Muscle, Nerve and Connective Tissue Flashcards
What does the muscle tissue produce when it contracts?
As a result of contraction, muscle tissue produces body movements, maintains posture and generates heat.
What are the structure of skeletal muscle?
They are long, striated, multi nucleated and cylindrical cells. Inside the muscle cell, there are myofribils which are thread like structures. Myofibirls are made up of 2 myofilaments : thick filament (myosin) and thin filament (actin). Then, they are arranged in compartments called sarcomeres.
Name the different types of neurones in the CNS.
Multipolar nurones Have 2 or more dendrites and a single axon. Bipolar nureons have a cell body between
axon and dendrite and it only has 1 axion and 1 dendrite. Unipolar has dendrites and axon are continuous.
What are the 5 functions of astrocytes (CNS)?
- They have syntium network, star shaped and more nuermous of neuroglia.
- They maintain blood barrier via the endothelium to influences the permeability.
- Regulate ions (maintain environment)
- Communicate with nueron via gliotramsiiters.
- Support (have microfilaments)
and repair (scar).
What do oligodendrocytes do? (CNS)
Oligodendrocytes:
– Form insulating
multilayered myelin sheath
( protein lipid layer) around
CNS axon, to increase the speed of cells.
– Can myelinate more than
one neuron cell’s axon.
Accelerate the action
potential.
What do microglia do?
Microglia:
Phagocytic (resident
macrophages) - protection
What do the Purkinje fibers do and where are they located?
The Purkinje fibers allow the cardiac muscle to conduct electrical impulses and they are located in the inner ventricular walls of the heart.
What is the function for the intercalated discs in the cardiac muslce cells?
The intercalated discs in cardiac muscle allow for synchronized contractions.
What is the primary protein that makes up the dense bodies in smooth muscle cells?
Actinin
What is the sarcoplasmic reticulum?
It is a specialised organelles found in the muscle fibres that stores calcium ions.
What are the 3 main functions of CT?
It binds, supports and strengthens other body tissues.
A major transport system of the body (blood is a connective tissue).
A major site of stored energy reserves (fat or adipose tissue is a
connective tissue).
What are Glycosaminoglycans and what is the other name for it?
Glycosaminoglycans are a special type of sugar molecule found in the GS of the ECM. Another name for it is mucopolysaccharides.
What is the difference between hylaronic acid and
Dermatan sulphate
* Heparin sulphate
* Keratan sulphate
* Chondroitin sulphate?
Hylaronic acid does not have a sulphate group attached and does not directly bind to the protein backbone but is joined to various PGs. However, the other ones do have a sulphate group AND they bind to core proteins to form proteoglycans (PGs).
What is the function for hylaronic acid?
Because it is highly polar, it can attract large amounts of water, making the ECM more viscous substance that binds cells together, lubricates joints and maintains shape of eyeball.
What is Hyaluronidase produced by?
White blood cells, sperm and some bacteria.
Where can you find Dermatan sulphate, Keratan sulphate, Chondroitin sulphate?
Dermatan sulphate can be found in skin and tendons, Keratan sulphate can be found cornea of the eye and Chondroitin sulphate can be found in blood vessels. Both keratan and chondroitin can be found in bone and cartilage.
What are another name for muscle cells?
Myocytes
What is collagen, reticular and elastic and what is the difference between them?
- Collagen is thick parallel bundles that are strong and flexible.
- Reticular fibres are collagen fibres but with a glycoprotein. They are thin bundles and have a branched network.
- Elastic fibres are thin fibrous that can stretch and made up of protein called elastin and a glycoprotein called fibrilin surrounds it.
What is Marfan syndrome?
Syndrome which is a defect in the fibrillin (glycoprotein) of elastic fibres. People who have Marfan syndrome are tall, long limbed.
What can fibroblasts do?
They are migratory and produce components of the matrix (ECM).
What are the two types of Embryonic Connective Tissue?
- Mesenchyme is a type of CT. It gives rise to ALL other CT. Consists of mesenchemyal cells in the semi-fluid GS which contain reticular fibres.
- Mucous has widely scattered fibroblasts and found in the umbilical cord.
Describe the mature connective tissue.
Mature connective tissue has 3 sub categories: CT proper, fluid CT, and Supporting CT.
In CT proper : Loose and Dense .
In Fluid CT: Blood and Lymph.
In supporting CT: Cartilage and Bone.
SOMETIMES fluid CT, and Supporting CT are called SPECIALISED CTS.
Describe DENSE CT.
Dense CT is a sub-category for CT proper which comes under the Mature CT. There are three types: dense regular, dense irregular and elastic.
Regular dense: Parallel bundles of collagen fibres, which resist tensile forces. Tendons, ligaments, aponeuroses.
Irregular dense: Random arrangement of collagen fibres, withstands forces from ALL directions.
Elastic: Elastin fibres, areas to need to stretch.
Describe Supporting CT.
In supporting CT, there are 3 types of cartilage and then bone.
1. Hyaline cartilage is Dense network
of collagen and elastic fibres. It is more flexibility and movement.
2. Elastic cartilage has MORE elastic elastic fibre, but still has collagen and its highly flexible.
3. Chondrocytes & thick collagen fibres
