Overview of Respiratory, Urinary, and Digestive Systems

Nasal Path

Optimal air route to respiratory system.

Oral Path

Alternative air route, diverts to respiratory tract.

Laryngopharynx

Connects to esophagus, directs air to larynx.

Larynx

Cartilage structure, houses vocal folds.

Epiglottis

Cartilage covering larynx during swallowing.

Vocal Folds

Resonate to produce sound during speech.

Trachea

Main airway leading to lungs.

Negative Pressure Breathing

Air enters lungs due to volume expansion.

Diaphragm

Muscle aiding lung expansion during inhalation.

Internal Intercostals

Muscles assisting in lung dimension changes.

Primary Bronchioles

First division of trachea into lungs.

Secondary Bronchioles

Branching bronchioles supplying lung lobes.

Lobes

Lung sections; left has 2, right has 3.

Segments

Each lobe contains 10 segments.

Tertiary Bronchioles

Branch from segments, lead to lobules.

Terminal Bronchioles

Final bronchioles before alveolar sacs.

Alveolar Sacs

Structures where gas exchange occurs.

Alveoli

Spherical units surrounding alveolar ducts.

Type 1 Pneumocyte

Simple squamous cells for gas exchange.

Type 2 Pneumocyte

Cells producing surfactant to reduce surface tension.

Respiratory Epithelium

Mucus membrane lining upper respiratory tract.

Pseudostratified Columnar Epithelium

Ciliated cells in respiratory tract for mucus movement.

Hyaline Cartilage

Supports trachea structure, prevents collapse.

Smooth Muscle

Muscle type controlling airway diameter in lungs.

Alveoli

Air sacs in lungs for gas exchange.

Perfusion

Blood flow matching to lung ventilation.

Ventilation

Airflow into and out of lungs.

Trachea

Main airway with cartilage and cilia.

Primary Bronchi

First branches of trachea into lungs.

Secondary Bronchi

Branches from primary bronchi with less cartilage.

Tertiary Bronchi

Further branching with increased smooth muscle.

Terminal Bronchioles

Smallest airways with smooth muscle only.

Alveolar Ducts

Passages leading to alveoli for gas exchange.

Simple Squamous Epithelium

Thin tissue type in alveoli for diffusion.

Kidney

Organ filtering blood and producing urine.

Ureter

Tube transporting urine from kidney to bladder.

Bladder

Storage organ for urine before excretion.

Urethra

Tube for urine exit from body.

Renal Corpuscle

Glomerulus and capsule filtering blood.

Glomerulus

Capillary network for blood filtration in kidneys.

Renal Capsule

Surrounds glomerulus, part of nephron.

Proximal Convoluted Tubule (PCT)

First nephron segment for reabsorption.

Loop of Henle

Nephron segment with descending and ascending limbs.

Distal Convoluted Tubule (DCT)

Nephron segment further from renal corpuscle.

Juxtaglomerular Apparatus (JGA)

Structure regulating blood pressure in nephron.

Collecting Ducts

Final urine passage to renal pelvis.

Podocytes

Specialized cells aiding filtration in glomerulus.

Gastric Pits

Stomach structures producing digestive secretions.

Pyloric Sphincter

Muscle controlling food passage to small intestine.

Duodenum

First small intestine section after stomach.

Mucosal Layer

Innermost digestive tract layer with epithelium.

Submucosal layer

Middle layer with glands entering mucosal layer.

Muscularis layer

Outer layer of smooth muscle, includes longitudinal and circular.

Serosal layer

Lines outer layer of intestines.

Glottis

Opening between vocal cords controlling airflow.

Epiglottis

Covers glottis during swallowing to prevent aspiration.

Uvula

Covers nasopharynx during swallowing.

Hard palate

Upper oral cavity made of bone structures.

Soft palate

Continuation of palate without bony structure.

Lingual tonsil

Lymphatic tissue near tongue.

Palatine tonsil

Lymphatic tissue near nasopharynx.

Stratified squamous tissue

Protective tissue lining oral cavity and esophagus.

Skeletal muscle in esophagus

Upper ⅔ under voluntary control.

Gastroesophageal sphincter

Valve preventing backflow from stomach to esophagus.

Pyloric sphincter

Valve preventing backflow from small intestine to stomach.

Rugae

Inward folds allowing stomach expansion.

Chyme

Acidic mixture produced in stomach for digestion.

Gastric pits

Folds opening onto stomach surface containing gastric glands.

Mucus producing cells

Protect inner stomach cells from acidic chyme.

Parietal cells

Secrete hydrochloric acid in gastric pits.

Chief cells

Secrete pepsinogen, converting to pepsin enzyme.

Duodenum

First part of small intestine, site of digestion.

Ileum

Final section of small intestine, joins large intestine.

Ileocecal valve

Valve between small intestine and large intestine.

Cecum

First part of the large intestine.

Appendix

Small pouch attached to the cecum.

Pancreas

Organ producing digestive enzymes and hormones.

Acinar cells

Cells in pancreas that produce digestive enzymes.

Pancreatic duct

Duct transporting enzymes to the small intestine.

Duodenum

First section of the small intestine for digestion.

Jejunum

Middle section of the small intestine for absorption.

Ileum

Final section of the small intestine for nutrient absorption.

Liver

Organ producing bile for fat digestion.

Bile

Substance that emulsifies fats for digestion.

Hepatic duct

Duct transporting bile from the liver.

Bile duct

Duct carrying bile to the duodenum.

Cystic duct

Duct connecting gallbladder to bile duct.

Villae

Folds in the small intestine increasing surface area.

Simple columnar cells

Cells lining the intestines for absorption.

Brush border

Microvilli on apical surface of intestinal cells.

Goblet cells

Cells producing mucus in the intestines.

Lymphatic tissue

Tissue in ileum protecting against pathogens.

Chyme

Partially digested food moving through intestines.

Microvilli

Tiny projections increasing absorption surface area.

Regions of large intestine

Cecum, colon, and rectum structure.

Constipation

Condition of hard feces due to water absorption.