PLANT AND ANIMAL TISSUE 10 APRIL 2013

Lesson Description

In this lesson we:

Discuss important terminology

Look at the organisation of Life

Discuss animal tissue and specialised cells

Key Concepts

Terminology

blood

connective tissue

dermal tissue

epithelium tissue

ground tissue

muscle

nerve

stem cell

The Organisation of Life

Diagram showing the organisation of Life

Animal Tissue

Animal cells with the same structure and function are organised into tissues.

Embryonic Tissue

Embryonic tissue can be divided into two kinds of stem cells:

Embryonic stem cells- tissue in an embryo that produces all other tissue during growth

Adult stem cells- tissue in adult that produces new tissue cells to replace old and damaged

ones.

Structure and Function of Embryonic Tissue Structure Function

Embryonic stem cells Produces cells for specialised tissues

Adult Stem cells Replaces old and damaged cells and tissues

Large nucleus

Cellular extensions of cytoplasm

Animal tissues consist of four major types of permanent tissue:

1. Epithelial tissue

2. Connective tissue

3. Muscle tissue

4. Nerve tissue

Diagram showing how different types of tissue make up humans

Permanent Tissue

The four groups of permanent tissue have different structures and functions.

These are:

Epithelial tissue: Tissue for covering and lining

Connective tissue: tissue for structure, strength, binding and transport

Muscle tissue: tissue for movement

Nerve tissue: tissue for communication

Epithelial Tissue

Some epithelial tissues are squamous, meaning flat-shaped and some are columnar, meaning tall.

Stratified means “in layers”

Pseudo stratified means it seems to be in layers, but is not (pseudo means false)

Cuboidal means “like a cube”

Ciliated means that they may have tiny hair like outgrowths.

Structure and Function of Epithelial Tissue Structure Function

Has three cell types: - Flat squamous cells - Cuboidal cells - Columnar cells

Found in layers:

Single layers: simple epithelium

Many layers: stratified epithelium

Cells lie on basement layer (membrane) – connects epithelium to other tissues

May contain special cells or structures: goblet cells, cilia (hairs)

Line body surface inside and outside.

Make up glands that secrete sweat, enzymes, hormones, milk, sebum, oils.

Allow gases, water, nutrients, mineral salts in solution to pass through.

Goblet cells secrete mucus that helps with movement over epithelium layer.

Cilia remove dust particles from internal surfaces.

Diagram showing Simple columnar epithelium Diagram showing Simple cubiodal epithelium

Muscle Tissue

Muscle tissue is tissue that allows our bodies to move.

There are three different types of muscle tissue that are well suited to their function.

Skeletal muscle

Smooth muscle

Cardiac muscle

Skeletal muscle

tissue: is attached to the bones and moves the joints. These muscles are responsible for voluntary

movement.

Diagram showing striated muscle tissue

Smooth muscle tissue: is found in the soft organs of the body, for example, digestive canal, bladder,

skin, arteries and veins. These muscles are responsible for involuntary movements which are

movements that happen automatically.

Cardiac muscle tissue: is found only in the heart where it makes up most of the hear wall. Cardiac

muscle is responsible for involuntary movements of the heart. It is nearly as strong as skeletal muscle

but unlike smooth muscle, it does not tire easily.

Diagrams showing Cardiac muscle tissue

Structure and Function of Muscle Tissue Structure Function

Consists of three tissue types: - Skeletal striated voluntary muscle. - Cardiac striated involuntary muscle. - Smooth, unstriated involuntary muscle.

Made of muscle fibres

Nuclei found on side; may be more than one

Striated muscles have contraction fibrils – myofibrils.

For voluntary actions: walking, lifting, etc.

For involuntary contracting and relaxing of organs: heart, blood, vessels, bladder, stomach, etc

Connective Tissue

Connective tissues are found in all parts of the body where they hold, support and protect the organs

and other tissues.

The special feature of connective tissue is that the living cells are found in a large amount of non

living extracellular substances called the matrix.

The matrix makes each kind of connective tissue different and gives it a different texture.

We can divide connective tissue into four groups:

Connective tissue with a jelly like matrix

Connective tissue with a rubbery matrix

Connective tissue with a rigid matrix

Connective tissue with a liquid matrix

3.1. Connective tissue with a jelly like matrix

This tissue can be divide into two groups.

Loose or areolar connective tissue.

