Module 1 | TISSUES

What are the 4 major categories of tissues?

1. epithelial

2. connective

3. nervous

4. muscle

Describe EPITHELIAL tissue?

Sheet of cell covering body surface or lining body cavity

Describe CONNECTIVE tissue?

includes C.T proper (fat and ligaments)
Provides support, cartilage, bone and blood

Describe NERVOUS tissue

main component of the nervous system; provides control

Descrive MUSCLE tissue?

Includes skeletal, cardiac, and smooth muscle tissue; provides movement

what is HISTOLOGY

• the study of tissues. Provides the structural basis fro the study of organ physiology

describe EPITHELIA

-Covers the external body surface

-lines its cavities and tubules

-marks off our insides from outsides

where do GLANDS develop

-develop from epithelial membranes

what are 6 unique characteristics of epithelia?

1-Cellularity
2-Special Contacts
3-Polarity (apical)
4- Supported by C.T.
5-Avascular (innervated)
6- High Regenerative Capacity

What is the difference between SIMPLE & STRATIFIED arrangements of epithelia?

SIMPLE = one layer of cells attached to the basement membrane

STRATIFIED= consists of two or more layers of cells

What are the different SHAPES of epithelial tissue:

SQUAMOUS = (platelike) cells are wider than taller

CUBOIDAL= (cubelike) cells are wide as the are tall

COLUMNAR = (column like) cells are taller than they are wide

What are 2 less easily categorized types of epithelia?

-Pseudostratified Epithelium
- Transitional Epithelium

Describe PSEUDOSTRATIFIED epithelium?

-it's simple columnar (one layer)
-cell vary in height
-has nuclei at different levels
-give false impression of being stratified
-often ciliated

Describe TRANSITIONAL epithelium?

-stratified squamous
-ability to slide over one another
-allows organ to STRETCH
-found ONLY in URINARY system organs (BLADDER)

Which of the less easily characterized epithelia is CILIATED?

pseudostratified epithelium

Where is transitional epithelium found?

urinary system organs (bladder)

What is the FUNCTION of SIMPLE SQUAMOUS epithelium?

-passive diffusion
-filtration
-secretes lubricating substances to membranes

What is ENDOTHELIUM?

-inner covering

-slick lining of hollow organ

What is MESOTHELIUM

-middle covering

-lines peritoneal, pleaural & pericardial cavity

what is the LOCATION of SIMPLE SQUAMOUS Epithelium?

-renal corpuscles

-alveoli of lungs

-lining of heart

-blood &lymphatic vessels

-lining of ventral body cavity

What is SIMPLE CUBOIDAL epithelium

-single layer of cube-like cells

-large spherical central nuclei

what is the function of SIMPLE CUBOIDAL epithelium?

secretion & absorption

What is LOCATION of SIMPLE CUBOIDAL epithelium?

-kidney tubules
-secretory portions of small glands
-ovary surface

What is SIMPLE COLUMNAR epthilium?

-single layer of column shape cells
-oval nuclei
-some have cilia at apical surface
-may contain goblet cells (mucus secreting)

What is the FUNCTION of SIMPLE COLUMNAR epithilium?

-absorption
-secretion of mucus
-ion transport
-ciliated type propels mucus or reproductive cells by ciliary action

What is the LOCATION of SIMPLE COLUMNAR epithelium?

NON CILIATED

line digestive track, gall bladder, ducts & some glands

CILIATED

line small bronchi, fallopian tubes, uterus

What is PSEUDOSTRATIFIED COLUMNAR epithelium?

- all cells originate at basement membrane
- only tall cells reach the apical surface
- may contain goblet cells & cilia
- nuclei lie at varying heights
within cells
-false impression of stratification

What is the FUNCTION of PSEUDOSTRATIFIED COLUMNAR epithelium?

-secretion of mucus
-propulsion of mucus by cilia

What is the LOCATION of PSEUDOSTRATIFIED COLUMNAR epithelium?

NON CILIATED

-ducts of male reproductive tubes

-ducts of large glands

CILIATED

-lines trachea

-most upper respiratory track

What is STRATIFIED SQUAMOUS epithelium?

-many layers of cells
-thickest epithelial tissue
-superficial layer is squamous in shape
-deeper layers appear cuboidal or columnar
- adapted for protection

What is the FUNCTION of STRATIFIED SQUAMOUS epithelium?

protect underlying tissues in areas subject to abrasion

What is the LOCATION of STRATIFIED SQUAMOUS epithelium?

KERATINIZED forms

- epidermis

NON KERATINIZED

- esophagus, mouth, vagina

What is STRATIFIED CUBOIDAL epithelium?

two layers of cube-shaped cells

What is the FUNCTION of STRATIFIED CUBOIDAL epithelium?

protection

What is the LOCATION of STRATIFIED CUBOIDAL epithelium?

-largest ducts of sweat glands
-forms ducts of mammary glands
-salivary glands

What is STRATIFIED COLUMNAR epithelium?

-several layers
- superficial cells elongated
-basal layer usually cuboidal

What is the FUNCTION of STRATIFIED COLUMNAR epithelium?

protection & secretion

What is the LOCATION of STRATIFIED COLUMNAR epithelium?

-rarest tissue type
-male urethra
-large ducts
-some glands

What is TRANSITIONAL epithelium?

-undergoes transition in shape
-actively moves & stretches
-basal cells usually cuboidal or columnar
-superficial cells dome shaped or squamous

What is the FUNCTION of TRANSITIONAL epithelium?

