Tissues in animals

Question 1

What is a tissue?

Answer 1

a tissue is made up of a collection of differentiated cells that have a specialised function or functions

each tissue is adapted for a particular function

Question 2

What are the four main categories of tissues in animals?

Answer 2

nervous tissue - support the transmission of electrical impulses

epithelial tissue - cover the body surface, internal and external

muscle tissue - contract

connective tissue - hold tissue together or as a transport medium

Question 3

How is squamous epithelium tissue specialised to perform its function?

Answer 3

made up of specialised squamous epithelial cells (flattened)

thin due to the flat cells that make it up and also because it is one cells thick

present when rapid diffusion across a surface is essential

it forms the lining of the lungs and allows rapid diffusion of oxygen into the blood

Question 4

How is cilliated epithelium tissue specialised to perform its function?

Answer 4

made up of cilliated epithelial cells

cells have hair like structures called cilia on one surface that move in a rhythmic manner

ciliated epithelium lines the trachea, e.g. causing mucus to be swept away from the lungs

goblet cells are also present, releasing mucus to trap any unwanted particles present in the air

prevents the particles, which may be bacteria from reaching the alveoli once inside the lungs

Question 5

How is cartilage specialised to perform its function?

Answer 5

connective tissue found in the outer ear, nose and at the ends of (and between) bones

contains fibres of the proteins elastin and collagen

firm, flexible connective tissue composed of chondrocyte cells embedded in an extracellular matrix

prevents the ends of bones from rubbing together and causing tissue

many fish have whole skeletons made of cartilage

Question 6

How is muscle tissue specialised to perform its function?

Answer 6

needs to shorten in length (contract) in order to move bones

skeletal muscle fibres - attached to bones contain myofibrils which contain contractile proteins

Question 7

What is an organ?

Answer 7

collection of tissues working together to perform a specific function e.g. gas exchange for lungs