Vertebrate Integumentary System (Part 2)

Two main types of glands in the skin:

Four types of sudoriferous (sweat) glands:

Released through sweat pores.

Release watery secretions in evaporative cooling

Produces sweat that contains antimicrobial compounds to prevent the growth of pathogens.

Also function in thermoregulation

Active over most of the body in horses, bears, and humans.

In other animals (dogs, cats, cattle, and sheep) they are active only on the pads of the paws or along the lip margins and may be entirely absent over the rest of the body (such animals depend on panting for effective temperature control)

Smaller animals such as rodents cannot endure dehydration and hence possess no eccrine glands.

Sweat released into hair pores.

Only in certain parts of the body such as the armpits, areolas, and the anal area.

Sweat metabolized by bacteria which produces an odor.

Release a mixture of salt, urea, and water, which microorganisms on the skin convert to odorous products.

Associated with the presence of hair in human beings (as on the scalp, armpit, and genital region)

Continuously secrete a concentrated fatty sweat into the gland tube.

Skin bacteria break down the fats into ________ that possess a pungent odor.

Secretes a thick fluid called cerumen (earwax) into hair follicles.

Cerumen also known as ______.

_______ lines the ears and functions to lubricate the eardrum.

Cerumen lines the ears and functions to _______.

Involved in skin problems such as acne and keratosis pilaris.

A blocked sebaceous gland.

______, also known by the medical term ______, is a yellowish, waxy substance secreted in the ear canal of humans and many other mammals.

It plays a vital role in the human ear canal, assisting in cleaning and lubrication, and also provides some protection from bacteria, fungus, and insects.

Produces sweat called milk.

Contains proteins, lipids, sugars, and immune cells to nourish a newborn.

Milk contains ____ to nourish a newborn.

These exocrine glands are enlarged and modified sweat glands and are the characteristics of mammals which gave the class its name.

___ are branched glands with clusters of small ducts surrounded by secretory cells called ____.

The ducts empty a waxy oily liquid called _____ into either a _____ or through a small pore.

They function to coat the skin and hair with moisture.

Produce sebum (oil)

In _____, acini cell will accumulate products such as ____ and different types of ____ until it ruptures. However, some bacteria can thrive in sebum, causing _____.

Secrete their product using ______, in which the secretory cell (acini cell) accumulates its product until ruptures occur.

Have tiny ducts that open into each hair follicle.

Also called oil glands.

The amount of secretion varies with ____.

Are hard structures located at the end of our digits that contain _____.

Function of the nails

______ are hard keratin structures that protect the ends of the fingers and toes.

Fingernails and toenails are ______ structures that protect the ends of the finger and toes.

Also called germinal matrix or nail bed.

Begins several millimeters into the finger and extends to the edgge of the white, crescent-shaped ______.

This is where the growth occurs approximately 0.5mm-1mm per week.

The under-surface of the nail plate or body of the nail has _____ that help anchor it.

Also called cuticle

It fuses the nail plate and the skin of the finger together to form a waterproof barrier.

Is under the free edge of the nail.

Also creates a waterproof barrier, fusing the skin of the finger to the underside of the nail plate.

Modification of the epidermis.

Flat, horny plates (fingers and toes)

Claws and hooves

Exaggerated nails

Horns (not the antler, made of bone and not formed in the epidermis)

Baleen plates

One of the most common conditions of the nail.

Usually occur in the toenail (big toe)

A condition in which the nail grows into the tissue medial or lateral to the nail.

Happens when the corner of edge of your toenail curves and grows into the surrounding skin.

Symptoms of an ingrown nail:

Ingrown nail can be treated by _____.

Common causes of an ingrown nail:

Part of the nail that rests on top of the epidermal nail bed.

Deep to the nail plate, nourishes and protects the nail.

Visible part of the nail.

With living, dividing cells. Supplies oxygen to the nail, sight of nail growth.

Covers the edge of the root.

Also known as the cuticle

Found at the base of the nail

Protects matrix from infection

Overlapping of skin that borders the nail laterally and medially.

Skin that lies under the free edge of the nail

Crescent-shaped area where keratin accumulates.

Integumentary of birds consist of the _____.

Bird's skin is divided into:

Areas where feathered skin do grow.

Areas where feathered skin do not grow.

