Musculoskeletal System Flashcards
What are the four types of primary tissue?
Epithelial Tissue
Connective Tissue
Nervous Tissue
Muscle
Where are epithelial tissues found?
Body coverings (outside) Body linings (outside) Glandular tissue (tubes)
What are the functions of epithelial tissues?
Protection
Absorption
Filtration
Secretion
How are epithelia classified (according to two features) and what are the names and features of these different classifications (5 in total)?
Classified according to:
Number of cell layers
Shape of cells
Different categories: Simple - one layer of cells Stratified - more than one layer of cells Squamous - flattened Cuboidal - cube-shaped ('square') Columnar - column-like (tall rectangle)
How many layers of cells do simple epithelia have?
One layer
How many layers of cells do stratified epithelia have?
more than one layer
What shape are squamous epithelia?
Flattened
What shape are cuboidal epithelia?
Cube-shaped (‘square’)
What shape are columnar epithelia?
Column-like (tall rectangle)
Which type of cells have a single layer of flat cells with flat nuclei
Simple Squamous epithelium
Which type of cells are often involved in diffusion of substances across the barrier they form?
Simple Squamous epithelium
Give two examples of simple squamous epithelium
Endothelium - epithelial cells lining the blood and lymph vessels
Mesothelium - lining of the body cavities
Which cells are a single layer of cube like cells?
Simple cuboidal epithelium
Which cells are common in glands and their ducts?
Simple cuboidal epithelium
Which cells are often polarised?
Simple cuboidal epithelium
Which cells are important for absorption and secretion?
Simple cuboidal epithelium
Which cells form walls of kidney tubules?
Simple cuboidal epithelium
Which cells form a single layer of tall cells?
Simple columnar epithelium
Which cells are a variety of heights depending on the function of the cell?
Simple columnar epithelium
In which cells would you normally see nuclei on the basal part of the cell?
Simple columnar epithelium
Goblet cells are what type of epithelial cell, and where are they found?
Simple columnar epithelium, found in the lining of the digestive tract
What is psuedostriated epithelium?
Single layer of epithelial cells but some are shorter than others, meaning it often looks like a double cell layer
What cell type is he most common epithelium?
Stratified Squamous Epithelium
What type of epithelium can be keratinised or non-keratinised?
Stratified Squamous Epithelium
Give two examples of Stratified Squamous Epithelium
Skin
Oesophagus
What are the functions of connective tissue?
Binds body tissues together
Supports the body framework
Wound repair/ inflammatory response
What makes up connective tissue?
Cells (free and fixed)
Fibres and extracellular matrix
What are the two main classes of connective tissue?
Loose connective tissue
Dense connective tissue
What are the subgroup within dense connective tissue?
Dense regular connective tissue eg tendons and ligaments
Dense irregular connective tissue eg skin
What are some examples of dense irregular connective tissue?
Skin
What are some examples of dense regular connective tissue?
Tendons and ligaments
What is the function of dense regular connective tissue?
Resistance to traction forces
What is the function of dense irregular connective tissue?
Mechanical support
What is the most common form of connective tissue?
Loose connective tissue
Which type of connective tissue contains all fibre types?
Loose connective tissue
Which type of connective tissue can retain excess fluid?
Loose connective tissue
Which type of connective tissue is NOT resistant to stress?
Loose connective tissue
Which type of connective tissue provides structural support of the epithelia of the major organs?
Loose connective tissue
What is the most common native cell type of connective tissue?
Fibroblasts
What are the role of fibroblasts?
Synthesise collagen and components of the ECM
How are the structure of fibroblasts related to their function?
Elongated nuclei
Small amount of cytoplasm
Spindle/ elongated shape
What is the extracellular matrix?
Proteoglycans that occupies the space between cellular and fibrillary elements of the connective tissue.
What is the role of the extracellular matrix?
Determine permeability of the connective tissue layer to solutes and proteins
Which type of cartilage is the most common, with a ‘glassy’ appearance?
Hyaline cartilage
What is hyaline cartilage composed of?
Chondrocytes
Collagen fibres (type II)
Extracellular matrix
In adults, where is hyaline cartilage found?
