Anatomy and Physiology I - EXAM 1

EXAM 1 - INTEGUMENTARY

What is Chemical Energy

potential energy found in molecular bonds (covalent and ionic)

What are Polar bonds

a greater difference in electronegativity pull electrons unequally

What are Ionic Bonds

atoms of opposing charges (electrolytes) join together or dissociate in water

What is Electrical Energy

kinetic energy found in movement of charged particles

What is Mechanical Energy

transfered from object to object to power movement

What is Simple Diffusion

passive transport; nonpolar molecules diffuse over membrane (O2, CO2, steroid hormones)

What is Facilitated Diffusion

passive transport; polar substance require channel proteins (glucose, ions, amino acids)

Define uniporter, symporter, antiporter

Channel proteins that transport one/two molecules across or switch one for one

What is Osmosis

passive transport; water passes through aguaporin to follow osmotic gradient

What is Primary transport

active transport; molecules go against gradient using ATP for energy

What is Secondary Transport

active transport; molecules go against gradient using electrochemical concentration gradient (potential) energy

What is Vesicular transport

active transport; phagocytosis (immune system) and pinocytosis (extracellular fluid)

What is Epithelial Tissue

sheets of cells covering surfaces and lining organs (avascular); attached by connective tissue

What is Connective Tissue

anchors structures of the body; made of cells, protein fibers, and ground substance

What makes up Ground Substance

extracellular fluid, proteins, and carbs that cushion and support tissue

What two substances make up Extracellular matrix

ground substance and protein fibers making up connective tissue

Cells of Connective Tissue

adipocytes, chrondrocytes, osteocytes

What is Muscle Tissue

low regeneration; contractile and highly vascular cells

What is Nervous Tissue

10% neurons and 90% neuroglia to support conduction of signals

Fibrosis

tissue is replaced with connective tissue (collagen) to become scar tissue; loses original function

Influences of Regeneration

nutritional intake, age, blood supply, cell mitotic capacity, injury extent

What is the Epidermis

top layer of skin; keratinized squamous epithelium

Cells of Epidermis

Keratinocytes (produce keratin), melanocytes, dendritic cells (phagocytotic), tactile cells (sensory)

Layers of Epidermis (bottom to top)

basal lamina (basement membrane), stratum basale/germinativum, stratum spinosum, stratum granulosum, stratum lucidum, stratus corneum

Stratum Basale/Germinativum

(bottom layer) attached to dermis, single row of constantly dividing stem cells; contains melanocytes; closest to dermal vascularity

Stratum Granulosum

(above spinosum) start of keratinization; contains hydrophobic lamellar granules for water retention; too far for capillaries

Topical vs. Transdermal Medications

Topical (polar) cannot cross lamellar coating and are localized

Transdermal (nonpolar) cross lamellar coating and are systemic

Stratum Lucidum

(Second to top layer) only in THICK skin; extra protection

Thick vs thin skin

thick contains stratum lucidum and sweat glands, but no hair follicles

thin lacks stratum lucidum and has sweat gland and hair follicles (less mechanical stress)

Stratum Corneum

(top layer) thickest layer to protect deeper cells; retains water (keratinocytes shed regularly)

Types of Pigment

Eumelanin (brown and black)

Pheomelanin (yellow and red)

Carotene (orange; through diet; converts to Vit A)

Hemoglobin (red; seen when keratinocytes are more transparent)

Dermis

middle layer of skin; papillary (top) and reticular (bottom) layers

Papillary layer

upper layer of dermis; areolar loose connective tissue and ground material for water retention

Dermal papillae (Friction ridges)

made of capillaries, nerves, and touch receptors (friction ridges combine papillae and epidermis)

Reticular Layer

deeper layer of dermis; dense irregular connective tissue for multidirectional strength; contains nerves, blood vessels, and lymphatic vessels

Striae

tears to dermis from extreme stretching (stretch marks)

What is the Hypodermis

deepest layer of skin; adipose and areolar tissue that anchors skin to muscle (highly vascular and insulating)

What are Wrinkles

reduction in protein fibers, ground substance, and adipose tissue in dermis/epidermis

Categories of Burns

1st - only epidermis (erythema)

2nd - all epidermis, some dermis (blisters and infection risk)

3rd - epidermis, dermis, and some hypodermis (nerve damage and medical intervention required)

Accessory Structures

Hair, nails, glands

What is Hair

Column of keratinized squamous epithelial cells

Shaft

Portion of hair above the skin; dead keratinocytes

Root

Portion of hair below the skin; living keratinocytes & dividing stem cells

Follicle

Layer of epidermal tissue anchoring root to dermis

Arrector pili

smooth muscle that contracts for piloerection

Hair matrix

region of dividing cells adjacent to papilla

Parts of the Shaft

Medulla (center), cortex (middle), cuticle (outside)

Medulla

Core of loosely arranged keratinocytes; soft keratin for some durability and much flexibility

Cortex

Several layers of keratinocytes tightly packed; hard keratin prevents shedding (pigmentation granules here)

Cuticle

single layer of overlapping cells to prevent hair strands fusing; most keratinized & hard keratin

Split Ends

Damage to the cuticle exposing underlying layers (not repairable)

Types of Hair

Lanugo (unpigmented fetal hair)

Vellus (fine body hair)

Terminal (coarser hair of scalp, face, axillary publc regions)

What Determines Hair Texture

Cross-sectional shape of hair follicle

Growth Cycle of Hair

Anagen (nourished by blood supply)

Catagen (follicle detaches from blood supply)

Telogen (resting phase where hair dies and falls out)

Terminal Hair Growth Times

Scalp (6 years w/ higher mitotic rate)

Eyebrows/lashes (30 days)

All growth slows around 50 y/o

What are Nails

Modified epidermis w/ keratinocytes producing only hard keratin

Parts of the Nail

Plate (body and root), Nail bed, Nail matrix

Nail plate

Made of internal root portion and external body portion

Nail bed

No melanocytes in the body so clear bed gives view of epidermis

Nail matrix

Site of new growth

What are Glands

modified epithelial tissue for specific function; anchored in DERMIS

What type of glands are in the integumentary system?

Exocrine glands (non-hormonal secretions)

Types of Sweat Glands

Eccrine glands, apocrine glands

MODIFIED: ceruminous and mammary glands

Eccrine glands

Secrete sweat to skin surface and found throughout the body

Sweat contains 99% water with some solutes, waste, and antibacterial compounds

Apocrine glands

Secrete sweat to hair follicle and found in axillary/genital regions (puberty)

Sweat contains fatty acids & proteins (odor)

Ceruminous glands

Secretes cerumen to ear canal for protection

Mammary glands

Secrete milk in adipose breast tissue

Milk contains protein, lipids, carbs, hormones, antibodies