unit 2 anatomy tissues

Tissues

A group of cells that work together to perform a certain function

What are the 4 major types of tissues

Epithelial, connective, muscle, and nervous

What is the main function of epithelial tissue

Coverage and lining

What is the main function of connective tissue

Support

What is the main function of muscle tissue

Movement

What is the main function of nervous tissue

Control

What are the 3 embryonic germ layers

Ectoderm, mesoderm, and endoderm

What does ectoderm give rise to (outside)

Epithelial tissue and nervous tissue

What does mesoderm give rise to (middle)

Epithelial, connective, and muscle tissue

What does endoderm give rise to (inside)

Epithelial tissue

What is extracellular fluid (ECF)

Fluid outside of cells

What is interstitial fluid

Fluid that fills the spaces between cells and tissues

What is plasma

Liquid portion of blood

Where is lymph found

In lymphatic vessels

Transcellular fluid

Fluid in specific spaces, such as cerebrospinal fluid and synovial fluid

What are the main characteristics used to classify epithelial tissue

Cell shape and number of layers

Simple

One layer of cells

Stratified

Many layers of cells

Squamous

Flattened cells

Cuboidal

Square shaped cells

Columnar

Elongated cells

Cellularity

Cells are tightly packed together

Avascularity

No blood vessels

Polarity

Epithelial cells have a free surface facing the outside or an internal space

How do epithelial tissues receive nutrients if they have no blood vessels

Nutrients diffuse from nearby tissues

Regeneration

It can replace damaged cells rapidly

Where is epithelial tissue located

It covers body surfaces and lines internal spaces/organs

Functions of Epithelial tissue

Protection, absorption, secretion, excretion, and filtration

General characteristics of muscle cells

All cells are elongated

Fibers are contractile -can change shape or shorten to cause their attachment to move

Fibroblasts (Major cell type)

Most common fixed cells. Produces Fibers by secreting proteins into matrix

Macrophages (major cell type)

Specializes in phagocytosis -can move to areas to eat foreign materials

Mast cells (major cell type)

Usually near blood vessels

-secrete heparin (anticoagulant) prevents blood clotting

-secrete histamine which promotes inflammation and allergies

Collagen (fiber)

Composed of protein → collagen

Provides high tensile strength to matrix (pink stain)

Tensile Strength

The maximum amount of pulling or stretching force a material can handle before it snaps or breaks

Elastic -protein elastin (fiber)

Provides rubbery resiliency to matrix

-found in skin, lungs, and blood vessels (stain purple)

Reticular (fiber)

Fine collagenous fibers (stain purple)

Delicate network of fibers that surround small blood vessels and support soft tissue organs found in basement membrane

Matrix

Ground substance with fibers

Areolar (connective tissue)

Description- Gell like matrix with all 3 fiber type cells (fibroblast, macrophages, mast cells, some white blood cells)

Function- Binds organs, wraps + cushions organs

Location- Beneath skin, between muscle, beneath epithelial tissue

Adipose white+brown (connective tissue)

Description- cells are packed closely together, giving a chicken-wire appearance to the tissue

Function- White: stores nutrients mainly for other cells Brown: contains abundant mitochondria, which use the lipid fuels to heat the blood stream to warm the body

Location- Lies beneath the skin, in spaces between muscles, around the kidneys, behind eyeballs, in certain abdominal membranes, on the surface of the heart, and around certain joints

Reticular (connective tissue)

Description- composed of thin, reticular fibers in a three dimensional network

Function- helps provide the framework of certain internal organs, such as liver and spleen

Dense regular connective

Description- consists of many closely or “densely” packed, thick, collagen fibers and a fine network of elastic fibers. It has few cells, most of which are fibroblasts

Function- enabling the tissue to withstand pulling forces. It often binds body structures as part of tendons and ligaments

Location- part of tendons and ligaments. It is also in the protective white layer of the eyeball in the deep skin layer

Hyaline cartilage (connective tissue)

Description- the most common type, has very fine collagen fibers in its extra cellular matrix and looks somewhat like white glass

Function- supports, protects, provides framework

Location- ends of bones, nose, rings in the walls of respiratory passages

Elastic cartilage (connective tissue)

Description- has a dense network of elastic fibers and thus is more flexible than hyaline cartilage

Function- supports, protects, provides flexible framework

Location- Framework of external ear and parts of larynx

Fibrocartilage (connective tissue)

Description- a very tough tissue and has many collagen fibers

Function- supports, protects, absorbs shock

Location- between bony parts of spinal column, parts of pelvic girdle and knee

Bone (connective tissue)

Description- Most rigid connective tissue. This extra cellular matrix also has many collagen fibers, which are flexible and reinforce the mineral components of bone

Function- supports, protects, provides framework. Protects vital parts in the cranial and thoracic cavities and is an attachment for muscles

Location- Bones of skeleton

Blood (connective tissue)

Description- is composed of formed elements suspended in a fluid extra cellular matrix called plasma

Function- transports substances, helps maintain stable internal environment (homeostasis)

Location- Throughout the body within a closed system of blood vessels and heart chamber

Skeletal Muscle

Description- Long thin cells (fibers) with many nuclei, with alternating light and dark bands called striations

Control- Voluntary, Conscious control

Function- moves bones of the skeleton

Location- attaches muscle to bones by tendons

Cardiac muscle

Description- Network of cells (branched) with one nucleus with striations and intercalated discs

Control- Involuntary

Function- Pump blood from heart to body and lungs

Location- Heart

Smooth muscle

Description- spindle shaped cells with one nucleus that is centrally located. No striations

Control- Involuntary

Function- movement of food and blood vessels. Vasoconstriction and vasodilation

Location- stomach internal hallow organs

Nervous Tissue

Description- Neurons are branching cells- looks like they have a tail. Have support cells known as glial cells

Function- Transmits signals from sensory receptors to control center to effectors

Location- Brain, spinal cord, nerves