Tissues, Glands, and Membranesbioblocks.weebly.com/uploads/8/7/0/...5_histology.pdf · connective tissue. 5. Describe the different structures and functions of epithelium tissue

Tissues, Glands, and

Membranes

Chapter Five

Mrs. Hornacek

Objectives

1. Name the four main groups of tissues and give the

location and general characteristics of each.

2. Differentiate between voluntary and involuntary muscles.

3. Describe the structure of the neuron.

4. Describe the function and location of the major types of

connective tissue.

5. Describe the different structures and functions of

epithelium tissue.

6. Distinguish among the 4 major types of membranes.

7. Describe the difference between endocrine and exocrine

glands.

8. Identify tissues under a microscope and on diagrams.

Tissues

• Groups of cells that are similar in structure

and perform a common or related function

• Histology is the study of tissues

Chemical Cell Tissue Organ Organ System Whole Organism

Tissue Classification

Four main types of tissue:

Epithelial: covers surfaces, lines cavities,

and forms glands

Connective: supports

and forms the framework

of all parts of the body

Tissue Classification

Four main types of tissue:

Muscle: contracts and produces

movement

Nervous: conducts

nerve impulses

Epithelial Tissue – General

Characteristics

• Epithelium forms a protective covering for

the body

• It is the main tissue of the skin’s outer

layer

• Forms membranes, ducts, and lines body

cavities and hollow organs

Epithelial Tissue – General

Characteristics• Usually has no vascular tissue-blood

supply

– Nutrients obtained by diffusion

• Cells reproduce rapidly (rapid healing)

• Cells are tightly packed together with no

intercellular material

• Basement Membrane: Anchors epithelial

tissue to connective tissue

– Thin, non-living

Structure of Epithelial Tissue

Each epithelium is given two names:

First name indicates # cell layers present

• Simple: single cell layer

• Stratified: two or more layers

Structure of Epithelial Tissue

Second name describes the shape of its

cells

• Squamous: flattened and scale-like

• Cuboidal: boxlike, tall as they are wide

• Columnar: tall and column shaped

6 types of epithelial tissue follow

Simple Squamous

DESCRIPTION: Single layer of very thin, flattened cells

FUNCTION: Diffusion and filtration where protection is not important

LOCATION: air sacs of lungs, walls of capillaries and blood vessels, lining of heart

11

Fig05.01

(b)(a)

(d)(c)

Free surface

of tissue

Simple

squamous

epithelium

Basement

membrane

Nucleus

Free surface

of simple

squamous

epithelium

Nucleus

Connective

tissue

Copyright ©The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

©The McGraw-Hill Companies, Inc./Al Telser, photographer


Simple Cuboidal

D: single layer of cube shaped cells

F: secretion and absorption

L: lining of kidney tubules, ducts of glands,

covering surface of ovaries

13

Fig05.02

Nucleus

Basement

membrane

Free surface

of tissue

Simple

cuboidal

epithelium

Connective

tissue

Lumen

(a) (b)



Simple Columnar

D: single layer of elongated cells, some have cilia and some may contain mucus-secreting goblet cells

F: absorption, secretion, protection, ciliated type propels substances (mucus, reproductive cells) by ciliary action

L: lining of digestive tract, uterus, gallbladder

15

Fig05.03

Nucleus

Basement

membrane

Microvilli

(free surface

of tissue)

Connective

tissue

Mucus

Cytoplasm

Goblet cell

(a) (b)©The McGraw-Hill Companies, Inc./Al Telser, photographer

Pseudostratified Columnar

D: appear “stratified” but really are a single layer with nuclei at various levels giving appearance of layered cells.

F: secretion (mostly mucus), movement of mucus by cilia

L: lining air passages like the trachea and upper respiratory tract

17

Fig05.04

(a) (b)

Cilia

(free surface

of tissue)

Goblet cell

Basement

membrane

Nucleus

Connective

tissue

Cytoplasm

©The McGraw-Hill Companies, Inc./Dennis Strete, photographer


Stratified Squamous

D: multi-layered, dry, thick tissue. Surface

cells are flat, full of keratin and dead.

Basal cells are cuboidal or columnar.

