Chapter 4

Question 1

Tissue

Answer 1

group of cells with a common embryonic origin in embryo + function together

Question 2

Layers of Embryonic Germ

Answer 2

• OUTER : Ectoderm — Superficial layer of skin
• MIDDLE: Mesoderm — Mesothelium
• INNER: Endoderm — Endothelium

Question 3

4 tissue types

Answer 3

Epithelial
Connective
Muscular
Nervous

Question 4

Epithelial

Answer 4

• covers body surfaces, lines hollow organs / body cavities / ducts
• forms glands

Question 5

Connective

Answer 5

• protects/supports body + organs.
• bind organs together, store energy reserves as fat,
• provide body with immunity.

Question 6

Muscular

Answer 6

• Stretch + shorten
• Generates heat ; warms body

Question 7

Nervous

Answer 7

• detects condition changes inside + outside body
• nerve action potentials/impulses; activate muscular contractions + glandular secretions.

Question 8

Cell junctions

Answer 8

Points of contact between cells

Question 9

5 junction types

Answer 9

Tight
Adherens
Desmosomes
Hemideamosomes
Gap

Question 10

Tight junction

Answer 10

• Hold plasma membrane together
• Prevent harmful chemicals from passing between cells
• Cells of epithelial tissue ; lines stomach, intestines, bladder

Question 11

Adherens Junctions

Answer 11

• Microfilaments bunch ‘adhesion belt’ create plaque inside plasma membrane
• cadherins — Transmembrane glycoproteins , joins cells

Question 12

Desmosomes

Answer 12

• contain plaque in disc-like area
• Intermediate filaments (stronger than microfilaments) attach to disc-like area
• Held very tightly together
• Prevent cardiac muscles from separating in contraction
• Keratin — transmembrane protein

Question 13

Hemidesomosomes

Answer 13

• 1/2 Desmosome — don’t link adjacent cells
• Links cell to protein on basement membrane (below epithelium)
• Only proteins — no cells
• Integrins— transmembrane protein

Question 14

Gap junction

Answer 14

• Between 2 adjacent cells
• Plasma membranes separated by narrow intercellular gap
• Chemical/electrical communication between neighbours
• Force between proteins
• Small particles + fluid go through cells
• In cardiac muscle + nervous system (electrical communication)
• connexins — membrane proteins

Question 15

Membranes

Answer 15

flat sheets of pliable tissue that cover or line a part of the body

Question 16

Epithelial membranes

Answer 16

made of connective tissue + epithelium tissue

Question 17

Mucous

Answer 17

lines body cavity ; opens directly to exterior

Question 18

Serous

Answer 18

lines body cavity ; doesn’t open directly to exterior; covers organs in cavity

Question 19

Cutaneous

Answer 19

lines outer skin; epidermis + dermis

Question 20

Synovial membranes

Answer 20

only made of connective tissue — lines joints, secretes synovial fluid

Question 21

Electrical excitability

Answer 21

ability to respond to stimuli by producing electrical signals; travel along plasma membrane due to specific voltage-gated channels

Question 22

Excitable cells exhibiting electrical excitability

Answer 22

1. Neurons
2. Muscle fibers

Question 23

Tissue repair

Answer 23

process that replaces worn out, damaged, or dead cells

Question 24

Epithelial tissue repair

Answer 24

replaced by division of stem cells

Question 25

Connective tissue repair

Answer 25

not all cells can repair

Question 26

Muscle tissue repair

Answer 26

cells perform limited repair

Question 27

Nervous tissue repair

Answer 27

some cells perform limited repair, others cannot

Question 28

Fibrosis

Answer 28

formation of scar tissue

Question 29

Younger bodies generally experience

Answer 29

• A better nutritional state
• A better blood supply to tissues
• A faster metabolic rate

Question 30

Aging slows process of

Answer 30

Tissue repair

Question 31

Aging results in

Answer 31

stiffening + loss of elasticity in tissues

Question 32

Disorders of Epithelial tissues

Answer 32

specific to individual organs, such as ulcers in the stomach

Question 33

Disorders of connective tissues

Answer 33

in nature, such as lupus