Test 3 master Deck

List the 3 major functions of the lymphatic system.

Fluid balance, lipid absorption via lacteals, and immune surveillance/defense.

How is lymph formed?

Interstitial fluid enters lymphatic capillaries and becomes lymph.

Trace the flow of lymph from tissues to blood.

Interstitial fluid → lymphatic capillaries → vessels → trunks → ducts → subclavian veins.

Why does lymph only flow one direction?

Lymphatic vessels contain valves that prevent backflow.

What helps move lymph through vessels?

Skeletal muscle contractions, respiratory movements, and thoracic pressure changes.

What are the structural features of lymphatic capillaries?

Blind-ended vessels with overlapping endothelial cells that act as mini-valves.

What is edema?

Accumulation of excess interstitial fluid due to imbalance between filtration and reabsorption.

What is lymphedema?

Protein-rich fluid accumulation caused by impaired lymphatic drainage.

What does the right lymphatic duct drain?

Right head/neck, right thorax, and right upper limb.

What does the thoracic duct drain?

The entire body except the regions drained by the right lymphatic duct.

What is the cisterna chyli?

An enlarged sac at the beginning of the thoracic duct that collects lymph from lower body and digestive organs.

What are primary lymphoid organs?

Sites where lymphocytes mature: red bone marrow and thymus.

Where do B cells mature?

Red bone marrow.

Where do T cells mature?

Thymus.

What are secondary lymphoid organs?

Sites where immune responses occur: lymph nodes, spleen, tonsils, and MALT.

What is found in the cortex of a lymph node?

B cells and germinal centers.

What is found in the medulla of a lymph node?

T cells and macrophages.

Why are there more afferent than efferent vessels in lymph nodes?

To slow lymph flow and maximize filtration and immune activation.

What are the functions of the spleen?

Filters blood, removes old RBCs, stores platelets, and supports immune responses.

Difference between white pulp and red pulp?

White pulp = immune surveillance; red pulp = RBC removal and platelet storage.

What is MALT?

Mucosa-associated lymphoid tissue that protects mucosal entry points.

Examples of MALT?

Tonsils, Peyer's patches, appendix, respiratory and GU mucosa.

Types of tonsils?

Palatine, pharyngeal (adenoids), and lingual.

Characteristics of innate immunity?

Rapid, nonspecific, present at birth, and no memory.

What are first-line defenses?

Skin, mucous membranes, secretions, gastric acid, and normal microbiota.

Five signs of inflammation?

Redness, heat, swelling, pain, and loss of function.

What does histamine do?

Causes vasodilation and increased capillary permeability.

Steps of phagocytosis?

Chemotaxis → Recognition → Engulfment → Phagolysosome formation → Digestion → Antigen presentation.

Major phagocytes?

Neutrophils, macrophages, and dendritic cells.

Function of NK cells?

Kill virus-infected and cancer cells without prior exposure.

How do NK cells kill targets?

Release perforin and granzymes that induce apoptosis.

What is MHC I?

Protein on all nucleated cells that presents intracellular antigens to CD8 T cells.

What is MHC II?

Protein on APCs that presents extracellular antigens to CD4 helper T cells.

Examples of APCs?

Macrophages, dendritic cells, and B cells.

Functions of complement?

Opsonization, inflammation, and membrane attack complex formation.

Characteristics of adaptive immunity?

Specific, slower initially, and generates memory.

Humoral immunity definition?

B-cell mediated immunity involving antibodies.

Cell-mediated immunity definition?

T-cell mediated immunity targeting infected or abnormal cells.

What activates a B cell?

Antigen binding plus helper T-cell stimulation.

What are plasma cells?

Differentiated B cells that secrete antibodies.

What are memory B cells?

Long-lived cells responsible for rapid secondary responses.

Structure of an antibody?

2 heavy chains, 2 light chains, Fab region, Fc region.

Function of Fab region?

Binds antigen.

Function of Fc region?

