Tissues EXAM 2

8/2/2019 Tissues EXAM 2

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MATERIALS FOR EXAM 2 11

I. Tissues: Groups of Cells; Same structure, Same intercellular

substances and same function

A. General Types: Epithelial, Connective, Nervous and

Muscular

B. Epithelial Tissues

1. General Characteristics

a. Intercellular Substance: Minimal amounts

between cells

b. Basement Membrane: Basal surface of cells

Cells rest on this structure include

glycoproteins, proteoglycans and

collagen fibers from epithelium and

underlying connective tissue (slide 4

picture)

c. Cells have a Free (Apical) Surface that is

opposite the Basal surface

d. Blood Vessels: not present in epithelia; cells

exchange substances by diffusion between

intracellular fluid, extracellular fluid and

blood plasma within blood vessels of

underlying connective tissue (Lamina

Propria)

e. Very few epithelia contain nerve endings


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f. High regenerative capacity: Old dying cells

constantly replaced by mitosis

Ex: Skin epidermis and inner lining of

digestive tract

g. Found at actual and potential free surfaces

Actual Free surfaces

i. Skin epidermis

ii. Inner lining of respiratory,

intestinal, excretory and both

reproductive tracts

iii. Inner surface of closed body

cavities; internal spaces in

which body organs are located

(Mesothelium)

Potential Free surface

i. Inner lining of heart and blood

vessels (Endothelium)

ii. Glands develop from Epithelia

(slide 9)

2. Functions

a. Protection of underlying tissues from injury

Skin Epidermis: Bacterial infection


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Respiratory Epithelium: Moves

particulate embedded in mucus out of

the system (slide 11)

b. Absorption: Epithelial cells with Microvilli

Small intestine cells absorption of

digested nutrients

Kidney Tubule Cells: Reabsorb Ions

(Na+1, K+1) Molecules (Glucose and

Amino Acids) from forming urine back

into plasma from which they were

initially filtered

c. Filtration: Endothelial Cells of Blood

Capillaries (slide 13 picture)

d. Secretion: epithelial cells that form glands

to produce a product that is secreted

(Released) onto the surface of an

epithelium (exocrine) or into the blood

(endocrine)

3. Classification of Epithelia

a. Number of Cell Layers

One= Simple Epithelium

Two or more = Stratified epithelium

(slide 16)


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b. Shape of Cells*

Flat= Squamous

Cubed (equal dimensions on all

surfaces)= Cuboidal

Taller that wide or long= Columnar

* For stratified epithelia use shape of

cells in top layer

4. Specific Types of Epithelia

a. Simple Squamous Epithelium

Where Found:

i. Walls of Alveoli in lungs

ii. Inner lining of heat and blood

vessels (endothelium)

iii. Inner lining of closed body

cavities (Mesothelium) (slide 19)

b. Simple Cuboidal Epithelium

Single layer of cubed-shaped cells

Basal Surface lies on basement

membrane

Epithelium and basement membrane

attached to connective tissue

Examples


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i. Secretory portion of thyroid

gland

ii. Inner lining of exocrine gland

ducts (salivary glands, liver and

pancreas

iii. Some kidney tubules

iv. Outer surface of eye lens

c. Simple Columnar Epithelium: Single layer

columnar cells rest on basement membrane

that attaches to connective tissue

May or may not contain goblet cells

Cells May or may not be ciliated

Cells may NOT have cilia nor goblet

cells

Non-ciliated and Non-goblet

i. Inner lining of uterus

Non-ciliated, goblet cells present

i. Inner lining of digestive tract

from stomach to rectum (slide

23 Microvilli present in small

intestine)

Ciliated, without goblet cells

i. Inner lining fallopian tube


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Ciliated, with goblet cells

i. Inner lining of bronchioles of

lungs

d. Pseudostratified ciliated columnar

epithelium (simple epithelium)

Structure

i. All cells in contact with

basement membrane not all

cells have a free surface

ii. Nuclei occur at different levels

in cells

iii. Ciliated

iv. Contains goblet cells

Locations

i. Nasal cavities, nasopharynx,

trachea and bronchi of

respiratory tract

ii. Inner lining of epididmysis and

vas deferens (NO goblet cells)

e. Stratified Squamous Epithelium

Keratinized or cornified Epithelium

because it contains keratin (protein)

