Tissue/Integumentary Test Review

Anatomy and Physiology 2026-27

what does it mean when cells are keratinized

the cells are filled w/ keratin + transformed into waterproof structures that are hard and dead

what is keratin

tough, fibrous protein

what type of connective tissue is blood

fluid

what connective tissue is bone

supporting

what connective tissue is the functional unit of bone

ossous/bone tissue

what makes loose connective tissue

fibers form open framework

what makes dense connective tissue

fibers packed densely

how is cartilage different from bone

• cartilage = solid, rubbery matrix

• bone = solid crystalline matrix

what are the percentages of tissue types in the human body

• connective 45%

• epithelial 3%

• nervous 2%

• muscle 50%

characteristics of skeletal muscle tissue

• striated

• voluntary

functions of skeletal muscle tissue

• move/stabilize position of skeleton

• guard entrances + exits to the digestive, respiratory, and urinary tracts

• generate heat

• protect internal organs

characteristics of cardiac muscle tissue

• striated

• involuntary

functions of cardiac muscle tissue

moves blood and maintains blood pressure

characteristics of smooth muscle tissue

• non- striated

• involuntary

functions of smooth muscle tissue

• moves food, urine, + reproductive tract secretions

• controls diameter of respiratory passageways + regulates diameter of blood vessels

what part of a neuron is responsible for transmitting the message to either the next neuron, a gland, or a muscle?

axon/synaptic terminal

4 cardinal signs of inflammation

• increased local temp.

• increased O2 + nutrients

• increased phagocytosis

• removal of toxins + wastes

what 2 layers make up the cutaneous membrane

epidermis + dermis

what are 2 components of the integumentary system

cutaneous membrane + accessory structures

functions of the integumentary system

• protection

• excretion

• body temp, regulation

• produce melanin + keratin

• vitamin D3 synthesis lipid storage

• sensory input

stratum corneum

• outermost/protective region

• dead cells still tightly connected by desmosomes

• water resistant, not waterproof

• 15-30 layers of keratinized cells (filled w/ keratin)

• lose water through insensible perspiration (unable to see or feel) and sensible perspiration (sweat)

stratum lucidum

• “clear layer”

• found only in thick skin

• separates stratum corneum from underlying layers

• flattened, densely packed dead cells filled with keratin and keratohylin

stratum granulosum

• “grainy layer”

• composed of 3-5 layers of keratinocytes

• most cells have stopped dividing and started producing keratin + keratohyalin

• cells grow thinner + flatter

• cell membranes thicken + become less permeable

stratum spinosum

• “spiny layer”

• 8-10 layers of keratinocytes bound together by desmosomes

• only looks spiny when on a prepared slide

• contains dendritic (Langerhans) cells

• part of immune response defending against microorganisms and superficial skin cancers

stratum basale

• basal/bottom layer of the epidermis

• attached to basement membrane by hemidesmosomes

• most cells here are basal cells, stem cells that divide to replace more superficial keratinocytes

• merkel cells that respond to touch are also found here

thin skin characteristics

• 4 strata layers (stratum corneum, granulosum, spinosum, basale)

• about as thick as a plastic sandwich bag (0.08mm)

• covers most of body surfaces

thick skin characteristics

• found on palms of hands + soles of feet

• contains 5 strata (stratum corneum, lucidum, granulosum, spinosum, basale)

• about as thick as a paper towel (0.5mm)

why is basal cell carcinoma less dangerous than malignant melanoma?

• Basal cell carcinoma = virtually no metastasis (spread of cancer cells)

• malignant melanoma = cancerous melanocytes grow rapidly + metastasize through the lymphatic system

pigment that can make the skin look orange

carotene

what pigment is lacking in an individual with albinism

melanin (they still have melanocytes)

1st degree burns

• partial-thickness burns

• only the surface of the epidermis is affected

• painful

• skin redness (erythema) results from inflammation

• ex - sunburns

2nd degree burns

• partial-thickness burns

• entire epidermis + some dermis damaged

• accessory structures not affected

• blistering, pain + swelling

• healing = 1-2 weeks

• scar tissue may form

• infection can develop from ruptured blisters

3rd degree burns

• full-thickness burns

• destroys epidermis, dermis, + damage extends into hypodermis

• less painful than 2nd degree burns → sensory nerves are destroyed

• extensive burns of this type cannot repair themselves

• epithelial cells unable to cover the injury

• skin grafting usually necessary

what happens when the arrector muscle contract

hair stands erect/straight up - creates goosebumps

vellus hair

fine hairs that cover a lot of the body surfaces

terminal hairs

coarse hairs found on the scalp, eyebrows, armpits, + pubis area following puberty

nail body covers the

nail bed

why do older people get wrinkles?

their dermis gets thinner + there are less elastic fibers

what vitamin is produced by the skin when it is exposed to sunlight

vitamin D3

stages of skin regeneration after injury

1. homeostasis - stop losing blood

2. inflammation - clear debris

3. proliferation - rebuild tissue

4. strenghtening/remodeling