Body Tissue Flashcards
What is a Epithelial Tissue?
A membranous tissue made up of cells
What are the two types of epithelial tissue?
membranous epithelium and glandular epithelium
What is the membranous epithelium function?
It lines the blood vessels, lymphatic vessels, respiratory tract, digestive tract,
What is the glandular epithelium?
Follicles in endocrine and exocrine glands
What are the functions of epithelial tissue?
Protection, absorption, excretion, secretion, sensory.
What is an example of protection?
tough and impermeable skin
What is an example of absorption?
epithelium of gut and lungs
What is an example of excretion?
release of waste products in kidney
What is an example of secretion?
discharge of
hormones from glands e.g mucus, sweat
What is an example of sensory?
epithelial structures on ear, nose, eye and skin
What are general properties of epithelia?
Tightly packed between cells with fine spaces, it constantly regenerates, it is attached to connective tissue via the basement membrane, and they are avascular
What can be found between the fine spaces in tightly packed cells?
Interstitial fluid
What is the extracellular matrix?
The outer shell of mammalian cells and packing material
Are epithelial tissues high or low in ECM?
low in ECM
Are connective tissues high or low in ECM?
high in ECM
What are some types of ECM?
proteinaceous fibres and mineralised crystals
What are examples of proteinaceous fibres?
collagen and elastin
What are examples of mineralised crystals?
bone, dental hard tissues
What does ECM contain?
secreted proteins and membrane proteins which are essential for structure and connectivity
What is the function of collagen?
Provides flexible strength to tissue
What is the function of elastin?
Allows flexibility and elastic recoil of tissues
How are collagen fibres made?
Three collagen protein chains twist into a fibrous molecule, then twists into staggered collagen strands, then bundles twist into fibrils, fibrils then twist into proper rope-like collagen fibres
How are elastin fibres made?
Elastin exists in random coil formations that can be easily stretched, and are held together by microfilaments
What is connective tissue?
It is made up of mostly extracellular matrix, it connects tissue to each other, is the supportive framework for organs and body, it allows transport between tissues and organs, and defends the body against bacteria
What are the types of connective tissue?
Fibrous connective tissue, blood, bone and cartilage
Why is blood an important connective tissue?
It is mainly liquid and should not contain fibres
What does blood transport?
gases ( oxygen and carbon dioxide), nutrients and waste products
What are the main functions of blood?
transport, homeostasis, defence
How does blood undergo homeostasis?
It maintains body temperature and pH levels
What does blood defence?
Immune system to destroy invaders
How is blood formed?
by haematopoiesis in red bone marrow
What can blood be divided into?
Plasma and formed elements
How much blood is divided into plasma?
55% of whole blood
How much blood is divided into formed elements?
45%
What is plasma made of?
90% water, 10% solutes
What can the cellular fraction be further divided into?
red blood cells (99%), white blood cells (>1%), platelets(>1%)
What type of red blood cells are cellular fractions divided into?
Erythrocytes
What type of white blood cells are cellular fractions divided into?
Leukocytes
What type of platelets are cellular fractions divided into?
Thrombocytes
What is the function of erythrocytes?
Transportation of respiratory gases (O2 and CO2) and are flexible and can change shape due to its flexible cytoskeleton (spectrin fibres)
What is the function of platelets?
Releases clot-activating substances and helps in formation of actual blood clot by forming platelet plugs
What are erythrocytes made of?
mainly haemoglobin and has antigens on its membrane surface, as it has no nucleus, no ribosomes, no mitochondria
What is it called when someone has not enough red blood cells?
Anaemia
What is it called when someone has too many red blood cells?
polycythaemia
What forms the basis of ABO blood groupings?
Antigens on red blood cells and antibodies in blood plasma
What can happen if there are incompatible blood transfusions?
Agglutination (clumping) and can cause death
What are the blood types?
Type A, Type B, Type O, Type AB
What does Type A blood have?
Type A antigens on red blood cells, Type B antibodies in blood plasma and will attack type B antigen
What does Type B blood have?
Type B antigens on red blood cells, Type A antibodies in blood plasma and will attack type A antigens
What does Type O blood (Universal Donor) have?
no antigens on red blood cells, and both Type A and Type B antibodies will attack both Type A and B
What does Type AB (Universal Acceptor) have?
Both antigens on red blood cells, no antibodies so will not attack any blood type
What is the main purpose of Coagulation (blood clotting)?
To plug up leaks in blood vessels, also help defend against bacterial invaders by isolating and trapping them
What happens if blood clotting is not controlled?
The clot could block the blood vessel
What are essential for blood clotting?
platelets
What does thrombin cause?
Fibrinogen which becomes fibrin
