Chapter 38

Question 1

Which of the following sequences place the terms from simplest to more complex?

Answer 1

Cells, Tissues, Organs, Organ Systems, Human Body

Question 2

Evolution of Multicellarity

Answer 2

-the transition begins with the evolution of cooperation, where cells unite together(b/c of environmental changes) and gain an advantage over solitary cells(predation)

Question 3

Unicellular Organisms

Answer 3

-consists of only one cell that does everything
-Reproduce asexually(fragmentation, budding, and binary fission)
-More challenging for survival
-Interact directly with environment
Ex: Bacteria

Question 4

Multicellularity

Answer 4

-Multiple different types of cells with different functions
-Macroscopic
-Most reproduce sexually
-Size of organism increases, as # of cells increase
-Don’t interact directly with environment to exchange materials
-Survival advantages

Question 5

Levels of Organization in multicellular organism

Answer 5

Epithelial tissue, connective tissue, muscle tissue, and nervous tissue

Question 6

Cell Theory

Answer 6

Humans contain 2 general classes of cells.
1. Somatic cells or body cells
2. Germ cells or reproductive cells: sperms and eggs

Question 7

Tissues

Answer 7

-Made of cells that carry out a limited number of functions and they also form organs
-Formed by the same type of cells to act together in a function

Question 8

Organ System

Answer 8

-functions share significant overlap
-Nervous system and endocrine system both operate via the shared organ, the hypothalamus

Question 9

4 basic types of tissue

Answer 9

1. Epithelial Tissue
2. Connective Tissue
3. Muscle Tissue
4. Neural Tissue or Nervous Tissue

Question 10

Epithelial Tissue

Answer 10

lines internal passageways and covers exposed external surfaces, forms glands(such as exocrine and endocrine

Question 11

Connective Tissue

Answer 11

Fill internal free spaces, transports materials like blood within the body, stores energy like triglycerides, and form supportive framework

Question 12

Muscle Tissue

Answer 12

Specialized in contraction, produce movement

Question 13

Neural Tissue or Nervous Tissue

Answer 13

Generate and conducts nervous impulses

Question 14

Junctions of various kinds link cells into tissues

Answer 14

1. Tight Junctions
2. Anchoring Junctions
3. Gap Junctions

Question 15

Tight Junctions

Answer 15

Plasma membrane proteins of adjacent cells interact to fuse the two cells partly together and thus create a barrier between cells(tissue lining the urinary bladder prevent waste molecules/ions from leaking out of the bladder into other body tissues

Question 16

Anchoring Junctions

Answer 16

Form button like spots or belts that weld cells together(most abundant in tissues subject to stretching like skin and heart muscle)

Question 17

Gap Junctions

Answer 17

Open direct channels between cells in the same tissue(cardiac cells help heart contract in unison)

Question 18

Epithelium Tissue(epithelia)

Answer 18

-Covers body surfaces(skin)
-Lines body cavity and tubular structures
-Function: Form barriers between body’s internal and external environment and different fluid compartments in body

Question 19

Certain epithelia(such as those lining the stomach, intestine, and secretory glands) are able to

Answer 19

-Transport materials into the internal environment from outside(absorption)
-Transport materials from the internal environment to the outside(secretion)

Question 20

Epithelium Tissue Characteristics

Answer 20

-Highly cellular(exclusively made of cells)
-Highly polar(structural and functional differences b/w exposed and attached surfaces
-Avascular(lack blood vessels)
-Attached to basement membrane or basal lamina
-Ability to regenerate(damages epithelial cells can be replaced by the division of epithelial stem cells)

Question 21

Epithelial tissue functions

Answer 21

-Protect internal environment from abrasion and invasion of microorganisms
-Mediate exchange or materials(gases, ions, etc) b/w internal and external environments
-Absorption or secretion(produce glands(sweat, etc))

Question 22

General Structure of Epithelium: Barrier

Answer 22

-adjacent cells are joined by tight junctions that limit the passage of material through the spaces b/w cells(paracellular spaces)
-permit fluids on either side of cell layer to differ in composition
-Tight junctions important in maintaining homeostasis
-“tightness” of these junctions varies from location to location; tight epithelia have junctions with extremely low permeabilities, whereas leaky epithelia have junctions that are more permeable

Question 23

General Structure of an Epithelium: Absorption

Answer 23

-for absorption, cells that make up the epithelial tissue must transport substances inward across the membrane on one side of cell and outward across membrane on opp. side of cell.
-must possess different transport systems
-b/c membranes on the two sides are distinctly different(in both structure and function), epithelial cells are said to be polarized

Question 24

Classification of Epithelia Based on Cell Shape

Answer 24

1. Squamous(flat)
2. Cuboidal(box-like)
3. Columnar(elongated)

Question 25

Squamous(flat)

Answer 25

-Scalelike, flat, thin, irregular shape

Question 26

Cuboidal(box-like)

Answer 26

-Cubelike, hexagonal boxes, nucleus round/circular located almost centrally

Question 27

Columnar(elongated)

Answer 27

Column-shaped, nucleus elongated located basally

Question 28

Classification of Epithelia: Number of Cell Layers

Answer 28

1.Simple
2. Stratified

Question 29

Simple Epithelia

Answer 29

Single layer of cells

Question 30

Stratified Epithelia(Multilayered)

Answer 30

2 or more layers of cells

Question 31

Polarity of Epithelial Tissue

Answer 31

-Apical Surface: Exposed to outside environment or fluid in body
-Basal Surface: Basal lamina or basement membrane. Anchors epithelia to the connective tissue

Question 32

Simple Squamous epithelium

Answer 32

-layer of flattened cells
-Locations: Blood vessel inner lining(endothelium) and air sacs of lungs
-Function:Diffusion

Question 33

Stratified Squamous epithelium

Answer 33

-Several layers of flattened cells
-Locations: Skin and other surfaces subject to abrasion such as the mouth, esophagus, and the vagina
Function:Protection against abrasion; usually not subject to secretion and absorption

Question 34

Cuboidal epithelium

Answer 34

-Layer of tubelike cells; free surface may have microvilli
-Locations: Glands(sweat, etc) and tubular parts of nephrons in kidneys
-Function: secretion and absorption

Question 35

Simple columnar epithelium

Answer 35

-Layer of tall, slender cells with nuclei near base. Free surface may have cilia or microvilli; may contain secretory vesicles
-Locations:Lining of gut, cervical canal and gallbladder
-Function:Secretion, absorption, such as secreting digestive enzymes and absorbing nutrients in the gut; protection; secreting mucus

Question 36

Simple pseudo(false)stratified columnar epithelium

Answer 36

-Single layer of columnar cells of differing heights; some cells do not reach the apical surface. b/c of this, nuclei are staggered.
-Locations:Nasal Cavities, trachea, and upper digestive tract; some parts of male reproductive system
-Function: Protection, secretes mucus and moves it across surface

Question 37

Stratified Columnar epithelium

Answer 37

-Locations: Small areas of the pharynx, epiglottis, anus, mammary glands, and salivary gland ducts, and urethra
-Function: Protection

Question 38

Transitional Epithelium

Answer 38

-Locations: Urinary bladder; renal pelvis; ureters
-Functions: Permits repeated cycles of
stretching without damage