-distention of urinary bladder
-from 6-->3 layers when filled

What is the LOCATION of TRANSITIONAL epithelium

-ureters
-urinary bladder
-parts of urethra

What do GLANDS make?
What are the products like?

- make & secrete products
-products are aqueous fluids containing protein

Where do glands remove material from?

remove material from blood

What are glands classified by?

- site of release
(endocrine vs. exocrine)
- relative number of cells forming the gland

Where do ENDOCRINE glands secrete hormones?

directly into blood or lymphatic vessels that weave through glands to specific organs

Where do EXOCRINE glands secretions go?

empty through ducts to epithelial surface

What do GOBLET CELLS produce?

MUCIN
(mucin + water = mucus)

What are 3 factors that act to bind epithelial cells to one another?

1-adhesion proteins
2-special cell junctions
3-wavy contours if adjacent cells

What is CONNECTIVE TISSUE?

-found in all parts of body
-discrete structures
-parts of various body organs

What is the FUNCTION of CONNECTIVE TISSUE?

-protect
-support
-bind (tendons/ligaments) to other tissues of body

What are the 4 main types of CONNECTIVE TISSUE?

1. connective tissue proper
2. cartilage
3. bone
4. blood

Where does CT originate from

all types of CT originate from embryonic tissue called MESENCHYME

Does CT have blood vessels?

- YES
- rich supply of blood vessels

What is the EXTRACELLULAR MATRIX?

-it distinguishes CT from other tissue
-account for the strength of CT

What are 2 component of the EXTRACELLULAR MATRIX?
What hold interstitial fluid?

1-Ground Substance (holds interstitial fluid)

2- Fibers (provide support)

What is AEROLAR CT?
What does it store?

-defense cells
-originate of blood cells
-stores energy as fat

What are the categories of LOOSE CT?

LOOSE CT (more cells / less matrix)

-aerolar

-adipose

-reticular

What are the categories of DENSE CT?

DENSE CT (less cells/more matrix)

-regular (tendon)

-irregular CT

-elastic CT (aorta)

What is the FUNCTION of AREOLAR CT?

-wraps & cushions organs
-holds & conveys tissue fluid

What is the LOCATION of AREOLAR CT?

-found under epithelia of body
-lamina propia of mucus membrane
-surrounds capillaries

What is ADIPOSE CT?
Where is it found in the body?

-90% of mass consist of FAT CELLS
-found in hypodermis & mesenteries
-skin, kidneys, abdomen, breast

What are the fibers like in RETICULAR CT?

-resemble aerolar
-only reticular fibers present in membrane

Where is RETICULAR CT found

-bone marrow
-spleen
-lymph nodes

What are fibers like in IRREGULAR CT?

-collagen fibers are much thicker

-fibers run in different planes

-resist tension from different direction

What are fibers like in REGULAR CT?

collagen fibers run in same direction, parallel to directional pull

Where in the body is DENSE REGULAR CT found?

-tendons
-most ligaments

What one kind of cell makes up cartilage?

Chondrocytes

What is the FUNCTION of HYALINE CARTILAGE?

-support & reinforce
-resilient cushion properties
-resists compressive stress

What is the LOCATION of HYALINE CARTILAGE?

-NOSE
-end of long bones
-trachea
-larynx

What is the FUNCTION of FIBROCARTILAGE?

-tensile strength
-absorbs compressive shock

What is the LOCATION of FIBROCARTILAGE?

-knee joints
-intervertebral discs

What is the FUNCTION of ELASTIC CARTILAGE?

-maintain shape & structure
-great flexibility

What is the LOCATION of ELASTIC CARTILAGE?

-ear
-epiglottis

What is the difference between OSTEOBLASTS & OSTEOCYTES?

OSTEOBLASTS

- immature cells

-secrete collagen fiber

- have matrix

OSTEOCYTES

-mature bone cells in lacunae

-very well vasularized

What are the FUNCTION of BONES

-support & protect organs

-lever & attachment site for muscles

-store calcium, fat, minerals

-marrow site of blood formation

Why is BLOOD classified as Connective Tissue?

1. develops from mesenchyme
2. consists of blood cells surrounded by a nonliving matrix (plasma)

What is the FUNCTION of BLOOD?

transport of respiratory gases, nutrients, wastes, and other substances

What is the LOCATION of BLOOD?

contained within blood vessels

What are the 3 types of MUSCLE tissue?

1. Skeletal
2. Cardiac
3. Smooth

How does SKELETAL MUSCLE appear?

-striated , long cylindrical
-contain many nuclei

What is the FUNCTION of SKELETAL MUSCLE?

-voluntary movement
-facial expression

Where does CARDIAC MUSCLE occur?

walls of the heart

What is the appearance of CARDIAC MUSCLE?

-one nucleus
-striated
-intercalated discs

What allow Cardiac Muscle to join?

intercalated discs

What is the FUNCTION of CARDIAC MUSCLE?

contracts to propel blood through blood vessels

Where is SMOOTH MUSCLE found?

-found in hollow walls of visceral organs
-digestive, urinary organs, uterus, blood vessels
-no visible striations
-one central located nucleus

How does the SMOOTH MUSCLE FUNCTION or act?

squeeze substance through organs

What 2 cells form NERVOUS TISSUE?

1-neurons
2-supporting cells

What are NEURONS?

-generate & conduct electrical impulses
-transmit impulses

What are SUPPORTING CELLS?

-NON conducting
-nourish
-insulate
-protect nuerons