Respiratory System

Models or Diagrams

The respiratory system is responsible for gas exchange, supplying oxygen to the body and removing carbon dioxide. Understanding its anatomy is essential for recognizing how air travels from the external environment to the lungs.

• External nares: The nostrils; openings to the nasal cavity.

• Paranasal sinuses: Air-filled spaces within the skull that lighten its weight and help humidify air.

• Superior, middle, and inferior nasal concha/meatus: Bony structures and passageways in the nasal cavity that increase surface area for warming and filtering air.

• Opening of auditory (Eustachian) canal: Connects the middle ear to the nasopharynx, equalizing pressure.

• Nasal cavity: Main passageway for air entering the respiratory system.

• Nasopharynx, oropharynx, laryngopharynx: Regions of the pharynx that direct air and food to the appropriate channels.

• Hard and soft palate: Separate the nasal and oral cavities.

• Uvula: Prevents food from entering the nasal cavity during swallowing.

• Pharyngeal, palatine, and lingual tonsils: Lymphatic tissue involved in immune defense.

• Larynx: Voice box; contains vocal cords and is involved in sound production.

  • Ventricular fold (false vocal cord)

  • Vocal fold (true vocal cord)

  • Epiglottis: Flap that prevents food from entering the trachea.

  • Thyroid, cricoid, and arytenoid cartilages: Support and protect the larynx.

• Trachea: Windpipe; conducts air to the lungs.

• Esophagus: Tube for food passage to the stomach (not part of the respiratory system but located nearby).

• Primary, secondary, and tertiary bronchi: Branches of the airway leading into the lungs.

• Bronchioles: Smaller branches of the bronchi.

• Respiratory bronchiole, alveolar duct, alveolus: Sites of gas exchange in the lungs.

• Pulmonary arteries and veins: Carry blood to and from the lungs for oxygenation.

• Lobes of lung (R: U, M, L; L: U, L): Right lung has three lobes; left lung has two lobes.

• Respiratory system: respiratory lobes: Functional units of the lung.

Microscope Slides or Diagrams

Histological examination of respiratory tissues helps identify their structure and function.

• Lung normal

• Simple squamous epithelium: Thin layer for efficient gas exchange.

• Alveolus: Air sac where gas exchange occurs.

• Alveolar sac: Cluster of alveoli.

• Alveolar pores: Openings that connect adjacent alveoli.

• Lung: emphysema (note the large pockets): Disease characterized by destruction of alveolar walls.

• Lung: adenocarcinoma: Type of lung cancer.

• Trachea:

  • Mucosa / Pseudostratified ciliated columnar epithelium: Moves mucus and trapped particles out of the airway.

  • Goblet cells: Produce mucus.

  • Submucosa: Connective tissue layer beneath the mucosa.

  • Tracheal cartilage (C-shaped rings): Maintain airway patency.

  • Trachealis muscle (smooth): Controls diameter of the trachea.

Respiratory Volumes and Capacities

Respiratory volumes and capacities are measurements used to assess lung function. They are determined using spirometry.

• Tidal volume: Volume of air inhaled or exhaled in a normal breath.

• Inspiratory reserve volume: Additional air that can be inhaled after a normal inhalation.

• Expiratory reserve volume: Additional air that can be exhaled after a normal exhalation.

• Vital capacity: Maximum amount of air a person can expel from the lungs after a maximum inhalation.

Formula:

Example: Spirometry is used in clinical settings to diagnose respiratory diseases such as asthma and COPD.

Urinary System

Models or Diagrams

The urinary system is responsible for filtering blood, removing waste, and maintaining fluid and electrolyte balance. Its anatomy includes the kidneys, ureters, bladder, and associated blood vessels.

• Inferior vena cava: Returns deoxygenated blood to the heart.

• Abdominal aorta: Supplies oxygenated blood to abdominal organs.

• Renal artery and vein: Supply and drain blood from the kidneys.

• Segmental artery, lobar artery, interlobar artery/vein: Branches of renal circulation.

• Afferent and efferent arteriole: Regulate blood flow into and out of the glomerulus.

• Arcuate vessels: Arch over the base of the renal pyramids.

• Interlobular (cortical radiate) artery/vein: Supply the cortex of the kidney.

• Kidney:

  • Hilus: Entry/exit site for vessels and nerves.

  • Cortex and medulla: Outer and inner regions of the kidney.

  • Medullary pyramids: Cone-shaped tissues in the medulla.

  • Renal columns: Extensions of cortex between pyramids.

  • Renal pelvis: Funnel for urine flowing to the ureter.

  • Major and minor calyces: Collect urine from the pyramids.

• Nephron: Functional unit of the kidney.

  • Glomerulus: Capillary network for filtration.

  • Bowman's capsule: Surrounds the glomerulus.

  • Proximal convoluted tubule: Reabsorbs water, ions, and nutrients.

  • Loop of Henle: Descending and ascending limbs for concentrating urine.

  • Distal convoluted tubule: Further reabsorption and secretion.

  • Collecting tubule: Collects urine from nephrons.

  • JGA (juxtaglomerular apparatus): Regulates blood pressure and filtration rate.

• Ureter: Transports urine from kidney to bladder.

• Urinary bladder: Stores urine.

  • Trigone area: Triangular region at the base of the bladder.

  • Ureteral openings: Entry points for urine from the ureters.

Microscope Slide or Diagram

Histological analysis of urinary tissues reveals their specialized structures for filtration and urine storage.

• Kidney:

  • Glomerulus (Bowman's capsule): Site of blood filtration.

  • Simple squamous epithelium: Thin cells lining Bowman's capsule.

  • Capsular space: Space between glomerulus and capsule.

  • Renal tubules (simple cuboidal epithelium): Tubes for reabsorption and secretion.

• Bladder:

  • Mucosa (transitional epithelium): Allows stretching as bladder fills.

  • Detrusor muscle: Smooth muscle for bladder contraction.

  • Lumen of urinary bladder: Cavity where urine is stored.

Urinalysis

Urinalysis is a diagnostic procedure used to assess the composition of urine and detect abnormalities.

• Understand and be able to explain procedures involved in determining urine values such as pH and urinalysis.

• Understand what type of cells should and should not be typically found in a urine sample.

Example: The presence of red blood cells or proteins in urine may indicate kidney disease.

Comparison Table: Respiratory vs. Urinary System Key Structures