AP2 lecture exam 1

Organs in order and functions

1) Nose/Nasal cavity - filter, warm, humidify air

Organs in order and functions

2) Pharynx - passageway for air and food

Organs in order and functions

3) Larynx - voice production; protects airway

Organs in order and functions

4) Trachea - conducts air

Organs in order and functions

5) Bronchi - conduct air to lungs

Organs in order and functions

6) Bronchioles - regulate airflow

Organs in order and functions

7) Alveoli - gas exchange

What are 3 parts of the pharynx?

1)Nasopharynx: posterior to nasal cavity; above soft palate

2)Oropharynx: soft palate to epiglottis

3)Laryngopharynx: epiglottis to esophagus/larynx

What is external ?

External: gas exchange between alveoli and blood

What is internal ?

Internal: gas exchange between blood and tissues

What is cellular respiration?

Cellular: use of O₂ by cells to make ATP

Pulmonary is what?

Pulmonary: heart ↔ lungs

Systemic Circulation is what?

Systemic: heart ↔ body tissues

Arteries do what?

carry blood away from heart

Veins do what?

carry blood toward heart

List in order from nose to alveoli the pathway for air entering the body

Nose → nasal cavity → pharynx → larynx → trachea → primary bronchi → secondary bronchi → tertiary bronchi → bronchioles → terminal bronchioles → respiratory bronchioles → alveolar ducts → alveoli

what is Conducting Zone?

Nose → terminal bronchioles

Air transport, filtering, warming

what is Respiratory Zone?

Respiratory bronchioles → alveoli

Gas exchange

what is the function of the Epiglottis?

prevents food entering airway

what is the function of the Vestibular folds?

protect vocal folds

what is the function of the Vocal folds?

sound production

Which two cartilage tissues make up the larynx?

Hyaline cartilage and Elastic cartilage

Which forms the epiglottis and why is that an important structure/function relationship?

elastic cartilage this allows flexibility and repeated bending.

Describe the mechanism by which you can vocalize and adjust volume and pitch

Air passes through vocal folds causing vibration.

Increased tension = higher pitch

Greater force of air = louder sound

What are the three layers of the trachea?

mucosa, submucosa, adventitia

From question 25, which best transports mucous?

Mucosa transports mucus via cilia.

What structure keeps the trachea from collapsing during negative pressure breathing?

C-shaped hyaline cartilage rings prevent collapse.

What are the inward and outward forces that keep the alveolus inflated?

Inward: elastic recoil and surface tension

Outward: negative intrapleural pressure

What happens during a pneumothorax?

Air enters pleural cavity → lung collapses due to loss of negative pressure.

What is the distribution of cartilage and smooth muscle in the bronchial tree?

-Cartilage decreases deeper into lungs

-Smooth muscle increases in bronchioles

-No cartilage in bronchioles

define mediastinum

Space between lungs that contains heart, blood vessels, lymph nodes, nerves and the esophagus.

define Visceral pleura

on the lungs surface

define Parietal pleura

lines the thoracic cavity

define the Pleural cavity

space containing pleural fluid

What are alveoli?

Microscopic air sacs where gas exchange occurs.

Describe where and how gas (CO2 & O2) exchange takes place.

Occurs across respiratory membrane between alveoli and pulmonary capillaries by diffusion.

Describe the overall functions of the respiratory system.

Gas exchange

Acid-base balance

Voice production

Olfaction

Air conditioning/filtering

Explain Boyle's Law.

Pressure and volume are inversely related.

↑ Volume = ↓ Pressure

↓ Volume = ↑ Pressure

Define ventilation

movement of air in and out of the lungs

Define inspiration/Inhalation

air enters the lungs

define Expiration/Exhalation

air leaving the lungs

define atmospheric

outside air pressure

define Intrapulmonary

pressure in lungs

define Intrapleural

pressure in pleural cavity

define Partial pressure

pressure contributed by one gas

Describe the process of inhalation

Diaphragm contracts

External intercostals contract

Thoracic volume increases

Describe the process exhalation and the muscles involved in each.

Mostly passive

Muscles relax

elastic recoil expels air

What is the difference between expiration and forced expiration?

Normal expiration = passive

Forced expiration = internal intercostals And abdominal muscles

Describe the three factors that influence pulmonary air flow (ventilation).

1.Pressure gradients

2.Airway resistance

3.Lung compliance

Which tissue is most responsible for constriction and dilation in bronchioles?

Smooth muscle controls diameter

What is the last type of bronchiole before entering an alveolar duct?

respiratory bronchiole

What is the respiratory membrane and what is it composed of?

Alveolar epithelium

Basement membranes

Capillary endothelium

Very thin for diffusion

Define surface tension

the attractive force between water molecules lining the alveoli.

How does surface tension influence lung expansion?

Water molecules attract each other, tending to collapse alveoli.

Explain the purpose of pulmonary surfactant and how it relates to respiratory distress in premature babies.

Reduces surface tension and prevents alveolar collapse.

Premature babies may lack surfactant → respiratory distress syndrome.

Which cells secrete surfactant?

Type II alveolar cells (Type II pneumocytes)

Describe the exchange of oxygen and carbon dioxide between the atmosphere and the pulmonary capillaries, and between systemic capillaries and body tissue.