Nose, larynx, knee joints
What is the difference in structure between hyaline and elastic cartilage?
The ECM in elastic cartilage contains more elastin fibres
Give two example of where you would find elastic cartilage
External part of the ear
Some parts of the larynx
Which type of cartilage is opaque in appearance and contains low amounts of proteoglycans?
Fibrocartilage
Where is fibrocartilage found?
The discs between the vertebrae
What sort of tissue is loose and contains adipocytes?
Adipose tissue
What are the functions of adipose tissue?
Insulation
Energy storage (fats)
Protection
True or false - diffusion through a membrane increases with a high concentration gradient?
True
Does diffusion through a membrane increase with a high or low molecular weight?
Low molecular weight
Does diffusion through a membrane increase with a high or low lipid solubility?
High lipid solubility
True or false - diffusion through a membrane increases with a high degree of ionisation
False - diffusion through a membrane increases with a low degree of ionisation
What are aquaporins?
Transmembrane proteins with a narrow hour glass shape and charged walls, allowing only H2O through.
How is the body’s fluid distributed (solid vs fluid)
1/3 solid - 2/3 fluid
How is the body’s fluid distributed intracellularly vs extracellularly?
1/3 extracellular - 2/3 intracellular
15L : 30L
How is the body’s extracellular fluid distributed invtravacular vs intersitial?
1/3 intravascular - 2/3 intersitial
10L : 5L
What are the differences in Na+ concentration between interstitial:plasma:intracellular?
140:140:10
What are the differences in K+ concentration between interstitial:plasma:intracellular?
4:4:140
What are the differences in Ca2+ concentration between interstitial:plasma:intracellular?
2:2:0
What are the differences in Mg2+ concentration between interstitial:plasma:intracellular?
1.5:1.5:2.5
What are the differences in Cl- concentration between interstitial:plasma:intracellular?
100:100:4
What are the differences in HCO3- concentration between interstitial:plasma:intracellular?
25:25:15
What are the differences in HPO42- concentration between interstitial:plasma:intracellular?
2:2:100
What are the differences in protein concentration between interstitial:plasma:intracellular?
0:1.2:2.6
Which body compartments is water able to move between?
All of them, speed greatly enhanced by aquaporins
How does glucose move between body compartments?
Passes through endothelium easily and readily into most cells via glucose transporters
How do electrolytes move between body compartments?
They pass through endothelium easily but not cell membranes (except via specific mechanisms)
How do proteins move between body compartments?
Minimal movement between compartments - transfer by pinocytosis when needed
What is pinocytosis?
Transfer from extra to intracellular fluid, via invaginated membrane which forms vesicle around particle.
Eg Immunoglobulin transfer across placenta
What is endocrine signalling?
Hormone secretion into blood by endocrine gland.
Used for slow long range signalling
Examples: Testosterone and insulin
What is paracrine signalling?
Short range signalling involving release of chemical messenger from secretory cell to adjacent target cells
Examples: Cytokines released from immune cells.
VEGF and NO release
What are the four types of cell signalling classes?
Endocrine signalling
Paracrine signalling
Direct contact
Synaptic signalling
What type of signalling molecule is adrenaline?
Small molecule
What type of signalling molecule is hCG?
Peptide/ protein
What type of signalling molecule is LH?
Peptide/ protein
What type of signalling molecule is Insulin?
Peptide/ protein
What type of signalling molecule is Testosterone?
Steroid
What are the 4 main types of cellular receptor?
Steroid receptor
G protein coupled receptor
Ligand gated ion channels
Enzyme linked
Whats the ratio of Na+:k+ exchanged in the ATPase pump?
3 Na+ out
2 K+ in
What are the three types of muscle tissue
Skeletal
Cardiac
Smooth
What are the properties and location of skeletal muscle?
Voluntary or striated muscle, it is the muscle attached to bones
What are the properties and location of cardiac muscle?
Striated muscle, found in the walls of the heart
What are the properties and location of smooth muscle?
Involuntary or visceral muscle, found in the walls of hollow organs - blood vessels, GIT, uterus etc.
