B3 Flashcards
what is epithelial tissue?
what are the different types called?
-Epithelial are found lining organs and surfaces eptihelial tissues can be divided into different types:
-Squamous
-Columnar
-Endothelium
what is squamous epithelial tissue structure?
how can the epithelium cells be damaged by smoking?
what are all of those symptons of?
-Squamous lining tissue one cell thick
-It is made from flattened specialised squamous epithelial cells.These cells form a thin smooth flat layer this makes them ideal when rapid diffusion is necessary
eg is alveoli in the lungs which provide a short diffusion pathway to allow rapid diffusion of oxygen into the blood and carbon dioxide into the lungs
-Epithelium cells can be damaged by smoking.Smoking irritates and causes inflammation in the epithelium tissue in the lungs.The alveoli walls become thicker due to scarring and produce more mucus.The damage to the air sacs causes emphysema and lungs lose their natural elasticity.This causes:
-breathlessness
-persistent coughing
-Phlegm
These symptons are all asociated with COPD
what is ciliated columnar tissue made up?
describe its structure?
what does the trachea do?
what are goblet cells?
-Ciliated columnar epithelial tissue made of column shaped ciliated cells with hair like structures called ciliacovering the exposed cell surface
-Cilia epithelium line the trachea in the respitartotry system in order to protect the lungs from infection they do this by sweeping any pathogens away from the lungs
-Goblet cells are column shaped and are also present in the respiratory tract.They secrete mucus to help trap any unwanted particles that are present in the air that you breathe.This protects the lungs because it prevents bacteria from reaching the alveoli
what is endothelial tissue?
what do cells provide a short diffusion pathway for the movement of what substances?
what are the number of risk factors that can cause damage to the endothelium?
-Endothelial tissue consists of a layer of flattened cells one layer thick.Found in the heart blood vessels and lymphatic vessels.The cells provide a short diffusion pathway for the movement of various substances:
-products of digestion into blood capilleries
-blood plasma and tissue fluid in and out of blood capilleries
-Carbon monoxide amd high blood pressure can damage the inner lining of the arteries white blood cells repair the damage and ecourage the growth of smooth muscle and the deposition of fatty substances such as chlosterol under the endotheliumlining of arteries not on the surface.This process of deposition called artherosclerosis
Development of atheresclorosis
-Damages the endotholeila cells
-Triggers inflammatory response and migration of white blood cells in that area
-Phagocytosis of LDL and formation of foam cells
-Build up of chlosterol
-Atheromas may build up enough to break through the inner endothelial lining of the artery eventually forming plaque in the lumen of the artery.
-This reduces the size of the lumen and restricts blood flow
-Smoking is a lifestlye hard to give up addictive
-Increases other risk factors
-Nicotine and carbon monoxide in cigarrette smoke damages the endothelium which sets the stage for the build up of plaque
what is muscles?
what are 3 types of muscles tissues?
-Muscles are composed of cells that are elognated and form fibres.They contain protein filaments called actin and myosin that enables muscles to contract and cause movement
3 types:
-Skeletal muscle is found attached to the bones
-Cardiac muscle is only found in the heart
-Smooth muscle is found in walls of hollow organs eg stomach
SkELETAL MUSCLE FIBRE
what do muscle tissue need to be able to do?
in muscle what do cells join up to make?
what is the sarcoplasmic reticulumn?
what is each muscle fibre surrounded by?
what is the appearence of skeletal muscle fibre?
what is skeletal muscle fibre made up of?
-Muscle tissue needs to be able to contract (shorten in length) in order to move bones.In a muscle cells join up to make muscle fibres.These are long strands of cells sharing nuclei and cytoplasm known as the sarcoplasm
-Inside the muscle cell cytoplasm are many mitochondria specialised endoplasmic reticulumn known as sarcoplasmic reticulumn and a number of microfibrils/
-Each muscle fibre is surrounded by a cell surface membrane called the sarcolemma
-Skeletal muscle shows a stripy/banding appearance under the microscope
-Skeletal muscle is made up of thousands of muscle fibres each muscle fibre is made up of myofibrils
what is myofibrils made up from ?
what is the different coloured bands called and their colours?
when the muscle is relaxed in the sarcomere what length is it ?
why does the length change?
which one is thick and thin myosin or actin?
-Myofibrils are made from proteins called myofilaments which enable contraction to take place because of the contracile nature of proteins in the filament
-They appear different coloured bands
-A BANDS AND I BANDS
-A BANDS DARK
-I BANDS LIGHT
-When the muscle is relaxed approx 2.5 micrometere in length.This length reduces when the muscle contracts because the I band and H zone lengths are reduced.The a band does not change in length during contraction
mysoin thick
actin-thin
what happens during muscle contraction
what are the 2 types of muscle fibres and what do they do?
-The thin actin move and overlap the thick myosin filaments.The sarcomere shortens decreasing the size of the overall muscle
-slow and fast x
-Influence how muscles respond during physical activity
what is slow twich fibres?
what is fast twich fibres (2)?