F: protection

L: lining of esophagus, mouth, vagina,

epidermis of the skin

Fig05.05

Basement

membrane

Layer of

dividing

cells

Connective

tissue

Free surface

of tissue

Squamous

cells

(b)(a)©The McGraw-Hill Companies, Inc./Al Telser, photographer


Transitional Epithelium

D: resembles both stratified squamous and

stratified cuboidal

F: stretches and also forms barrier to block

diffusion

L: lining of urinary bladder, ureters, urethra

21

Fig05.08

©Ed Reschke

©Ed Reschke

Stretched

transitional

epithelium

Basement

membrane

Underlying

connective tissue

Basement

membrane

Underlying

connective tissue

Unstretched

transitional

epithelium

(b)(a)

(d)(c)

Free surface

of tissue

Free surface

of tissue


Glands

• A gland is an organ specialized to produce

a substance that is sent out to other parts

of the body, made of glandular epithelium

Glands

• Glands are divided into two categories

based on how they release secretions:

1. Exocrine: use ducts or tubes

2. Endocrine: secrete into the blood or

tissue fluid

Types of Exocrine Glands

• Merocrine

– Releases fluid product

through membrane by

exocytosis

– Salivary glands, sweat

glands in skin


• Apocrine

– Cellular product and

portions of gland cells

pinch off during

secretion

– Mammary glands


• Holocrine

– Release entire cells

filled with secretory

products

– Sebaceous glands of

the skin

Connective Tissue- General

Characteristics

• Functions: bind, support, framework, store

fat, fill spaces, produce blood cells, protect

against infection, and repair tissue

damage

• Most has a good blood supply, except

cartilage

• Composed of

scattered cells with

abundant non-living

extracellular matrix

• Extracellular matrix

contains fibers (for

support) and ground

substance (fluid,

proteins)

Connective Tissue Characteristics

Connective Tissue – Major Cell Types

• Fibroblast

– most common

– secretes fibers

– very large, star-

shaped


• Macrophage

– scavenger cells and

defend against

infection


• Mast Cells

– release heparin and

histamine

– Large

– located near blood

vessels

Connective Tissue - Fibers

• Collagenous Fiber:

strength

• Elastic Fiber:

flexibility

• Reticular Fiber:

supportive networks

5 Categories of Connective Tissue

1. Loose: areolar, adipose

2. Dense: tendons, ligaments

3. Cartilage: hyaline, elastic, fibrocartilage

4. Bone

5. Blood

1. Loose Connective Tissue

Areolar

D: gel-like matrix with fibers and different

types of cells

F: cushions organs, holds tissue fluid

L: surrounding organs, under the skin,

between muscles

35

Fig05.13

Elastic

fiber

(a) (b)

Collagenous

fiber

Fibroblast

Ground

substance



Areolar Connective Tissue

Adipose

D: sparse matrix, closely packed

F: insulates, supports, protects, reserve

energy supply (fat storage)

L: under skin, around joints, padding organs

1. Loose Connective Tissue

38

Fig05.14

(a) (b)

Fat droplet

Nucleus

Cell

membrane

y.



Adipose Connective Tissue

• Strong

• Lacks good blood supply

Dense

D: dense with collagen and elastic fibers

F: structural strength, attach muscle to bone

and bone to bone

L: vocal cords, tendons, ligaments

2. Dense Connective Tissue

41

Fig05.15

Fibroblasts

Collagenous

fibers

(a) (b)©The McGraw-Hill Companies, Inc./Dennis Strete, photographer


Tendon. The fibers are oriented in parallel arrays. Note the

thin, dark staining nuclei of the fibroblasts. Their cytoplasm

cannot be distinguished.

Dense Regular

3. Cartilage

Hyaline Cartilage

• D: fine collagenous fibers in extracellular

matrix with chondrocytes

• F: stiff but flexible support, reduces friction

• L: nose, ends of bones, ribs, larynx,

trachea

• MOST COMMON TYPE

Fig05.16

Chondrocyte

Nucleus

Extracellular

matrix

(a) (b)

Lacuna



Hyaline Cartilage

Hyaline cartilage contains cells called chondrocytes embedded in a unique matrix

that gives the tissue both strength and flexibility.

3. Cartilage

Elastic Cartilage

• D: dense network of elastic fibers in

extracellular matrix with chondrocytes

• F: elasticity, support

• L: external ear, parts of larynx

Fig05.17

Chondrocyte

Elastic fibers

Nucleus

Extracellular

matrix

(a) (b)

Lacuna



Elastic Cartilage

elastic cartilage can be distinguished by the stain for elastin that brings

out the dense bundles

3. Cartilage

Fibrocartilage Cartilage

• D: many collagenous fibers in extracellular

matrix

• F: strong, resists compression

• L: invertebral discs and joint capsules

(knees)

Fig05.18

Chondrocyte

Nucleus

Collagenous

fiber

Extracellular

matrix



Fibrocartilage

Fibrocartilage from an intervertebral disk. It is distinguished by very scattered,

infrequent chondrocytes (see the tiny dark nuclei) and collagen fibers running in

the matrix.

