Digestive System

Mouth

The mouth is the entry point of the digestive tract and is responsible for the initial mechanical and chemical breakdown of food.

• Labia: The lips, which help contain food and aid in speech.

• Oral cavity: The main space within the mouth.

• Hard palate: The bony anterior roof of the mouth.

• Soft palate: The muscular posterior roof of the mouth.

• Teeth: Structures for mechanical digestion; types include:

  • Dentin

  • Enamel

  • Root canal

  • Cementum

  • Periodontal ligament

  • Gingiva (gums)

  • Alveolus (tooth socket)

• Uvula: A small projection hanging from the soft palate, involved in speech and swallowing.

• Salivary glands: Produce saliva for digestion; include parotid, sublingual, and submandibular glands.

• Frenulum: Folds of tissue that secure the tongue and lips.

Pharynx and Esophagus

These structures transport food from the mouth to the stomach.

• Oropharynx: The part of the pharynx behind the oral cavity.

• Esophagus: Muscular tube connecting the pharynx to the stomach.

Stomach

The stomach is a muscular organ that continues the process of digestion by mixing food with gastric juices.

• Lesser curvature: The inner curve of the stomach.

• Greater curvature: The outer curve of the stomach.

• Rugae: Folds in the stomach lining that allow expansion.

• Cardia, Fundus, Body, Pylorus: Regions of the stomach.

• Pyloric sphincter: Controls passage of food into the small intestine.

Small Intestine

The small intestine is the primary site for nutrient absorption.

• Duodenum: First section, receives chyme from the stomach.

• Jejunum: Middle section, major site of absorption.

• Ileum: Final section, connects to the large intestine.

• Ileocecal junction: Where the ileum meets the cecum of the large intestine.

Large Intestine

The large intestine absorbs water and forms feces.

• Ascending, transverse, descending, sigmoid colon: Main regions of the colon.

• Rectum: Stores feces before elimination.

• Anus: Opening for fecal elimination.

Pancreas

The pancreas produces digestive enzymes and hormones.

• Head, body, tail: Anatomical regions.

• Main pancreatic duct: Delivers enzymes to the duodenum.

• Accessory pancreatic duct: Additional duct for enzyme delivery.

Liver

The liver processes nutrients and detoxifies substances.

• Lobes: Right, left, caudate, quadrate.

• Hepatic ducts: Transport bile.

• Bile duct: Delivers bile to the duodenum.

• Faliform ligament: Separates lobes.

Gallbladder

The gallbladder stores and concentrates bile.

• Cystic duct: Connects gallbladder to bile duct.

Urinary System

Kidney

The kidneys filter blood and produce urine.

• Hilum: Entry/exit for ureter, renal artery, and vein.

• Cortex: Outer layer containing nephrons.

• Medulla: Inner region with renal pyramids.

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

• Papilla: Tip of the pyramid where urine drains.

• Calyx (major and minor): Collects urine from papillae.

Ureters

Ureters transport urine from the kidneys to the bladder.

• Urinary bladder: Stores urine.

• Trigone: Triangular area in the bladder formed by the openings of the ureters and urethra.

Male Reproductive System

Testes

The testes produce sperm and testosterone.

• Tunica vaginalis: Outer covering.

• Tunica albuginea: Inner fibrous capsule.

• Seminiferous tubules: Site of sperm production.

• Rete testis: Network for sperm transport.

• Scrotum: Sac holding the testes.

• Epididymis (head, body, tail): Sperm maturation and storage.

• Vas deferens: Transports sperm.

• Spermatic cord: Contains vas deferens, blood vessels, nerves.

• Cremaster muscle: Raises and lowers the testes.

Accessory Structures

• Seminal vesicle: Adds fluid to semen.

• Ejaculatory duct: Passage for semen.

• Prostate gland: Adds prostatic fluid to semen.

• Prostatic urethra: Urethra segment through the prostate.

• Membranous urethra: Urethra segment between prostate and penis.

• Bulbourethral gland: Secretes lubricating fluid.

Penis

• Penile (spongy) urethra: Urethra segment within the penis.

• Corpora cavernosa: Erectile tissue.

• Corpus spongiosum: Surrounds urethra.

• Glans: Tip of the penis.

• Prepuce: Foreskin.

Female Reproductive System

Ovaries

The ovaries produce eggs and hormones.

• Ovarian ligament: Anchors ovary to uterus.

• Broad ligament: Supports uterus, fallopian tubes, and ovaries.

• Round ligament: Supports uterus.

Uterine (Fallopian) Tubes

These tubes transport eggs from the ovaries to the uterus.

• Isthmus: Narrow region near the uterus.

• Ampulla: Wider region where fertilization often occurs.

• Infundibulum: Funnel-shaped end near the ovary.

• Fimbriae: Finger-like projections that help capture the egg.

Uterus

• Fundus: Top portion.

• Ovarian ligament, Broad ligament, Round ligament: Support structures.

• Cervix (internal and external os): Lower part opening into the vagina.

Vagina and External Genitalia

• Labia majora: Outer folds.

• Labia minora: Inner folds.

• Vestibule: Area between labia minora.

• Clitoris: Erectile tissue.

• Urethral orifice: Opening of the urethra.

• Mons pubis: Fatty area over pubic bone.

Mammary Glands

Mammary glands produce milk for nourishment of infants.

• Areola: Pigmented area around the nipple.

• Alveoli: Milk-producing sacs.

• Lactiferous ducts: Transport milk.

• Lactiferous sinus: Milk storage area before release.