Dense connective tissue

Areolar connective tissue is the most widely spread connective tissue in the body. It is found under

skin and filling spaces between the organs and muscles.

Areolar connective tissue is well suited to its function

It is soft and supple which makes it a good packing tissue between organs and other tissues.

Diagrams showing areola connective tissue

Dense connective tissue : there are two types of dense connective tissue with jelly –like matrix that

are well suited to their functions

Tendons: are made up of a dense network of strong white fibres. They join muscle to bones.

They are very strong so that the muscle can pull on the bones to cause movement

Ligaments: are made up of dense network of elastic yellow fibres .They join bones together

at joints. They are elastic so that the bones in the joints can move easily in relation to one

another.

3.2. Connective tissue with a rubbery matrix

Connective tissue with a rubbery matrix is called cartilage. The cartilage cells are called

chondrocytes.

There are three main types of cartilage that are well suited to their functions.

Hyaline cartilage: is found mostly in articulating surfaces of bones where they meet in joints. The

unspecialised cells in this tissue are suitable where two parts rub together because they can easily

regenerate when they are worn.

Diagrams showing Hyaline cartilage

White fibrous cartilage: is very strong and is found as discs between the vertebrae and covering the

bones in joints such as the knee, hip and shoulder joints. The strength of white fibrous cartilage

makes it suitable for padding in joints.

Yellow elastic cartilage: can bend easily without breaking. It supports the external ear and the tip of

the nose, which stick out from the body and need to bend.

3.3 Connective tissue with a rigid matrix

Connective tissue with a rigid matrix is called bone. The bone cells are called osteocytes. Bones

support the body and protect the organs.

Bone is well suited for its function.

Minerals such as calcium and phosphates that are found in the matrix make the bone very

strong.

The matrix also has fibres which make it strong but give it easily elasticity .

3.4. Connective tissue with a liquid matrix

Blood is the connective tissue with a liquid matrix called plasma. Plasma make up over half the

volume of blood. It is 90% water with plasma proteins and dissolved substances such as minerals,

nutrients and gases. Blood flows around the body to all cells in special tubes called blood vessels.

There are three main types of blood cells that are well suited to their functions.

Red blood cells are also called erythrocytes. They carry oxygen to all the cells in the body. Red

blood cells are filled with red pigment called haemoglobin that carries oxygen. Haemoglobin readily

combines with and releases oxygen.

White blood cells are also called leucocytes. They protect the body from disease by feeding on the

microorganisms that cause disease. Some white blood cells are called lymphocytes produce

chemicals called antibodies which poison and destroy the disease- causing microorganisms.

Platelets, which are also called thrombocytes, are small pieces of cells. They are very important for

the clotting of blood when a blood vessel is damaged and has to be healed.

Nerve Tissue

Nerves are made up of cells called neurons.

Neurons can be classified by their function, structure or the special they use.

Sensory neurons carry impulses from receptors to the central nervous system (CNS)

Motor neurons carry impulses from the CNS to the muscle cells and glands, which are effectors.

Axons are covered by Schwann cells with spaces between them called nodes of Ranvier.

Axons end up in fine extensions called terminal fibres of terminal branches.

Connector Neurons: carry impulses to the motor neurons and connect neurons together.

Questions

Question 1

The diagram shows the various tissues found in the knee region of a chimpanzee.

a.) Identify tissue A and D. (2)

b.) Name the types of cells found in D (3)

c.) Which tissue provides food and oxygen to the knee joint? (1)

d.) A vet carried out a “knee jerk” test on the chimpanzee to determine its reflex response. Name

the neuron responsible for transmitting this impulse to the central nervous system. (1)

Links

Magnification simulation http://www.cellsalive.com/howbig.htm

Animal / Plant Cell http://www.cellsalive.com/cells/cell_model.htm

3D animation of a cell: http://www.xvivo.net/the-inner-life-of-the-cell/

Reference List

1. Via Afrika Life Sciences; Grade 10 Learner’s Book; M. Bowie, A. Johannes, R. Mhlongo, E.

Pretorius.

2. Shuters Top Class Life Sciences Grade 10 Learners Book; P. Ayerst, R. Langely, P. Majozi,

A. Metherell, D. Smith.

3. 3. Spot On, Life Sciences Learners’ Book, C Dawson, P Holm, G Jackson; H Skinner