4. Bone

Bone

• D: hard, calcified matrix with collagen

fibers, vascular, deposits of mineral salts

• F: supports, protects, stores calcium,

marrow inside is site for blood cell

formation

• L: skeletal system

54

Fig05.19

Canaliculi

Lacuna

Central

canal

Lamella

Osteon


(c)

©Prof. P. Motta/Univ."La Sapienza"/Photo Researchers


(a) (b)

Bone

Ground Bone

Compact Bone

5. Blood

Blood

D: red and white blood cells in a fluid matrix

F: transports gases, waste, nutrients, etc

L: in blood vessels

Fig05.20

Red blood

cells

Plasma

(extracellular

matrix of blood)

Platelets

White blood

cell



Blood

Red Blood Cells and Lymphocytes

Neutrophils and Eosinophils

Muscle Tissue

General Characteristics:

• Highly cellular

• Very vascular

• Muscle fibers can contract and are

responsible for most movement in the

body

Muscle Tissue


• Cells elongated

• Cells close together with little extracellular

material

• Does NOT regenerate well, usually

replaced with connective tissue

Types of Muscle Tissue (3)

1. Skeletal

• D: long, cylindrical, multinucleate cells,

and striated

• F: voluntary movement, locomotion,

generate heat when they contract

• L: attached to bone

62

Fig05.21

Striations

Portion of a

muscle fiber

Nuclei



Skeletal muscle (l.s.), 400x, demonstrating peripheral nuclei and banding pattern of

skeletal muscle


2. Smooth

• D: spindle-shaped, uninucleate cells,

arranged closely to form sheets, NO

STRIATIONS

• F: involuntary, move substances along

internal passageways

• L: walls of hollow organs, stomach,

gallbladder, urinary bladder

65

Fig05.22

Nucleus

Cytoplasm



Smooth muscle (x.s. and l.s. small intestine) 400x, demonstrating size

variation and cell shape.


3. Cardiac

• D: branching, uninucleate cells, appears

striated, fit together at junctions called

intercalated discs

• F: involuntary, contractions propel blood

into circulation

• L: bulk of the heart wall known as the

myocardium

68

Fig05.23


Intercalated

disc

Nucleus

Striations


Cardiac muscle (l.s.), 400x, demonstrating smaller size of cardiac cells,

central, single nucleus, and intercalated discs

Nervous Tissue


• Main component of the nervous system

• Aware of our external environment

• Longest cells in the body

• Limited ability to repair themselves after

an injury

Nervous Tissue


Contain two major cell types:

1. Neuron: highly specialized that generate

and conduct nerve impulses

2. Neuroglia: supporting cells, insulate and

protect neurons

The Neuron

Dendrite: carries messages/impulses to the nerve cell body

Axon:

The single fiber

that carries impulses

away from the body

Myelin: insulating matter that

covers the axon

Soma

Nucleus

Schwann cell

Node of

Ranvier

Axon

Terminal

http://upload.wikimedia.org/wikipedia/commons/b/ba/Neuron-no_labels.png

http://upload.wikimedia.org/wikipedia/commons/b/ba/Neuron-no_labels.png

Nervous Tissue

• D: Neurons and neuroglia

• F: Regulate and control body functions

• L: Brain, spinal cord, and nerves

74

Fig05.24


(a) (b)

Nucleus

Cell

membrane

Cytoplasm

Cellular

process

Nuclei of

neuroglia

©Royalty-Free/Corbis

Nervous tissue (Purkinje cell of cerebellum), 1000x

Membranes

• Membranes are thin sheets of tissue

• They are made of both epithelial tissue

and connective tissue

• Cover body surfaces and line body

cavities

Epithelial Membranes

4 Types

1. Serous

2. Mucous

3. Cutaneous

4. Synovial

1. Serous Membrane

• Line body cavities that lack openings to

the outside

– thorax

– abdomen

– cover the organs in these cavities

• Secrete a thin, watery lubricant (serous

fluid) so organs can move with minimum

friction

2. Mucous Membrane

• Line cavities and tubes that open to the outside of the body

– oral and nasal cavities

– tubes of digestive, respiratory, urinary, and reproductive

• Produce a thick and sticky substance called mucus

3. Cutaneous Membrane

• Known as the skin

• Has an outer layer of epithelium

• Complex

4. Synovial Membrane

• Made of connective tissue

• Lines joints

• We will discuss more in the skeletal

system

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Tissues, Glands, and Membranesbioblocks.weebly.com/uploads/8/7/0/...5_histology.pdf · connective tissue. 5. Describe the different structures and functions of epithelium tissue