Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Chapter 4 Lecture Slides

Learning Outcomes Epithelial Tissues 1. Describe the distinguishing characteristics of each type of epithelial tissue. 2. Indicate the common locations and general functions of epithelial tissues. Connective Tissues 3. Describe the distinguishing characteristics of each type of connective tissue. 4. Indicate the common locations and general functions of connective tissues.

Learning Outcomes Muscle Tissues 5. Describe the distinguishing characteristics and locations of each type of muscle tissue. 6. Indicate the general function of muscle tissues. Nerve Tissue 7. Describe the distinguishing characteristics and general functions of nerve tissue. 8. Indicate the common locations of nerve tissue.

Learning Outcomes Body Membranes 9. Compare epithelial and connective tissue membranes. 10. Give examples of each type of membrane.

Tissue: a group of similar cells with similar functions Four basic types of tissues 1.Epithelial 2.Connective 3.Muscle 4.Nerve

4.1 Epithelial Tissues Five distinguishing characteristics 1.Closely packed cells 2.Attached to connective tissue by a basement membrane 3.Tissue surface opposite the basement membrane is not attached to other tissues 4.Tissue has no blood vessels 5.Tissues regenerate rapidly

Functions vary with location and tissue type –Protection, absorption, filtration, secretion Glandular epithelium can be found inside glands –Exocrine glands –Endocrine glands

Simple Epithelium –Single layer of flat, cube-like, or column-like cells –In places of diffusion, secretion, or filtration

–Simple squamous epithelium Single layer of thin flat cells Aids in osmosis, diffusion, and filtration Found in the lungs, kidneys, serous membranes of ventral cavity, endothelium

–Simple cuboidal epithelium Single layer of cube-like cells Aids in absorption and secretion Found in the secretory part of glands, kidney tubules, surface of ovaries

–Simple columnar epithelium Single layer of column-like cells Aids in secretion and absorption Can also possess goblet cells, cilia, and/or microvilli Found in the uterus, uterine tubes, stomach, intestines

–Pseudostratified ciliated columnar epithelium Single layer but visually looks like many layers Possess goblet cells Line upper respiratory passageways

Stratified Epithelium –Consist of more than one layer of cells –Innermost layer undergoes mitotic cell division –Surface cells are continuously lost –Protection is an important function

–Stratified squamous epithelium Provide resistance to abrasion Keratinized type forms the epidermis –Keratin protein Nonkeratinized type lines mouth, esophagus, and vagina

–Transitional epithelium Accommodates stretching of the urinary bladder Unstretched: cells are large and rounded Stretched: surface cells become thin and flat

4.2 Connective Tissues Most abundant body tissues Support and bind other tissues Never found on exposed surfaces Have the ability to regenerate Consist of few, loosely arranged cells and intercellular substance called matrix

Two broad categories of connective tissues –Connective Tissue Proper Common tissues that bind other tissues and organs –Connective tissues with specialized functions

Connective Tissue Proper –Functions Bind together other tissues Basic supporting framework of organs –Matrix consists of ground substance –Fibroblasts are the most abundant cells –Two types of protein fibers Collagenous fibers Elastic fibers

–Loose connective tissue, or Areolar Most abundant in body Named for its loosely arranged protein fibers Attaches skin to muscles Supporting framework for internal organs, nerves, blood vessels Site for immune reactions

–Adipose tissue Has large numbers of adipocytes that store fat droplets Common beneath skin and around internal organs Aids in fat storage and body insulation Provides a protective cushion

–Fibrous connective tissue Has an abundance of tightly packed collagenous fibers and few cells Great strength and flexibility Component of ligaments, tendons, and dermis Poor blood supply resulting in slow healing

–Elastic connective tissue Has an abundance of elastic fibers Found where elasticity is needed Lungs, air passages, arterial walls

Cartilage –Semisolid matrix with embedded chondrocytes living in lacunae –Major functions are support and protection –There are three types of cartilage Hyaline cartilage Elastic cartilage Fibrocartilage

–Hyaline cartilage Most abundant cartilage Protective covering on bones at joints Forms part of the nose Supports walls of air passages Forms most of embryonic skeleton

–Elastic cartilage Has an abundance of elastic fibers that provide resiliency Found in the larynx and external ear

–Fibrocartilage Has an abundance of tightly packed collagenous fibers Designed to resist compression and tension Forms intervertebral discs, cartilagenous pads in knees, cushion for the symphysis pubis

Bone or osseous tissue –Hardest and most rigid due to calcium salts in its matrix, along with collagenous fibers –Provides rigidity and strength to support the body –Matrix is deposited in lamellae around osteonic (Haversian) canals –Osteocytes, located between lamellae, are connected by canaliculi

Blood –Consists of numerous cells in a liquid matrix –Three types of cells Red blood cells White blood cells Platelets –Vital role in transporting material throughout the body

4.3 Muscle Tissues Cells are unable to divide so regeneration is not possible Cells are called muscle fibers due to their long, thin appearance Cells use specialized protein fibers for contraction Contraction moves the body and produces heat

Skeletal Muscle Tissue –Attached to bones and move the body –Voluntary muscle –Cells are elongated and cylindrical, with many nuclei and striations

Cardiac Muscle Tissue –Found only in walls of heart –Involuntary muscle –Branching muscle fibers that interconnect at intercalated discs –Possess one nucleus and striations

Smooth Muscle Tissue –Occurs in the walls of hollow organs –Involuntary muscle –Cells possess a spindle shape, one nucleus, and not striations

4.4 Nerve Tissue Found in brain, spinal cord, and nerves Two main types of cells –Neurons –Neuroglia Neuroglia are supporting cells that nourish, insulate, and protect neurons

Neurons –The functional units of nerve tissue –Possess a cell body and one or more neuron process –Respond to environmental changes by making neural impulses

4.5 Body Membranes Thin sheets of tissue Line cavities, cover surfaces, or separate tissues or organs Two types of body membranes –Epithelial membranes –Connective tissue membranes

Epithelial Membranes –Composed of epithelial tissue overlying loose connective tissue –Serous membranes Line ventral body cavity and cover internal organs Secrete serous fluid to reduce friction Examples: pleurae, pericardium, peritoneum

–Mucous membranes Line tubes and cavities open to the exterior Possess goblet cells to make mucus Keeps cells moist and lubricated Examples: digestive and respiratory tracts –Cutaneous membrane Skin

Connective Tissue Membranes –Formed only of connective tissue –Examples: 1.Meninges 2.Perichondrium 3.Periosteum 4.Synovial membrane