Respiratory and Cardiovascular Systems

Introduction

• The respiratory and cardiovascular systems work together to supply oxygen and eliminate carbon dioxide.
• The respiratory system brings in air and expels carbon dioxide.
• The cardiovascular system transports respiratory gases.
• Respiration is the exchange of gases between the atmosphere, blood, and cells in three steps.
• Ventilation (breathing) moves air in and out of the lungs.
• External (pulmonary) respiration involves gas exchange between the lungs and blood.
• Internal (tissue) respiration involves gas exchange between body cells and blood.

Function of Lungs

• Lungs facilitate oxygen and carbon dioxide exchange.
• Speech and vocalization rely on lungs.
• Lungs help control the body fluids via carbon dioxide elimination.
• Lungs produce chemical mediators like ACE for blood pressure regulation.
• Breathing creates a pressure gradient for lymph and venous blood flow.
• Olfaction occurs when airborne molecules enter the nasal cavity.
• Lungs protect against microorganisms by preventing their entry.

Anatomy of Respiratory System

• The respiratory tract consists of passageways for air transport.
• The anatomical conducting passageways includes the:
  • Upper respiratory tract: nose, pharynx etc...
  • Lower respiratory tract: larynx, trachea, bronchi etc...
• The respiratory system is divided into two parts
  • The conducting part consists of cavities and tubes that delivers air into lungs. This area includes the nose, pharynx, larynx, trachea, bronchi, bronchiole, and terminal bronchioles.
  • The respiratory part is where gas exchange takes place. This area includes respiratory bronchioles, alveolar ducts, alveolar sacs, and alveoli.

Nose

• The nose consists of the visible external portion and an internal portion.
• The external portion warms, moistens, filters air and modifies speech vibrations.
• The bony framework of the external nose consists of the frontal bone, nasal bones, and maxillae.
• The cartilaginous framework consists of hyaline cartilage pieces.
• Septal cartilage forms the anterior nasal septum, dividing the nasal cavity into nostrils.
• Lateral nasal cartilage is below the nasal bones.
• Alar cartilages form nostril walls.
• The Internal portion, or nasal cavity, is between the skull base and mouth roof.
• The vestibule is the cavity's anterior portion, lined with stratified squamous epithelium and hair.
• The nasal septum divides the cavity into halves, consisting of cartilage and facial bones.
• Nasal conchae extend from lateral walls, dividing the cavity into superior, middle, and inferior meatuses. These serve as air passageways and prevent dehydration of nasal cavities.
• Paranasal sinuses (frontal, sphenoidal, etc.) open into the nasal cavity and contribute to voice tone.
• The nasolacrimal duct connects each eye to the nasal cavity, moisturizing it.
• Internal nares (choanae) are at the nasal cavity's back, opening into the pharynx.
• The nasal cavity has a larger respiratory region and a smaller olfactory region.
• Respiratory region contains ciliated pseudostratified columnar epithelium.
• Olfactory epithelium in the upper nasal cavity contains sensory nerve endings.

Pharynx

• The pharynx (throat) is a muscular tube lined with a mucous membrane, about 13 cm long.
• The pharynx starts at internal nares and extends to the larynx (voice box).
• The pharynx contains the following: Air and food passageway, Resonating chamber for speech sounds, and Tonsils.
• The regions of the pharynx are as follows:
  • The nasopharynx is the superior portion cleaning inspired air via the ciliated epithelium lining.
  • Auditory tubes equalize pressure.
  • Posterior wall contains the pharyngeal tonsil.
• The oropharynx is Between the soft palate and hyoid bone.
  • Oropharynx is separated from mouth by the fauces opening.
  • The fauces is common passageway for air, food, and drink.
  • Location of palatine and lingual tonsils.
• The laryngopharynx is Lower pharynx, connects to esophagus and larynx. This area serves as air and good passageway lined with non-keratinized stratified squamous epithelial cells.

Larynx

• The Larynx or voice box is a cartilaginous structure at C5-C6 for sound production.
• Larynx contains:
  • Thyroid cartilage: triangular, prominent in males.
  • Is attached to hyoid bone by thyrohyoid membrane.
  • Epiglottis cartilage moves during swallowing.
  • Protects larynx opening.
  • Dislodges food/drink via cough reflex.
• The cricoid cartilage is Lower larynx wall and is fixed to thyroid cartilage.
• The cricoid cartilage is attached to trachea by cricotracheal ligament.
• The arytenoid cartilages located posterior to cricoid cartilage. They are attached to vocal folds and intrinsic pharyngeal muscles for contracting and relaxing and move vocal cords.
• The corniculate cartilages have horn shape and located at arytenoid cartilage apexes.
• The cuneiform cartilages are club shape to support vocal folds.
• The membrane of larynx forms two fold pairs:
  • The Vestibular folds does not function involved production.
  • Vocal folds are the production structures.
  • Rima vestibule is the Opening between the vestibular folds.
• In terms of sound production, contraction of larynx intrinsic muscles adjust rima glottidis position.
  • Also posterior cricoarytenoid muscle moves folds apart opening, while lateral cricoarytenoid muscles moves folds together closing.
• Pitch is controlled by tension.
  • Male hormones thicken vocal folds, vibrating slower.
  • Origin of sounds includes vibration of vocal folds and is impacted by mouth, nasal cavity, pharynx and other factors.
  • Whispering involves changes in oral cavity shape without vibrating vocal folds.

