Unit 2 - Anatomy & Physiology

Integumentary system

skin, accessory structures, hair, glands and nails.

Functions of integumentary system

protection, sensation, vD, temp regulation, and excretion.

Skin

Made up of two major tissue layers: Epidermis & Dermis

Epidermis

Known as the cutaneous membrane: keratinized stratified squamous epithelium.

Prevents water loss and resists abrasion.

Strata

Distinct layers of epidermis

Stratum Corneum

 the most superficial stratum of epidermis, consists of dead squamous cells filled w/ keratin.

Dandruff

Excessive slogging of stratum cornea cells from surface of scalp.

Callus

Numbers of layers in the stratum cornea increase, and produce a thickened area.

Corn

Over a bony prominence, stratum corner can thicken to form a cone-shaped structure.

Dermis

Dense collagenous connective tissue containing fibroblasts, adipocytes and macrophages.

Cleavage Lines:

(tension lines) resistant to stretch.

Dermal Papillae

Projects toward the epidermis found in the upper part of the dermis.

*LYMPHATIC = (color)

GREEN

Skin color

pigments in the skin, blood circulating and thickness of stratum cornea determines it.

Melanin and carotene

*Melanin

group of pigments primarily responsible for skin, hair and eye color.

Carotene

Yellow pigment found in plants.

Suntan

sunlight → stimulates melanocytes → increases melanin production

Cyanosis

Decrease in blood O2 content, produced a bluish color of the skin.

Skin cancer

metastasizing and malignant

Basal cell carcinoma

Cells in stratum are affected

Cancer removed by surgery

Squamous Cell Carcinoma

Cells above stratum basale are affected

Can cause death

Malignant Melanoma

Arises from melanocytes in a mole

Rare type & can cause death

Hypodermis is

NOT a part of the skin

Subcutaneous Tissue

Skin rests on it.

Attaches the skin to the underlying bone & muscle and supplies it w/ blood vessels and nerves.

Functions of Subcutaneous Tissue

Padding & insulation

Estimate total body fat (21-30%f) (13-25% M)

Hair Follicle

invagination of the epidermis that extends deep into the dermis

Hair Shaft

Protrudes above the surface of the skin

Root

below the surface

*Hair Bulb

Expanded base of the root.

Where hair comes from

Cortex & Medulla

the __ surrounds the softer center, the __.

Cortex is covered by the ___. What is it?

Cuticle.

Single layer of overlapping cells that holds the hair in the hair follicle.

Hair Papilla

Extension of the dermis that protrudes into the hair bulb and contains blood vessels.

Growth Stage

Hair is formed by mitosis of epithelial cells within the hair bulb; its cells divide and undergo keratinization.

Resting Stage

Growth stops and hair is held in the hair follicle.

Eyelashes

Grow for 30 days & rest for 105.

Scalp Hairs

Grow for 3 years and rests for 1-2.

*Arrector Pilli

Contract and cause the hair to become perpindicular to the skins surface.

Sebaceous glands

simple branched acing glands, connected by a duct to the superficial part of the hair follicle.

produces sebum (oily antibacterial)

Eccrine Sweat glands

Released sweat by merocrine secretion.

Located everywhere but mostly palms & soles.

Apocrine Sweat Glands

Becomes active at puberty b/c influence of sex hormones.

Glands open into hair follicles in the armpits & private parts.

Nail

Thin plate, consisting of layers of dead stratum corner that contains a ver yard type of keratin.

Nail Body

visible part of nail

Nail root

part of nail covered by skin

cuticle / eponychium

stratum corner that extends onto the nail body and root extends distally from nail matrix.

Lunula

whitish, crescent-shaped area at the base

Sensory Receptor

associated w/ the skin

can detect pain, heat, cold & pressure

vitamin D production

UV light causes skin to produce a precursor molecule of __.

Stimulated the small intestine to absorb calcium and phosphate for body functions.

Temperature Regulation

Important B/C the rate of chemical reactions within the body can be increased or decreased by changes in body temp.

Slight temperature can make enzymes operate less efficiently.

Excretion

Removal of waste in the body

First Degree Burn

Burns only epidermis & red and painful.

Caused by sunburn, or brief exposure. No scarring.

Second Degree Burn

Burns both epidermis and dermis.

2 weeks healing time, no scarring.

Third Degree Burn

Burns damage the complete epidermis & dermis

Painless b/c sensory receptors have been destroyed.

Scarring either white, tan, brown, black.