O₂ diffuses from high PO₂ to low PO₂

CO₂ diffuses from high PCO₂ to low PCO₂

Describe how oxygen is transported in the bloodstream.

98.5% bound to hemoglobin

1.5% dissolved in plasma

Why does O2 move from alveoli to pulmonary capillaries?

Alveolar PO₂ > pulmonary capillary PO₂

Why does CO2 move from the blood to lungs just as well as O2 even though it has a much smaller partial pressure gradient?

CO₂ is about 20 times more soluble than O₂.

How is the oxygen-carrying capacity of blood affected by PO2, pH, PCO2 and temperature?

Decreases with:

↓ pH

↑ PCO₂

↑ Temperature

Bohr effect: hemoglobin releases O2 more easily

Explain how bicarbonate is formed from water and carbon dioxide.

CO₂ + H₂O ⇌ H₂CO₃ ⇌ H⁺ + HCO₃⁻

How is most CO2 transported in blood? Which enzyme assists in its temporary conversion? Conversion to what?

About 70% as bicarbonate ion (HCO₃)

Enzyme: Carbonic anhydrase

How might you influence blood pH with slow shallow breathing? Why?

Retains CO₂ → increases H⁺ → lowers pH (more acidic)

What does the pons (pontine center) do to breathing?

Smooths transition between inhalation and exhalation.

Which gas influences breathing most?

CO₂ (through pH changes)

If you inhaled an irritant to the bronchioles, what would be the response?

Bronchoconstriction and coughing.

How does the Hering-Breuer reflex protect us?

Prevents overinflation of lungs.

Describe how arterial PO2, PCO2 and pH influence ventilation.

↑ PCO₂ → ↑ ventilation

↓ pH → ↑ ventilation

↓ PO₂ → ↑ ventilation (strong effect only when very low)

Describe the effects of asthma, emphysema (COPD), tuberculosis and cancer. What are some of the changes in the respiratory system that you might expect from each of these conditions?

1.Asthma

Bronchoconstriction

Inflammation

Excess mucus

2.Emphysema/COPD

Alveolar destruction

Reduced surface area

Air trapping

3. Tuberculosis

   bacterial infection

   lung scarring

4. Cancer

   uncontrolled cell growth

   obstructed airways

   reduced gas exchange

How much blood does an adult have?

Approximately 5-6 liters

Describe the general components of blood as a connective tissue.

Plasma (~55%)

Formed elements (~45%)

Name and give the function of the blood formed elements and the plasma proteins

1)Erythrocytes (RBCs)

O2 and CO2 transport

2) leukocytes (WBC)

Defense

3) platelets

Clotting

4)Plasma proteins

Albumin

Globulins

Fibrinogen

Define hemoglobin, erythropoiesis, hemopoiesis, and erythropoietin; know the life cycle of erythrocytes.

1)Hemoglobin

Oxygen -binding protein

2) hemopoiesis

Blood cell formation

3)Erythropoiesis

RBC production

4)Erythropoietin (EPO)

Hormone from kidneys stimulating RBC production

5)RBC lifespan:

120 days

Removed by spleen/ liver

What components of erythrocytes allow them to transport oxygen and carbon dioxide? What is the importance of carbonic anhydrase?

Hemoglobin transports O₂/CO₂

Carbonic anhydrase converts CO₂ ↔ bicarbonate

Review the antigen and antibody relationship in blood. Ie. Antigens (aka agglutinogens) occur as surface markers on your erythrocytes. Antibodies (aka agglutinins) float freely in your bloodstream poised to attack surface markers which are considered foreign. Why is someone with type O blood considered a universal donor?

Has A and B antigens but no anti-A or anti-B antibodies.

Why can a transfusion reaction be fatal?

Agglutination and hemolysis can block vessels and damage organs.

Define Rh factor and Hemolytic disease of the newborn

Rh antigen (D antigen) on RBCs.

Hemolytic disease of newborn Rh− mother develops antibodies against Rh+ fetus.

Know the structural and functional features of the different types of granulocytes and agranulocytes

1)Granulocytes

Neutrophils: bacterial defense

Eosinophils: parasites/allergies

Basophils: histamine release Argranulocytes

4)Lymphocytes: immunity

5)monocytes :become macrophage

Describe the steps in hemostasis.

Vascular spasm

Platelet plug formation

Coagulation

What's the difference between the extrinsic and intrinsic pathways in hemostasis?

Extrinsic- triggered by tissue damage outside vessel

Intrinsic- Triggered by vessel damage within bloodstream

Both lead to Factor X activation.

What stimulates activation of prothrombin? Once activated, what does thrombin stimulate?

Prothrombin activator converts prothrombin → thrombin.

Thrombin converts fibrinogen → fibrin.

Clot retraction makes use of __________ and ____________ to pull on fibrin strands and draw the blood vessel tighter

Uses platelets and actin-myosin contractile proteins.

Define thrombus

Stationary clot

define embolism (embolus)

Traveling clot

define serum (plural sera).

Plasma without clotting proteins

Name the general components of plasma

Water

Plasma proteins

Electrolytes

Nutrients

Hormones

Gases

Waste products