Chapter 4 Tissue

Question 1

Tissue

Answer 1

Collection of specialized cells that perform limited number of functions

Question 2

Histology

Answer 2

the study of tissues

Question 3

Four main types of tissue

Answer 3

1. Epithelial tissue (covering, surfaces, linings, glands)
2. Connective tissue (support fill space, structure, strength, transport, storage
3. Muscle tissue ( movement)
4. Nervous tissue (Control, transmit info)

Question 4

Primary Germ layers

Answer 4

embryonic layers, give rise to all four tissue types in adult

Question 5

Epithelial Tissue (2 categories)

Answer 5

1. Epithelia- covering
2. Glands- produce fluid secretions

Question 6

Features of Epithelial Tissue

Answer 6

1. Cellularity: little extracellular matrix mostly cells
2. Contacts: cells linked by strong junctions
3. Polarity: apical + basal surfaces, separate functions
4. Attachment: attached to CT via basal lamina
5. Avascularity: diffusion from CT
6. Regeneration: high turnover, stem cells at basal surface

Question 7

Functions of epithelial tissue

Answer 7

1. Provide Physical protection
2. Control permeability
3. Provide sensation
4. Produce specialized secretions

Question 8

Structure of Epithelial tissue

Answer 8

1. Apical Surface: exposed to environment may have: microvilli: absorption or secretion
   cilia: fluid movement
2. Basolateral Surface: attachment to neighboring cells via intercellular connections

Question 9

Basal lamina ( a.k.a basement membrane)

Answer 9

1. Lamina lucida: from epithelia
   glycoproteins + fine filaments
   restrict large molecule movement
2. Lamina densa: from CT
   coarse protein fibers
   provide strength

Question 10

Squamous

Answer 10

flat, disc shaped nucleus

Question 11

Cuboidal

Answer 11

Cube, center round nucleus

Question 12

Columnar

Answer 12

tall, basal oval nucleus

Question 13

simple

Answer 13

one cell layer

Question 14

stratified

Answer 14

2 or more protection

Question 15

Simple squamous epithelium

Answer 15

-thin, delicate
-in protected regions
-Locations:
-mesothelium
(serosa)
-endothelium
(blood vessels, heart)
-kidney tubules
-conjunctiva
-alveoli of lungs
-Functions:
absorption, diffusion, filtration or secretion

Question 16

Stratified Squamous Epithelium

Answer 16

-basal cells look cuboidal, apical cells
squamous
-on exposed surfaces
-two types:
A. Nonkeratinized = mucosa
-kept moist
-all cells nucleated
Locations:
-mouth, esophagus
-anus
-vagina
B. Keratinized = epidermis
-dry, apical cells dead
-cells contain keratin protein
to resist dehydration
-Functions:
provide protection from abrasion,
pathogens, chemicals

Question 17

Simple Cubodial Epithelium

Answer 17

-Locations:
-kidney tubules
-pancreas
-salivary glands
-thyroid
-Functions:
-secretion or absorption

Question 18

Transitional Epithelium

Answer 18

-relaxed: looks like stratified cuboidal
-stretched: looks squamous
-Locations:
-urinary bladder
-ureters
-Function:
-tolerate excessive stretching

Question 19

Simple Columnar Epithelium

Answer 19

-nuclei line up near basal lamina
-apical surface of cells often has microvilli =
“brush border” (in intestine)
-goblet cells often present: secrete mucus
-Locations:
-stomach
-intestine
-gallbladder
-uterine tubes
-collecting ducts of kidney
-Functions:
-absorption or secretion

Question 20

Pseudostratified Columnar Epithelium

Answer 20

-several cell types:
varying shapes and functions
-all cells contact basal lamina
-some too short to reach apical surface
-nuclei scattered so it appears stratified
-tall cells have cilia on apical surface
-goblet cells (mucus) often present
-Locations:
-nasal cavity, trachea, bronchi
-male reproductive tract
-female uterine tubes
-Functions:
-move material across surface

Question 21

Stratified Columnar Epithelium

Answer 21

-rare
-two layers or multiple layers with only
apical layer columnar
-Locations (tiny parts of):
-pharynx, epiglottis
-anus
-mammary glands
-salivary glands
-urethra
-Functions
-minor protection

Question 22

Glandular Epithelium

Answer 22

for secretion makes up glands

Question 23

Endocrine glands

Answer 23

“internally secreting” secrete into interstitial flood, blood secretions= hormones

Question 24

Exocrine Glands

Answer 24

“externally secreting”
secrete into duct, epithelial surface
e.g. digestive enzymes, perspiration,
tears, milk, mucus
Classified three ways:
a. mode of secretion
b. type of secretion
c. structure

Question 25

Modes of secretion

Answer 25

1. Merocrine secretion 2. Apocrine secretion 3. Holocrine secretion

Question 26

Merocrine secretion

Answer 26

-product released from secretory vesicles by exocytosis e.g. mucus, sweat

Question 27

Apocrine secretion

Answer 27

-product accumulates in vesicles -apical region of cell with vesicles is shed to release product e.g. milk

Question 28

Holocrine secretion

Answer 28

product accumulates in vesicles -whole cell is lysed to release product -cell dies, must be replaced by stem cells e.g. sebum

Question 29

Type of secretion

Answer 29

1. Serous glands: water + enzymes e.g. parotid salivary gland 2. Mucus glands: mucin (+water = mucus) e.g. goblet cell 3. Mixed exocrine glands: serous + mucus secretion e.g. submandibular salivary gland

Question 30

Gland Structure

Answer 30

1. Unicellular Gland: 1 cell e.g goblet cell 2. Multicellular gland: group of cells named for shape and structure

Question 31

Connective Tissue (CT) features

Answer 31

-never exposed to environment -usually vascularized -consists of cells in matrix

Question 32

Components of