Lymphatic, Immunity, and Respiratory System Lab Study Guide

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The immune system protects the body from pathogens through two main types of immunity: nonspecific (innate) and specific (adaptive) immunity.

Nonspecific (Innate) Immunity: Provides general defense against pathogens. Includes physical barriers (skin, mucous membranes), phagocytic cells, natural killer cells, inflammation, and fever.
Specific (Adaptive) Immunity: Targets specific pathogens. Involves lymphocytes (B cells and T cells) and the production of antibodies. Has memory, allowing for a faster response upon re-exposure.
Comparison: Nonspecific immunity acts quickly but is not tailored to particular pathogens, while specific immunity is slower to develop but highly targeted and has memory.

Humoral immunity involves the production of antibodies by B cells. Immunity can be acquired actively or passively:

Active Immunity: The body produces its own antibodies after exposure to an antigen. Can be natural (infection) or artificial (vaccination).
Passive Immunity: Antibodies are transferred from another source. Can be natural (maternal antibodies crossing the placenta) or artificial (injection of antibodies).
Example: Receiving a flu vaccine (active, artificial); receiving antivenom after a snake bite (passive, artificial).

Key lymphatic structures include lymph nodes, tonsils, spleen, and thymus. Each has unique features and locations:

Lymph Nodes: Small, bean-shaped structures found along lymphatic vessels; filter lymph and house immune cells.
Tonsils: Located in the pharyngeal region; contain crypts and are covered by epithelium.
Spleen: Located in the upper left abdomen; filters blood, recycles old red blood cells, and stores immune cells.
Thymus: Located in the mediastinum; site of T cell maturation, especially active in children.

Lymphocytes: White blood cells (B cells and T cells) central to adaptive immunity.
Macrophages: Phagocytic cells that engulf pathogens and present antigens to lymphocytes.
Antibodies: Proteins produced by B cells that bind to specific antigens to neutralize or mark them for destruction.

Identifying lymphatic tissues under the microscope requires recognizing distinguishing features:

Tonsils: Have crypts and are covered by stratified squamous epithelium.
Lymph Nodes: Have a cortex and medulla, with lymphatic nodules and sinuses.
Spleen: Contains white pulp (lymphatic tissue) and red pulp (blood-filled sinuses).
Thymus: Has lobules with a cortex and medulla; contains Hassall's corpuscles.

Additional info: When identifying tissues, always note the presence or absence of features like crypts, epithelium, nodules, and sinuses.

The respiratory system consists of structures that conduct air and those involved in gas exchange:

Nasal Cavity: Entryway for air; warms, moistens, and filters air.
Pharynx: Passageway for air and food; divided into nasopharynx, oropharynx, and laryngopharynx.
Larynx: Contains vocal cords; routes air and food into proper channels.
Trachea: Windpipe; supported by C-shaped cartilage rings.
Bronchi: Large airways branching from the trachea into each lung.
Bronchioles: Smaller airways lacking cartilage; lead to alveolar ducts.
Alveoli: Tiny air sacs where gas exchange occurs.

Trachea: Lined with pseudostratified ciliated columnar epithelium and goblet cells.
Bronchi: Similar to trachea but with less cartilage and more smooth muscle.
Bronchioles: Lined with simple cuboidal or columnar epithelium; lack cartilage.
Alveoli: Lined with simple squamous epithelium for efficient gas exchange.

Conducting Zone: Includes all structures that transport air but do not participate in gas exchange (nasal cavity, pharynx, larynx, trachea, bronchi, bronchioles).
Respiratory Zone: Includes structures where gas exchange occurs (respiratory bronchioles, alveolar ducts, alveoli).
Example: The trachea is part of the conducting zone; alveoli are part of the respiratory zone.

The respiratory membrane is the site of gas exchange between air in the alveoli and blood in pulmonary capillaries.

Components: Alveolar epithelium, fused basement membrane, and capillary endothelium.
Function: Allows for rapid diffusion of oxygen and carbon dioxide.

Be able to identify tissue types in each respiratory structure using distinguishing features (e.g., cilia, cartilage, smooth muscle, epithelial type).
Important Note: Distinguish between bronchus (has cartilage, larger diameter) and bronchiole (no cartilage, smaller diameter).

Understand definitions and concepts from lab manual exercises (e.g., ventilation, gas exchange, lung volumes).
Review feedback from quizzes to reinforce key physiological principles.

Structure	Location	Key Features	Function
Lymph Node	Along lymphatic vessels	Cortex, medulla, lymphatic nodules	Filters lymph, immune response
Tonsil	Pharyngeal region	Crypts, epithelium	Traps pathogens, immune surveillance
Spleen	Upper left abdomen	White pulp, red pulp	Filters blood, immune response
Thymus	Mediastinum	Lobules, Hassall's corpuscles	T cell maturation
Trachea	Neck, thorax	C-shaped cartilage, ciliated epithelium	Conducts air to bronchi
Bronchus	Lungs	Cartilage, ciliated epithelium	Conducts air to bronchioles
Bronchiole	Lungs	No cartilage, smooth muscle	Conducts air to alveoli
Alveolus	Lungs	Simple squamous epithelium	Gas exchange