tissues (animals) Flashcards
tissues and the cells that they consist of
what are tissues?
tissues are groups of specialised cells that work together to perform a specific function in the organism.
how many types of tissue are found in animals?
there are four general types of tissue found in complex animals.
epithelial tissue, connective tissue, muscle tissue & nervous tissue.
what is epithelial tissue?
epithelial tissue is a tissue that covers body surfaces, protects organs and forms glands.
what is the structure of epithelial tissue?
epithelial tissue is made up of densely packed cells, occurring in sheets or layers.
it doesn’t contain blood vessels and relies on connective tissuer for nutrients.
what are the two distnict surfaces that epithelial tissue is found?
- surfaces exposed to the exterior or the body cavity.
- ither side is exposed to the adjacent tissue.
where is epithelial tissue found?
it is found in the skin and surface of organs in the digestive, repiratory, and many others.
it can also be specialised for absorption or secretion.
for example; epithelial tissue that lines the larynx secretes mucus to keep the surface moist.
what is connective tissue?
connective tissue supports, binds, and connects other tissues and organs. it is vital for providing structurasl support, protecting organs, storing energy, and facilitating the transportation of substances in the body.
what are the different types of connective tissue?
fibrous
loose
adipose
cartilage
blood and bone
what is the extracellular matrix (ECM)?
the ECM is a non-living material that surrounds the cells of the connective tissue and gives it its strength and flexibility.
it is made up of:
protein fibres : collagen, elastin, and reticular fibres
ground substances: a gel like material that fills the space between cells and fibres, composed of water, proteins, and polysaccharides.
what is fibrous connective tissue?
fibrous connective tissue is a type of connective tissue that has a lot of densly packed fibres, mainly collagen, which provide support and elasticity.
the fibres can eoither be arranged in a regular or irregular pattern depending on the specific function and use.
where is fibrous connective tissue primarily found?
dense regular fibrous tissue is arranged in parallel fibres, found in tendons and ligaments, while dense irregular fibrous tissue has a more disorganised fibre arrangement, found in the skin dermis and organ capsules.
what is loose connective tissue?
loose connective tissuye is a type of connective tissue that is characterised by loosely arranged fibres and an abundant ECM, providing flexiblity and cushioning to the body.
it acts as a filler material between organs, tissue and structures, supporting and binding them while allowing for nutrient exchange and waste removal.
what are the cells that make up loose connective tissue?
fibroblasts
macrophages
adipocytes
mast cells
what are fibroblasts?
fibroblasts are responsible for producing fibres and ground substance <- ECM.
they are the main connective tissue cells present in the body.
what are macrophages?
they are a type of white blood cell, playing a role in immune responses, helping to phagocytize pathogens and debris.
what are adipocytes?
adipocytes are fat cells that store energy and provide insulation.
what are mast cells?
mast cells are found throughout the body in loose connective tissue, playing a role in inflammatory response by releasing histamine and other chemicals during allergic reactions.
what are some types of loose connective tissue?
areolar tissue
adipose tissue
reticular tissue
what is areolar tissue?
function, structure, location
loose connective tissue
it provides support, strength and elasticity to tissues, also playing a role in nutrient and waste exchange between the blood and cells.
it contains a mix of collagen and elastic fibres in a loose irregular arrangement. it has a soft, gel-like matrix that allows flexibility.
areolar tissue is found widely throughout the body, including: beneath the skin (subcutaneous tissue), around blood vessels, nerves and organs, in the muscous membranes lining the respiratory, digestive, and urinary tracts.
what is adipose tissue?
function, structure, location
loose connective tissue
adipose tissue is specialised for stroring fat (energy), insulating the body, and providing cushioning to organs.
it is composed of large adipocytes (fat cells) that store lipids, with very little ECM.
it’s found beneath the skin (subcutaneous fat), around internal organs (visceral fat), in bone marrow, and in breast tissue.
what is reticular tissue?
function, structure, location
loose connective tissue
it provides a supportive framework for soft organs, particularly those involved in flitering or immune functions.
it contains a network of reticular fibres (thin collagen fibres) that form a scaffold to support the cells within the tissue.
it’s found in lympoid organs (e.g. lymph nodes, spleen, bone marrow, liver).
what are the types of adipose tissue and where are they found?
white adipose tissue is the most common for, primarily for energy storage, insulation, and cushioning.
brown adipose tissue is found mainly in newborns and some adults, it helps generate heat through non-shivering thermogenesis.
what is cartilage?
it is a type of connective tissue that is firm yet flexible, providing structure and support to various parts of the body.