Bird's skin on the lower legs and feet

Bird's skin on the beak and toenails

The stratum corneum is thick, lacks glands, and is modified into sclaes/scutes (thick scales), beaks in turtles, rattles on snakes, claws, plaques, and spiny crests on others.

Thick, keratinized layer, functions in protection, slows down dehydration and resists abrasions.

The dermis is provided with chromatophores.

The dermis of reptile skin is provided with _____, color bearing cells that give many lizards and snakes their colorful hues.

Skin has no respiratory functions

Skin does not secrete pheromones that function in sex recognition and defense.

Is also known as ecdysis.

No blood supply in the epidermis, therefore the outer epidermal layers lose contact with the blood supply and die.

Typically begins around the head and come off in one piece (snakes and most lizards) and in little pieces (skin simply flakes off).

Reptiles such as _____, shed or molt the outer layer of the epidermis, diffusion of fluid between the layers assists in this _____.

Are transitional between aquatic and terrestrial vertebrates.

Contain epidermis with thin stratum corneum and very little keratin; Leydig cells; dermis with chromatophores, poison glands, and mucous glands.

The mucous glands prevent ______, aid in gas exchange, and make the body slimy; which is advantageous when trying to escape predators.

Scales are rare

Types of scales:

Concentric ridges (milkfish)

With spines or ctenii

Rhomboid shape

Spines directed caudally (sharks, skates)

Skin is permeable and functions in gas exchange.

Epidermis also has mucous glands (prevents bacterial and fungal infections, as well as reduces friction when the fish swims) and granular glands (secrete an irritating/poisonous alkaloid)

The skin of _____ contains scales (cycloid, ctenoid, ganoid)

_____ are composed of dermal bone and are not shed; grow at the margins and over the lower surface; have growth rings (used to age fish).

Sharks and rays are ____.

Skin is covered in placoid scales (bony, spiny projections with an enamel-like covering) or dermal denticles, tooth-like scales different from the flat scales found on bony fish.

The dermal denticles is structurally homologous with vertebrate teeth.

Placoid scales do not grow with the animal; they are of a single size. Instead, when the animal grows, space opens up and new denticles grow to fill.

The scales/denticles of _____ are discrete, they do not overlap as do the scales of bony fishes.

Sandpaper texture

The most common type of skin pathology.

Any disruption of the skin's integrity.

They may disrupt the epidermis, dermis, or deeper.

Different kinds of wounds:

A laceration may be treated with _____, whereas a burn may be treated with _____.

Common diseases and disorders of the skin:

A skin wound caused by heat, extreme cold, chemicals, and/or radiation.

Types of burns:

Only the epidermis is damaged with redness (erythema), swelling, and minor pain.

Most minor, also called superficial burns.

Usually rewuire no treatment, no blisters, no permanent damage.

The epidermis and upper region of the dermis is involved.

Also called partial thickness burns

Symptoms are pain, blistering, and scarring

Usually require medical treatment

All layers of the skin burned (most severe)

Skin graft is necessary to repair. Skin looks cherry red or blacken.

Most damaging kind of burn

Also known as full thickness burn

Muscle and bone may be damaged

Symptoms: severe scarring, lost of hair follicles, and dehydration due to fluid loss.

Treatment may result in skin grafting

Most skin tumors are ____.

Cause of cancer is unknown, but probably due to overexposure to UV radiation of the sun.

A very common skin disease

Caused by mutations in the DNA that cause cells to lose control over their cell cycle.

Three main types of skin cancer:

Most common type of skin tumor; usually benign

Cells of stratum basale are affected, as they cannot form keratin and begin to invade into the dermis.

A cancer of keratinocytes

Arises from keratinocytes in stratum spinosum

Mostly in the scalp, ears, or hands

Grows and migrates rapidly

Cancer of the melanocytes in stratum basale

Most dangerous and usually deadly

Only 5% of all skin cancer, but the frequency is increasing.

Grow and migrates extremely rapidly.

To avoid these skin tumors...

Inherited, melanocytes do not produce melanin.

Inflammation of hair follicles and sebaceous glands, infection spread to dermis.

Itching and redness and swelling forming blisters. It is caused by chemical burns.

Characterized by reddened epidermal lesions covered by dry silvery scales.

Redness of the skin around eyes and nose accompanied by rash-like lesions, it gets worse with alcohol, hot water, and spicy food.

Skin pigmentation disorder caused by loss of melanocytes and uneven dispersal of melanin (unpigmented skin surrounded by normally pigmented areas)