Burn healing

All 2nd degree burns, epidermis is damaged.

Epidermis regenerated from epithelial tissue in hair follicles & sweat glands.

Split skin graft

Epidermis and part of dermis are removed from another part of the body and placed over the burn.

Aging and the integument

Blood flow decreases and the skin becomes thinner due to decreased amounts of oxygen

Loss of elastic fibers cause skin to sag & wrinkle.

Components of skeletal system

bones, cartilages, tendons and ligaments

bone matrix

35% organic - collagen and proteoglycans

65% inorganic - calcium phosphate crystal (hydroxyapatite)

Osteoblasts

(Build) Formation of bone and repair of remodeling.

Osteocytes

Cells that maintain bone matrix and form osteoblasts after bone matrix has surrounded it.

Lacunae

Cell bodies within a bone matrix

Canaliculi

CANALS! Narrow, long spaces

Aversion Canals

bone-destroying cells

Contributes to bone repair and remodeling by removing existing bone. (bone reap)

Lamellar Bone

Mature Bone

Organized into thin, concentric sheets of layers (Lamallae)

Spongy bone

Less bone matrix, more space.

Interconnecting rods/plates called trabecular.

Between trabeculae filled wi/ bone marrow and blood vessels

Compact Bone / Aversion Canal

More bone matrix, less space.

Solid outer layer surrounding each bone.

diaphysis

center portion of the bone which is composed of compact bone surrounds a hollow center - medulallaruy cavity

epiphysis

end of a long bone.

contains mostly spongy bone (compact on outside)

*Articular Cartilage

within joints, end of long bone covered with hyaline cartilage

Epiphyseal Plate

Located between epic and dia, growth in bone length occurs there.

*Adulthood - turns into the line & doesn’t get taller.

Ossification

Process of bone making

Marrow

Cavities in spongy bone and the medullary cavity in the diaphysis are filled w/ soft tissue.

Red Marrow

Location of blood forming cells.

Yellow Marrow

Fat

Fetus - bone has red marrow.

Adults - red marrow in flat bones. Y

Periosteum

Outer surface of a bone is covered by a connective tissue membrane.

Endosteum

Single layer of connective tissue that lines the internal surfaces of all cavities within bones.

Contains osteoblasts and osteoclasts

Intramembranous Ossification

When osteoblast begin to produce bone within connective tissue.

Endochondral Ossification

Cartilage is replaced by bone.

Primary & Secondary ossif. center: bone in diaphysis in long bone, and then bone in epiphysis.

Bone Growth in Width

Occurs by definition of new bone lamellae onto existing bone.

Osteoblasts put new bone matrix on bones between periodontal matrix, increases width. (Appositional Growth)

Bone Growth in Length

A major source of increased height in an individual occurs in epiphyseal plate, occurs through endochondral ossification.

Calcium

A critical ingredient involves in stimulation of skeletal and cardiac muscle contraction, and exocytosis of cellular molecules.

Bone

Major storage site for calcium.

Movement of calcium in and out of bone helps determine blood levels of calcium.

Parathyroid Hormone (PTH)

Increases formation and activation of osteoclasts.

Stimulates reabsorption of Ca+ from urine in the kidney, reducing the amount excreted from the urine.

Calcitonin

Secreted from C cells in the thyroid glands when blood Ca+ levels are too high.

Lowers blood Na+ levels by inhibiting osteoclast activity.

*average amount of bones in adult body

206

*Axial skeleton

Auditory muscles (malleus, inc, stapes) 6 total

22 bones in brain & face

14 facial (only 1 not)

Bones of skull

Hyoid Bone

Vertebral column

thoracic cage

Appendicular Skeleton

Bones of upper limbs, lower, and 2 girdles.

Long bone

upper and lower limb bones

short bones

wrist and ankle

Flat bones

skull and sternum

irregular bone

vertebrae & facial bones

*Foramen Magnum

base of skull

Formane

Hole

Foramen Magum

Fossa

Depression

Glenoid Fossa

Process

Projection

Condyle

Smooth, rounded end

Occipital condyle

Meatus / Canal

Canal - like passageway

External auditory meatus

tubercle / tuberosity

Lump of bone

Greater tubercle

Cranial Structures

connected by immovable joints (sutures)

4 principle sutures

coronal

sagittal

lambdoid

squamous

Sphenoid Bone

Forms part of cranium floor, lateral posterior portions of eye orbits, lateral portions of cranium anterior to temporal bones

(Sella Turcica)