Body Tissues and Body Layers

Question 1

Name the 4 basic tissues of the body

Answer 1

• Epithelial
• Connective
• Nervous
• Muscle

Question 2

Define ‘tissue’ and ‘organ’

Answer 2

• Tissue: a collection of cells and their surrounding structures
• Organ: a structure which is a mixture of the 4 basic tissues in order to perform one or more functions

Question 3

Describe the composition of fascia and its functions:

Answer 3

• Superficial fascia: Storage of water and fat, protection (physical cushion against force placed against body’s surface), thermal insulation, conduction (transports nerves and blood vessels to the skin), metabolic (fat is an energy store)
• Deep fascia: Movement of muscle (muscles are wrapped in deep fascia so can slide over one another), attachment for some muscles, conduction (blood vessels and nerves are transported via the fascias), capsule around some organs (continuous with periosteum of bone and perichondrium of cartilage)
• *Also visceral fascia: surrounds all organs

Question 4

Name the location and function of serous membranes

Answer 4

• Location: between the body wall and mobile organs, or between mobile organ and surrounding tissue
• Function: to permit movement and reduce friction of the organs with body wall/surrounding structures

Question 5

Outline basic arrangement of the vascular system

Answer 5

• Arteries
• Veins
• Capillaries

Question 6

Explain the processes of systemic circulation

Answer 6

• Aorta leaves left side of the heart and pumps oxygenated blood to the rest of the body minus the lungs via arteries, arterioles, capillaries where gas exchange happens.
• Blood then returns via venules, veins, and back into right side of heart via superior and inferior vena cava

Question 7

Explain the process of pulmonary circulation

Answer 7

• Deoxygenated blood leaves R side of heart via pulmonary trunk through pulmonary arteries to lungs
• Gas exchange happens in the capillaries and then pulmonary veins take blood back to L side of heart to become part of systemic circulation again

Question 8

Explain the process of a portal system

Answer 8

• Arrangement by which blood collected from one set of capillaries passes through a large vessel (eg hepatic vein) to another set of capillaries (eg for monitoring of blood content) before returning to the systemic circulation

Question 9

Define the terms ‘anastomoses’ and explain the difference between anatomical and functional end arteries

Answer 9

• Anastomoses: Where arteries do not end up as capillaries, but instead combine with other arteries
• Anatomical end arteries: when an artery is a sole contributor to a tissue bed
• Functional end arteries: where there is more than one artery supplying a tissue bed via an anastomoses, but the loss of the main artery still leads to tissue death – principle artery is functional-end artery

Question 10

Explain the arrangement of the lymphatic system and give and account of its functions

Answer 10

• Superficial lymphatics: lie in superficial fascia and follow veins
• Deep lymphatics: lie in deep fascia and follow arteries
• Is organised into right and left sides, but are not equal – R: only does R upper quadrant of the body
• Function: to maintain fluid levels in our body tissues by removing all excess interstitial fluid and to produce immune cells (lymphocytes)