tissues Flashcards
physical properties of epithelial tissue
- Densely arranged layers with fine spaces
- Sheet like arrangements (glands)
Types of epithelial tissue
Membranous, glandular
What does membranous epithelial tissue do?
Lines the blood vessels, lymphatic vessels, respiratory tract, digestive tract (oesophagus)
What does glandular epithelium do?
Follicles in endocrine and exocrine glands
What are 5 functions of epithelial tissue?
- Protection- skin
- Absorption- epithelium of gut and lungs
- Excretion- waste in kidneys
- Secretion- hormones
- Sensory- ear, nose, eye, skin
What is found in the spaces between epithelial cells?
Interstitial fluid
Describe interstitial fluid.
Fluid which helps to bring oxygen and nutrients to cells and remove waste.
What connects epithelial tissue and connective tissue?
The basement membrane.
What is the function of the basement membrane
To feed epithelial cells.
What are some types of epithelium?
Squamous, cuboidal, columnar, transitional, (simple, stratified)
What is the extracellular matrix
the outer shell of mammalian cells
are epithelial cells high or low in ECM?
low-tightly packed
Are connective tissues high or low in ECM?
high- loosely packed
What are some types of ECM?
- proteinaceous fibres
- mineralised crystals
what does the phospholipid bilayer do?
surround, support, give structure to cells and control entry and exit of waste and nutrients
Describe collagen.
the most abundant structural protein fibre, a triple helix of collagen fibres
What is the structure of elastin?
Random coil formations that can be easily stretched- held together by microfilaments.
What is connective tissue mostly made up of?
ECM
What does connective tissue do?
Connects tissues to each other
What are the two main types of connective tissue?
- Fibrous connective tissue
- Blood
Connective tissue is the human version of what?
The cytoskeleton
What are some types of fibrous connective tissue?
- loose
- dense irregular
- dense regular
- reticular (bone marrow)
- Adipose (fat)
What are some types of ‘blood’ connective tissue?
- Bone
- Cartilage
What are some additional types of connective tissue?
Bone, muscle, nervous tissue
Describe loose fibrous connective tissue.
The most commonly distributed type in the body, like an elastic glue- hyaluronic acid (formed by fibroblasts)
What are the two types of dense fibrous connective tissue?
- Regular
- Irregular
What does dense fibrous connective tissue have few of?
Fibroblasts
What is the arrangement of irregular dense fibrous connective tissue?
Forms a tough mat ie dermis of skin, outer layer of muscles
What is the arrangement of regular dense fibrous connective tissue?
mainly collagen (tendons) or elastin bundles (arteries)
Why is blood a unique connective tissue?
It is a liquid
What are the main functions of blood?
- Transport of gas, nutrients, waste
- Homeostasis of temp, glucose, pH
- Defence (immune system to destroy invaders)
How and where is blood formed?
Haemotopoiesus in the red bone marrow
What organelles do red blood cells have?
ribosomes, mittochondria, no nucleus (they are mainly haemoglobin)
What makes red blood cells flexible?
Their spectrin fibre cytoskeleton
What is it called when there are too few red blood cells?
Anaemia
What is it called when there are too many red blood cells?
polycythemia
What do red blood cells have on their surface?
Antigens
What does plasma have?
Antibodies
What forms the basis for ABO blood groupings?
Antigens on RBCs and Antibodies in plasma.
What will incompatible blood transfusions result in?
- Agglutination (clumping)
- Possibly death
Describe type A blood.
- A antigens on RBCs
- B antibodies in plasma (attack B antigens)
Describe type B blood.
- B antigens on RBCs
- A antibodies in plasma (attack A antigens)
Describe type AB blood.
- Both A and B antigens on RBCs
- No antibodies in plasma- dont attack!
What is type AB blood also referred to as?
Universal acceptor.
Describe type O blood.
- No antigens on RBCs
- Both A and B antibodies in plasma- attacks A and B!
What is type O blood also referred to as?
Universal donor.
What is the significance of blood clotting (coagulation)
- Plugs leaks in blood vessels
- Can isolate and trap invaders
Why must blood clotting be controlled?
Conditions such as deep vein thrombosis (clot in deep vein ie leg) can occur, clot can become dislodged and move to lungs-death
What are responsible for blood clotting?
platelets
How does a blood clot form?
Thrombin (clotting enzyme) -> fibronigen -> fibrin
