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
What is epimysium?
Epimysium is the CT layer that covers a whole muscle. It can blend with the deep fascia surrounding muscle compartments
How can CT layers extend beyond muscle to attach to bone?
CT layers can extend beyond the length of the muscle fibres to attach it indirectly to bone via tendons or aponeurosis
What is an agonist?
An agonist (prime mover) is the muscle primarily responsible for a movement e.g. the biceps is the agonist of elbow flexion
What is an antagonist?
An antagonist is the muscle which opposes movement. They need to lengthen in order to allow the agonist to move e.g. in elbow flexion the triceps brachia is the antagonist
What is a synergist?
A synergist is a muscle which assists the prime mover by also producing the same movement e.g. the synergist in elbow flexion is the brachialis
What is a fixator?
A fixator is a muscle that stabilises one part of the body during movement of another part. In elbow flexion the fixator would be the deltoid muscle
What connective tissue surrounds a nerve?
Endoneurium (covers the myelin sheath of each myelinated nerve fibre in the peripheral nervous system), Perineurium (covers one nerve fascicle) and the Epineurium (covers the entire peripheral nerve)
What is the diencephalon made up of?
The diencephalon consists of the thalamus and the hypothalamus
What is the the role of the thalamus?
The thalamus relays sensory information (except for smell), motor information, cortical arousal, learning, and memory
What is the role of the hypothalamus?
The hypothalamus is the main visceral control centre of the body and important to overall body functions
What does the brainstem consist of?
The brainstem is made up of the midbrain, pons and medulla oblongata
What does the brainstem do as a whole?
The brainstem overall controls messages between the brain and the rest of the body. It controls basic body functions such as breathing, swallowing, hear rate, blood pressure and consciousness
What is the function of the cerebellum?
The cerebellum processes information from cerebral motor cortex, proprioceptors, and visual and equilibrium pathways. It is responsible for balance, posture, and smooth, co-ordinated movements
What is the cerebrum responsible for?
The cerebrum is responsible for conscious thought and memory
How is the grey matter of the spinal cord divided?
The grey matter of the spinal cord is divided into a motor half ventrally and a sensory half dorsally
What is the role of the dorsal columns?
The dorsal columns are found posteromedially in the spinal cord and are responsible for conscious muscle sense concerned with awareness of body position. They are crossed and sense touch, pressure, and vibration
What is the role of the dorsal spinocerebellar tract?
The dorsal spinocerebellar tracts are located posterolaterally in the spinal cord and are uncrossed. They convey unconscious muscle sense which is important in control of muscle tone and posture
What is the role of the ventral spinocerebellar tracts?
The ventral spinocerebellar tracts are located anterolaterally in crossed and convey unconscious muscle sense
What is the role of the lateral spinothalamic tract?
The lateral spinothalamic track is located laterally (medial to the ventral spinocerebellar tract) and is crossed. It is responsible for voluntary control of skeletal muscles
What is the role of the ventral spinothalamic tract?
The ventral spinothalamic tract is located medially, posterior to the vestibulospinal tract and it is crossed. It is responsible for touch
What is the role of the lateral corticospinal tract?
The lateral corticospinal tract is located posterolaterally and is crossed. It is responsible for voluntary control of skeletal muscles
What is the role of the rubrospinal tract?
The rubrospinal tract is located anterior to the lateral corticospinal tract and is crossed. It is responsible for involuntary control of skeletal muscles and is concerned with muscle tone and posture
What is the role of the ventral corticospinal tract?
The ventral corticospinal tract it located anteromedially and is uncrossed down the spinal cord before it crosses at the level of termination in the spinal cord. It is responsible for voluntary control of skeletal muscles
What is the role of the vestibulospinal tract?
The vestibulospinal tract is located anteriorly in the spinal cord and is uncrossed. It is responsible for involuntary control of muscle tone in order to maintain balance and equilibrium
Why is it important to know the different spinal pathways of the CNS?
We need to know the CNS pathways so that when someone comes in with sensory or motor changes we know which tests to perform and what pathway there is an issue in
What are the osteopathic principles?
The principles underpinning osteopathy are: 1. The body is a unit 2. Structure and function are reciprocally inter-related 3. the body possesses self-regulating mechanisms and 4/ rational treatment is based on the previous principles
What is the function of the cardiovascular system?
The function of the cardiovascular system is to transport blood throughout the body which delivers nutrients, oxygen and horomones to the tissues while removing waste products
What are the different types of blood vessels?
Arteries, veins and capillaries
What is blood?
Blood is a special type of connective tissue which has the functions of transportation (of nutrients, oxygen, hormones and wastes), regulation (temperature, pH and water composition) and protection (immunity, inflammation and clotting)
What is the function of valves?
Valves are located in veins throughout the cardiovascular system and proven t the back flow of blood. Nearby arteries and muscles can assist in creating pressure in order for veinous return to occur
What are the main structures that assist in veinous return
While valves located in veins prevent back flow of blood, the main mechanisms of veinous return are the muscle and arterial pumps
What is the lymphatic system?
