A&P1 EXAM 2

where is the integumentary system in the body?

covers the entire body surface

what is the integumentary system composed of?

skin, nails, hair, and glands

what is the general appearance of the skin used for?

to estimate people’s overall health and age

what do the receptors in the integumentary system do?

regulate body temperature and tells us about the outside world 

what does the nervous tissue do in the integumentary system?

controls the smooth muscle and monitors sensory receptors that provide sensations of touch, pressure, temperature, and pain 

what are the 2 major components of the integumentary system?

cutaneous membrane (skin) and accessory structures 

what does cutaneous membrane (skin) contain?

epidermis and dermis

what do accessory structures contain?

hair, glands, and nails 

where are hair structures located?

in the dermis; petrude through epidermis to surface

what are the functions of the integumentary system?

physical protection, regulation of body temperature, secretion, nutrition, sensation, and immunity 

what is albinism?

Inherited disorder characterized by deficient melanin production; contains normal distribution of melanocytes but cells cannot produce melanin

what are melanocytes?

Specialized pigment-producing cells; produce melanin 

where are melanocytes located?

in the epidermis 

what are merkel cells?

skin surface that lack air (ex. lips and finger tips)

merkel cells are also known as sensory cells. what happens when they are compressed?

they release chemicals that stimulate sensory nerve endings, which provide information about the objects touching the skin 

What are merkel cells sensitive to?

touch

most humerous cells within the epidermis are___

keratoniocytes

what does keratin form?

structural component of hair and nails

what is the most superficial layer of the skin?

the stratum corneum

what does the stratum corneum consist of?

layers of flattened, dead cells

in what form do cells shed?

in sheets or large groups; rather than individually 

what is cells at the surface of your skin being dry a good thing?

its unsuitable for the growth of microorganisms (bacteria)

what is the maintenance of the stratum corneum?

coating the surface (sebaceous and sweat glands)

Where is the only open place where keratinization does not occur?

over the eyes 

what is insensible perspiration?

when water from interstitial fluid (sweat) evaportaes into the air around you 

how much water (sweat) do we loose a day?

500mL/1 pint, importance of staying hydrated

how long does it take for a cell to move superficially from the deepest epidermal later to the most superficial layer?

15-30 days

how long do dead skin cells stay at the surface until washed or shed away?

about 2 weeks 

what can the loss of skin lead to?

loss of excess fluids and absorption of toxins 

cyanosis

sustained reduction in the oxygen content in the blood (blueish); most apparent in areas of thin skin (lips and beneath finger nails)

what does melanin pigment protect?

the underlying dermis and prevents skin damage by absorbing UV radiation in sunlight 

where parts of the skin is effected by tanning long term?

dermis and epidermis 

why does the small intestine need vitamin D?

so it can absorb calcium and phosphorus 

where is little to no melanin produced?

in thick skin (palms and soles of the feet); if any, it is difficult to see because of the thickness of the stratum corneum 

what is skin cancer often caused by?

exposure to UV radiation; primarily sunlight

what is skin cancer?

abnormal growth of skin cells

basal cell carcinoma

most common type of skin cancer; deepest later of the epidermis; slow growing, almost never metastasizes

malignant melanoma

develops in melanocytes, multiply rapidly and metastasizes to distant sites, causes most deaths from skin cancer

function of the papillary layer in the dermis?

provides mechanical attachment to more superficial dermis

what are capilaries?

branching blood vessels that supply the epidermis

what do axons do in the papillary layer of the dermis?

monitor the epidermal receptors 

what are sebaceous glands?

microscopic exocrine glands in the skin that secrete an oily or waxy matter (sebum)

what is the arrangement of connective tissue fibers responsible for?

strength, toughness, and elasticity of the skin 

what can damage from UV do?

cause damage to thick skin leading to wrinkles or sagging skin 

what are stretch marks?

