L 3 tissues

what are the common set of functions of a cell?

Nutrient uptake

Energy metabolism

Division (replication)

tissues

Groups of cells in multicellular organisms that have a specific function that distinguishes them from other groups of cells in a whole organism. These groups of cells that have some common function

What is the extracellular matrix?

The extracellular matrix (ECM) is the non-cellular part within all tissues: it is the stuff in the spaces in and around the cells.

what does the extracellular matrix provide?

It provides essential physical scaffolding for the cells and is involved in other tissue processes incl. homeostasis.

what is the extracellular matrix composed of?

The ECM is typically composed of water, proteins, minerals or salts, and polysaccharides. Each tissue's ECM has a unique composition

what does thee extra cellular matrix contain?

The matrix may contain salts (bone) and structural molecules (collagen, elastin) help to hold the cells of the tissue together. Some extracellular matrix will be more fluid, some will be more solid.

Epithelial tissue description

The cells in epithelial tissues are tightly packed together with a small amount of extracellular matrix between cells.

connective tissue description

Connective tissues have only a relatively small number of cells but have a large amount of extracellular matrix between cells.

name the 7 different types of epithelium

Simple squamous epithelium Simple cuboidal epithelium Simple columnar epithelium Stratified squamous epithelium Stratified cuboidal epithelium Stratified columnar epithelium Transitional Epithelium

function of simple squamous epithelium

enable diffusion

where is simple squamous epithelium found?

inner lining of blood vessels, air sacs of lungs, inner lining of heart

explain the Simple Squamous epithelium.

a single layer of squamous cells: the structure (one layer of flay cells) is specially adapted to primary function.

explain the Simple Cuboidal epithelium

A single layer of cube shaped cells These types of cells are found in the inner linings of ducts and tubules.

function of the Simple Cuboidal epithelium

This epithelium is involved in absorbing and secreting materials (into ducts or tubules).

where is the Simple Cuboidal epithelium found?

kidney tubules pancreatic ducts salivary ducts.

explain the Simple Columnar epithelium

Single layer of tall narrow cells with a nucleus near the base of the cell. These cells will often have specialised extensions (cilia or microvilli) to support their function.

what is the function of the Simple Columnar epithelium?

adapted for secretory and absorptive activity:

it is specialised to function primarily in the gastrointestinal tract.(but can be found elsewhere)

where is the Simple Columnar epithelium found?

stomach

duodenum

ileum

explain the Stratified squamous epithelium?

A thick tissue composed of multiple layers of squamous cells.

Human skin stratified epithelial cells have a special protein in them called keratin (keeps them dry and impermeable).

what is the function of the the Stratified squamous epithelium?

primarily to act as a protective physical barrier

where is the Stratified squamous epithelium found?

skin inside mouth oesophagus

how many layer does the Stratified cuboidal epithelium have?

Only 2 layers the top most layer is cuboidal but the 2nd layer can often be a different cell type and different shape

function of the the Stratified cuboidal epithelium?

protection

where is the the Stratified cuboidal epithelium found?

inner linings of sweat glands mammary glands salivary glands

explain the Stratified columnar epithelium.

Tissue with multiple layers of columnar cells.

function of the Stratified columnar epithelium.

provides protection and supports secretion-secretion of waste materials inot the ducts and out of the body

where is the Stratified columnar epithelium found?

linings of pharynx

urethra

salivary gland ducts

mammary gland ducts

it is a rare type of epithelial tissue

explain Pseudostratified columnar epithelium

A type of epithelium that seems to be stratified but is not: consists of a single layer of irregularly shaped and differently sized columnar cells.

In pseudostratified epithelium, the nuclei of adjacent cells appear at different levels and gives the appearance of stratification

- but all cells touch the bottom and therefore only one layer of cells exists

where is Pseudostratified columnar epithelium found?

inner lining of trachea near cells that secrete mucous inner lining of the epididymis (tube that carries sperm)

what does transitional epithelium consist of ?

