Tissue structure and function

Question 1

Epithelial tissues

Answer 1

They are found in the lining of the organs and the surfaces. They divide into three different types Squamous, Columnar, Endothelium

Question 2

squamous epithelial tissue

Answer 2

Very flat and thin egg - shaped nuclei, often one cell thick and very good for surfaces where diffusion occurs as in the lungs. They line the alveoli in the lungs where oxygen needs to diffuse into the blood and co2 into the lungs.

Question 3

Ciliated Columnar Epithelial

Answer 3

The upper airway (trachea and bronchi) is mainly lined up with these cells. These cells have a lot of Mitochondria. The cilia move mucus away from the lungs, preventing any inhaled particles causing infection.

Question 4

Cilia

Answer 4

They are tiny hairs on the outer surface of Epithelial cells that waft back and forth to move dust and surface mucus out of lungs.

Question 5

Goblet cells

Answer 5

They secrete mucus to help trap any unwanted particles that are present in the air that you breathe. This protects your lungs because it prevents bacteria reaching the alveoli.

Question 6

Endothelial tissue

Answer 6

The Endothelial tissue consists of a layer of flattened cells, one layer thick which are orientated lengthways in the direction of blood flow. It is found lining the Blood vessels and lymphatic vessels. Their function is to provide a smooth surface so that blood flows easily over them.

Question 7

COPD

Answer 7

COPD includes several conditions and is more common in smokers than non smokers, because the substances in smoke damage the lungs.

Question 8

What causes COPD

Answer 8

The cigarette smoke causes the cilia of columnar epithelium to slow and stop beating and eventually die off so mucus builds up. This clogs the airways and this causes more coughing that ruptures the thin alveolar epithelial cells, reducing there surface area for gas exchange

Question 9

Emphysema

Answer 9

It is the loss of elasticity in the alveoli, which causes it to burst. The lungs have reduced surface area as larger air spaces are formed, meaning there is less surface area for gaseous exchange. The loss of elasticity in the alveoli makes it harder to exhale. The breathing will become shallow and more rapid, the blood is less well oxygenated and fatigue occurs.

Question 10

Atherosclerosis

Answer 10

Atherosclerosis is the disease process that leads to coronary disease and strokes (Cardiovascular diseases). Fatty deposits can either block an artery directly or increase its chance of being blocked by a blood clot (Thrombosis)

Question 11

Development of Atherosclerosis

Answer 11

First there is a raise in blood pressure. Damage to Endothelial tissue lining of artery e.g. smoking causing high blood pressure. Then the low density lipoproteins accumulate in the artery wall. White blood cells move into the artery wall. Builds - up of LDL, Cholesterol leading to plaque formation (atheroma). Narrowing of artery loss of elasticity restricts of blood flow, increasing risk of blood clotting.