BODY TISSUES & MEMBRANESTissues are groups of cells similar in structure and function

the 3 primary germ layers

1. Ectoderm2. Endoderm3. Mesoderm These give rise to all the basic

tissues of the body

The four types of tissues.

Epithelial Connective Muscle Nerve

Describe the characteristics & functions of epithelial tissue. LT#1 Forms continuous sheets over the body

surface & most of the bodies inner cavities Protects the body from drying out, injury,

bacterial exposure Inside specialized - cilia sweeps impurities

from GI tract, secretes mucus to protect from acids, microvilli in kidneys increases absorption

Replaces lost cells by cell division (regenerative)

Tissue cell shapes 101

Simple Stratified =

layering

Tissue cell shapes 101

Squamous, cuboidal, or columnar-cell shape

Name the major types of epithelial tissues, relate each one to an organ. LT#2

simple squamous simple cuboidal simple columnar pseudostratified columnar stratified squamous stratified cuboidal stratified columnar transitional

Visual

simple squamous (flattened) Single layer of flattened cells with

disc-shaped nuclei and sparse cytoplasm

Functions: Diffusion and filtration Provides a slick, friction-reducing

lining in lymphatic and cardiovascular systems

Simple squamous

Simple cuboidal

Single layer of cubelike cells with large, spherical central nuclei

Found in the liver – make insulin & glucagon

Also found on surface of ovaries, duct linings of glands, lining tubules of kidneys

Function in secretion and absorption

Simple cuboidal

Simple columnar

Single layer of tall cells with oval nuclei; many contain cilia

Goblet cells are often found in this layer

Function in absorption and secretion Non-ciliated type line digestive tract

and gallbladder Ciliated type line small bronchi,

uterine tubes, and some regions of the uterus

Cilia help move substances through internal passageways

Simple columnar

Simple columnar with goblet cells (secrete mucus)

Pseudostratified Columnar

Single layer of cells with different heights; some do not reach the free surface

Nuclei are seen at different levels Found in lungs and nasal cavities Also found in linings of repro sys

tubes Function in secretion and propulsion

of mucus & sex cells

Pseudostratified Columnar

Stratified Squamous

Thick membrane composed of several layers of cells

Function in protection of underlying areas subjected to abrasion

Forms the external part of the skin’s epidermis (keratinized cells), and linings of the esophagus, mouth, and vagina (nonkeratinized cells)

Stratified squamous

Stratified squamous from esophagus

Stratified squamous from skin

Stratified cuboidal

Quite rare in the body Found in some sweat and mammary

glands

Stratified cuboidal

Stratified columnar

Limited distribution in the body Found in the pharynx, male urethra,

and lining some glandular ducts, salivary ducts

Stratified columnar

Transitional

Several cell layers, basal cells are cuboidal, surface cells are dome shaped

Stretches to permit the distension of the urinary bladder

Lines the urinary bladder, ureters, and part of the urethra

Transitional

Transitional collapsed & distended

glandular epithelium and how it is classified

A gland is one or more cells that makes and secretes an aqueous fluid

Classified by: -Site of product release – endocrine

or exocrine -Relative number of cells forming

the gland – unicellular or multicellular

Glandular epithelium

22) What is an endocrine gland, what do they secrete and how do they do it?

23) What is an exocrine gland, what do they secrete and how do they do it?

24) Give the major types of connective tissue and some examples.25) What are the general functions of connective tissue?26) What are the common characteristics of connective tissue?27) What are the three major structural elements of connective

tissue?28) What type of cells do you find in connective tissue and where

would you find them?29) What are the two types of loose connective tissue proper

given and what characterizes them?30) What are the two types of dense connective tissue proper

given and what characterizes them?

31) Describe the three different types of cartilage: what they are made of, their functions and where you would find them?

1. Hyaline cartilage2. Elastic cartilage3. Fibrocartilage cartilage

1. Hyaline Cartilage

Looks like jelly – does not heal and usually is cut out when injured with hope of gaining muscle to compensate for the loss

Chondrocytes lie in lacunae (a small space containing an osteocyte in bone or chondrocyte in cartilage)

Supports, reinforces, cushions, and resists compression

Hyaline cartilage

Forms the costal cartilage Found in embryonic skeleton, the end of

long bones, nose, trachea, and larynx

2. Elastic Cartilage

Similar to hyaline cartilage but with more elastic fibers

Maintains shape and structure while allowing flexibility

Supports external ear (pinna) and the epiglottis

Elastic cartilage has “little eyes”

3. Fibrocartilage cartilage Matrix similar to hyaline cartilage

but less firm with thick collagen fibers

Provides tensile strength and absorbs compression shock

Found in intervertebral discs, the pubic symphysis, and in discs of the knee joint

Fibrocartilage

32) Give the characteristics and functions of osseous tissue.

Hard, calcified matrix with collagen fibers found in bone

Osteocytes are found in lacunae and are well vascularized

Osseous Tissue

Osseous Tissue cont’d

Supports, protects, and provides levers for muscular action

Stores calcium, minerals, and fat Marrow inside bones is the site of

hematopoiesis Bones will change shape with

pressure: braces/jawbone, tight shoes/bunions, hammer toe

Bone marrow: 2 kinds

1. Red marrow – site of hematopoiesis2. Yellow marrow – fat (this is why you

make soup from bones)

hematopoietic bone marrow of flat bones vertebrae, sternum, ribs, iliac. It represents 4-6% of body weight.

The fatty degeneration of red bone marrow (RBM) (25%) into yellow bone marrow (YBM) (75%) is completed around age 21 years.

Red marrow

C hematopoietic tissue forming new blood cells.

Yellow marrow

33) Give the characteristics and functions of blood.

Red (carry O2, CO2) and white cells (defense) in a fluid matrix (plasma)

Contained within blood vessels Functions in the transport of

respiratory gases, nutrients, and wastes

Blood

34) Describe and give the functions of nervous tissue? Where is it found? Branched neurons with long cellular

processes and support cells Transmits electrical signals from

sensory receptors to effectors (using ions)

Found in the brain, spinal cord, and peripheral nerves

Nervous Tissue: unique shape carries signals (like wire) but uses ions – not electricity

35) Describe and give the functions of the three types of muscle tissue.1. Skeletal2. Cardiac3. Smooth

1. Skeletal Muscle - voluntary

Skeletal Muscle - voluntary Muscles contract and things move

The food muscle

LONG cells that can stretch from knee to hip and have multiple nuclei

Skeletal Muscle cells are cylindrical and multinucleated

2. Cardiac muscle - involuntary

Cardiac muscle special jxns An intercalated disc is an

undulating double membrane separating adjacent cells in cardiac muscle fibers. Intercalated discs support synchronized contraction of cardiac tissue.

3. Smooth muscle

Sheets of spindle-shaped cells with central nuclei that have no striations

Propels substances along internal passageways (i.e., peristalsis)

Found in the walls of hollow organs

Smooth muscle

Smooth muscle