NVCC BIO 141 Chapter 4

Define tissue

group of structurally/functionally related cells and their external environment that together perform common functions

List the four main tissue types

epithelial, connective, muscle, nervous

Define Epithelial Tissue

sheets of cells tightly packed together with little visible ECM

cover/line all body surfaces/cavities

specialized cells form glands

Define Connective Tissue

connects all other tissues in the body together

ECM most prominent feature; cells scattered throughout

bind, support, protect, allow transport

Define Muscle Tissue

contract and generate force, little ECM

Define Nervous Tissue

unique ECM; cells generate/send/receive messages

Describe the two major components of the extracellular matrix

Ground Substance: shapeless, gel-like; contains interstitial/extracellular fluids with water, ions, nutrients, and other solutes

Protein Fibers: multiple fibrous proteins subunits that entwine to form a long, rope-like structure with great tensile strength

Define Collagen Fibers

composed of multiple subunits of a fibrous protein, resistant to tension (tendons)

Define Elastic Fibers

can stretch a lot and return to regular shape

Define Reticular Fibers

thinner/shorter and interweave to form meshwork that supports cells and ground substance. Forming webs in certain organs to trap foreign cells

List the three different large molecules found in ground substance

Glycosaminoglycans

Proteoglycans

Glycoproteins

Define Tight Junctions and give an example

holds cells tightly together making space between impermeable (some leak) - between cells of blood vessels preventing substance from leaving the blood

Define Desmosomes and give an example

act like buttons, ECF can pass; strengthens tissues by mechanical stress that is evenly distributed - epithelia of the skin

Define Gap Junctions and give an example

small pores in adjacent plasma membranes formed by protein channels, allow small substance to pass freely between cytosol of two cells - communicate with electrical signals (cardiac muscle)

Describe the main characteristics of epithelial tissue

found on every internal/external body surface, acting as barriers between body and external environment and between our organs and fluid-filled cavities

Describe the main characteristics of epithelial tissue.

Protection: shields underlying tissues from mechanical/thermal injury

Immune Defense: barrier against invading microorganisms

Secretion: forms glands that produce oils/hormones secreted either via duct or into blood

Transport into other tissues

Sensation: detect change in internal/external environment including olfactory

Classify two different epithelial tissues based on number of cell layers

Simple: single layer

Stratified: multiple layers

Classify three different epithelial tissues by cell shape

Squamous: flattened

Cuboidal: short

Columnar: tall/elongated

Describe Simple Squamous and give examples

single layer of flat cells; extremely thin that allows O2/CO2/fluids/ions to diffuse quickly

(air sacs of lungs, kidney tubules, blood vessels lining)

Describe Simple Cuboidal and give examples

single layer of cube-shaped cells; thin enough to allow substance to diffuse quickly

(kidney tubules, respiratory passages, ducts of glands, thyroid)

Describe Simple Columnar and give examples

tall rectangular; microvilli to increase surface area for absorption

(small intestine, gallbladder, kidney tubules)

Describe Pseudostratified Columnar and give examples

Nuclei of cells are at different heights but each cell reaches the base; protective function

(larger respiratory passages, nasal cavity)

Describe Keratinized Stratified Squamous and give examples

top cells lack nuclei, cells no longer living are filled with keratin that makes it tough/resistant to friction

(forms on outer layers of skin)

Describe Non-Keratinized Stratified Squamous and give examples

top cells nucleated, cells living, each cell is distinct; organs that require protection from mechanical abrasion but need moist surface

(mouth, throat, esophagus, anus, vagina)

Describe Stratified Cuboidal and give examples

relatively rare; 2 layers and lines ducts of sweat/salivary glands/male urethra

Describe Transitional and give examples

only in urinary system, bottom cells are cuboidal that transition to round on the top

(allow urinary organs to stretch)

Differentiate between ciliated epithelium and nonciliated epithelium

Ciliated: have cilia and goblet cells

Noncilitated: does not have cilia or goblet cells

What epithelial tissue type is the Skin?

Keratinized stratified squamous

What epithelial tissue type is the Nasal cavity?

Pseudostratified Columnar

What epithelial tissue type is the Urinary Bladder?

Transitional Epithelium

What epithelial tissue type is the air sacs in the lung?

Simple Squamous

What epithelial tissue type is the small intestine?

Simple Columnar

What epithelial tissue type is the mouth and esophagus?

Non-keratinized Stratified Squamous

What epithelial tissue type is the kidney tubules?

