1. Info is encoded in genes

2. located on specific regions of chromosomes

3. code for polypeptides

4. discreet units

5. RNA involved in making polypeptides

6. only 1.5% of DNA codes for p.p.

7. 8.5% considered junk DNA

Scraps left over from unsuccessful mutations

Does not make polypeptides

Mutations in these regions cause common diseases: diabetes, some cancers

1.  Genes are fragmented, segments may even be on different chromosomes

2.  Junk DNA may be responsible for the complexity of higher organisms

3.  74%-94% codes for various types of RNA

4.  Many new types of RNA

5.  RNAs are regulatory

25,000

not many more than fruit fly or roundworm

Interactions between genes yield complexity

Human genes interact in about 650,000 ways

10 times more than fruit flies or roundworms

1.      First name tells number of cell layers

2.      Second name defines cell shape

First name:

SIMPLE

First Name:

Stratified

Second name:

squamous

Second Name:

CUBOIDAL

Second Name:

COLUMNAR

column shaped

longer than it is wide

1. lining or covering

2. glandular

i.                    Outer covering of external surfaces and some internal organs

ii.                  Lines body cavity

iii.               Inside surfaces of the respiratory, GI tracts, blood vessels and ducts (endothelium)

iv.                Involved in the sense organs

v.                   Tissue from which gametes develop

1. merocrine

2. holocrine

3. apocrine

A.      Secrete products by exocytosis

B.      Sweat and salivary glands do this

A.      Cell ruptures and secretion is released

B.      Oil glands do this

a.       Top part of the cell pinches off

b.       Mammary glands do this

most abundant tissue in body

cells are widely scattered

tissue contains lots of intercelluar matrix

i.                    Protection (bone in the skull, ribs)

ii.                  Support (internal skeleton)

iii.               Binding organs together (cartilage)

iv.                Separates structures (like skeletal muscle)

v.                   Transports materials (via blood)

i.                    Cells called fibroblasts are most numerous (cell that makes a fiber)

ii.                  Many different cells present

iii.               Embedded in a fluid intercellular matrix (fluid like molasses)

iv.                Many subtypes

i.                     fibers, white blood cells, and various cells involved in the immune response

ii.                  Semi-fluid matrix

iii.               Continuous throughout the body

iv.                Present in:

A.      Mucus membranes

B.      Around blood vessels nerves and organs

C.       Beneath the skin

i.                    Specialized for fat storage (can be added but not gotten rid of)

ii.                  Located below the skin and around many organs

iii.               Reduces heat loss from the body

iv.                Major energy reserve

v.                   Supports and protects some organs

i.                    Closely packed fibers that are regularly or irregularly arranged

ii.                  Covers bone and many organs

iii.               Main component of tendons and ligaments

i.                    Composed of stretchy and branched fibers

ii.                  A component of walls of arteries and of passages in the respiratory system (gives diastolic pressure in heart)

RETICULAR connective tissue

i.                    Web-like fiber system

ii.                  Binds together and supports cells of many organs

iii.               Ex. Found in liver, spleen, lymph nodes, and smooth muscle

1.      Capable of enduring stress

2.      A dense network of fibers in a jelly-like substance

3.      Found between bones

4.      Forms parts of the nose and the respiratory system (rings in throat)

5.      External part of the ear (pinna) & the eustachian tubes (inner ear to throat)

1.      Fibers and mineral salts of calcium and phosphorous

2.      Functions

i.                    Support & protection

ii.                  Movement

iii.               Calcium & phosphorous storage

iv.                Red marrow produces blood cells

1.      Liquid connective tissue

2.      Consists of plasma & formed elements

i.                    Straw colored fluid

ii.                  Primarily water

iii.               Contains dissolved substances (gases, nutrients, enzymes, and hormones)

i.                    Red blood cells- gas transport

ii.                  White blood cells- immune responses and allergic reactions

iii.               Platelets- blood clotting

1. cells are highly specialized for contraction

2. functions:

i. movement

ii. maintenance of posture

iii. heat productions

1. what we normally think of as muscle

2. attatch to bones to make body movements

3. striated- striped

4. voluntary

1. found in walls of tubes or hollow organs

2. non-striated

3. involuntary

4. Functions: churn or move material through a tube

1. muscle of the heart

2. self-stimulating

3. striated

4. involuntary

Nerve Tissue

Neurons and Nerve Cells

1. highly specialized for receiving stimuli

2. translating stimuli into nerve impulses

3. conducting those impulses to other nerves cells, muscle fibers, or glands

Nerve Tissue

Supporting Cell

A. External covering of the body

B. Complex system

C. Skin surface area about 20 square ft. on adult human

1. Maintains body temp. (sweat glands, hair)

2. Protection (barrier between external and internal env.)

3. Stimulus perception (touch)

4. Excretion

5. Vitamin D synthesis

4-5 layers of stratified squamous epithelium

4 main cell types

avascular but innervated; nerves but no blood vessels

1. keratinocytes

2. melanocytes

3. langerhans cells

4. avascular cells

a. make up 90% of skin

b. produce keratin

c. attached tightly to one another

a. about 8%

b. produce pigment called melanin

c. melanin contributes to skin color

d. protects from UV radiation

a. aid in immune response within the epidermis

b. develop in the bone marrow and migrate to the epidermis

c. interact with helper-T cells

d. easily damaged by UV radiation (tannin suppresses immune system)

