BMD 310 - Tissues

4 Basic Tissue Types

Epithelial

Connective

Muscular

Nervous

Functions of Epithelial Tissue

• Selective Barrier (allows/limits substances that travel in and out of the body)

• Releases products onto free surfaces

• Protection against abrasive influences

Structure of Epithelial Tissue

• Single or Multiple Layers

• Continuous sheets

• Covers + Lines the body

What are the Surfaces of Epithelial Tissue?

Apical

Lateral

Basal

Basement Membrane

Describe the Apical Surface

• May contain cilli or micro villi

• Faces body surface/cavity/lumen

• Free Space

Describe the Lateral Surface of Epithelial Tissue

• Faces adjacent cell

• Cell to cell junctions

Describe the Basal Surface of Epithelial Tissue

• Opposite apical

• Deepest layer

• Anchors to the basement membrane

Describe the Basement Membrane of Epithelial Tissue

Secreted by epithelium

Simple Cuboidal

Stratified Squamous

Simple Squamous

Stratified Cuboidal

Transitional

Simple Columnar

Pseudostratified Columnar

Functions of Simple Epithelium

• Diffusion

• Osmosis

• Secretion

• Absorption

• Filtration

Functions of Pseudostratified Epithelium

• May contain cilia

• May contain goblet cells (secret mucus)

Functions of Stratifed Epithelium

Protects underlying tissue from wear and tear

Functions of Transitional Epithelium

• Cells change from squamous to cuboidal

  example: bladder

What do Exocrine Glands do?

Secrete into ducts »»» ducts empty onto skin or hollow organs

Types of Secretions

• Saliva

• Sweat

• Sebum

• Cerumen

• Digestive enzymes

Describe Unicellular Exocrine Glands

• single celled

• Goblet cells

• Secrete mucous directly onto apical surface

Functions of Connective Tissue

• Binds, Supports, and Strengthens

• Protects and insulates organs

• Main source of immune response

Blood serves as the main transport system in

Connective Tissue

What are the 2 elements of Connective Tissue?

Extracellular Matrix and Cells

What is the source of connective tissue?

Embryonic tissue (mesenchyme)

List the 5 Connective Tissue Cells

• Fibroblast

• Adipocytes

• Plasma Cells

• Mast Cells

• Macrophages

Describe Fibroblasts

• Large, flat, branching

• Typically MOST abundant

Describe Macrophages

• developed from monocytes (WBC)

• Irregular shape

• Can be fixed or wandering

• Phagocytize bacteria and cell debris

Describe Adipocytes

• Fat cells

• Store triglycerides

• Around organs + deep beneath skin

Describe Plasma Cells

• IMPORTANT for immunity

Describe Mast Cells

Produce histamine after infection or injury

Fibroblast

Macrophages

Adipocyte

What are the 2 components of the Extracellular Matrix?

Ground Substance and Fibers

Describe Ground Substance

• Supports and binds cells

• Store Water

• Allows for exchange of substances b/w blood and cells

What are the 3 Fibers within the Extracellular Matrix?

Collagen, Elastic, and Reticular

What fiber is strong and flexible?

Collagen

What fiber can stretch up to 150% and return to its shape?

Elastic

What fiber has a collagen and glycoprotein coating and supports blood vessel walls and tissue networks?

Reticular

What are the 5 types of Mature Connective Tissue?

• Loose

• Dense

• Cartilage

• Bone

• Liquid

3 Types of Loose Connective Tissue

Areolar, Adipose, Reticular

Describe Areolar Loose Connective Tissue

Located: skin, mucous membrane, around blood vessels/nerves/organs

Function: strength, elasticity, and support

Describe Adipose Loose Connective Tissue

Located: deep in skin, around heart/kidneys, behind the eye ball, bone marrow

Function: Reduce heat loss, energy reserve, and support/protect organs

Describe Reticular Loose Connective Tissue

Located: liver, spleen, lymph nodes, red bone marrow, portion of basement membrane, around vessels + muscles

Function: stroma of organs, binds and smooths muscle, filters old RBC

What are the 3 types of Dense Connective Tissue?

Regular, Irregular, and Elastic

Describe Regular Dense Connective Tissue

It’s a strong attachment located in tendons, most ligaments, and aponeuroses

Describe Irregular Dense Connective Tissue

Provides pulling or tensile strength to fasciae, dermis, periosteum, pericardium, capsules, surrounding organs, heart valves.

Describe Elastic Dense Connective Tissue

Allows stretching in lung tissue, walls of elastic arteries, trachea, bronchial tubes, vocal cords, and ligaments.

What are the 3 types of cartilage?

Hyaline, Fibrocartilage, and Elastic