In terms of the development of the musculoskeletal system, what do dermatomes give rise to?
Gives rise to the connective tissues and dermis of the skin
In terms of the development of the musculoskeletal system, what do myotomes give rise to?
Give rise to the skeletal muscles (dorsal and ventrolateral muscle of the body wall & migrate into limb buds).
In terms of the development of the musculoskeletal system, what do sclerotomes give rise to?
Give rise to vertebrae
In embryology, where are smooth muscles derived from?
Lateral plate mesoderm and neural crest cells
In embryology, where are cardiac muscles derived from?
Splanchnic (visceral) layer of lateral plate mesoderm surrounding developing heart tube
What branch of the nervous system are the spinal nerves part of?
Somatic nervous system
How many pairs of spinal nerves are there?
31 pairs of spinal nerves
What is a myotome?
Group of muscles innervated by spinal nerves derived from the same segmental level of the spinal cord as the somite
What is a motor unit?
Groups of muscle fibres and single motor neuron that supplies them
What dictates the size of the motor unit?
Which muscle is involved and what sort of movement it has to produce eg gross or fine motor movement
What is the generic structure of a muscle fibre?
Fascicle –> muscle fibre –> myofibril –> sarcomere
Define tendon
Thick band/ cord of dense connective tissue attaches muscle to bone
Define aponeurosis
Broad sheet of dense connective tissue with which muscle attaches to bone
Define muscle attachment site origin
Attachment site of muscle tendon/ aponeurosis to less moveable or stationary bone
Define muscle attachment site insertion
Attachment site of muscle tendon/ aponeurosis to more moveable bone
Give some symptoms of compartment syndrome (6 Ps)
Pain out of proportion
Palpably tense compartment
Pain with passive stretch
Parathesia/ hypothesia
Paralysis
Pallor
What is a synergistic contraction?
Synergistic muscles contract to prevent unwanted movements or aid the action of the agonist.
When would you see a winged scapula?
Paralysis of the serratus anterior muscle due to damage of the long thoracic nerve
What is neuromuscular disease?
Occurs due to disease or damage of somatic motor neuron, neuromuscular junctions or muscle fibres
What is Myasthenia Gravis?
Autoimmune damage to NMJ (nicotinic ACh receptors blocked or destroyed).
Leads to muscle weakness and fatigue
What is Duchenne’s r Becker’s muscular dystrophy?
X-linked inherited skeletal muscle fibre degenerative disease.
Causes muscle weakness and wasting, affects mainly boys.
What is muscle hypertrophy?
Skeletal muscle growth after birth.
Occurs through enlargement of existing muscle cells.
Influenced by hormones and exercise.
What is disuse atrophy?
Inactivity for extended period of time causes loss of protein mass leading to decreased muscle size.
My be due to paralysis or prolonged bed rest
What is sarcopenia?
Reduction in muscle mass due to ageing.
What factors influence sarcopenia?
Influenced by reduced hormonal signalling (IGF, insulin, testosterone), reduced nervous stimulation, muscle disuse, protein synthesis and poor diet.
Where is calcium normally distributed within the body and in what proportions?
99% in skeleton & teeth
- 9% is intracellular
- 1% in the ECF
What form is calcium found as in bones?
Hydroxyapetite crystals Ca3(PO4)2
What is the role of calcium within bones?
Provides structural strength to bones - makes them hard
What is the role of calcium within the nervous system?
Release of neurotransmitters from pre synaptic neurons and the NMJ is triggered by calcium entry from the ECF
What is the role of calcium within muscle contraction?
Entry of Ca2+ into cardiac and smooth muscle cells from the ECF is a key step in excitation contraction coupling
What is the role of calcium within the endocrine system?
Movement of extracellular Ca2+ into endocrine cells triggers hormone release.
eg Ca2+ influx causes membrane depolarisation which causes pancreatic islet cells to release insulin
What is the role of calcium within the blood?
Calcium is a cofactor in several steps within the clotting cascade
What is the role of calcium within intracellular processes?
Calcium functions as a second messenger in cell signalling pathways and as a cofactor for enzyme function in chemical reactions