Simple Cuboidal

Define the Exocrine Gland

release their secretions to surface of epithelium; generally to outside of body; secreting through a duct lined with epithelial cells

(local actions only, affect cells in general vicinity)

Define Endocrine Gland

lacks ducts; secretes their products (hormones) directly into the blood, reaching distant cells

Define Goblet Cells

most common unicellular gland, found in lining of the digestive/respiratory tracts; secreting mucus

Define Merocrine Secretion

majority of exocrine glands including salivary/sweat glands; package products into secretory vesicles for release by exocytosis

Define Holocrine Secretion

secretory cells accumulate their product in their cytosol; product not released until the cell raptures and dies

(sebaceous glands that produce sebum)

Define Apocrine Secretion

portions of cytoplasm pinched off with product being secreted (lactating mammary glands and armpit sweat glands)

Name the three basic components of connective tissue

Specialized Cells

Protein Fibers

Ground Substance

Describe four functions of connective tissue

Connecting/Binding: connect structures in the body, bind other tissue layers together

Support: bone/cartilage - supports weight of the body

Protection: bone tissue - protects internal organs, cartilage and fat tissue provide shock absorption, includes immune system components

Transport: blood is fluid connective tissue that is the main transport system

Describe Loose Connective Tissue

primarily made of ground substance + all 3 types of protein fibers, fibroblasts, and other cells such as adipocytes are suspended

-in membranes lining body cavities/layers in the walls of hollow organs

(support/contains many blood vessels + immune cells)

Describe Dense Irregular Connective Tissue

collage fiber arranged haphazardly making it strong/resists tension; found in dermis and around organs and joints

Describe Dense Regular Connective Tissue

thick collagen fibers arranged parallel to form bundles; strong but resist tension only in ONE plane

Tendons/Ligaments

Describe Dense Elastic Connective Tissue

parallel elastic fibers with randomly oriented collagen fibers, allows some organs to stretch

lining or large blood vessels and certain ligaments like those in the spine

Describe Reticular Tissue

Delicate network of fibers and cells, Only found in lymphoid organs such as spleen, lymph nodes, and bone marrow

Describe Adipose Tissue

fat cells

provide insulation, energy reserve and protection

Describe Cartilage

Tough but flexible tissue that absorbs shock/resistant to tension, compression, and shearing forces

(found in joints between bones, ear, nose, and certain respiratory passages)

Describe Hyaline Cartilage

Large amount of ground substance with uniform, glassy appearance; covers the ends of bonds/protects underlying bone where strong but flexible support is needed

Describe Fibrocartilage

filled with collagen fibers leaving hardly any room for ground substance

great tensile strength with fair amount of elasticity

(found in joints/intervertebral discs)

Describe Elastic Cartilage

tissue that contains a network of elastic fibers, providing strength, elasticity, and maintenance of shape; located in the external ear/parts of larynx

Describe Bone Tissue

supporting our bodies, vital organs; providing place of attachment of muscles of voluntary movement; storing calcium salts, housing bone marrow

Describe Bone Remodeling

Osteoblasts (bone builders)

Osteocytes (mature bone cells)

Osteoclasts (bone destroyers)

Describe Blood Tissue

ECM of blood is plasma, doesn't have protein fibers

Describe parts of the Blood

Erythrocytes: Red blood cells

Leukocytes: White blood cells

Platelets: role in blood clotting

Identify connective tissue type of bone

Bone

Identify connective tissue type of Blood

Blood

Identify connective tissue type of Subcutaneous Layer

Adipose Connective Tissue

Identify connective tissue type of Spleen

Reticular Connective Tissue

Identify connective tissue type of Tendons

Dense Regular Connective Tissue

Identify connective tissue type of Elastic Arteries

Dense Elastic Connective Tissue

Identify connective tissue type of Tip of Nose

Hyaline Cartilage

Identify connective tissue type of External Ear

Elastic Cartilage

Identify connective tissue type of Intervertebral Discs

Fibrocartilage

Identify connective tissue type of Upper layer of Dermis

Loose Connective

Identify connective tissue type of Lower layer of Dermis

Dense Irregular Connective Tissue

Describe Skeletal Muscle Tissue

attached to skeleton, contraction produces body movement-voluntary, consisting of striated muscle cells arranged parallel to one another (muscle fibers)

Describe Cardiac Tissue

only in the heart, striated muscle cells, involuntary

relatively short/thick muscle cells that are uninucleate, has intercalated discs containing gap junctions allowing the heart to contract

Describe Smooth Muscle Tissue

smooth muscle cells, involuntary; in walls of hollow organs/ducts of some glands; cells flattened with single ovoid nucleus in center of cell

Describe Neurons

receive and send messages

Describe Neurological Cells

anchor neurons/blood vessels in place; monitor composition of ECF, speeding up rate of nerve impulse

Describe the structure of a neuron

Cell Body: large centralized portion (soma) biosynthetic where nucleus/organelles housed

Axon: single arm responsible for moving nerve impulse from body cell to target cells

Dendrites: short extensions radiating from body; receiving messages from axon of other neurons into cell body

Describe Serous Membrane

-top layer is simple squamous epithelium

-bottom layer is areolar connective tissue

-line body cavities that are closed to the exterior

-occurs in pairs separated by serous fluid: visceral and parietal

Describe Synovial Membranes

line joint cavities and produce the fluid within the joint

Describe Mucous Membrane

-produces a fluid called mucus

-line body cavities that open to the outside

mucus: clear white fluid, moistens, protects

Describe Cutaneous Membrane

Skin - dry outermost membrane with dermis and epidermis

Regeneration vs Fibrosis

regeneration- cells being replaced

fibrosis- scar tissue

Scar Tissue

dense irregular connective tissue

Summarize tissue repair in the four main tissues

Epithelial: regeneration

Connective: regeneration except Cartilage

Smooth Muscle: regeneration

Cardiac/Skeletal Muscle: Fibrosis

Neurons do not regenerate