Structural organisation in animals Flashcards
Tissue level organisation is first seen in?
Coelenterates/cnidaria
Examples of simple squamous epithelium
Respiratory zone(alveoli), bowman’s capsule and descending LH, endothelium of blood vessels and mesothelium of body cavity.
Examples of normal cuboidal epithelium
Germinal epithelium of gonads, vesicles of thyroid gland, tubules and ducts of glands, ascending LH, DCT and CD.
Brush border epithelium
Have microvilli on their free body surface, present in PCT.
Cilia and microvilli are only seen in?
Cuboidal and columnar epithelium.
Goblet cells
Single celled glands present inside columnar epithelium, secrete mucus.
Describe nucleus in columnar epithelium
Oval nucleus is present in the base.
Normal columnar epithelium
Glands of GIT
Brush border columnar epithelium
Small intestine and gall bladder
Kinociliated columnar epithelium
Upper respiratory tract, fallopian tube.
Stereociliated columnar epithelium
Epididymis, vas deferens and cochlea(internal ear)
Glandular epithelium is?
Modified cuboidal or columnar epithelium.
Unicellular glands
Goblet cells(mucus) and paneth cells(antibacterial lysozyme).
Exocrine glands
Have specialised ducts for secretions.
Ex:- milk, mucus, saliva and enzymes releasing glands.
Endocrine glands
Ductless glands, pour secretions in blood.
Example:- all hormone releasing glands.
Heterocrine glands
Show secretions via duct and ductless means.
Example:- pancreas, testes and ovaries.
Tight junctions
To stop leakage across tissue.
In epithelial cell only.
Adherens junction
Aka desmosomes, glue 2 cells.
In epithelial tissue only.
Gap junctions
For rapid transport of ions, small particles and even some large particles.
Like plasmodesmata.
In epithelial, muscular and nervous tissue.
Most abundant tissue?
Connective tissue
Matrix of connective tissues is composed of?
The matrix of connective tissues is made of mucopolysaccharides (hyaluronic acid and glycoaminoglycans)
Describe all 5 types of cells in connective tissues.
1/Mesenchymal cells- stem cells that change into fibroblast, osteoblast and chondroblast.
2/Fibroblast- largest cells in connective tissue that secrete matrix and fibres.
3/Macrophage- phagocytic cells
4/Mast cells- like basophils that scerete heparin(anticoagulant), histamine(vasodilator) and serotonin(bronchio constrictor).
5/Plasma cells- activated B lymphocytes taht form antibodies.
Describe loose connective tissue
Loose connective tissues have more matrix and less fibre.
They are further divided into areolar and adipose.
1/Areolar- parking tissue between body organs and cavity, are used to fill areola(space) and attach skin to muscles.
2/Adipose- fat storing cells(adipocytes), present beneath skin, around heart, kidneys and eyeballs to help in shock absorption, are great insulators and can metabolise the fat in them for energy.
Describe dense connective tissue
Dense connective tissues have less matrix and more fibres. They are divided into regular and irregular based upon the pattern of fiber present in them.
Regular connective tissue
1/Tendon- muscles to bone, made of white collagen.
2/Ligament- joins bones to bones, yellow elastin and some collagen.
Irregular connective tissue
1/Yellow- covering of lungs
2/White- pericardium, periosteum, perichondrium and glisson’s capsule(liver cells sheath).