extensive distortion of the dermis over the abdomen often exceeds the elastic capabilities of the skin 

tension line

at any one location, most of the collagen and elastic fibers are arranged in parallel bundles 

what does the oriental of bundles depend on?

the stress places in the skin during normal movement

bundles are aligned to resist what?

applied forces

what role do surgens platy when it comes to tension lines?

they need to cut in the same direction of the tension line in that specific part of the body in order to reduce scarring and lead to faster healing 

what do dermal networks contain?

blood vessels, lymph vessels, and nerve fibers 

what is skin important for?

thermoregulation

T/F: circulation to the skin must be tightly regulated

true

why is it important for the core to stay warm?

in order to stay alive

why does blood go to the skin?

to release excess heat

what systems are involved in adequate blood flow?

nervous, cardiovascular, and endocrine systems

why is the subcutaneous layer important? 

stabilizes the position of the skin while still permitting independent movement (ex. pinching the skin)

what does the subcutaneous layer contain?

loose connective tissue with abundant adipocytes

where do men hold extra fat?

neck, upper arms, lower back, butt

where do women hold extra fat?

breasts, hips, thighs, butt

what are some factors of scar tissue?

inflexible and densely packed

what is the skeletal system made of?

bones, cartilage, ligaments, and connective tissue to stabilize the skeleton

what are bones?

dynamic organs

what happens when muscles contract?

the skeletal moves

what are the 2 divisions of the skeletal system?

axial and appendicular regions 

what minerals does the skeletal system store?

calcium ions (98% are in bones) and phosphate ions

what is the most abundant mineral in the human body?

calcium (2.2 - 2.4 lbs) 

what system do blood cells come from?

skeletal system

what organs does the skeletal system protect?

ribs protect heart and lungs

skull protects the brain 

vertebrae protects the spinal cord

pelvic bones protect the reproductive organs 

muscles pull on___to provide___

bones; movement (they change direction and magnitude of the forces generated by skeletal muscle)

what is another word for bone tissue?

osseous tissue (supporting connective tissue)

what does calcium phosphate covert to?

hydroxyapatite crystals (they resist compression)

how much bone mass does calcium phosphate contain?

2/3 

how much bone mass does collagen fibers contain?

1/3

what makes bone tissue strong?

collagen and hydroxyapatite

what bone cells are mature?

osteocytes

what bone cells are immature?

osteoblasts

osteocytes cause the release of what?

calcium ions from the bone to the blood

where do osteocytes sit?

in depressions called lacunae

what are the matrix layers associated with osteocytes called?

lamellae

what are canaliculi?

small channels that extend from the osteocytes to the bone capillaries

where are osteoblasts found?

in the inner and outer surface of bone

what do osteoblasts produce?

osteoid (involved in making the matirx)

osteogenesis

process of osteoblasts making a new bone (can be caused by mechanical stress and hormonal stress)

how will an osteoblast become an osteocyte?

when it becomes embedded in the bone matrix

Osteoprogenitor cells are also known as…

stem cells

which oseto is heavily involved in repair of bones after a break?

Osteoprogenitors

where are Osteoprogenitors found?

the innermost layer of the periosteum and the inner lining of the endosteum

what is the function of osteoclasts?

osteolysis - secretes acids which dissolve the bones, causing the release of stored calcium ions and phosphate ions into the blood 

where are osteoclasts found?

sites where bone is being removed

how can your bones become weaker?

when osteoclasts release calcium faster than osteoblasts

how can your bones become stronger?

when osteoblasts are more active then osteoclasts

factors of compact bone

dense and solid, forms walls of bone

factors of spongy bone

trabecular, cancellous bone, open network of plates, surrounds the medullary cavity

what does the medullary cavity contain?

bone marrow

what do compact bones consist of?

osteocytes (arranged in circular layers around a central canal which contains blood vessels that supply the osteon) 

what arrangement is spongy bone in?

trabeculae (lattice-like network of branching rods and plates)