BIO421 Animal Histology: Exam 4 Learning Objectives

Vocabulary flashcards covering the histological structures and functional units of the integumentary, respiratory, and digestive systems for BIO421 Exam 4.

Interpapillary pegs

Downward epidermal projections of the skin that interdigitate with dermal papillae.

Papillary layer

The superficial layer of the dermis, situated directly beneath the epidermis.

Reticular layer

The deeper, thicker layer of the dermis located beneath the papillary layer.

Subpapillary plexus

A network of blood vessels located directly beneath the dermal papillae in the dermis.

Deep plexus

A network of blood vessels situated in the deeper part of the dermis.

Arteriovenous anastomosis

A direct vascular communication connecting an artery and a vein in the dermis.

Dermal papilla

An upward projection of the papillary dermis into the epidermal pegs.

Arrector pili

The smooth muscle bundle attached to the hair follicle in the dermis.

Hypodermis

The subcutaneous layer of tissue underlying the dermis of the skin.

Hair follicle

The epidermal tube-like skin appendage that surrounds and produces the hair root.

Hair bulb

The expanded base of the hair follicle that encloses the hair papilla.

Hair papilla

A vascular connective tissue projection located at the base of the hair bulb.

Nail matrix

The proliferative region beneath the nail root responsible for nail growth.

Nail bed

The epidermal surface upon which the nail plate rests.

Sebaceous glands

Exocrine glands of the skin associated with hair follicles that secrete sebum.

Eccrine sweat glands

The standard, widespread skin sweat glands involved in thermoregulation, distinct from apocrine sweat glands.

Apocrine sweat glands

A specialized type of skin sweat gland distinct from eccrine glands.

Granulation tissue

New vascular tissue formed during cutaneous wound healing that undergoes remodeling to produce scar tissue.

Conducting zone

The subdivision of the respiratory system that transports air to the respiratory zone without performing gas exchange.

Respiratory zone

The subdivision of the respiratory system containing alveoli where gas exchange takes place.

Respiratory mucosa

The mucous membrane of the airways consisting of specialized respiratory epithelium, lamina propria, glands, and a venous plexus.

Olfactory mucosa

The specialized lining of the olfactory area containing olfactory epithelium, lamina propria, and olfactory glands.

Vestibular folds

The mucosal folds of the larynx located superior to the vocal cords (true vocal cords).

Vocalis muscle

The intrinsic muscle of the vocal cords within the larynx, distinct from breathing muscles.

Primary bronchus

The structural airway subdivision of the bronchial tree that supplies air to one lung.

Secondary bronchus

The structural airway subdivision of the bronchial tree that supplies air to one lung lobe.

Bronchiole

The structural airway subdivision of the bronchial tree that supplies air to one lung lobule.

Respiratory bronchiole

The structural airway subdivision that supplies air to one alveolar sac.

Respiratory membrane

The thin histological barrier in the lungs through which gas exchange takes place between alveolar air and capillary blood.

Submucosal (Meissner) plexus

The autonomic nerve plexus located in the submucosa layer of the GI tract wall.

Myenteric (Auerbach) plexus

The autonomic nerve plexus located within the muscularis externa layer of the GI tract wall.

Enamel

The hardest calcified substance of the tooth that covers the crown.

Cementum

The mineralized tissue covering the root of the tooth.

Dentin

The calcified tissue underlying the enamel and cementum that forms the bulk of the tooth.

Periodontium

The complex of specialized tissues that surrounds and supports the tooth within the alveolar bone.

Esophageal cardiac glands

Mucus-secreting glands located in the lamina propria near the esophagocardiac junction, distinct from the submucosal esophageal glands.

Gastric pits

Depressions in the gastric mucosa of the stomach that lead down into the gastric glands.

Pyloric sphincter

A muscular thickening of the circular muscularis externa at the gastroduodenal junction regulating stomach emptying.

Plicae circularis

Permanent circular folds of the mucosa and submucosa lining the small intestine.

Teniae coli

Three distinct longitudinal ribbons of smooth muscle in the muscularis externa of the large intestine.

Hepatic plates (cords)

Linear arrangements or sheets of hepatocytes that radiate within a hepatic lobule.

Kupfer cells

Specialized resident macrophages located in the liver sinusoids.

Space of Disse

The perisinusoidal space located between the hepatocytes and the sinusoidal endothelial cells in the liver.

Portal triad

A histological feature of the liver lobule containing branches of the hepatic artery, portal vein, and bile duct.

Bile canaliculi

Narrow intercellular channels formed by hepatocytes that collect and drain bile.

Islets of Langerhans

The endocrine clusters of cells scattered among the exocrine acini of the pancreas.