LEC 5: Mammalian Biology and Anatomy Flashcards

Vocabulary flashcards covering key concepts from lecture notes on mammalian biology, skin structures, hair types, adipose tissue, organ systems, and sensory anatomy.

Endothermy

An energetically costly condition in mammals requiring constant intake of food, water, and oxygen to metabolize for energy (ATP) production to grow and maintain tissues.

Integument

The skin of mammals, shaped by major selective forces including the prevention of water loss, retention of heat loss, and feeding (lactation).

Sebaceous Glands

Epidermal glands whose secretions are the product of their own cellular breakdown.

Sebum

A product composed of lipids and cell debris secreted by sebaceous glands to keep hair from becoming dry and brittle and to assist in waterproofing pelage.

Sweat Glands

Epidermal glands whose cells secrete a substance not produced by the gland's cell; also called sudoriferous, tubular, serous, or apocrine glands.

Mammary Glands

Specialized exocrine glands that secrete milk to nourish post-natal young.

Prolactin

A pituitary hormone released during nursing that stimulates milk production.

Oxytocin

A hormone released by the pituitary during nursing that acts as an infant bonding hormone.

Keratin

A sulfur-containing protein that strengthens dead, specialized epidermal cells forming hair, claws, nails, and horns.

Pelage

The coat or fur of an animal.

Cuticular Scales

The outer scale-like, typically transparent epidermal cells of a hair shaft.

Cortex

Highly packed epidermal cells within hair that provide structure and contain color pigment.

Medulla

Cuboidal cells in the center of hair that contain color pigment, though not always present.

Vibrissae

Hairs with specialized follicles containing erectile tissues, also known as feelers, whiskers, or tactile hairs.

Overhairs

The longest and coarsest hairs on a mammal, characterized by a circular cross-section.

Guard Hairs

Hairs shorter and less coarse than overhairs, featuring distinct medullary cross-sections and patterns used for species identification.

Underhair

Fine and uniformly soft hair whose primary function is thermal insulation; also known as wool hair.

Molting

The periodic loss and replacement of hair, usually occurring once or twice per year.

Countershading

A coloration pattern where an animal's back is lighter than its belly, making its silhouette less conspicuous.

White Fat

Typical adipose tissue stored in subcutaneous, visceral, and intramuscular locations, used for lipolysis and energy generation via efficient oxidation.

Brown Fat

Adipose tissue stored in specific areas primarily dedicated to thermogenesis.

Septum Transversum

A structure found in chordates that divides the peritoneal cavity (gut) from the pericardial cavity where the heart is located.

Striated Muscle

Muscles attached to the skeleton (skeletal muscles) responsible for movements of the trunk, appendages, respiratory organs, eyes, and mouthparts.

Smooth Muscle

Involuntary muscle organized into sheets circling the walls of the alimentary canal, blood vessels, respiratory passages, and urogenital ducts.

Cardiac Muscle

Tough, fibrous, pumping muscle fibers that compose the mammalian heart.

Neopallium

A mantle of gray matter, often folded for increased surface area, that constitutes most of the expanded size of the mammalian brain.

Corpus Callosum

A concentrated area of nerve fibers in Eutherians that connects the two halves of the neopallium.

Vomeronasal Organ

A sensory organ (also called Jacobsen's organ) that detects pheromones to alter the behavior or physiology of the recipient.

Tapetum Lucidum

A reflective membrane within the eye choroid that enhances night vision by reflecting light back to the retina.

Baculum

A supportive bone inside the penis (also called os penis) present in many mammalian species.