BIO 211 Study Guide: Lymphatic and Respiratory Systems

Comprehensive vocabulary flashcards covering key terms, anatomical structures, physiological laws, volumes, and transport mechanisms of the lymphatic and respiratory systems.

Lymph

Interstitial fluid once it has entered lymphatic vessels.

Fluid Balance and Drainage

A function of the lymphatic system that returns interstitial fluid and leaked plasma proteins back to the blood.

Lymphatic Capillaries

Very permeable vessels with blunt, blind endings, endothelial cells that overlap to form one-way mini-valves, and collagen filaments that anchor them to prevent collapse; they take up cell debris, pathogens, and cancer cells.

Right Lymphatic Duct

Duct that drains lymph from the right upper quadrant of the body, including the right arm and the right side of the head and thorax.

Thoracic Duct

The larger of the two lymphatic ducts; begins at the cisterna chyli and drains lymph from the rest of the body.

Cisterna Chyli

An enlarged sac where the thoracic duct begins that drains the abdominal region.

T Cells

Lymphocytes that manage the immune response and attack and destroy foreign cells.

B Cells

Lymphocytes that produce plasma cells, which secrete antibodies.

Primary Lymphatic Organs

The sites where lymphocytes are created, mature, and proliferate (bone marrow and thymus).

Bone Marrow

A primary lymphoid organ made of a loose collection of cells and reticular fibers; performs hematopoiesis for the formed elements, serves as the site of B-lymphocyte maturation, and sends T-lymphocytes to the thymus for maturation.

Thymus

A primary lymphatic organ that secretes thymosin and provides the environment where T-lymphocytes mature and become immunocompetent; it is most active and grows during childhood, stops growing in adolescence, and atrophies without directly fighting antigens.

Secondary Lymphatic Organs

Sites where immune responses arise and naïve lymphocytes are released when the body needs immunity; most contain centers for dividing lymphocytes, fixed macrophages performing phagocytosis, and a heavy blood supply.

Lymph Nodes

Secondary lymphoid organs arranged in clusters along lymphatic vessels covered by a strong connective tissue capsule; they filter lymph using macrophages, activate lymphocytes to attack antigens, and can perform hematopoiesis if necessary.

Spleen

The largest lymphoid organ, located in the abdominal cavity lateral to the stomach; acts as a site of lymphocyte proliferation and immune surveillance, cleanses blood of aged cells, platelets, and debris, stores formed elements, and can perform hematopoiesis under extreme conditions.

Pharyngeal Tonsils

Tonsils located in the posterior wall of the nasopharynx.

Palatine Tonsils

Tonsils located at the posterior end of the oral cavity.

Lingual Tonsils

Tonsils grouped at the base of the tongue.

Pulmonary Ventilation

The movement of air into and out of the lungs.

External Respiration

Oxygen and carbon dioxide exchange between the lungs (alveoli) and the blood (alveolar capillaries).

Internal Respiration

Oxygen and carbon dioxide exchange between systemic blood vessels (capillaries) and tissues.

Conducting Zone

The respiratory passages that conduct air to the lungs: nose (nasal cavity), pharynx (nasopharynx, oropharynx, laryngopharynx), larynx, trachea, primary bronchi, secondary bronchi, tertiary bronchi, conducting bronchioles, and terminal bronchioles.

Respiratory Zone

The actual site of gas exchange, comprising respiratory bronchioles, alveolar ducts, alveolar sacs, and alveoli.

Thyroid Cartilage

The largest cartilage of the larynx.

Cricoid Cartilage

Laryngeal cartilage that forms a full ring around the larynx.

Epiglottis

The most important laryngeal cartilage that prevents choking by keeping food and liquid out of the airway.

Arytenoid Cartilages

Two paired laryngeal cartilages that serve as attachments for the vocal cords and muscles.

Surfactant

A detergent-like lipid and protein complex that reduces the surface tension of alveolar fluid and discourages alveolar collapse.

Boyle's Law

A gas law stating that increasing the volume inside a cavity decreases pressure, and decreasing volume increases pressure

Atmospheric Pressure

The pressure of the combined molecules in the atmosphere at sea level at a constant temperature.

Intra-alveolar Pressure

The changeable air pressure within the alveoli (also called intrapulmonary pressure).

Intrapleural Pressure

The changeable air pressure in the pleural cavity between the parietal and visceral pleura.

Thoracic Wall Compliance

The ability of the lungs to stretch.

Tidal Volume (TV)

Volume of air expired after a normal (typical) inspiration; average is $500\,\text{mL}$.

Inspiratory Reserve Volume (IRV)

Largest additional volume of air that can be forcibly inspired over and above a normal inspiration; average is $3{,}000\text{--}3{,}300\,\text{mL}$.

Expiratory Reserve Volume (ERV)

Largest additional volume of air that can be forcibly expired over and above a normal expiration; average is $1{,}000\text{--}1{,}200\,\text{mL}$.

Residual Volume (RV)

Volume of air that remains in the lungs after ERV is expired and cannot be forcibly expired; average is $1{,}200\,\text{mL}$.

Minimal Volume (MV)

The percentage of residual volume that remains after the majority of residual volume is eliminated (as in a collapsed lung); equal to $40\%$ of RV.

Vital Capacity (VC)

The largest volume of air an individual can move in and out of the lungs; average is $4{,}500\text{--}5{,}000\,\text{mL}$.

Inspiratory Capacity (IC)

The maximal amount of air an individual can inspire after a normal expiration ; average is $3{,}500\text{--}3{,}800\,\text{mL}$.

Functional Residual Capacity (FRC)

The amount of air left in the lungs after a normal expiration average is $2{,}200\text{--}2{,}400\,\text{mL}$.

Total Lung Capacity (TLC)

The total volume of air the lungs can hold average is $5{,}700\text{--}6{,}200\,\text{mL}$.

Anatomic Dead Space

A normal feature of the bronchial tree consisting of inhaled air that enters the respiratory tract but does not reach the alveoli, thus taking no part in gas exchange.

Medullary Respiratory Center

The primary control center in the medulla oblongata that sets the basic breathing rate.

Dorsal Respiratory Group (DRG)

A respiratory center component that controls normal breathing and maintains a constant breathing rhythm.

Ventral Respiratory Group (VRG)

A respiratory center component that controls forced breathing and stimulates the muscles used for forced breathing.

Pneumotaxic Center

A pontine respiratory center that inhibits the DRG to control breathing rate.

Apneustic Center

A pontine respiratory center that controls the depth of breathing.

Dalton's Law

A gas law stating that each gas in a mixture of gases exerts its own pressure, and the sum of the individual pressures equals the total pressure.

Henry's Law

A gas law stating that the concentration of a gas in a liquid is directly proportional to the solubility and partial pressure of that gas.

Bicarbonate Ion

The chemical form ($\text{HCO}_3^-$) in which approximately $70\%$ of carbon dioxide is transported through the bloodstream.