Epidermis of Skin


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Non-keratinized: lining of oral cavity,

pharynx (throat), esophagus and anal

cavity

f. Stratified Cuboidal Epithelium (not

common): Two layers of cells with cubed-

shaped cells in the top layer

Location: inner lining of sweat gland

ducts

g. Stratified columnar Epithelium (not

common)

Ciliated: lines Larynx or (voice box

Non-Ciliated: lines distal male Urethra

h. Transitional Epithelium (Uroepithelium)

Stratified Epithelium

Top layer cells: dome-shaped or

flattened (when tissues is stretched)

Locations: inner lining of ureters,

Urinary Bladder, female urethra and

proximal male urethra

5. Epithelia and Glands

a. Development of glands cells in layer of

epithelium proliferate (increase in number

by cell division) cell penetrate into


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underlying connective tissue in form of a

tube

b. Functions of Glands

Obtain substances from ECF

Synthesize (anabolism) New

substance (secretions)

Release Secretion on to an actual free

surface through a duct (exocrine) or

into the blood (endocrine)

c. Classification of Glands

Number of Cells

i. Unicellular (one cell); Goblet

Cells or digestive and

respiratory tracts

ii. Multicellular: All others

Functional Characteristics

i. Exocrine Glands- Posses a duct

system; section released on to

an actual free surface

ii. Endocrine Glands- NO DUCTS;

secretion released into blood

Morphological Characteristics

(Exocrine Only)


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i. Duct system

1. Simple: 1 duct only

2. Compound: Many internal

ducts fuse together; only

one opens on to the

surface of an epithelium

ii. Shape of Secretory Portion

1. Tubular Coiled (tubular) is

a modification of tubular

2. Alveolar of sac shape

iii. Specific Examples

1. Simple Tubular (small

intestine)

2. Simple coiled tubular

(Sweat glands)

3. Simple branched tubular

(stomach and uterus)

(picture slide 9)

4. Simple Alveolar or Acinar

(Sebaceous Glands Skin)

5. Simple Branched Alveolar

(sebaceous glands-skin)

6. Compound Tubular (liver)


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7. Compound Alveolar

(pancreas, salivary and

mammary glands)

8. Compound tubulo-Alveolar

(some salivary glands)

iv. Manner of secretion

1. Holocrine: Glandular cell

ruptures; release secretion

into a duct and dies

a. EX: Sebaceous

glands of skin

Goblet cells

2. Apocrine: small portion of

cytoplasm breaks off;

droplet released into duct

for secretion; remaining

part of cell repairs itself

and continues to make

more secretion

a. EX: Axillary sweat

glands and

mammary glands


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e. Insulation and storage of energy (adipose tissue)

3. Components

a. Cells: predominant type is the fibroblast: other more specific types

include: (adipocytes, chondrocytes, osteocyes and various blood cells)

1) Cells produce intercellular substance except blood

b. Intercellular substance: Occupies space outside and between cells

1) Matrix or ground substance homogeneous, amorphous can be fluid,

weak gel, semisolid or solid in consistency (depends upon tissue

type)

2) Fibers: Produced by connective tissues cells: are embedded in

matrix

a) White/Collagenous made of the protein collagen: inelastic

( cannot be stretched): flexible

b) Yellow/elastic: made of protein elastin:can be stretched out of

shape and can rebound to normal shape

c) Reticular made of collagen:Delicate fibers present in a network:

break easily

4. Specific connective tissues

b. Loose connective or Areolar tissue

2) Cells

a) fibroblasts: produce protein fibers and matrix


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b) Macrophages/ histiocytes: destroy bacteria that get into this

tissue

c) Mast cells: contain heparin (blood anticoagulant) and histamine:

Present in large numbers in Areolar tissue associated with blood

vessels heparin prevents intravascular blood clotting histamine

dilates blood vessels inflammatory reactions

3) Matrix: Weak Gel = Intercellular fluid + high concentration of

proteoglycans

4) Fibers: White and yellow 50/50

5) Functions

a) Connects skin to skeletal muscle as part of the subcutaneous

tissues

b) packing material of body: fills in spaces around body organs

c) Surrounds muscles, nerves, blood vessels and duct of glands:

for support and strength

Keeps organs in place and still allows movement

d) Aids in fighting bacterial infections

5) Clinical Note: Edema

c) Abnormally high localization of fluid in areolar tissue spaces:

