Tissue Level

Question 1

Many cells of the same type make up tissue e.g. muscle cells make up muscle tissue. The study of tissues is called?

Answer 1

Histology.

Question 2

There are four main types of tissue, what are they?

Answer 2

1. epithelial
2. connective
3. muscle and
4. nervous

Question 3

1. Fill in the blanks: Epithelial tissue generally consists of ______(a)_____, arranged in ____(b)___, with little _____(c)_________ between them.
2. Epithelial tissue forms the ___(i)____ and ____(ii)___ of many ___(iii)___ and ___(iv)____ in the body.

Answer 3

1. a) closely packed cells,
   b) arranged in layers,
   c) extracellular material
2. i) Linings
   ii) coverings
   iii) organs
   iv) vessels

Question 4

There are 2 main types of epithelial what are they? Describe them & give examples…

Answer 4

1. Simple Epithelium

Comprised of a single layer of cells.

It is used to line body cavities such as the heart, blood vessels, lungs, and digestive tract.

Although due to its thinness simple epithelium is fragile it does allow substances to be absorbed quickly through it.

2. Compound Epithelium

Contains more than one layer of cells.

As it is thicker and stronger than simple epithelium it protects areas that are subjected to wear and tear.

For example, compound epithelium lines the oesophagus and forms the epidermis.

Question 5

There are 3 main types of simple epithelium and 2 main types of compound epithelium. Name them:

Answer 5

Epithelial Simple;

1. Squamous
2. Cuboidal
3. Columnar

Epithelial Compound

1. Stratisfied
2. Transitional

Question 6

Appearance, attributes, examples

Name this type and give a description and examples of?

Answer 6

Simple squamous epithelium Or “pavement epithelium” due to its appearance.

The cells are flat with a central nucleus.

The thinness of this tissue is highly adapted for diffusion, osmosis and filtration but it is fragile and so is found in areas which are not subjected to wear and tear.

It lines the alveoli, Bowman’s capsule of the kidney, heart, blood vessels and lymph vessels.

It also forms the walls of capillaries where it is called endothelium.

Question 7

Name this type and give a description and examples of?

Answer 7

Simple Cuboidal

The cube-shaped cells arranged in rows.

Performs the functions of secretion and absorption.

It covers the surface of the ovaries, lines the back of the eye and the kidney tubules. It is also found in the smaller ducts of many glands.

Question 8

Name this type and give a description and examples of?

Answer 8

Simple Columnar

Tall, column-shaped cells.

Offer a little more protection than the flat cells of squamous epithelium.

Lines the ducts of most glands and much of the digestive tract.

May also contain goblet cells. (Goblet cells secrete mucus which serves to protect and lubricate.)

May be ciliated or have microvilli.

Question 9

Name this type and give a description and examples of?

Answer 9

Compound Stratified

Composed of a number of layers of cells of different shapes and its role is mainly to protect.

Can be squamous, cuboidal or columnar depending on the shape of the cells that make up the surface layer, but squamous is by far the most common.

Question 10

Name this type and give a description and examples of?

Answer 10

Compound Transitional

Permits stretching.

It can therefore vary in appearance depending upon whether it is relaxed or distended.

When relaxed the upper cells look large and rounded.

Due to its ability to stretch, transitional epithelium is found in hollow structures that are subjected to expansion such as the urinary bladder and portions of the ureters and urethra.

Question 11

Connective tissue is the most abundant tissue. What are its properties? (5)

Answer 11

• It binds,
• protects,
• strengthens and supports other tissues,
• protects and insulates internal organs and
• compartmentalises some structures.

Question 12

1. Connective tissue consists of cells, ground substances and fibres. The ground substances and fibres, are called the __(a)___, and are located outside the cells.
2. Describe, connective tissue…
3. How can the (a) vary? Give example.

Answer 12

1. Matrix
2. Generally consists of relatively few cells in a great deal of intercellular substance.
3. The matrix can be liquid, gel-like or solid and so connective tissue can range from fluid (e.g. blood) to bone which is the hardest.

Question 13

There are several types of connective tissue. List 8 of them…

Answer 13

1. Areolar
2. Adipose
3. White fibrous
4. Yellow elastic
5. Lymphoid
6. Blood
7. Bone
8. Cartilage

Question 14

Describe Areolar tissue.

Answer 14

• Areolar tissue is the most widely distributed connective tissue in the body.
• It consists of large, flat cells in a watery gel supported by a network of fine, white collagen fibres and elastic fibres.
• This white tissue surrounds blood vessels, nerves and muscles and connects the skin to the underlying tissues and muscles.

Question 15

Describe Adipose tissue.

