Histology

Question 1

Epithelial Tissue: General Characteristics

Answer 1

1. Cover all body surfaces - inside & out
2. Major tissue of glands
3. Reproduce rapidly (thanks to vascular underlying connective tissue)
4. Tightly packed

Question 2

Epithelial Structure

Answer 2

1. one side is free (exposed to outside or internal space)
2. other side is attached to connective tissue by thin, nonliving layer called the basement membrane (basal lamina & reticular lamina)

Question 3

Epithelial Classification
1. Simple vs. Stratified

Answer 3

Simple: single layer of cells
Stratified: many layers of cells

Question 4

Epithelial Classification

Squamous vs. Cuboidal vs. Columnar

Answer 4

Squamous: thin & flat Cuboidal: cube-shaped Columnar: elongated

Question 5

Simple Squamos Epithelium

Answer 5

Structure: single layer of thin, flat cells
Function: diffusion & filtration
Location: air sacs, walls of capillaries, inside of blood & lymph vessels
*Can Be Damaged Easily b/c so thin

Question 6

Simple Cuboidal Epithelium

Answer 6

Structure: single layer, cube-shaped Function: secretion & absorption Location: covers ovaries, lines kidney
tubules, & gland ducts (salivary, liver, pancreas)

Question 7

Simple Columnar Epithelium

Answer 7

Structure: single layer, elongated (column shaped) Function: absorption
Location: lining of digestive tract *microvilli
*goblet cells

Question 8

Psuedostratified Columnar Epithelium

Answer 8

Structure: appear layered but are not
Function: trap & move foreign particles & move sex cells
Location: lines respiratory & reproductive passages
*cilia

Question 9

Stratified Squamous Epithelium

Answer 9

Structure: outermost layer is thin, flat; deep layers cuboidal or columnar
Function:
Keratinized: dry protective coating Non-keratinized: moist & protective
Location: K = skin
Not K = esophagus, mouth, vagina

Question 10

Stratified Cuboidal Epithelium

Answer 10

Structure: 2 layers of cubed cells Function: protection
Location: largest ducts of glands (sweat,
mammary, & salivary)

Question 11

Stratified Columnar Epithelium

Answer 11

Structure: superficial layer elongated Function: protection
Location: male urethra, ducts of lg. glands
*rare

Question 12

Transitional Epithelium

Answer 12

Structure: changes, squamos & cuboidal depending on stretching
Function: expandable lining & barrier
Location: ureters, urinary bladder, part of urethra

Question 13

Four types of tissues

Answer 13

Epithelial
Connective
Muscle
Nervous

Question 14

Muscle Tissue: Skeletal description

Answer 14

Long, cylindrical, multinucleate cells; obvious striations

Question 15

Muscle Tissue: Skeletal location

Answer 15

In skeletal muscles attached to bones or occasionally to skin

Question 16

Muscle Tissue: Skeletal function

Answer 16

Voluntary movement; locomotion; manipulation of the environment; facial expression, voluntary control

Question 17

Muscle Tissue: Cardiac description

Answer 17

Branching striated, generally uninucleate cells that interdigitate at specialized junctions

Question 18

Muscle Tissue: Cardiac location

Answer 18

The walls of the heart

Question 19

Muscle Tissue: Cardiac function

Answer 19

As it contacts, it propels blood into the circulation; involuntary control.

Question 20

Muscle Tissue: Smooth description

Answer 20

Spindle-shaped cells with central nuclei

Question 20

Nervous Tissue description

Answer 20

Neurons are branching cells; cell processes that may be quite long extended from the nucleus-containing cell body; also contributing to nervous tissue are nonirritable supporting cells

Question 21

Nervous Tissue function

Answer 21

Transmit electrical signals from sensory receptors and to effectors (muscles and glands) which control their activity

Question 22

Nervous Tissue location

Answer 22

Brain
spinal cord
nerves

Question 23

Connective Tissue

Answer 23

1. Found everywhere in the body
2. Most abundant and widely distributed tissues

Question 24

Connective tissue functions

Answer 24

a) Binds body tissues together | b) Supports the body c) Provides protection

Question 25

Connective Tissue Characteristics

Answer 25

• All Types Come from Mesenchyme – – embryonic connective tissue • Variations in blood supply – Some well vascularized, some poor, some avascular

Question 26

Connective tissue 3 Components

Answer 26

1. Ground substance: mostly water, proteins & polysaccharides 2. Fibers: Produced by FIBROBLASTS, 3 types Collagen (white) fibers, Elastic (yellow) fibers, Reticular fiber 3. Cells *1+2 = Extracellular Matrix

Question 27

Mesenchyme description

Answer 27

Embryonic connective tissue; gel-like ground substance containing fibers; star-shaped mesenchymal cells.

Question 28

Mesenchyme function

Answer 28

Gives rise to all other connective tissue types.

Question 29

Mesenchyme location

Answer 29

Primarily in embryo

Question 30

Areolar

Answer 30

Connective Tissue Proper: Loose

Question 31

Areolar description

Answer 31

Gel-like matrix with all three fiber types; cells: fibroblasts, macrophages, mast cells and some white blood cells.

Question 32

Areolar function

Answer 32

Wraps and cushions organs; its macrophages phagocytosis bacteria; plays important role in inflammation; holds and conveys tissue fluid

Question 33

Areolar location

Answer 33

Widely distributed under epithelia of body, forms lamina propria of mucous membranes; packages organs, surrounds capillaries.

Question 34

Adipose

Answer 34

Connective Tissue Proper: Loose

Question 35

Adipose description

Answer 35

Matrix as in areolar, but very sparse; closely packed adipocytes, or fat cells, have nucleus pushed to the side by large fat droplet.

Question 36

Adipose function

Answer 36

Provides reserve food fuel; insulates against heat loss; supports and protects organs

Question 37

Adipose location

Answer 37

Under skin; around kidneys and eyeballs; within abdomen; in breasts.

Question 38

Reticular

Answer 38

Connective Tissue Proper: Loose

Question 39

Reticular description

Answer 39

Network of reticular fibers in a typical loose ground substance; reticular cells lie on the network.

Question 40

Reticular function

Answer 40

Fibers from a soft internal skeleton (stroma) that supports other cell types including white blood cells, mast cells, and macrophages

Question 41

Reticular location

Answer 41

Lymphoid organs (lymph nodes, bone marrow, and spleen).

Question 42

Dense Regular description

Answer 42

Primarily parallel collagen fibers; a few elastin fibers; major cell type is the fibroblast.

Question 43

Dense regular function

Answer 43

Attaches muscles to bones or to muscles; attaches bone to bones; withstands great tensile stress when pulling force is applied in one direction

Question 44

Dense regular location

Answer 44

Tendons, most ligaments, aponeuroses

Question 45

Dense irregular description

Answer 45

Primarily irregularly arranged collagen fibers; some elastic fibers; major cell type is the fibroblast