questions

Erectile tissue in the nasal concha

Contains a venous plexus that rhythmically engorges with blood to shift air flow.

Larynx position in infants

Infants have a higher larynx position, allowing simultaneous breathing and swallowing.

Muscle contraction during forced exhalation

Both abdominal muscles and internal intercostals contract to assist in forceful exhalation.

Mucociliary escalator function

Trachea is lined with goblet cells and ciliated epithelium to move particulates away from lungs.

Inspiration process

Diaphragm and external intercostals contract, increasing thoracic volume and decreasing pressure, drawing air in.

Pleural compartment function

Reduces friction, helps prevent lung infections, and creates pressure gradients for breathing.

Intrapleural pressure at rest

Slightly lower than intrapulmonary pressure.

Forced expiration

Involves elastin fibers, internal intercostals, and abdominal muscles to decrease chest volume.

Factors not leading to bronchoconstriction

Sympathetic stimulation does not cause bronchoconstriction.

Cells not found in alveoli

Red blood cells are not found in alveoli.

Air processing as it moves to alveoli

Air is warmed, moistened, and filtered as it flows into the alveoli.

Surfactant role

Reduces hydrogen bonding to keep alveoli inflated.

Pons and medulla oblongata centers

Pons contains the apneustic center; medulla contains expiratory and inspiratory centers.

Breathing regulation

The apneustic center leads to slower and deeper breathing.

Partial pressures of gases

Inspired air has PO2 of 159 and PCO2 of 0.3.

Ventilation-perfusion coupling

Decreased airflow to an alveolus reduces blood flow to that capillary.

Leftward shift of hemoglobin dissociation curve

Caused by cold temperatures.

O2 dissociation at alveolar capillary

O2 dissociates from hemoglobin due to H+ ions being released.

Consequences of tissue activity

More active tissues produce CO2, reducing pH, leading to O2 dissociation.

Major stimulus for respiration

CO2 concentration in aortic body is the most powerful stimulus.

Pneumonia

Causes increased interstitial fluid between capillaries and alveoli.

Epistaxis

Commonly known as a nosebleed.

Valsalva maneuver

Increases abdominal pressure.

Atelectasis

Is the term for lung collapse due to insufficient surfactant.

Role of pleurae

Secretes solution allowing the lungs to glide over thoracic wall.

Intrapulmonary pressure

Pressure within the alveoli.

CO2 levels increase in blood

When one stops breathing.

Effect of increasing plasma CO2 levels on pH

As CO2 levels increase, plasma pH goes down.

Transport of CO2 in blood

CO2 is mostly transported as carbonic acid.

Major circulating plasma antibody

IgG is the major type of antibody in plasma.

Antibody found in saliva and breast milk

IgA is found in saliva, breast milk, and gut mucosa.

MHC proteins

MHC-2 displays exogenous antigens.

T cell maturation requirements

All are required for T cell maturation.

Rapid division of B cells upon antigen encounter

Clonal expansion occurs when B cells encounter antigens.

Number of different antigenic determinants recognized by the body

The body recognizes about 100,000,000 different antigenic determinants.

Antibody stem region function

Attachment to B cells and activation of complement.

True statement about allergies

IgE on mast cells binds allergens, leading to histamine release.

Primary lymphoid tissue

Thymus is an example of a primary lymphoid tissue.

Correct sequence in B cell activation

1-3-2-4-5 is the correct order of B cell activation processes.

Natural passive immunity example

Breastfeeding is an example of natural passive immunity.

Role of IL-1

Acts as a pyrogen and activates lymphocytes.

Role of IL-2

Leads to clonal expansion of T cells.

True statement about CD-4 cells

Cells with CD-4 markers can become helper, regulatory, or memory T cells.

Cytotoxic T cells facts

Cytotoxic T cells can destroy bacteria-infected cells and cancer cells.

Antigen presentation to T cells

Macrophages and dendritic cells present antigens to helper T cells.

Helper T cells function

Can activate both B and cytotoxic T cells.