causes swelling

b. White fibrous or collagenous connective tissue

4) Cells: fibroblast produce very large quantities of collagen


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5) fibers: collagen densely packed such that fibroblasts are

compresses

6) Matrix: weak gel

7) Functions

c) Tendons: Attach muscles to bones

d) Ligaments: Attach bone to bone

e) Aponeuroses: thin flat tendons: connect thin flat muscles to other

muscles or tendons

f) Fascia: thin sheets of collagenous tissues that cover skeletal

muscles

g) Sclera: white of eye

h) Scar tissue: forms after wound healing, fibroblasts multiply by

mitosis, and produce large amounts of collagen that contributes

to scars

c. Yellow Fibrous or Elastic connective tissue

4) Cells: Fibroblasts

5) Fibers: Elastin

6) Matrix: Weak

7) Functions- provides rigid structural support as well as flexibility and

elasticity


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c) Intervertebral elastic ligaments also referred to as ligamentum

flavum: Interconnect lamina of vertebrae and allows for slight

movement of individual vertebrae

d) Makes up a portion of walls of the Aorta and large arteries

d. Reticular Tissue

4) Cells: reticulum cells

5) Fibers: reticular composed of thin collagenous fibers in a network

6) Matrix: Weak gel

7) Function: Makes up Stromal tissue of: liver bone marrow, lymph

nodes, tonsils, spleen and peyers patches

e. Adipose Tissue

4) Cells: Adipocytes (highly specialized fibroblasts): Cytoplasm so full

of fat that nuclei are pushed over to one side

5) Fibers: Very few collagen and reticular fibers present

6) Matrix: Weak gel

7) Functions

c) Storage or energy: fat

d) Insulation: fat in subcutaneous tissue (below the skin)

e) Protection of Organs in Form of fat pads of cushions: around

kidneys, intestines, Heart: behind eyes and in the greater and

lesser omenta

a. Cartilage


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1) Components common to all cartilages

a) Perichondrium: Layer of connective tissue; covers

surface of cartilage

(Peri comes from: ORIGIN from greek Peri about,

around.)

b) Chondroblasts associated with perichondrium

produce white or yellow fibers that are found in cartilage

matrix: Chondroblasts divide by mitosis and differentiate

into chondrocytes while making matrix

c) Chondrocytes and lacunae mature cells

(chondrocytes) located in spaces (lacunae) that are

surrounded by matrix (Chondrin)

d) Matrix (Chondrin): Semisolid mare of chondroitin or

chondroitin sulfate + proteins = proteoglycans

(1) Territorial matrix (capsule): Around the edge of

a lacuna

(2) Inter-territorial matrix between lacunae

e) Fibers: Variable: collagenous or elastic: embedded in

matrix

2) Growth of Cartilage

a) Appositional: Mitosis of chondroblasts adds tissue

mass at sides of the tissue


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b) Interstitial: Mitosis of chondrocytes in lacunae (2-3

cells in a group)

3) Types of Cartilage: Determined by types of fibers found in

matrix

a) Hyaline Cartilage: Most prevalent: contains FEW

collagen fibers

(1) Functions: forms external nasal cartilages

(2) Functions: forms costal cartilages associated

with ribs

(3) Functions: forms rings of Trachea and rings of

bronchi

(4) Functions:forms articulating cartilage at

moveable joints

(5) Functions forms epiphyseal plate or

epiphyseal disc in long bones

(6) Functions: forms most of the fetal skeleton

b) Fibrocartilage: contains high levels of collagenous

fibers in matrix

(1) Functions: forms pubic symphysis: connects

pubic bones to each other

(2) Functions: forms intervertbral discs

(3) Functions: forms menisci of knee joint


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c) Elastic cartilage: High levels of yellow (elastic) fibers