Activates immune defenses and complement.

IgG function?

Most abundant antibody; long-term immunity and crosses placenta.

IgA function?

Protects mucosal surfaces; found in tears, saliva, and breast milk.

IgM function?

First antibody produced; strong complement activator.

IgE function?

Allergies and parasite defense.

IgD function?

Acts as a B-cell receptor.

Primary immune response characteristics?

Slow, IgM first, memory cells formed.

Secondary immune response characteristics?

Rapid, stronger, IgG dominant due to memory cells.

Helper T cells (CD4)?

Coordinate immune responses and activate other immune cells.

Cytotoxic T cells (CD8)?

Directly kill infected or cancerous cells.

Regulatory T cells?

Suppress excessive immune responses.

Natural active immunity?

Acquired through infection.

Artificial active immunity?

Acquired through vaccination.

Natural passive immunity?

Maternal IgG and IgA.

Artificial passive immunity?

Antivenom and antibody injections.

Type I hypersensitivity?

Immediate IgE-mediated allergy.

Type II hypersensitivity?

Cytotoxic reaction against body cells.

Type III hypersensitivity?

Immune complex deposition.

Type IV hypersensitivity?

Delayed T-cell mediated response.

What is HIV?

Retrovirus that infects CD4 helper T cells.

What defines AIDS?

CD4 count below 200.

Why does HIV weaken immunity?

Loss of helper T cells impairs humoral and cell-mediated immunity.

Major functions of respiratory system?

Gas exchange, pH regulation, voice production, olfaction, and protection.

Difference between conducting and respiratory zones?

Conducting zone moves air; respiratory zone performs gas exchange.

Structures in conducting zone?

Nasal cavity, pharynx, larynx, trachea, bronchi, bronchioles.

Structures in respiratory zone?

Respiratory bronchioles, alveolar ducts, alveoli.

Functions of nasal cavity?

Warms, humidifies, and filters air.

What creates turbulence in the nasal cavity?

Nasal conchae/meatuses.

Three regions of the pharynx?

Nasopharynx, oropharynx, laryngopharynx.

Function of epiglottis?

Prevents food from entering airway during swallowing.

Function of larynx?

Maintains airway and produces sound.

What forms the Adam's apple?

Thyroid cartilage.

Purpose of tracheal cartilage rings?

Maintain airway patency while allowing flexibility.

Why do aspirated objects enter the right bronchus more often?

It is wider, shorter, and more vertical.

Order of airflow?

Nose → pharynx → larynx → trachea → bronchi → bronchioles → alveoli.

Type I pneumocytes?

Thin squamous cells responsible for gas exchange.

Type II pneumocytes?

Produce surfactant.

Function of surfactant?

Reduces surface tension and prevents alveolar collapse.

What is the respiratory membrane?

Alveolar epithelium + fused basement membrane + capillary endothelium.

Right vs left lung?

Right has 3 lobes; left has 2 lobes and cardiac notch.

Boyle's law?

Pressure is inversely related to volume.

What happens during inspiration?

Thoracic volume increases, pressure decreases, air enters.

What happens during expiration?

Thoracic volume decreases, pressure increases, air exits.

Primary muscle of inspiration?

Diaphragm.

External intercostal function?

Assist inspiration.

Internal intercostal function?

Assist forced expiration.

What is intrapulmonary pressure?

Pressure inside alveoli.

What is intrapleural pressure?

Pressure in pleural cavity; normally negative.

Why is intrapleural pressure negative?

Opposing recoil forces create suction keeping lungs expanded.

What is pneumothorax?

Air in pleural cavity causing lung collapse.

What is atelectasis?

Collapsed lung.

Define compliance.

Ease with which lungs expand.

Low compliance examples?

Pulmonary fibrosis and pneumonia.

High compliance example?

Emphysema.

What is tidal volume?

Air moved in a normal breath.

IRV?

Inspiratory reserve volume.

ERV?

Expiratory reserve volume.