Chapter 4: Histology

Question 0

What is epithelial tissue? (6)

Answer 0

• Mostly composed of cells
• Covers body surfaces
• Distinct cell surfaces
• Cell and matrix connections
• Nonvascular
• Capable of regeneration

Question 1

What is the matrix?

Answer 1

the noncellular substances surrounding the cell consisting of a ground substance and proteins

Question 2

What are the functions of Epithelial Tissue? (5)

Answer 2

• protecting underlying structures
• acting as a barrier
• permitting the passage of substances
• secreting substances
• absorbing substances

Question 3

What is a free/ apical surface?

Answer 3

cell surface that is not attached to other cells

Question 4

What is a basal surface?

Answer 4

cell surface that is attached to the basement membrane

Question 5

What is a basement membrane?

Answer 5

specialized type of extracellular material secreted by epithelial and connective tissue cells. (think of it like tape)

Question 6

What does simple mean in terms of cells?

Answer 6

single layer of cells

Question 7

What does stratified mean in terms of cells?

Answer 7

Multiple layers

Question 8

What does pseudo stratified mean in terms of cells?

Answer 8

Looks as if there are multiple layers but in actuality there is only one layer as each cell directly hits the basement layer

Question 9

What does squamous mean?

Answer 9

flat

Question 10

What does cuboidal mean?

Answer 10

cube shaped

Question 11

What does columnar mean?

Answer 11

Rectangular shaped

Question 12

What are desmosomes?

Answer 12

Reinforces the binding between cells. often in places that are subjected to stress.

Question 13

What are tight junctions?

Answer 13

hold cells together, and form permeability barrier
Types:
-zonula adherans: weak glue between cells
-zonula occludens: permeability barrier, found in stomach, bladder, so chemicals cannot pass through

Question 14

What are gap junctions?

Answer 14

protein channels that aid in intercellular communication, coordinates functions of cardiac and smooth muscle

Question 15

What are exocrine glands?

Answer 15

open contact maintained with exterior; ducts

Question 16

What are endocrine glands?

Answer 16

No open contact with exterior, no ducts, produce hormones, release through blood

Question 17

What are multicellular glands?

Answer 17

simple and compound ducts

• ducts end in tubules or sac-like structures: acini
• ducts end in simple sacs: alveoli

Question 18

What is an example unicellular gland?

Answer 18

goblet cells

Question 19

What is a merocrine gland?

Answer 19

cells of the gland produce secretions by active transport, use exocytosis

Question 20

What is an apocrine gland?

Answer 20

portion of the cell is pinched off containing secretory products

Question 21

What is a holocrine gland?

Answer 21

Entire cells are shed off containing secretions and are replaced by other cells deeper in the gland by mitosis

Question 22

Blasts vs. Cytes vs. Clasts

Answer 22

Blast: build matrix
Cytes: maintain matrix
Clasts: break down matrix

Question 23

What are mast cells?

Answer 23

contain inflammatory chemicals which release in sites of injury

Question 24

What are mesenchymal cells?

Answer 24

connective tissue stem cells

Question 25

What are collagen fibers?

Answer 25

strong, flexible microscopic ropes. found in tendons, ligaments, and bones

Question 26

What are reticular fibers?

Answer 26

very fine collagen fibers, the branch out (like strings of the collagen rope)

Question 27

What are elastic fibers?

Answer 27

Has a spring like appearance/function. stretches in respond to force and recoils when relaxed. not as strong as cartilage but, more flexible

Question 28

What is hyaluronic acid?

Answer 28

has a glassy like appearance, good lubricant in joints, found in synovial fluid, vitreous eye fluid, and connective tissue, reduces friction

Question 29

What is proteoglycan?

Answer 29

attaches to hyaluronic acid, to trap water like sponges

Question 30

What are glycosaminoglycans?

Answer 30

polysaccharide components of proteoglycan

Question 31

What is chondroitin sulfate?

Answer 31

a type of proteoglycan

Question 32

What are adhesive molecules?

Answer 32

Hold proteoglycan aggregates together (-nectin)

Question 33

What is a mesenchyme?

Answer 33

Source of all adult connective tissue

Question 34

What is mucus connective tissue?

Answer 34

found only in the umbilical cord. *wharton's jelly*

Question 35

What is connective tissue proper?

Answer 35

Loose: areolar, reticular, adipose Dense: dense regular collagenous, dense regular elastic, dense irregular collagenous, dense irregular elastic

Question 36

What are the supporting connective tissues?

Answer 36

hyaline cartilage, fibrocartilage, elastic cartilage, bone

Question 37

What is the fluid connective tissue?

Answer 37

Blood, bone marrow

Question 38

What is areolar connective tissue?

Answer 38

has loose packing material called stroma, attaches skin to underlying tissues, contains collagen, reticular, elastic fibers, cells include fibroblasts, mast, lymphocytes, adipose, macrophages

Question 39

What is adipose tissue?

Answer 39

fat tissue

Question 40

What is reticular tissue?

Answer 40

- forms structure of lymphatic and hemopoietic tissues - fine reticular fibers - spaces between cell contain white cells and dendrite cells

Question 41

What is the difference between tendons and ligaments?

Answer 41

Tendons connect muscle to bones, ligaments connect bones to bones

Question 42

What is perichondrium?

Answer 42

dense irregular connective tissue that surrounds cartilage, fibroblasts in this structure can differentiate into chondroblasts

Question 43

What are chondrocytes?

Answer 43

cartilage cells

Question 44

What are lacunae?

Answer 44

spaces in which chondrocytes are located, surrounded by matrix, without this cells would die.

Question 45

What is hyaline cartilage?

Answer 45

large amount of collagen fibers, evenly distributed in proteoglycan matrix. found in areas for strong support and a little flexibility (ribs, trachea, bronchi, on ends of bones (epiphysis)

Question 46

What is fibrocartilage?

Answer 46

thick collagen fibers distributed in the proteoglycan matrix, slightly compressible and very tough, found in pressure areas, as shock absorber (knee, jaw, vertebrae disks)

Question 47

What is elastic cartilage?

Answer 47

elastic and collagen fibers embedded in proteoglycans, rigid but elastic. found in external ears, and epiglottis

Question 48

What is trabeculae?

Answer 48

beam in bone anchoring strands of spongy bone

Question 49

What is lamellae

Answer 49

layers of compact bone

Question 50

What is skeletal muscle?

Answer 50

voluntary, striated, multi-nuclei

Question 51

What is cardiac muscle?

Answer 51

involuntary, striated, branched, single nuclei

Question 52

What is smooth muscle?

Answer 52

involuntary, no striations, single nucleus

Question 53

What are intercalated disks?

Answer 53

Faint lines located between cells, containing gap junctions, found in cardiac tissue

Question 54

Multipolar vs bipolar vs unipolar?

Answer 54

- several dendrites one axon - one dendrite one axon - axon and dendrite are one unit

Question 55

What is synovial fluid?

Answer 55

rich in hyaluronic acid, reducing friction to allow movement. found in joints

Question 56

What is a labile cell?

Answer 56

one that goes through cycling mitosis

Question 57

What is a stable cell?

Answer 57

one that has no mitosis after growth ends, but can divide incase of injury (liver, pancreas, endocrine cells)

Question 58

What is a permanent cell?

Answer 58

if killed will be replaced by a different type of cell, very limited regenerative ability (nervous, skeletal, and cardiac muscle)

Question 59

What is a primary union?

Answer 59

edges of wound are close together, allows for easier healing

Question 60

What is a secondary union?

Answer 60

edges of wound are not close, greater chance of scarring and infection