The lymphatic system is a network of vessels present throughout most of the body which acts as an overflow system which allows the drainage of tissue fluid.
In what regions is there a concentration of lymphatic vessels?
Around the armpit and groin there are catchment sites for lymphatic fluid from the upper and lower limbs. There is also a concentration of lymphatic vessels around glandular tissue such as the breasts.
What can trigger inflammation?
Inflammation can be triggered as a non-specific response to damaged tissue by factors such as heat, abrasion, chemical irritation, distortion or disturbance of cells
What is the function of inflammation?
The function of inflammation is to remove the infectious agent, limit its effect on the body, repair or replace the damaged tissue and then alter adaptive immunity
What maintains a stable environment for cells?
Homeostasis is the process which looks after a cells environment so that it is stable enough for them to live without stress
How do cells cope with stress
Cells cope with stress through cell adaptation which requires the cell to change normal processes through altered cell biology
what are the responses to a change in cell environment?
Stress response is either reversible cell injury (cell returns to normal or deals through adaptation) or irreversible cell injury which results in death (either by apoptosis or necrosis)
How does cellular adaption to injury occur?
Cellular adaption to injury can occur in response to normal (physiological) conditions and in adverse (pathophysiological) conditions. Cellular adaptions to adverse conditions are only generally successful for a short period of time. If the stress is severe or longterm then the cell will become overwhelmed and death will occur.
How do cells age?
cellular raging causes structural and functional changes that may lead to cell death. Mechanisms that explain this are not fully understood so it is often difficult to differentiate between physiological and pathophysiological processes.
How is a cells stress response determined?
The stress response of a cell depends on 1. the type of injury or stress 2. the intensity 3. the duration. the effect of stressors can be measured and observed by the performance of the tissue, organ, or organ system.
What are the causes of cellular injury?
The causes of cellular injury are hypoxia, chemical agents, nutritional imbalances, physical agents, infectious agents and genetic causes
What is Hypoxia?
Hypoxia is a cause of cell death due to insufficient oxygen to the cell. It is the most common cause of cellular injury and is usually caused by ischaemia although other common causes include inadequate oxygen due to respiratory diseases such as asthma and insufficient transport of oxygen through the body e.g. decreased haemoglobin
How do chemical agents cause cellular injury?
Direct contact of the cell with a toxic substance causes the cell membrane to have an increase in permeability. There are generally 2 mechanisms in which this can occur; direct toxicity by contact of the chemical with a part of the cell membrane and/ or organelles OR the formation of substances that cause lipids in the cell membrane to damaged. Examples of cellular injury via chemical agents include inhalation of carbon monoxide, recreational/ pharmaceutical drugs and air pollutants/ insecticides
How do nutritional imbalances cause cellular injury?
Nutritional imbalances due to a deficiency or over supply in the body can cause injury due to their availability to the cells. examples include protein deficiency and hyperlipidaemia
How can physical agents cause cellular injury?
Physical agents can cause cellular injury through hypothermia, hyperthermia, atmospheric pressure, sunlight and trauma. examples of this include musculoskeletal sprains and strains, burns and, frostbite
How can infectious agents cause cellular injury?
Infectious microorganisms can enter the body and cause widespread or local damage to cells. they may enter the cell like viruses or bacteria or microorganisms that release harmful toxins. Examples of this are HIV and meningococcal meningitis
How can genetics cause cellular injury?
Cellular injury can be caused through genetics as they change the DNA of a cell which can cause changes in structure, function and metabolism as well as making the cell more susceptible to injury. An example of this is cystic fibrosis.
What are the common cellular adaption processes?
Atrophy, hypertrophy, hyperplasia, metaplasia and dysplasia
What are the changes that occur due to atrophy and hypertrophy?
Atrophy= decrease in cell size hypertrophy= increase in cell size
What are the changes that occur due to hyperplasia, metaplasia and dysplasia?
Hyperplasia= increase cell production (number of cells) Metaplasia= transformation from one cell type to another Dysplasia= transformation of a cell into an abnormal version of itself
What is chronic inflammation?
Chronic inflammation is a prolonged inflammatory response that can lasts weeks, months or years. it occurs due to persistent exposure to infections, mechanical injury, toxic agents or autoimmune diseases. It is characterised by both tissue destruction and repair proceeding simultaneously
What does chronic inflammation involve?
Chronic inflammation involves both non-specific (e.g. macrophages) and adaptive (e.g. lymphocytes) immune cells. the process will be ongoing unless the initial cause is removed e.g. antibodies, foreign object, mechanical stress etc. It can result in systemic manifestations such as malaise, recurrent infection and depression due to the ongoing nature of the immune response and pain.
What are the 2 types of chronic inflammation?
The two types of chronic inflammation are non-specific proliferative and granulomatous inflammation
What is non-specific proliferative inflammation?
Non-specific proliferative inflammation is presence of non-specific granulation tissue formed by infiltration of mononuclear cells, proliferation of fibroblasts, connective tissue, vessels and epithelial cells. An example is inflammatory polyp
What is granulomatous inflammation?
Gran
