Bio Unit 2 test

• Epidermis
• Dermis
• Hypodermis

superficial region; outer most region

middle region of the skin

• - deepest region
• - subcutaneous layer deep to skin (not technically part of skin)
• - made up of mostly adipose tissue

Keratinized stratified squamous epithelium

• - keratinocytes
• - melanocytes
• - epidermal dendritic (langerhans) cells
• - tactile (merkell) cells

• - Stratum Basale (basal layer)
• - stratum Spinosum (prickly layer)
• - stratum Granulosum (granular layer)
• - stratum corneum (horny layer)

Stratum Lucidum

• - deepest epidermal layer firmly attached to the dermis
• - has a single row of stem cells

- made up of cells that contain a weblike system of intermediate prekeratin filaments attached to desmosomes

- and abundant melanin granules and dendritic cells

- thin; 3 to 5 cell layers in which the cells flatten

- where keratohyaline and lamellated granules accumulate

- located only in thick skin

- thin transparent band superficial to the stratum granulosum

- has a few rows of flat, dead keratinocytes

- strong, flexible connective tissue

• - fibroblasts
• - macrophages
• - occasionally mast cells and white blood cells

• papillary
• reticular

- areolar connective tissue with collagen and elastic fibers and blood vessels

- dermal papillae

• - capillary loops
• - meissners corpuscles
• - free nerve endings

• - 80% of the thickness of dermis
• - collagen fibers provide strength and resiliency
• - elastic fibers provide stretch-recoil properties

• - melanin
• - carotene
• - hemoglobin

yellow to reddish- brown to black, responsible for dark skin colors

yellow to orange, most obivious in the palms and soles

responsible for the pinkish hue of skin

• - sweat glands
• - oil glands
• - hair and hair follicles
• - nails

• - Eccrine
• - apocrine

• - protects from abrasion and penetration
• - waterproof
• - barrier against biological, chemical, and physical assaults

palms, soles, and forehead

• 99% water
• NaCI
• Vitamin C
• Antibodies
• Metabolic Wastes

- confined to axillary and anogenital areas

sebum

sweat + fatty substances and proteins

apocrine

• - ceruminous glands- in external ear canal
• - mammary glands

• - widely disribted
• - most develop from hair follicles
• - becomes active at puberty
• - releases sebum

sebum

• -Alerting the body to the presence of insects on the skin
• - guarding the scalp against physical trauma, heat loss, and sunlight

• palms
• lips
• nipples
• and portions of external genitalia

• - dead keratinized cells
• - contains hard keratin
• - hair pigments: melanins

decreased melanin production, increased air bubbles in shaft

• Epidermal
• dermis

• outer connective tissue root sheath
• inner epithelial root sheath

the expanded deep end of hair follicle

sensory nerve endings

sensory nerve endings

• smooth muscle attached to follicle
• responsible for goose bumps

• vellus
• terminal

• type of hair
• pale, fine body hair of children and adult females

coarse, long hair of eyebrows, scalp, axillary, and pubic regions (and face and neck of males)

hair thinning in both sexes after 40

• -genetically determined and sex-influenced condition
• -male pattern baldness is caused by follicular response to DHT

• - protection
• - body temp regulation
• - cutaneous sensations
• - metabolic waste

• chemical
• physical/mechanical barriers
• biological barriers

exocytosis

the cell is constantly dividing

doesnt divide

up to 5% of bodys blood volume

nitrogenous wastes and salt in sweat

• - overexposure to UV radiation
• - frequent irritation of the skin

• - basal cell carcinoma
• - squamous cell carcinoma
• - melonoma

• - stratum basale cells proliferate and slowly invade dermis and hypodermis
• - cured by surgical excision in 99% of cases

• - involves keratinocytes of stratum spinosum
• - most common on scalp, ears, lower lip, and hands
• - good prognosis if treated by radiation therapy or removed surgically

• - highly metastatic and resistant to chemotherapy
• - treated by wide surgical excision accompanied by immunotherapy

A- Asymmetry; the two sides of the pigmented area do not match

B- Boder exhibits indentations

C- color is black, brown, tan and sometimes red or blue

D- diameter is larger than 6 mm (size of a pencil eraser)

• Heat
• electrical
• radiation
• chemical

• tissue damage
• denatured protein
• cell death

dehydration and electrolyte imbalance, leading to renal shutdown and circulatory shock

used to estimate the volume of fluid loss from burns

• epidermal damage only
• - localized redness, edema, and pain

• epidermal and upper dermal damage
• - blisters appear

• entire thickness of skin is damaged
• - gray/white, cherry red, or black
• - no initial edema or pain (nerve endings destroyed)
• - skin grafting usually necessary