Slow twich muscle fibres:
More effective at using oxygen to generate energy in the form of ATP for continuous and extended muscle contractions over a long time.They help marathon runner to continue for hours.They havce:
-Less sarcoplasmic reticulumn
-More mitchondria for sustained contraction
-more myoglobin
-dense capillary network
-release atp by aerobic respiration
Fast twich muscle fibres
can be divided into two kinds
-Fast twich oxidative muscle fibres similar in structure to slow twitch they contain many mitochondria myoglobin and blood capilleries but they are able to hydrolyse ATP much more quickly thye are relatively resistant to fatigue
Fast twitch glcolytic muscle fibres relatively have less myoglobin few mitchondria and few capilleries.They contain a large concentration of glycogen that provides fuel for anaerobic respiration.They contract rapidly but also fatigue quickly
what is the cns consist of?
what are neurons?
-Central nervous system consists of the brain and spinal cord.It is made ip of billions of non-myelinated nerve cells and long myelinated axons and dendrons that carry nerve impulses.Nerveous tissue is made of nerve cells called neurons
-Nervous- nuerons are cells that receive and facilitate nerve impulses or action potenials across their membranes pass em onto to the next neuron
what are the differences between myelinated neurons and non-myelinated?
Non myelinated
-Do not have a myelin sheath
-Grey
-Transmit impulses slower
-Do not have nodes of ranvier
Myelinated
-Have a myelin sheath
-White
-Transmit impulses very fast
-Do not have nodes of ranvier
what is the motor neuron?
what is the relay neuron?
what is the sensory neurone?
-Motor from CNS to effectors
-Relay found in the CNS
-Sensory from sensory receptors to the CNS
what is the action potential?
-Action potential neurons send electric impulses these are generated by changes in concentration of ions inside and outside the nerve cell causing a potential difference called an action potential whcih transmits an electrical signal between nerve cells
If the action potential is at rest its at -70mv
-inside is negative outside is positive
-This changes as the signal goes down the inside becomes positive and outisde becomes negative
-potassium ions and sodium ions
what happens if the threshold potential isn’t reached?
what happens in depolarisation?
what happens in repolarisation?
what happens in recovery?
Depolarisation:
-na+ gates open
-na+ diffuse into the cell carrying positive charge
-na+ gates close
Repolarisation:
-K+ gates open
-K+ diffuses out of cell taking the positive charge with it
-K+ gates closes
Recovery:
-K+ moves back into the cell through non-voltage gated channels
-Attracted by negative charge as hyperpolerised
-Resitng potential equilibrium is stored
what happens in the saltatory conduction?
-Action potential travel faster in myelinated neuron so the signal jumps from one node of ranvier to another it leaps alot quicker
-It jumps because the myelinated sheath stops the sodium from entering so depolarisation can’t happen so the signal has to jump
what is synapse?
what crosses the synapse?
what is aceytlcholine?
-Synapse is the junction between two neurons the presynaptic membrane (before the gap) allows release of neurotransmitters when impulses are arriving to stimulate impulses in the cell post synaptic
-Neurotransmitter crosses the synapse and initiate aciton potential
-Aceltylcholine is a neurotransmitter molecules released by exocytosis and they diffuse across the cleft.Acetlycholine molecules bind to the receptor sites on the sodium channels .Can produce excitatory affects/inhibtory depending on the type of receptors on the post synaptic membrane
what is ecg?
-ECG electrical activity ofthe heart it can be monitored in electrocardiograph
-several electrodes attached to specific places in a persons chest
components of ecg ?
-P wave time of the contraciton (atrial systole)
-pr interval the time taken for the wave to comeby
-qrs complex time of the ventricular systole
-t wave caused by repolarisation of ventricles
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what is agonists?
what is antagonists?
-Agonists drugs occupy repectors activate them eg atrophine
-Antagonists drugs occupy receptors but do not activitate them eg nicotine block recprtorrs activation
what is the neurotransmitter for depression and parksons?
-Serotonin depression
-Parkisons dopamine
both multifactorial could have genetic link
Parkinsons
-disorder of the cns its degnerative
-causes dopamine producing cells to die
-affects substarita nigra
-they arent produce dopamine naturally
-u get diagnosed until 80 percent of cells r gone
SYMPTONS
-TREMBLING HANDS
-SLOWNESS OF MOVEMENT
-STIFNESS WITHIN MUSCLES
TREATMENT
-l dopa converted into dopamine temporary reduces symptons
-dopamine agnosts drugs one of main to treat parkinsons disease
-acts like dopamine to stimulate nerve cells
MAOB INHIBTORS
-BREAKING DOWN DOPAMINE
-INHIBOTRS FOR MAOB REDUCES DESTRUCTION OF ANY DOPAMINE
SEROTONIN EVERYTHING
-symptons
-insomina
-low energy levels
-feeling intense sadness anxiety hopelessness
-loss of self esteem
neurotransmitter is made of amino acids neurons which respond to the serotonin have specific serotonin receptors in their post synaptic memrvane
treatment
-anti depressant drugs
-prozac
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