Consists of multiple layers of cuboidal or columnar cells that can contract and expand.

functions of transitional epithelium

distension- it can expand or contact to adapt to the level of stretching needed

where is transitional epithelium found?

urinary bladder ureters- tissues that need to stretch

what kind of cells are in the bladder?

it has several layers of large dome-shaped cells on its surface

what are the 4 major tissue types

1. epithelial tissue

2.connective tissue

3. muscular tissue

4. nerve/nervous tissue

what is a fibre?(general)

any long strand of material

what is a fibre? (anatomy)

any elongated, thread-like structure

what are the main types of fibre

collagen and elastic fibre

what us the most common tissue type in the body

connective tissue

what is the most widely distributed form of tissue in the body

connective tissue

what does connective tissue refer to

several different tissues of the body that function to Connect, Support, and Bind other tissues

how much extracellular matrix does connective tissues have?

a large amount within which cells and fibres are located

what do most connective tissues have?

cells

extracellular matrix

fibres

forms of connective tissue

solid

semi-solid

fluid

collagen fibres

contain Collagen (white in colour)-

a protein chain that provides the dual qualities of strength

& flexibility Collagen fibres are usually straight and thick.

elastic fibres

contains Elastin, another protein chain (yellow in colour)

- that is not as strong as collagen

but is more flexible (elastic)

Elastic fibres are branched

loose fibrous connective tissue

1. Loose fibrous connective tissue contains many blood cells: fibroblast cells, fat cells, and white blood cells

2. Its Extracellular Matrix contains a lot of soft jelly-like ground substance with mainly 2 types of protein fibres running through it:

- Collagen

- Elastin

3. Found in lungs, arteries, muscle, and bladder and supports the expansion and contraction of these organs Loose connective tissue can also contain reticular fibres

dense fibrous connective tissue

1. Dense fibrous connective tissue contains Fibroblast cells

2. Its Extracellular Matrix has much less ground substance and is tightly packed with Collagen fibres

3. Found in Tendons and Ligaments where it forms the key part of these tissues

what does cartilage provide

Cartilage provides structure, shape, and protection in and around bones and other structures in the body.

how is cartilage similar to bone

Cartilage has a large amount of ECM.

Cartilage is very similar to bone but is less hard and more flexible.

This is because its ECM does not have minerals (it is not mineralised like bone).

are there fibroblasts in cartilage

In cartilage, there are a small number of cells including Fibroblasts,

and specially differentiated fibroblasts called Chondroblasts and Chondrocytes

does cartilage vary

Cartilage varies according to the fibre types it contains

does cartilage have a direct blood supply

Cartilage tissue does not have a direct blood supply.

what are the 3 types of cartilage

Hyaline Cartilage

Fibrocartilage

Elastic cartilage

what is the most common type of cartilage

Hyaline Cartilage

describe Hyaline Cartilage

most common, contains a small number of fine collagen fibres,

ECM is clear, cells are found scattered in small holes called lacunae.

Found in nose, ends of bones, ribs, rings around trachea.

describe Fibrocartilage

has an ECM containing a large amount of collagen fibres densely layered together.

Cells are smaller and often organised in rows inside lacunae.

Found in the discs between the vertebrae of the spine and in the knee joint (shock absorber)

describe Elastic cartilage

has an ECM containing a large number of elastic fibres and is flexible.

Cells are found scattered in called lacunae.

Found in the outer ear and epiglottis.

what are the 2 types of bone

compact

spongy

what forms the skeletal system

Bones form the skeletal system that broadly connects the body together.

what consists of mineralised salts

bones ECM is very hard and consists of mineralised salts

(mostly Ca & P salts)

deposited around collagen fibres (with some elastin).

cells in bones

osteoclasts

osteoblasts

osteocytes

what is blood made up of?

Blood consists of cells (red cells and white cells and platelets)

and a fluid extracellular matrix called plasma.

