The Basic Tissues and Body Layers Flashcards
What are the four basic tissue types?
- Epithelial tissue
- Connective tissue
- Nervous tissue
- Muscle tissue
what is epithelium
covers body surfaces, lines body cavities and forms glands
what is connective tissue
underlines or supports the other three basic tissues, both structurally and functionally
what is muscle tissue
is made up of contractile cells and is responsible for movement
what is nerve tissue
receives, transmits and integrates information from outside and inside the body to control
the activities of the body
what 2 things is tissue classification based on?
morphology or function
What is the difference between epithelium and endothelium?
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.
What do these epithelial sheets rest on?
They always rest on a thin layer of specialized extracellular matrix - the basal lamina - which separates them from the underlying connective tissue.
What is a simple epithelium?
An epithelium that is only one layer thick is a simple epithelium.
what 3 ways do we classify epithelia and give examples of each type?
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.
What is stratified epithelia?
When an epithelium has more that a single layer, we call it a stratified epithelium, and this too can be squamous, cuboidal or columnar.
where do we find simple squamous epithelial cells and whats is function
where do we find stratified squamous epithelial cells and whats is function
where do we find simple columnar epithelial cells and whats is function
where do we find pseudostratified columnar epithelial cells and whats is function
where do we find transitional (urothelium) epithelial cells and whats is function
What are the 3 types of connective tissue?
- Connective tissue proper (can be DENSE OR LOOSE)
- Fluid connective tissues (blood and lymph)
- Supporting connective tissues (cartilage and bones)
difference between dense and loose connective tissue?
Loose connective tissue = more cells (adipose or fat cells) and less fibre
dense connective tissue = more fibres (collagen) and fewer cells (fibroblasts).
where is loose and dense connective tissue found in the body?
We call these fascias, and there is a superficial fascia and a deep fascia.
What two groups of cells does nervous tissue contain?
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.
What are the 3 types of muscle and what are their functions?
- 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
whats the order of body layers?
- 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.
how thick is skin?
0.1 mm on the abdomen to 4 mm behind the neck.
What is fascia?
Fascia is essentially a term used to describe a layer of connective tissue.
What are the 3 types of fascia?
- Superficial
- Deep
- Visceral/sub-serous
What is contained within the superficial fascia?
Contained within the superficial fascia are blood vessels and nerves.
What are the two largest supercificial veins in the forearm?
The basilic and cephalic veins.
What are cutaneous nerves?
Nerves taking sensory information from skin are called cutaneous nerves.
Describe the deep fascia.
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.
what is systemic circulation.
left ventricle to right atrium
what is pulmonary circulation.
right ventricle to left atrium
what is portal circulation
where a venous system links two
capillary beds
what do capillaries do
Capillaries link arterioles and venules and allow
exchange of materials
Define anastomose.
Anastomose is to combine with other arteries.
Where are anastomoses most common in limbs?
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.
What do anastomoses forms the basis of?
Anastomoses form the basis of collateral circulation.
What is an anatomical end artery?
When an artery is the sole contributor to a tissue bed, then it is said to be an ‘anatomical end artery’.
What is a functional end artery?
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’.
What is lymph?
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.
What is the lymphatic system designed to do?
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.
what are lymph nodes and where are they found
– small masses of lymphatic tissue that filter lymph
(abundant on side of the neck, axilla and inguinal region)
