Cell structure + Epithelial Tissue

Question 1

What are the levels of anatomical organization in the body?

Answer 1

Atoms -> molecules -> macromolecules -> cells -> tissue -> organ -> system

Question 2

Two types of cells

Answer 2

Prokaryote and eukaryote cells

Question 3

What structures do ALL cells share?

Answer 3

Membrane

Genetic Material (dna)

Cytosolic fluid

Question 4

Define tissue, and what are the 4 types

Answer 4

Tissue: group of similar cells functioning together

Epithelial
Muscle
Nervous
Connective Tissue

Question 5

Define organ

Answer 5

2 or more tissues that do a specialized function

Question 6

Define System

Answer 6

group of organs function together

Question 7

Main cell organnelles (membrane, mitochodria, nucleus, smooth/rough ER, ribosome, golgi)

Answer 7

Membrane (barrier)
Mitochondria (creates ATP)
Nucleus (where dna is formed)
Smooth ER (no ribosomes attached)
Rough ER (ribosomes attached to it)
Ribosome (synthesizes protein)
Golgi apparatus (sorts and transports)

Question 8

How does the dev of tissue layers start in embryonic dev?

Answer 8

**starts of as 3 germ layers

Ectoderm - nervous tissue + all associated organs + epithelial

Mesoderm - muscular tissue + connective tissue + some epithelial

Endoderm - all epithelial

Question 9

Epithelial Tissue (function + locations)

Answer 9

• protective tissue made of sheets of ET cells
• covers all body surface, lines body cavities, hollow organs, and most glands (exps include digestive tract, and inside mouth)

Question 10

Common characteristics of epithelial tissue

Answer 10

• usually very organized
• not a lot of space b/w cells (packed)
• has direction (apical and basal sides)

Question 11

ET and CT are found together. True or False

Answer 11

TRUE

ET and CT are almost ALWAYS found together, but they are not the same, their structure and function is different

Question 12

General functions of ET

Answer 12

• protection
• secretion
• absorption
• excretion/filtration
• diffusion
• transport
• sensation (we don’t talk ab this a lot in class)

Question 13

Characteristics of epithelial tissue

Answer 13

1. Cellularity (tightly packed w cells)
2. Polarity (apical + basal sides)
3. Attachment (basement membrane)
4. Avascula (w/o blood vessels) - so it doesn’t survive that long
5. Regenerative (cells proliferate quickly) - they die and therefore divide quickly

Question 14

Why are common cancers in epithelial tissues?

Answer 14

ET regenerate and divide very quickly and they regenerate through life

Question 15

Does epithelial tissue have blood vessels?

Answer 15

No it is avascular.
but **connective tissue **does have blood supply

Question 16

classification of ET based on layers

Answer 16

• simple (1 layer)
• stratified (multiple layers)
• psuedostratified (part of simple, “fake stratified”)

Question 16

classification of ET based on shape

Answer 16

squamous (squished flat)
cuboidal
columnar
transitional (stretchy, example in bladder)

Question 16

simple squamous (functions + locations)

Answer 16

functions:
- absorption, secretion, filtration, diffusion (in lungs!)
- reduced friction

locations:
- alveoli (gas exchange, diffusion)
- endothelium (lining blood vessels, reduces friction so blood flows whoosh)

Question 16

stratified squamous (functions + locations)

Answer 16

functions:
- resists abrasion
- protection!

locations:
- epidermis (skin)
- mouth (helps resist abrasion)

Question 16

simple cuboidal (functions + locations)

Answer 16

functions:
- secretion/absorption, where ions and molecs are selectively secreted or reabsorbed

locations:
- ducts and glands, kidney tubules, ovaries, thyroid gland

Question 16

Simple columnar (functions + locations)

Answer 16

functions: absorption/secretion/protection, cilia aid in propulsion (movement)

locations: lining of digestive tract from stomach to anal canal (stomach, intestines, gallbladder), lining of respiratory tract

Question 16

pseudostratified ciliated columnar (functions + locations)

Answer 16

functions: secretion/propulsion (helps move mucous and trapped particles) along resp tract, provides protection

locations: lining of respiratory tract (nasal cavity, trachea, bronchi), male sperm duct

Question 16

Transitional (functions + locations)

Answer 16

functions: permits expansion and recoil after stretching

locations: lining of urinary tract (renal, pelvis, ureters, urinary bladder, urethra)

Question 17

Exocrine glands

Answer 17

• secretes onto epithelial surface
• unicellular or multicellular
• thermoregulation (sweat glands)
• usually has a duct

Question 18

Endocrine

Answer 18

- releases hormone (exocytosis) - direcetely into localized capillaries - no ducts

Question 19

Two types of unicellular exocrine glands

Answer 19

mucous cells (dig tract) goblet cells (resp tract) both these cells secrete mucins, which forms mucous when mixed w/ water maintains moisture and provide a protective lining

Question 20

two types of multicellular exocrine glands

Answer 20

formed by invagination of epithelium sheet + has variety of diff duct shapes sweat glands - secretes sweat sebaceous glands - secretes sebum

Question 21

merocrine (eccrine) vs apocrine vs holocrine

Answer 21

merocrine: secreted by exocytosis apocrine: secreted by pinching off apical portion cell (sweat) holocrine: cell bursts (zit that u can pop)