Intro to Biomedical Sciences Flashcards
What is connective tissue made up of?
Ground substance, fibres, and cells
What does ground substance consist of?
Interstitial fluid, proteins, and proteoglycans. Ground substance is gel like in texture
What are the fibre types in connective tissue?
Collagen, elastic/elastin, and reticular fibres
What are collagen fibres?
They are the strongest and most abundant type of fibres present in CT which provide high tensile strength to resist stretching/ pulling forces and appear pink and thick under a microscope
What are elastic/ elastin fibres?
Elastic/ elastin fibres are networks of long, thin fibres that allow stretch and recoil. They appear thin and dark purple in colour under a microscope
What are reticular fibres?
Reticular fibres are short, fine, highly branched collagenous fibres present in CT
What cells are present in CT?
Macrophages, fibroblasts, lymphocytes, fat cells, mast cells, and neutrophils
What are the classifications for proper CT?
CT proper can be classified as either loose or dense
What is the role of fibroblasts in CT proper?
Fibroblasts produce the extracellular matrix in CT proper and they also mature into fibrocytes
What are examples of loose CT?
Areolar (loose packing CT between tissue), adipose (fat storage) and reticular (like areolar)
What are examples of dense CT?
Regular, irregular and elastic CT
What is the fibre arrangement of dense regular CT?
The fibres are primarily parallel in arrangement and are collagen with few elastin fibres
What is the function of dense regular CT?
The function of dense regular CT is to withstand tensile stress when pulling in one direction
What cells are found in dense CT?
Fibroblasts and fibrocytes are found in dense CT
Where is dense regular CT located?
Dense regular CT is found in tendons (muscle attachment to bones), ligaments (bone to bone attachment) and deep fascia (surrounding muscles)
What is the fibre arrangement of dense irregular CT?
The fibres in dense irregular CT are sheets of irregularly arranged but tightly packed collagen fibres with few elastin fibres present
What is the function of dense irregular CT?
The function of dense irregular CT is to withstand tension that is exerted in many directions
Where is dense irregular CT located?
Dense irregular CT can be found in fibrous joint capsules and in the dermis of the skin
What fibres are found in elastic CT?
A high proportion of elastin fibres are present in elastic CT
What is the function of Elastic CT?
Elastic CT allows tissue to stretch and recoil
Where is elastic CT located?
Elastic CT can be found in the walls of large arteries and in the lungs
What form of dense CT appears different from the others and why?
Elastic CT looks different from irregular and regular CT as it has a high proportion of elastin fibres present which are a deep purple in colour whereas the others are predominantly collagen fibres which appear pink
What is cartilage characterised by?
Cartilage is characterised by few cells interspersed within high levels of extracellular matrix (ECM)
What are the main features of cartilage?
Few cells interspersed within high levels of ECM, high water content allows it to rebound after compression, avascular and gets nutrients via diffusion, thickness is limited and heals poorly, lacks nerve fibres, typically covered externally by perichondrium
What are the types of cartilage?
Hyaline, Fibrocartilage and elastic cartilage
What causes the different types of cartilage?
variation in ground substance and fibres results in the three different types of cartilage
What are the features of hyaline cartilage?
Hyaline cartilage has a glassy appearance and resists compressive stress. An example of it is articular cartilage
What are the features of fibrocartilage?
Fibrocartilage resists compression and tension. An example of it is intervertebral disks
What are the features of elastic cartilage?
Elastic cartilage allows great flexibility whilst holding its shape e.g. in the auricle of the ear (external)
What characterises muscle tissue?
Muscle tissue is characterised by its excitability (response to stimulus), contractibility (ability to forcibly shorten), extensibility (ability to stretch/ lengthen) and elasticity (recoil after stretching)
What are the three types of muscle?
Skeletal, Cardiac and Smooth muscle
What prefixes are used to indicate that something is muscular?
“myo” and “mys” refer to a structure that is muscle e.g. myocyte= muscle cell
What is the function of muscle?
The main functions of muscle are to produce movement (e.g. locomotion and manipulation, heart pumping, moving gastric contents) and to maintain posture and position, stabilise joints and generate heat
What are the connective tissue sheath layers?
The CT sheath layers are the endomysium, perimysium, and epimysium
What is endomysium?
Endomysium is the CT layer which covers only one muscle fibre (one skeletal muscle cell)
What is perimysium?
Perimysium is the CT layer which covers a group of muscle fibres called a fascicle