a. located in the stratum basale of hairless skin (lowest layer)

b. make contact with a tactile sensory neuron

c. function in touch

1. stratum basale

2. stratum spinosum

3. stratum granulosum

4. stratum lucidum

5. stratum corneum

a. 1 row of cuboidal or columnar cells

b. produces new cells called keratinocytes

c. cells eventually migrate to the surface ( pushed up by cells dividing underneath)

d. keratinocytes die & nuclei degenerate

e. layer rest on basement layer which holds it to the dermis

a. 8-10 rows of polyhedral cells with spines on surfaces

b. spines help support the layer

c. keratinocytes take in melanin by endocytosis form the melanocytes

a. 3-5 layers of flattened cells

b. contain granules of kertohyalin, a precursor to keratin

  1. keratin is a protein

  2. found in outer layers

  3. protects against injury & microbial infection

  4. waterproofs the skin

a. only found in thick skin of palms and soles

b. 3-5 layers of clear, flat, dead cells with indistinct boundaries

a. most superficial layer

b. 25-30 rows of flat, dead cells filled with soft keratin

c. complete new surface every 1-2 weeks

d. cells are constantly shed & replaced by cells from lower layers

e. barrier against heat, light, bacteria & many chemicals

1. Composed of connective tissue with collagen and elastic fibers

2. Contains blood vessels, nerves, hair follicles, & glands

3. Thick in palms & soles & thin in eyelids

Papillary Region

of Dermis

i. areolar connective tissue with fine elastic fibers

ii. dermal papillae greatly increase surface area

iii. meissner’s corpuscles of touch

iv. dermal papillae in thick skin produce ridges in the epidermis (fingerprints_

Reticular Region

of Dermis

i. deeper portion of dermis

ii. lower region contains (layer used to make leather)

   a. dense irregular bundles of collagen fibers

   b. coarse elastic fibers

   c. hair follicles

   d. oil glands

   e. ducts of sweat glands

   f. some adipose tissue

iii. varies in thickness

iv. connective tissue gives the skin the ability to stretch & to resume shape

1. Subcutaneous layer

2. Connects the dermis to the underlying organs

3. Contains Pacinein corpuscles or lamellated corpuscles

4. Composed of loose, fibrous connective tissue

5. Supplied with lymph, blood vessels & nerves

 group of cells with specific function

 *sensitive to pressure

A. Due to combinations of:

1. Melanin (pigment of the epidermis)

2. Carotene (pigment of the dermis)

3. Blood vessels in dermis

1. Located in the stratum basale of the epidermis

2. Varies skin color from pale yellow to black

3. Number of melanocytes is same in all people

4. Amount of pigment produced varies

i. melanin is synthesized from tyrosine with the aid of the enzyme tyrosinase

ii. exposure to UV radiation increases enzyme’s activity

iii. melanin production increases

iv. both amount & darkness of melanin increase

v. tans the skin

body's reaction to damage

like a scab on a cut

most common form of cancer

half of new diagnoses of cancer in western countries is skin cancer

people with light hair, light eyes, and fair skin are most susceptible

i. reduce your exposure, especially between 10:00 and 3:00

ii. wear protection

iii. wide-brimmed hats

iv. large sunglasses

v. sunblock, at least SPF 15

vi. report new unusual changing moles

1. yellowish & orange pigments

2. precusor of vitamin A

3. Found in:

    stratum corneum

    fatty areas of dermis & subcutaneous layer

1. Epidermis is transluscent when little melanin & carotene are present

2. red color of blood shows thru yielding pink to redish skin color

CAUCASIAN

Glands

Hair

Nails

sweat glands

1. eccrine

2. appocrine

a. most common

b. occur over most of body; dense in palms & soles

c. open thru pores onto skin 

d. produce watery secretion to cool body (perspiration)

H2O

Salt

Urea, ammonia, uric acid

Amino acids

Sugar

Lactic Acid

Ascorbic Acid

maintain body temp

waste elimination

Appocrine Glands

(sudiferous)

a. limited to armpit, pubic region, behind ears, & pigmented area around nipple

b. open into hair follicle

c. function @ puberty

d. thicker secretion than eccorine

e. musky odor

f. stimulated during emotional stress & sexual excitement

g. located in dermis or subcutaneous layer

Oil Glands

oily mixture of fats, cholesterol, proteins, phermones, & inorganic salts

lubricates & softens hair & skin

inhibits bacteria

associate w/& opens into hair follicle

1. protection & insulation

2. camouflage

3. tactile sense- detects stuff moving thru hair

4. ornamentation

70-100 per day

a. illness

b. diet

c. high fever

d. surgery

e. blood loss

f. severe emotional stress

g. childbirth

h. drugs and radiation therapy

1. shaft (above skin)

2. root

3. hair follicle (sheath around hair)

4. bulb (enlarged region @ base)

5. papilla (indentation into bulb)

6. matrix (germ layer)

a. arrector pili- smooth muscle attached to hair that adjusts height

b. root hair plexuses- nerve attached to hair & detects displacement

c. sebaceous gland

due to melanin

synthesized in matrix

variations in color of melanin

variation in melanin

more iron & sulfur

1. protect tips of fingers and toes

2. pick things up

3. scratch

4. weapons

5. ornamentation

1. free edge- extends beyond digit

2. nail body- attached to digit

3. lunula- semi-circle @ base

4. nail root- inside digit

5. cuticle- skin attached to nail