Blood is mostly plasma (fluid).

what is blood responsible for?

Blood is responsible for transporting O2 and nutrients into the extracellular fluid (also called interstitial fluid and part of the ECM of soft tissues)

which surrounds the cells in tissues (also enables removal of waste products incl. CO2)

Blood also is involved in transport, immunity, fluid balance, endocrine gland communications, pH balance

what connects the cells of the body

Blood serves as the connector (super- highway) among all cells of the body.

Blood does not contain fibres

what is lymph

Lymph is the second form of fluid connective tissue.

what does lymph contain

It has a clear fluid ECM and contains several white blood cell types:

lymph is non-blood fluid that drains into lymph vessels from the interstitial fluid (fluid ECM) around cells.

Lymph is mostly fluid.

what does lymph connect

Connects multiple organs and tissues:

Lymph transports absorbed fat from the intestine into the blood

and has an important role in transporting lymph for filtration (removing white cells) at the lymph nodes.

Lymph does not contain fibres.

what are the 3 types of muscle

skeletal

cardiac

smooth

what are muscle cells known as

They are known as fibres because of their elongated shape.

shape of a muscle cell

They are like long tubes/pipes in Skeletal and Cardiac muscle.

These cells are structured specially to enable contraction

muscle tissue cells

In muscle tissue the cells have a unique structure and are known as muscle fibres

what is inside a muscle cell

Packed inside tightly inside the cell are long bundles of protein chains called myofibrils.

filaments

The protein chains that make up the myofibrils

what do the interactions between filaments enable?

. The interactions between filaments enable muscle contraction & relaxation.

Skeletal muscle cells

1. Cylindrical and long (hence known as fibres)

2. They are densely packed with protein filaments.

3. They also have a striated appearance (light and dark bands) because of the way the filaments line up inside the cell.

4. ECM is fluid-based with structural proteins in and around the cells.

5. Function: movement under voluntary control

Smooth muscle

1. Smooth muscle cells are named this way as they have no striations.

2. Cell is less elongated and not tube/pipe-like in structure.

3. They contain a smaller number of protein filaments and do not have striations

4. ECM is fluid-based with structural proteins.

5. Found on the walls of the intestines and other organs.

6. Smooth muscle contracts more slowly but can stay contracted for longer- responsible for peristalsis, constriction of blood vessels, and other involuntary tissue movements.

Cardiac Muscle

1. Cardiac muscle: found only in the walls of the heart.

2. Cardiac cells are branched and appear fused together (they are not).

3. They are similar in structure to skeletal muscle cells in that they are elongated and tube-like (but have branches connecting them).

4. They are densely packed with protein filaments.

5. ECM is fluid-based with proteins in and around the cells.

6. Contraction & relaxation of this muscle is responsible for cardiac systole and diastole: it has features of both smooth and skeletal muscle: it has striations but is involuntary.

where is nervous tissue found?

brain

spinal cord

peripheral nerves

what is the ECM of nervous tissue composed of

The ECM of nervous tissue is composed of a fluid base substance along with many structural proteins providing support to the neurons and other cells.

3 key parts of a neuron

dendrites

cell bodies

axon

what are axons covered in?

myeline

what does the cell bodies contain?

nucleus

cytosol

organelles

what do cells support and service

neurons called neuroglia

neuroglia

10 times more of these cells than neurons in the human brain

types of neuroglia in the CNS

ependymal cells

oligodendrocytes

astrocytes

microglia

where is the cardiac muscle found

in the walls of the heart

shape of cardiac cells

Cardiac cells are branched and appear fused together (they are not)

They are similar in structure to skeletal muscle cells in that they are elongated

and tube-like (but have branches connecting them)

what is responsible for cardiac systole and diastole?

Contraction & relaxation of this muscle is responsible for cardiac systole and diastole:

it has features of both smooth and skeletal muscle:

it has striations but is involuntary