Anatomy unit 2 Review

Epidermis

The uppermost layer of skin, made of stratified squamous epithelium, continuously renewed with new layers pushed to the surface.

Dermis

The middle layer of skin, composed of dense connective tissue, containing collagen, elastic fibers, blood vessels, nerves, hair follicles, and glands.

Hypodermis

The lowest layer of skin, consisting of loose connective tissue and fat, not directly connected to the skin.

Protection

One of the skin's functions, providing a barrier against infection, waterproofing, and reflecting UV radiation.

Sensory

A function of the skin that involves detecting temperature, pressure, touch, and pain through nerve endings.

Thermoregulation

The skin's ability to regulate body temperature by preventing heat loss and expelling heat through sweating.

Storage

The function of the skin that involves storing adipose tissue for energy and thermal regulation.

Secretion

The process by which skin glands, such as sebaceous and sudiferous glands, release substances like oil and sweat.

Communication

The skin's role in conveying information through pheromones and visual signals, such as raised hackles.

Melanin

The pigment produced by melanocytes in the epidermis, responsible for skin color and UV radiation reflection.

Arrector pili muscle

A muscle that contracts to pull hair upright, causing goosebumps.

Keratin

A protein in the skin that provides waterproofing.

Nail root

The part of the nail from which it grows.

Hair follicles

Structures in the dermis where hair forms.

Vasodilation

The process of blood vessel dilation, where muscles around the vessel enlarge to increase blood flow.

Vasoconstriction

The process of blood vessel constriction, where muscles around the vessel tighten to decrease blood flow.

Cycloid scales

Thin, large, round/oval fish scales with overlapping growth rings, found in species like salmon and trout.

Ctenoid scales

Fish scales with spines or comb-like teeth on the edges, found in perches and sunfishes.

Placoid scales

Spiny, tooth-like projections found in cartilaginous fish like sharks and rays.

Ganoid scales

Bony fish scales covered with an enamel-like substance, found in gars and bowfin.

Respiration

A unique role of the skin in amphibians, allowing for gas exchange.

Scales

Adaptations in reptiles that help retain water and provide waterproofing.

Preen gland

A gland in birds that secretes oil to maintain feathers and skin.

Feather anatomy

Components of a feather, including vane, leading edge, trailing edge, quill, shaft, and afterfeather.

Structural colors

One of the ways birds express color, along with melanin, psittacofulvins, porphyrins, carotenoids, and spheniscins.

Guard hair

Coarse, long, and stiff hair in mammals that provides waterproofing.

Tactile hair

Whiskers that are thick, protrude, and are surrounded by nerves, mainly found on the face.

Wool hair

Soft, insulating hair that forms the innermost coat of mammals.

digital pads

covers distal interphalangeal joint

metacarpal pads

covers phalangeal metacarpal joint

carpal pad

distal to the carpal bones, stop pad

different functions of the skin

protection, sensory, storage, secretion, communication, production

shape of sudiferous gland vs shape of sebaceous gland

sudiferous: coiled, sebaceous: clump/sac

shape of epidermis

stratified squamous epithelium (flattened)

what is found in the dermis

collagen elastic, blood, nerves, hair follicles, glands

which is the thickest layer of the skin

dermis

what is found in the hypodermis

loose connective tissue (fat), elastic fibers

what do sudiferous glands do

secrete sweat

what do sebaceous glands do

secrete sebum (oil)

location of sudiferous glands

depends on species

what does sebum/oil do?

waterproofing/antiseptic, influence behavior and help with communication

what are the accessory organs of the integumentary system

nais/claws, hair/fur, glands, foot pads

where are hair follicles found

the dermis

why does vasodilation/vasoconstriction occur?

to regulate the bodies temperature/blood flow

how do reptile scales differ from fish scales

reptile scales form in the epidermis and fish scales form in the dermis

leading edge vs. trailing edge of feather

leading: first part to cut through air when flying, usually shorter and stronger

trailing: behind leading edge, follows path of leading edge, longer and less stiff

ways birds express color

structural colors, melanin, psittacofulvins, porphyrins, carotenoids, spheniscins