Veterinary Anatomy Physiology - Terminology - LP2

Veterinary Anatomy & Physiology Terminology

  • Focuses on the basic veterinary terminology related to the digestive, respiratory, and cardiovascular systems.

  • Source: Willis College

The Respiratory System

  • Key Components:

    • Nasal cavity

    • Costal arch

    • Larynx

    • Nostril

    • Trachea

    • Lung

    • Median line of diaphragm

Function of the Respiratory System

  • Oxygen Supply:

    • Delivers blood with oxygen and removes carbon dioxide.

    • Blood is responsible for oxygen transportation to body parts.

  • Carbon Dioxide Removal:

    • Waste product from metabolic processes in cells.

    • Needs to be expelled from the body.

  • Role of Hemoglobin:

    • Oxygen binds to hemoglobin in red blood cells (RBCs).

Organs of the Respiratory System

Nares

  • Function:

    • Entry points for air.

    • Filters air using mucus to trap debris, which can be sneezed out or swallowed.

    • Warms and moistens air to protect lung tissue.

Nasal Passages

  • Function:

    • Further filter and condition air.

    • Contains chemoreceptors responsible for the sense of smell.

Pharynx

  • Connection:

    • Links the mouth/nose to the esophagus/larynx.

    • Directs food to the esophagus and air to the larynx.

  • Location of Tonsils:

    • Contains tonsils (lymphatic tissue) in dogs and cats, enhancing immune response.

Larynx

  • Function:

    • Located at the top of the trachea.

    • Houses vocal cords responsible for sound production.

    • Regulates airflow into the lungs, guided by the epiglottis during swallowing.

Trachea

  • Function:

    • Connects larynx to lungs, serves as a passage for air.

    • Rigid structure prevents collapse and also aids in debris filtration.

Bronchi

  • Structure:

    • Divides into two main tubes reaching each lung and continues to filter incoming air.

Lungs

  • Gas Exchange Location:

    • Site for oxygen intake and carbon dioxide removal.

    • Bronchioles lead to alveoli where macrophages remove debris and gas exchange occurs.

Nasopharynx, Oropharynx & Laryngopharynx

  • Nasopharynx:

    • Upper throat part connecting nose and mouth, facilitating breathing through the nose.

  • Oropharynx:

    • Extends between soft palate and esophagus, aiding in propulsion of air and food.

  • Laryngopharynx:

    • Guides air into the larynx and food into the esophagus, protecting the airway.

Alveoli & Pleura

Alveoli

  • Function:

    • Tiny structures adjacent to capillaries for gas exchange in lungs.

    • Human lungs contain over 300 million alveoli.

Pleura

  • Role:

    • Membrane lining lungs and thoracic cavity; forms the pleural cavity for lung expansion lubrication.

Thoracic Cavity

Diaphragm

  • Function:

    • Divides thoracic and abdominal cavities.

    • Essential muscle for breathing; always contains air after first breath.

Lungs

  • Structure:

    • Composed of elastic, spongy tissue facilitating expansion and contraction.

Heart

  • Function:

    • Contracts to pump blood, delivering nutrients to organs effectively.

Thymus

  • Function:

    • Important for immunity, situated between lungs, and shrinks with age.

    • Produces hormones aiding in immune system regulation.

Cavity Structure

  • Protection:

    • Outlined by ribs, sternum, and thoracic vertebrae providing strong protection for essential organs.

Mediastinum

  • Location:

    • Central part of thoracic cavity containing critical structures like the heart and trachea.

Diaphragm

  • Muscular Function:

    • Principal respiratory muscle that contracts (inspiration) and relaxes (expiration) to control airflow.

How Breathing Works

Mechanics of Breathing

  • Negative Pressure Mechanism:

    • Helps maintain lung expansion; critical for breathing process.

  • Inhalation:

    • Involves contraction of diaphragm and intercostal muscles to lower thoracic pressure (air intake).

  • Exhalation:

    • Relaxation of respiratory muscles leading to increased thoracic pressure (air expulsion).

Control of Breathing

  • Involuntary Action:

    • Governed by the brain's respiratory center, responding to blood oxygen and carbon dioxide levels.

  • Sensor Role:

    • Detect fluid or debris in lungs, prompting coughing or changes in breathing rhythm.

Examining the Respiratory System

Auscultation

  • Procedure:

    • Listening to lung sounds using a stethoscope; requires quiet environment.

  • Sound Indicators:

    • Various sound patterns indicate conditions like fluid presence or airway obstruction.

Radiographic Evaluation

  • Method:

    • X-rays show lungs in a gas-filled state; light areas indicate possible issues (fluid or masses).

ET Tube Placement

  • Procedure:

    • Important for anesthesia; tube must not go too far down the bronchi to ensure airflow to both lungs.

Respiratory System Terminology

Important Terms

  • Alveoli: Site of gas exchange.

  • Auscultation: Listening to body sounds for diagnosis.

  • Diaphragm: Separates thorax from abdomen; crucial for respiration.

  • Expiration & Inspiration: Processes of breathing out and in respectively.

  • Intubation: Placing a tube in the trachea for airway management.

  • Pleura: Membrane covering the lungs.

Recommended Reading

  • Textbook: "Introduction to Veterinary Anatomy and Physiology" by Victoria Aspinall and Melanie Cappello, focusing on Chapter 8, "Respiratory System."