Trachea

• The rigid trachea/windpipe extends from the larynx to the T5 upper border, splitting into primary bronchi.
• Wall of trachea contains:
  • Mucosa has ciliated pseudostratified columnar epithelial cells
  • Submucosa is loose connective tissue.
  • Hyaline cartilage rings that keep is supported.
  • Adventitia is a layer of areolar connective for adjacent tissues to connect to trachea.
• There are Cartilaginous rings for trachea support, are connected by trachealis muscle. These rings prevent trachea collapse by semi ridged structure.

Bronchi

• Bronchi branched from trachea to lungs and are called the carina region.
• This Area includes the right main (primary) bronchus: Shorter, wider, more vertical than left.
• Bronchi divide into secondary (lobar) bronchi, with one entering each lung lobe.
  • The right has three lobes, and the left has two.
• Secondary Bronchi divides into tertiary (segmental) bronchi
• Each tertiary supplies bronchopulmonary segments within lobes
• The Tertiary bronchioles divide into bronchioles ending with (T) terminal.
• The terminal bronchioles have some smooth muscles and have no cartilage.
• Each terminal produces respiratory bronchi that have:
  • The alveolar ducts
  • alveolar sacs.
• Extensive branching from trachea through terminal is similar to tree known as brachial tree.
• Nasal air cavity movement through the (terminal) branches are as follows:
  • Nasal cavity → pharynx → trachea → (M) main bronchus → (L) lobar bronchi →(S) segmental bronchi → bronchioles → terminal bronchioles
• The Structurally change in branchial tree: Transition of ciliated pseudostratified columnar to simple cuboidal or columnar epithelium in smaller passages and disappearance of cartilage with increased smooth muscle. Also amount of cartilage decreases and is replaced by cartilage to mount of smooth muscle.

Lungs

• Lungs, in the thoracic cavity separated by the mediastinum and heart,are paired cone-shaped structures
• Lungs surfaces contains:
  • The Visceral covers surface.
  • Parietal covers thoracic wall inside..
• The Pleural cavity that contains Pleural fluid, has space between (V) visceral and ( P) parietal.
• Air in lungs pressure aids breathing since it less then the atmospheric pressure, and membrane also aids breathing as well.
• Pleurae separates those structures and lungs from (M) mediastinum location.
• Lungs start extends from diaphragm to clavicle.
• The Inferior portion of (L) lung is called the base, and The Superior portion of(L) lungs is the apex. The surface next to (R) ribs is (C) costal.
• Each lung has lobes from fissures.
  • The right has Three main lobes and (SMI) - Superior, Middle and Inferior and (TFH) - Two fissures, the horizontal and oblique.
  • The Left has two lobes from (O) oblique, and (CN) - contains concavity (aka cardiatch)..
• Hilum on each the lung's medial consists of: Pulmonary blood vessels and vessels entering exiting bronchi.
• Pulmonary segment (LT) - segment of lung tissue has each tertaiary supplies
• Lobules - region contains and elastic connective tissue artery vein Lymph Branch of terminal bronchi

The (T) terminal then ends braching (R) respiratory. Then branch in alveilor lead to which (AG) gas exchange, and which microscopic air is. Alveoli are functional capillary lung of the surrounded units. The Clustered provide gas as needed. The (G) group with opening in the ( AD ) is called a A(S) SAC or ALVEOLAR SAC. Gas Exchange structure is type 1 P are the squamous main GAS (E) Exchange. Type 2 ( P ) pneumocystes are are cubodial cells that surfactant, reduce and inflation surface, prevent lung collapse. Alveoli also has (A) alveolar macrophages adhering to alveolar walls to capture micro organisms

Pulmonary Ventilation

Pulmonary ventilation, also known as breathing, is the process involving gas exchange between the atmosphere and the lung as the alveoli. the lungs. This exchange is due to gradient of pressure:

• Air enters lung, then Air pressure inside or less compared to atmosphere. Inspiration (Inhaling) bringing air is active process to lung.
• Movement into the lung occurs dependent depends Boyle's Law. Boyle indicates Volume Varies inversely in temperature is assumes:
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Pressure

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Volume

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