• 25% of the body has second-degree burns
• 10% of the body has third-degree burns
• face, hands or feet bear third-degree burns

the covering of delicate hairs in fetal developement

epidermis

dermis and hypodermis

sebaceous gland secretion; protects skin of fetus

• - sebaceous gland activiy increases
• - effects of cumulative environmental assaults show after age 30
• - scaling and dermatitis become more common

• - epidermal replacement slows, skin becomes thin, dry and itchy
• - subcutaneous fat and elasticity decrease, leading to cold intolerance and wrinkles
• - increased risk of cancer

groups of cells similar in structure and function

• Epithelial tissue
• connective tissue
• muscle tissue
• nerve tissue

internal communication

brain, spinal cord, and nerves

Contracts to cause movement

attached to bones, heart, walls of hollow organs; skeletal, cardiac, smooth

forms boundaries between different environments, protects, secretes, absorbs filters

• skin surface
• lining of GI tract organs
• other hollow organs

supports, protects, binds other tissues together

• bones
• tendons
• fat and other soft padding tissue

• covering and lining epithelia
• glandular epithelia

• apical
• basal

• - upper free
• - may bear microvilli or cilia

noncellular basal lamina of glycoprotein and collagen lies adjacent to basal surface

• - composed of closely packed cells
• - supported by a connective tissue reticular lamina
• - avascular but innervated
• - high rate of regeneration

• 1. how many layers?
• 1= simple
• >1= stratified

• 2. what type of cell?
• - squamous
• - cuboidal
• - columnar

single layer of flattened cells with disc-shaped central nuclei and sparse cytoplasm; the simplest of the epithelia

Allows passage of materials by diffusion and filtration in sites where protection is not important; secretes lubricating substances in serosae

• Kidney glomeruli;
• air sacs of lungs;
• linings of heart,
• blood vessels,
• and lymphatic vessels;
• lining of ventral body cavity

Single layer of cubelike cells with large, spherical central nuclei

secretion and absorption

kidney tubules; ducts and secretary portions of small glands; ovary surface

single layer of tall cells with round to oval nuclei; some cells bear cilia; layer may contain muscus-secreting unicellular glands

Absorption; secretion of mucus, enzymes, and other substances; ciliated type propels mucus (or reproductive cells) by ciliary action

• Nonciliated type lines
• most of the digestive tract (stomach to anal canal)
• gallbladder
• and excretory ducts of some glands ciliated variety lines small bronchi uterine tubes
• and some regions of the uterus

single layer of cells of differing heights, some not reaching the free surface; nuclei seen at different levels; may contain mucus-secreting cells and bear cilia

Secretion, particularly of mucus; propulsion of mucus by ciliary action

Nonciliated type in males sperm-carrying ducts and ducts of large glands; ciliated variety lines the trachea, most of the upper respiratory tract

thick membrane composed of several cell layers; basal cells are cuboidal or columnar and metabolically active; surface cells are flattened (squamous); in the keratinized type, the surface cells are full of keratin and dead; basal cells are active in mitosis and produce the cells of the more superficial layers

Protects underlying tissues in areas subjected to abrasion

• nonkeratinized type forms the moist linings of the esophagus,
• mouth,
• and vagina;
• keratinized variety forms the epidermis of the skin,
• a dry membrane

resembles both stratified squamous and stratified squamous and stratified cuboidal; basal cells cuboidal or columnar; surface cells dome shaped or squamouslike, depending on degree of organ stretch

stretches readily and permits distension of urinary organ by contained urine

Lines the ureters, urinary bladder, and part of the urethra

a gland that is one or more cells that makes and secretes an aqueous fluid

• - site of product release- endocrine or exocrine
• - relative number of cells forming the gland- unicellular or multicellular

• - ductless glands
• - secrete hormones that travel through lymph or blood to target organs

• - more numerous than endocrine glands
• - secrete products into ducts
• - secretions released onto body surfaces(skin) or into body cavities
• - examples include mucous, sweat, oil and salivary glands

goblet cell

• - duct
• - secretory unit

• - duct type (simple or compound)
• - structure of their secretory units (tubular, alveolar, or tubuloalveolar)

• merocrine
• holocrine

- products are secreted by exocytosis

- pancreas, sweat and salivary glands

products are secreted by rupture of gland cells

connective tissue

• Connective tissue proper
• cartilage
• bone
• bone tissue
• blood

• - binding and support
• - protection
• - insulation
• - transportation (blood)

• - mesenchyme as their common tissue of origin
• - varying degrees of vascularity
• - cells seperated by nonliving extracellular matix

