Respiratory and Digestive System Lecture Flashcards

Comprehensive vocabulary flashcards covering the anatomical structures, physiological functions, and clinical conditions of the respiratory and digestive systems.

Breathing

The mechanical movement involving rib movement and the contraction of the diaphragm to inhale and exhale air using skeletal muscles.

Respiration

The process of gas exchange where oxygen and carbon dioxide move via diffusion in the Alveoli.

Gas conditioning

The respiratory function of cleaning, warming, and humidifying inhaled air.

Conducting portion

The tubing system of the respiratory tract responsible for the transport of air.

Exchange portion

The part of the respiratory system where the diffusion of $O_2$ and $CO_2$ occurs.

Nasal septum

The middle wall that divides the nasal cavity into right and left portions.

Conchae

Structures in the nasal cavity that cause air to spin, helping to clean out dust, pollen, and bacteria.

Nasopharynx

The uppermost part of the pharynx used only for air, lined with pseudostratified ciliated columnar epithelium.

Oropharynx

The middle part of the pharynx that conducts both air and food, lined with stratified squamous epithelium.

Thyroid Cartilage

The largest hyaline cartilage of the larynx, which includes the laryngeal prominence or Adam's apple.

Epiglottis

An elastic cartilage structure that covers the airway during swallowing to prevent food from entering the trachea.

Mucociliary escalator

A mechanism where cilia move dirty mucus toward the pharynx so it can be swallowed and digested.

Bronchioles

Small air passages where cartilage is absent and smooth muscle is thicker to regulate airway diameter.

Terminal Bronchioles

The last structures of the conducting zone in the respiratory system.

Alveolar type I cells

Simple squamous epithelial cells that provide the thinnest possible barrier for rapid gas diffusion.

Alveolar type II cells

Cuboidal cells that produce pulmonary surfactant to prevent the alveoli from collapsing.

Pleural cavity

An air-free space between the visceral and parietal pleura that acts as a vacuum with negative pressure to help expand the lungs.

Pneumothorax

A condition where air enters the pleural cavity, breaking the vacuum and causing the lung to collapse.

Dorsal respiratory group (DRG)

The respiratory control center in the medulla oblongata responsible for inspiration.

Pons

The part of the brainstem that modifies and fine-tunes the respiratory rhythm via the pneumotaxic and apneustic centers.

Peristalsis

Wave-like propulsion contractions used to slide food forward through the digestive tract.

Segmentation

Alternating mixing contractions that churn food but do not move it in a specific direction.

Salivary amylase

An enzyme in saliva that begins the chemical digestion of carbohydrates by breaking down starch.

Mucosa

The innermost tunic of the GI tract wall consisting of epithelium, lamina propria, and muscularis mucosa.

Submucosa

A layer of areolar connective tissue containing blood vessels, lymphatics, and nerves that connects the mucosa to the muscularis.

Muscularis Externa

The muscle layer of the GI tract wall generally composed of an inner circular layer and an outer longitudinal layer.

Pyloric sphincter

A thickened circular muscle that regulates the passage of food from the stomach to the duodenum, allowing only liquids through.

Parietal cell

A cell in the gastric gland that secretes $HCl$ (stomach acid) and intrinsic factor.

Chief cell

A stomach cell responsible for secreting pepsinogen, the precursor for protein digestion.

Circular folds

Ridges in the small intestine formed by the submucosa that increase surface area and protect the epithelium.

Villi

Finger-like projections of the mucosa in the small intestine that significantly increase surface area for nutrient absorption.

Bile

A substance produced by the liver and stored in the gallbladder that is used for fat emulsification.

Hepatic lobule

The functional unit of the liver characterized by a 6-sided shape, hepatocytes, and a central vein.

Portal triad

A structural grouping at the corners of hepatic lobules consisting of a branch of the hepatic portal vein, hepatic artery, and bile duct.

Acinar cells

Exocrine cells of the pancreas that secrete digestive enzymes like proteases, lipases, and amylases.

Teniae coli

Three bands of longitudinal muscle found in the large intestine.

Haustra

The pocket-like bulges of the large intestine formed by the partial contraction of circular muscles.

Internal Anal Sphincter

An involuntary smooth muscle that maintains tone to keep the anal canal closed and relates to the urge to defecate.

External Anal Sphincter

A voluntary skeletal muscle that allows for the control of defecation.

Celiac Disease

An autoimmune reaction to gluten that causes chronic inflammation and the flattening of villi, leading to malabsorption.