Answer 15

• Adipose is “fatty” tissue and is semi-solid.
• The cells are specialised for the storage of fat.
• Adipose tissue supports, protects and insulates.
• It also provides a store of energy.
• Found throughout the body but particularly in the subcutaneous layer of the skin and around the kidneys.

Question 16

Describe White fibrous tissue.

Answer 16

• Contains closely packed collagen fibres.
• It is strong and forms attachments. For example, white fibrous tissue is found in tendons (that attach muscle to bone) and ligaments (that attach bone to bone).

Question 17

Describe Yellow elastic tissue.

Answer 17

• As the name suggests, yellow elastic connective tissue consists of yellow elastic fibres.
• It allows organs to stretch and then return to normal size.
• For example, yellow elastic tissue is found in the walls of the arteries.

Question 18

Describe Lymphoid tissue.

Answer 18

• Lymphoid tissue - commonly called lymph - is semi-solid and
• contains cells called lymphocytes.
• Forms a part of the lymphatic system which is concerned with the control of disease.

Question 19

Describe Blood tissue

Answer 19

• Blood is a connective tissue.
• It contains 45% blood cells and 55% plasma (the matrix).

Question 20

Describe Bone tissue

Answer 20

• Bone consists of widely separated cells within a matrix.
• The matrix consists of approximately 25% water, 25% protein and 50% mineral salts.
• There are two types of bone – compact and cancellous.
  
  • As the name suggests, compact bone tissue contains few spaces. Compact is strong, providing protection and support.
  • Cancellous (spongy) is arranged in an interlacing network in which red bone marrow may be found in the spaces.

Question 21

Describe Cartilage tissue

Answer 21

• Cartilage is firm and the matrix is quite solid.
• It contains cells called chondrocytes.
• Cartilage connects and protects.
• There are three types of cartilage. Hyline, White Fibrous & Yellow Elastic.

Question 22

Cartilage connective tissue is firm and the matrix is quite solid. It contains cells called chondrocytes. Cartilage connects and protects. There are 3 types; name & describe them:

Answer 22

1. Hyaline:
   
   1. most common, also called articular cartilage.
   2. It is firm, elastic and reduces shock and friction in the joints.
   3. It is also used to connect bone to bone in joints such as those between the ribs and the sternum.
   4. Forms the rings that keep the trachea open.
2. White fibrous:
   
   1. is made up of bundles of white collagenous fibres with chondrocytes in between.
   2. It is very strong but slightly flexible.
   3. It is found in some pelvic joints and makes up the intervertebral discs.
3. Yellow elastic:
   
   1. This flexible cartilage consists of yellow elastic fibres.
   2. It forms the epiglottis and can be found at the tip of the nose and in the upper part of the pinna (external part of the ear).

Question 23

A membrane is a thin, flexible sheet of tissue that encloses a cell (e.g. the cell membrane) or a structure (e.g. the pleural membranes of the lung). There are 3 types of membrane, what are they & describe them…

Answer 23

1. Mucous membranes

Comprised of a layer of epithelial tissue and an underlying connective tissue.

They line body cavities that open to the exterior and line the entire digestive, respiratory and reproductive systems and most of the urinary system.

Secrete a fluid called mucus that lubricates and protects the underlying cells.

2. Serous membranes

Also comprised of a layer of epithelial tissue and an underlying connective tissue.

The connective tissue in serous membranes is areolar.

They line body cavities that do not open to the exterior and cover many organs. E.g. the pleura (covering the lungs) and the pericardium (covering the heart).

The epithelial layer secretes serous fluid that lubricates and allows the organs to glide against each other or against the walls of the cavities.

3. Synovial membranes

These line the cavities of freely moveable (synovial) joints.

Synovial membranes do not contain epithelium.

They are composed of areolar connective tissue, elastic fibres and fat.

Secrete synovial fluid to lubricate and nourish the cartilage that protects the bone at the joints.

Question 24

Muscle tissue consists of elongated cells capable of expanding and contracting. The contractile fibres are usually arranged in bundles and surrounded by connective tissue.

Muscle tissue facilitates what 3 things?

Categorised into what 3 types?

Answer 24

Facilitates:

1. movement,
2. maintains posture and
3. generates heat.

Types:

1. skeletal (voluntary),
2. smooth (involuntary) and
3. cardiac (involuntary).

Question 25

Nervous tissue is made up of nerve cells. What are the 2 types?

Answer 25

Neurons and neuroglia.

Neurons are sensitive to stimuli and are capable of initializing and transmitting nerve impulses. Nervous tissue therefore helps to co-ordinate body activities.