The Basic Tissues and Body Layers

Question 1

What are the four basic tissue types?

Answer 1

• Epithelial tissue
• Connective tissue
• Nervous tissue
• Muscle tissue

Question 2

what is epithelium

Answer 2

covers body surfaces, lines body cavities and forms glands

Question 3

what is connective tissue

Answer 3

underlines or supports the other three basic tissues, both structurally and functionally

Question 4

what is muscle tissue

Answer 4

is made up of contractile cells and is responsible for movement

Question 5

what is nerve tissue

Answer 5

receives, transmits and integrates information from outside and inside the body to control
the activities of the body

Question 6

what 2 things is tissue classification based on?

Answer 6

morphology or function

Question 7

What is the difference between epithelium and endothelium?

Answer 7

Epithelium is generally above or on the outside of and endothelium means within.

E.g. the inner layer of blood vessels has a layer of epithelium but it is an endothelium as it is within.

Question 8

What do these epithelial sheets rest on?

Answer 8

They always rest on a thin layer of specialized extracellular matrix - the basal lamina - which separates them from the underlying connective tissue.

Question 9

What is a simple epithelium?

Answer 9

An epithelium that is only one layer thick is a simple epithelium.

Question 10

what 3 ways do we classify epithelia and give examples of each type?

Answer 10

They can be flattened cells, and this we term a squamous epithelium. In the example on the right, we can see these lining a blood vessel.

They can be cuboidal in shape, and these often line ducts in the body, for example in the ducts of the kidneys.

Lastly the can be columnar, these are seen in the lining of the intestines for example. Columnar cells are particularly useful for secretion or absorption.

Question 11

What is stratified epithelia?

Answer 11

When an epithelium has more that a single layer, we call it a stratified epithelium, and this too can be squamous, cuboidal or columnar.

Question 12

where do we find simple squamous epithelial cells and whats is function

Answer 12

Question 13

where do we find stratified squamous epithelial cells and whats is function

Answer 13

Question 14

where do we find simple columnar epithelial cells and whats is function

Answer 14

Question 15

where do we find pseudostratified columnar epithelial cells and whats is function

Answer 15

Question 16

where do we find transitional (urothelium) epithelial cells and whats is function

Answer 16

Question 17

What are the 3 types of connective tissue?

Answer 17

• Connective tissue proper (can be DENSE OR LOOSE)
• Fluid connective tissues (blood and lymph)
• Supporting connective tissues (cartilage and bones)

Question 18

difference between dense and loose connective tissue?

Answer 18

Loose connective tissue = more cells (adipose or fat cells) and less fibre

dense connective tissue = more fibres (collagen) and fewer cells (fibroblasts).

Question 19

where is loose and dense connective tissue found in the body?

Answer 19

We call these fascias, and there is a superficial fascia and a deep fascia.

Question 20

What two groups of cells does nervous tissue contain?

Answer 20

The first group are called neurons and these conduct electrical signals to pass information through the body.

The second group of cells are called neuroglia or simply glia. These are often thought of as the supporting cells of the nervous system.

Question 21

What are the 3 types of muscle and what are their functions?

Answer 21

• Skeletal muscle is attached to the skeleton and provides voluntary movement.
• Cardiac muscle is particular to the heart.
• Smooth muscle possesses greater elasticity and is primarily found in the walls of hollow internal organs, where it contracts and relaxes involuntarily

Question 22

whats the order of body layers?

Answer 22

• Deep to skin is the superficial fascia, containing loose connective tissue, blood vessels and nerves.
• Deep to that is the deep fascia containing dense regular connective tissue.
• Deep to that are the muscles, and larger blood vessels and nerves, and of course bone.

Question 23

how thick is skin?

Answer 23

0.1 mm on the abdomen to 4 mm behind the neck.

Question 24

What is fascia?

Answer 24

Fascia is essentially a term used to describe a layer of connective tissue.

Question 25

What are the 3 types of fascia?

Answer 25

- Superficial - Deep - Visceral/sub-serous

Question 26

What is contained within the superficial fascia?

Answer 26

Contained within the superficial fascia are blood vessels and nerves.

Question 27

What are the two largest supercificial veins in the forearm?

Answer 27

The basilic and cephalic veins.

Question 28

What are cutaneous nerves?

Answer 28

Nerves taking sensory information from skin are called cutaneous nerves.

Question 29

Describe the deep fascia.

Answer 29

The deep fascia is a tough, collagenous membrane. It is well developed in the limbs and in the neck, but it is poorly developed over the trunk. It is an inexpansile layer and therefore would impede the movements of the trunk. This is particularly true in the abdomen, where it is almost non-existent.

Question 30

what is systemic circulation.

Answer 30

left ventricle to right atrium

Question 31

what is pulmonary circulation.

Answer 31

right ventricle to left atrium

Question 32

what is portal circulation

Answer 32

where a venous system links two capillary beds

Question 33

what do capillaries do

Answer 33

Capillaries link arterioles and venules and allow exchange of materials

Question 34

Define anastomose.

Answer 34

Anastomose is to combine with other arteries.

Question 35

Where are anastomoses most common in limbs?

Answer 35

**In limbs, anastomoses are most common around joints;** quite clearly they form an alternative route when the main flow is obstructed by, say, flexion of the joint. If you cut an artery which forms part of an anastomosis it will bleed from both ends, because the artery has connections both above and below the cut.

Question 36

What do anastomoses forms the basis of?

Answer 36

Anastomoses form the basis of collateral circulation.

Question 37

What is an anatomical end artery?

Answer 37

When an artery is the sole contributor to a tissue bed, then it is said to be an ‘anatomical end artery’.

Question 38

What is a functional end artery?

Answer 38

When there is more than one artery supplying a tissue bed (via an anastomosis), but loss of the main artery still leads to tissue death, then the principal artery is said to be a ‘functional end-artery’.

Question 39

What is lymph?

Answer 39

Capillaries allow fluid, nutrients, oxygen and hormones to leave the capillary and enter the tissue bed. - 90% of the fluid goes back to the circulatory system, taking the waste products from the cells with it. - However, the remaining 10% of the fluid stays behind in the tissues as lymph, which is a yellowish, protein-rich fluid.

Question 40

What is the lymphatic system designed to do?

Answer 40

To prevent an excess of fluid in the tissue, the macromolecules and fluid needs to be returned to the veins. The lymphatic system is designed to do this, but rather than drain locally to the veins in the tissue bed, the lymph is circulated in its own system to the neck, where it passes back into the venous blood stream through the subclavian veins.

Question 41

what are lymph nodes and where are they found

Answer 41

– small masses of lymphatic tissue that filter lymph (abundant on side of the neck, axilla and inguinal region)