• - ground substance
• - three types of fibers
• - cells

- a medium in which solutes diffuse between blood capillaries and cells

• - made up of 3 components:
• 1. interstitial fluid
• 2. adhesion proteins
• 3. proteoglycans

a protein core + large polysaccharides that trap water of the ground substance

• - collagen
• - elastic
• - reticular

• - (white fibers)
• - strongest and most abundant type
• - provides high tensile strength

networks of long, thin, elastin fibers that allow for stretch

short, fine, highly branched collagenous fibers

fibroblasts

• chondroblasts
• chondrocytes

• osteoblasts
• osteocytes

hematopoietic stem cells

• loose connective
• dense connective

melanocytes

• hyaline
• elastic
• fibrocartilage

• cutaneous membranes
• mucous membranes
• serous membranes

• 1. inflammation
• 2.organization and restored blood supply
• 3. regeneration and fibrosis

• ectoderm
• mesoderm
• endoderm

nerve tissue

muscle and connective tissue

all three germ layers

9%

36%

1%

36%

• compact bone
• spongy bone

• areolar
• adipose
• reticular

• regular
• irregular
• elastic

• threadlike strands of DNA
• 30% histone
• 60% proteins
• 10% RNA

• -arranged in fundemental units called nucleosomes
• -condense into barlike bodies called chromosomes when the cell starts to divide

- defines changes from formation of the cell until it reproduces

• includes
• interphase
• mitosis

Resting period for cells

- period from cell formation to cell division

• G1 (gap 1)
• G0 (gap)
• S(synthetic)
• G2 (gap 2)

a subphase of interphase

• metabolically active
• grows vigerously

the centrioles begin replicating

subphase of interphase

gap phase in cells that permanently cease dividing

subphase of interphase

DNA is replicating

makes sure that the future cells are identically copied

subphase of interphase

final preparations for mitosis are completed and centrioles finish replicating

• -DNA helices begin unwinding from the nucleosomes
• -helicase untwists the double helix and exposes complementary chains
• -the y-shaped site of replication is the replication fork
• -each nucleotide strand serves as a template for building a new complementary strand

• - continuous leading strand is synthesized
• - discontinuous lagging strand is synthesized in segments
• - DNA ligase splices together short segments of discontinuous strand

two DNA molecules formed from the original

this process is called semiconservative replication

body growth and tissue repair

• mature cells of nervous tissue
• skeletal muscle
• cardiac muscle

• Mitosis
• Cytokinesis

• prophase
• metaphase
• anaphase
• telophase

nuclear division of cells

division of cytoplasm by cleavage furrow

• - chromosomes become visible, each with two chromatids joined at a centromere
• - centrosomes separate and migrate toward opposite poles
• - mitotic spindles and asters form

• -centromeres of chromosomes are aligned at the equator
• - this plane midway between the poles is called the metaphse plate

• - shortest phase
• - centromeres of chromosomes split simultaneously
• - chromosomes (v shaped) are pulled toward poles by motor proteins of kinetochores
• - polar microtubules continue forcing the poles apart

• - begins when chromosome movement stops
• - the two sets of chromosomes uncoil to form chromatin
• - new nuclear membrane forms around each chromatin mass
• - Nucleoli reappear
• - spindle disappears

• - begins during late anaphase
• - ring of actin microfilaments contracts to form a cleavage furrow
• - two daughter cells are pinched aprart, each containing a nucleus identical to the original

gives the cells signals to start the division process when area of membrane is inadequate for exchange

tells the cell when to stop dividing

carries instructions for building a polypeptide, from gene in DNA to ribosomes in cytoplasm

a structural component of ribosomes that, along with tRNA, helps translate messages from mRNA

bind to amino acids and pair with bases of codons of mRNA at ribosome to begin process of protein synthesis

• - DNA is the master blueprint
• - deals with the coding of an amino acid

segment of DNA with blueprint for one polypeptide

specifies a particular amino acid

transfers DNA gene base sequence to a complementary base sequence of an mRNA

• - loosens histones from DNA in area to be transcribed
• - binds to promotor, a DNA sequence specifying start site of gene to be transcribed
• - mediates the binding of RNA polymerase to promotor

• - enzyme that oversees synthesis of mRNA
• - unwinds DNA template
• - adds complementary RNA nucleotides on DNA template and joins them together
• - stops when it reaches termination signal
• - mRNA pulls off the DNA template, is further processed by enzymes, and enters cytosol

• - converts base sequence of nucleic acids into the amino acid sequence of proteins
• involves all 3 types of RNA

each three-base sequence on DNa is represented by a codon

complementary three-base sequence on mRNA

true

• ribosome complex is directed to rough ER by a signal-recognition particle (SRP)
• - forming protein enters the ER
• - sugar groups may be added to the protein, and its shape may be altered
• - protein is enclosed in a vesicle for transport to golgi apparatus

- little chemical insults and free radicals have cumulative effects

autoimmune responses and progressive weakening of the immune response

cessation of mitosis and cell aging are programmed into genes