in matrix

(1) Functions: form the epiglottis: covers open of

trachea when swallowing

(2) Functions: forms structure associated with ear

(1) Pinna

(2) Wall of external Auditory meatus canal

(3) Wall of eustachian tube

4) Special Feature: Cartilage DOES NOT contain blood

vessels: therefore substances must exchange by diffusion

between blood capillaries in perichondrium, and chondrocytes

I. Epithelial Membranes: Line body cavities and passageways, cover internal

organs form inner lining of: heart, blood vessels and lymph vessels

A. Types

1. Mucous Membranes

2. Serous Membranes

B. Mucous Membranes: Line body cavities that open to the exterior

1. Mouth (buccal or oral cavity)

2. Nasal Cavity

3. Inner lining of the following:

a. Digestive

b. Respiratory tract


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c. Excretory tract

d. Reproductive tract

4. Composition

a. Epithelium: found at a actual free surface: all types

EXCEPT simple squamous and stratified cuboidal epithelia

b. Goblet Cells (secrete mucus) or associated mucus

glands in excretory system, urinary bladder has glands that

secrete mucus

c. Basement Membrane

d. Loose Areolar Tissue

e. Smooth of Skeletal Muscle lies under mucous

membrane (NOT PART OF THE MEMBRANE)

5. Functions

a. General: protection, absorption and secretion

b. Specifically: depends on type of epithelium present

and location in body

6. Continuities with Skin at body orifices

a. Mouth

b. Nostrils (External Nares)

c. Urethral Meatus

d. Anus

e. Vaginal Orifice


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C. Serous Membrane: Line closed body cavities (DO NOT open to the

outside): cover organs within closed body cavities; Form the inner lining

of heart, blood vessels and lymph vessels

3. Closed body cavities

a. Thoracic Cavity: Located above diaphragm

1) Contents: Structures inside rib cage. Lungs

mediastinum: space (between lungs) that contains:

heart, major blood vessels, tracheas and

esophagus

b. Pericardial Cavity: contains heart

1) Membrane (Pericardium) around heart creates

the space

c. Abdominopelvic Cavity: below diaphragm and into pubic

region: contains organs of digestive excretory and

reproductive systems

2. Types

a. Pleurae

1) Parietal Pleura: lines inner surface of thoracic

cavity

2) Visceral Pleura: covers outer surface of lungs

b. Pericardium:


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1) Parietal: makes up pericardial sac that

surround the heart

2) Visceral: covers outer surface of heart also

called Epidcardium

c. Peritoneum

1) Parietal Peritoneum: lines walls of

abdominopelvic cavity: forms double-layer

membranes called mesenteries: these connect

some internal organs to the wall of the

abdominopelvic cavity

(picture on slide 29)

mesentery | mez n ter ; mes-|noun ( pl. -teries) Anatomya fold of the peritoneum that attaches the

stomach, small intestine, pancreas, spleen, and other organs to the posterior wall of the abdomen.

ORIGIN late Middle English : via medieval Latin from Greek mesenterion, from mesos middle + enteron

intestine.

2)Visceral: covers most organs of abdominal-pelvic

Cavity Except: Kidneys rectum, Ureters uterus, urinary

bladder, ovaries, spleen, fallopian tubes, pancreas,

duodenum

(a) These organs are retroperitoneal because

they lie between the muscular wall of the


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abdominolpelvic cavity and the parietal

peritoneum

retro- | r tro | | r tr |combining form1 denoting action that is directed backward or is reciprocal :

retrocede | retroject.2 denoting location behind : retrosternal | retrochoir.ORIGIN from Latin retro

backward.

d. Inner lining of heart and blood vessels

3.Composition (serous Membranes)

a.Simple squamous epithelium (mesothelium or

endothelium) depending on location in body

b.Basement membrane

c.Loose Areolar Tissue

d. Muscular Layer: (Cardiac, skeletal or smooth muscle) NOT

PART OF SEROUS MEMBRANE

4. Functions

a. Protection

1)Friction: internal organs move over one another or

come into contact with wall of cavity in which it is

located

a)Epithelium of Serous membranes release a

serous (watery) Secretion: Secretion lubricates


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surfaces and reduces friction between organs

and walls of cavities

b.Absorption:Solutions that may be injected into peritoneal

cavity or fluid secreted by serous membranes are absorbed

by blood capillaries in Areolar tissue associated with

peritoneal membranes

c.Prevention of Atelectasis ( Collapsing of lungs) pleurae

atelectasis | atl ekt sis|noun Medicine partial or complete collapse of the lung. ORIGIN

mid 19th cent.: from Greek atel s imperfect + ektasis extension.

d. Formation of mesenteries

e. Prevention of intravascular blood clotting

1)Endothelium of heart and blood vessels is very

smooth: prevents blood clotting if these surfaces

become disrupted for some reason ( Plaques in

coronary arteries). Blood clots can form

Tissues EXAM 2

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