connective tissue - my own Flashcards
fwhat part of CT has no nerve supply
cartilage
what is marfan syndrome
a hereditary defect in the elastic fibres
what does marfan syndrome manifest in
height, long limbs, long fingers, chest deformities, weak heart valves and arterial wall
explain how marfan syndrome works
a mutation in chromosome 15 which codes for fibrillin. fibrillin is the structural scaffold for elastin. TGFb (transforming GF beta) can’t therefore bind normally to fibrillar, causing abnormal growth.
what does mesyncheme consist of?
ECM: semi-fluid ground substance, with reticular fibres
cells: mesynchemal cells
what does mucous embryonic CT consist of? what is its other name and location?
Whartons jelly of the umbilical cord. jelly-like ground substance with collagen fibres plus widely scattered fibroblasts
chondrocytes are
cartilage cells
what elements of blood are phagocytic (engulf pathogens)
neutrophils and monocytes
granular leukocytes:
neutrophils, basophils, eosinophils, immature mast cells
agranular leukocytes
monocytes, B and T cells
where do plasma cells originate from
B-cells
what are macrophages; where do they originate from
macrophages are cells in CT which are ‘master controllers’ for lots of responses against disease and injury. they originate from monocytes.
what is meant by ‘phagocytic’
a cell that engulfs and consumes foreign matter and debri
what two things secrete histamine
basophils and immature mast cells
what are platelets
fragments of megakaryocytes of the bone marrow, which aid in blood clotting
plasma cells produce:
antibodies
erythrocytes function:
transport co2 and o2 (regulate blood pH)
eosinophil function:
parasitic worms and acute allergic response
where is embryonic mucuos CT found
in umbilical cord only
structure of embryonic mesyncheme
mesynchemal cells in a semi-fluid ground substance with reticular fibres
describe the structural components of the osteon
lamellae: concentric rings (around the central canal) of mineralised bone matrix (hydroxyapatite)
lacunae: small gaps between lamellae housing osteocytes
osteocytes: bone cells
central canal: tube in centre of osteon housing blood, lymph vessels and nerves
describe the spongy bone tissue
has no osteons. encased inside the compact bone. contains red and yellow bone marrow.
describe the compact (cortical) bone tissue
forms the outside layer of bone, and the shafts of long bones. has osteons which run parallel to the bones axis/line of stress. stores calcium and phosphorous.
name the 4 types of bone cells
osteogenic cells, osteoblasts, osteocytes, osteoclasts
what are osteogenic cells; what do they do
mesynchemal stem cells for bone. lay down collagen matrix and differentiate into osteoblasts
what are osteoblasts; what do they do
immature bone cells. mineralise collagen, then differentiate into osteocytes once the bone ha been made.
what is a dust cell
a fixed macrophage located in the lung
what is a kupffer cell
a fixed macrophage located in the liver
what are osteoclasts; what do they do
multi nucleated cells formed from the fusion of blood’s monocytes. they are able to break down bone into minerals if the body needs.
3 types of fibres in the ground substance
collagen, reticular, elastic
what is a langerhaans cell
a fixed macrophage located in the skin
what are osteocytes; what do they do
osteocytes are mature bone cells. they maintain the bone’s structures and functions.
how do osteocytes communicate; what do they communicate and exchange/transport
through caniliculi, channels between lacunae. they allow communication of information about stresses on the bone between osteocytes, as well as exchanging nutrients, oxygen, and transporting waste.
ECM in bone tissue is:
mineralised
collagen fibres: function, composition, location
strong but flexible to resist pulling forces; tensile strength and structural support. made of collagen protein. found in bones, cartilage, tendons, ligaments.
reticular fibres: function, composition, location
fine bundles of collagen coated in glycoprotein, made by fibroblasts. provides strength and support. branches through vessels and tissues, (including the basement membrane -reticular lamina), particularly adipose, smooth muscle, and nerve fibres
elastic fibres: function, composition, location
provides flexibility, complementary to other two fibres. made of elastin and fibrillin (glycoprotein). found especially in areas needing stretch, e.g lungs, blood vessels, skin.
what is hyaluronidase; what does it do; what things might produce it
enzyme that breaks down hyaluronic acid; makes ground substance more liquidy/less viscous; sperm, bacteria, blood cells.
name the formed elements of blood.
erythrocytes, platelets, leukocytes; basophils, neutrophils, eosinophils, monocytes, immature mast cells, monocytes, B and T cells
basophil function:
release histamine in reactions
neutrophil function:
phagocytic.
monocyte function:
phagocytic.
B and T cell function:
immune response
when would leukocytes be found in solid CT?
if they’ve migrated out from the blood to reside in tissue to fight infection
mast cells function and location (mature)
in solid tissue, often alongside blood vessels. produces histamine
what does histamine do
increases blood flow and inflammation in nearby tissue.
outline ALL the different CT classifications
PROPER; loose & dense;
loose - areolar, adipose, and reticular. dense - regular, irregular, and elastic. FLUID; blood and lymph.
SUPPORTING; cartilage and bone. cartilage - hyaline, elastic, and fibrous. bone - compact and spongy.
fibroblasts location and function
migratory cells in most types of CT (all loose and dense types), secrete components of the ECM.
describe how exophthalmus may arise
autoimmune overreaction of thyroid leads to stimulation of fibroblasts in the eye ECM. GAG concentration increases and orbital becomes inflamed.
areolar tissue: composition, function, location
contains all 3 types of fibres. provides strength, support, and elasticity. surrounds most structures like a packing material.
adipose tissue: composition, function, location
contains adipocytes. nuclei are pushed to the cells’ sides as cell contains large vacuole/storage. can be white for energy storage, or brown for heat production. functions are therefore insulation, temperature control, and energy storage. found in the buttocks, flanks, abdomen.
general loose tissue composition:
less fibres, more GS and cells. more flexible.
general dense tissue composition:
lots of fibres and fewer cells.
reticular tissue: composition, function, location
lots of reticular fibres. form a soft and supportive framework for soft organs. found in the spleen, lymph nodes, and bone marrow, liver, kidneys, endocrine glands.
dense regular tissue: composition, function, location
collagen fibres in parallel bundles, to provide resistance against one-directional pulling forces. found in tendons, aponeuroses, ligaments.
dense irregular tissue: composition, function, location
collagen fibres in disorganised (irregular) bundles to provide resistance against multi-directional force. found in areas subject to stress from many directions. skin dermis, around joints, around many organs, bones, cartilage.
dense elastic tissue: composition, function, location
made of mainly elastic fibres to allow stretch (tho also has collagen and fibroblasts). allows flexibility and shape retention. found in large blood vessels, respiratory tubes, spine’s ligaments.
why does dense CT heal slowly?
because it is packed with collagen which isn’t a living tissue and has low blood supply.
hyaline cartilage tissue: composition, function, location
non-obvious collagen fibres. strong but flexible, providing support, flexibility, and cushioning. found in anterior ends of ribs, ends of long bones, and respiratory cartilage e.g nasal cartilage.
elastic cartilage tissue: composition, function, location
elastic fibres alongside collagen. elastic and flexible qualities for shape retention. found in the external ear and larynx.
fibrous cartilage tissue: composition, function, location
dense collagen fibres in parallel bundles. tough and resilient. provides support and shock-absorption. found in the invertebrate discs, as well as the the pubic joint and knee joint. (pubic symphysis and menisci)
explain what is meant by an aggrecan aggregate
an aggrecan is a glycoprotein consisting of the core protein and keratan and chondroitin sulphate sugars. multiple of these molecules bind to an HA molecule, forming an aggrecan aggregate.
