiency of gas exchange at the lungs is affected by (5)

1) pressure gradient: Fick's law diffusion=ΔP x solubility (bigger pressure gradient, the easier gas moves)

2) solubility (CO2 is more soluble that O2 by about 20x)

3) respiratory membrane thickness (thicker membrane= harder diffusion)

4) respiratory membrane surface area (loss of surface area is less area for gas exchange)

5) ventilation- perfusion coupling

what is ventilation-perfusion coupling

Matching the amount of gas reaching the alveoli to the blood flow in pulmonary capillaries. pulmonary capillaries associated with alveoli with a good supply of O2 will vasodilate to get more blood there and vice versa

do all tissues get equal O2

no, oxygen goes where it is needed

How does O2 travel in the blood? CO2

O2: 98.5% is bound to Hb, 1.5% is dissolved (there are up to 4 O2 her Hb, if there are 4 bound that Hb is 100% saturated, 3 bound is 75% saturated, etc)

CO2: 7% is dissolved, 23% is bound to Hb, 70% is carried as HCO3 (bicarbonate)

active tissues ____ O2, produce the byproducts of increased _________ activity which _________ pH, and generate ________

consume; metabolic; lowers; heat

What is Bohr effect

O2 is released from Hb if Ph drops

the respiratory center in ________________, and the ___________ which monitor the blood chemistry and pH to protect the brain. they set normal breathing rate called _______ and it is ______ beats per minute at rest.

pons and medulla (brainstem); chemoreceptors; eupnea; 12-16

what is the goal pH of the brain (set point)

7.4

t/f if CO2 increases, blood gets more acidic as CO2 can cross the blood brain barrier

true

blood pH of less than 7.35 is _____ and pH of more than 7.45 is _______

acidosis;alkalosis

elevated CO2 is __________ and low CO2 is _________

hypercapnia (PO2 greater than 43mmHg); hypocapnia (PO2 less than 37mmHg)

there are 3 nuclei in the respiratory center, what are they and what do they do

VRG: the expiratory and inspiratory neurons in the medulla which stimulate inspiration/ expiration muscles; primary generator of respiratory rhythm (causes you to breath)

DRG: modifies modifies the basic rhythm of the VRG; receives and integrates info from PRG, chemoreceptors, stretch/ irritant receptors, higher brain centers (emotions). Sends output VRG to adapt breathing to varying conditions

PRG: in the pons; integrates sensory info from higher brain center, sends output to DRG and PRG. Adapts breathing to special circumstances such as sleep, exercise, speaking, crying, laughing etc

if CO2 increases, what happens to pH of blood? if CO2 decreases? Does CO2 or O2 have a greater effect on changing ventilation rate?

decreases (more acidic); increases (more basic); CO2

What arterial PO2 value will stimulate a change in ventilation rate?

60mmHg

Pepsinogen

where is it made, what cell is it produced by, what does it do

-stomach

-chief cells

- becomes activated to "pepsin" by acid, pepsin is the active enzyme that digests proteins into peptides

Gastric lipase

where is it made, what cell is it produced by, what does it do

- stomach

- chief cells

- break down fats

Hydrochloric Acid (HCL)

where is it made, what cell is it produced by, what does it do

- stomach

- parietal cells

- lowers stomach pH, activated pepsinogen into pepsin, kills harmful bacteria

Intrinsic Factor

where is it made, what cell is it produced by, what does it do

- stomach

- parietal cells

- binds vit B12 for absorption in the small intestine. VitB12 is essential for red blood cell production

Mucus

where is it made, what cell is it produced by, what does it do

- stomach

- mucus-producing cells

- coasts and protects stomach lining, prevents damage from acid and enzymes, helps prevent ulcers

Histamine

where is it made, what cell is it produced by, what does it do

- stomach

- ECL cells

- stimulates HCL secretion by binding H2 receptors on parietal cells, works with gastrin and acetylcholine to acid digestion

Somatostatin

where is it made, what cell is it produced by, what does it do

- stomach

- D cells

- functions primarily as a "brake" to limit gastric acid secretion, regulate gastrin release, and control digestion speed (via negative feedback)

Gastrin

where is it made, what cell is it produced by, what does it do

- stomach

- G-cells

- hormone that stimulates acid secretion from parietal cells, promotes enzyme release and stomach motility

What are the 7 parts of the large intestine

cecum, ascending colon, transverse colon, descending colon, sigmoid colon, rectum, anal canal (cats and tigers don't skip road adventures)

what does the cecum do in the large intestine

- first part of the large intestine, connected to the ileum (last part of small intestine)

- receives chyme from small intestine

- begins the process of absorbing water and salt

- appendix is attached here- it plays a role in immune function and gut flora

what does the ascending colon do in the large intestine

- runs superiorly upward on the right side of the abdomen

- absorbs water and salts from material that arrives from the cecum

- houses gut bacteria that begin breaking down undigested materials

- bacteria here produce some vitamins (like K and biotin)

what does the transverse colon do in the large intestine

- runs across the abdomen, from right to left

- continues water and nutrient absorption

- fermentation (breakdown) of unabsorbed material

- gas production by bacteria

what does the descending colon do in the large intestine

- runs inferiorly down the left side of the abdomen

- stores the remains of digested food that will be emptied into the rectum

- less absorption here- more focused on storage and compaction

what does the sigmoid colon do in the large intestine

- S-shaped part of the large intestine that connects the descending colon to the rectum

- acts as a holding area for feces before defection

- strong muscular contractions help move stool into the rectum

what does the rectum do in the large intestine

- final straight section of the large intestine

- stores feces until a bowel movement occurs

- stretch receptors trigger the urge to defecate

what does the anal canal do in the large intestine

- controls the releases of feces via internal and external anal sphincters

what is the hepatic portal system. why does it matter

ensures that all orally ingested foods and medicine is processed by the liver before it ever reaches the rest of the body. this is known as the "first pass effect"

- it gives the liver first claim to all nutrients absorbed from your meal before that blood is distributed to the rest of the organs

- it allows the liver to metabolize medicines and other substances immediately after they are ingested

- it acts as a filter, allowing the blood to be cleansed of toxins and bacteria that may have been picked up from the intestines during digestion

what are the 5 stages of the digestive system

1) ingestion (taking a bite or drink)

2) digestion

3) absorption (from digestive tract to blood)

4) compaction

5) defecation