ans-bmi

Upload: arun-prakash

Post on 04-Jun-2018

215 views

Category:

Documents


0 download

TRANSCRIPT

  • 8/13/2019 Ans-bmi

    1/6

    1. Define Action and rsting potential.Equilibrium is reached with a potential difference across the membrane such that negative on inside and

    positive on outside. This membrane potential caused by the different concentration of irons is called RestingPotential.

    Cell has a slightly positive potential on the inside due to imbalance of potassium ions. This positive potential of the cell membrane during excitation is called Action Potential and is about ! m".

    2. What is meant by CNS?The central nervous system #C$%& is the part of the nervous system that functions to coordinate the activity

    of all parts of the bodies of multicellular organisms.

    3. What is meant by refractory period?A short period after a nerve or muscle cell fires during which the cell cannot respond to additional

    stimulation.

    4. Write the e pression goldman!s e"#ation

    '('('('('('(

    ln))out Cl in Nain K

    inCl out Naout K Cl K Na

    Cl P Na P K P

    Cl P Na P K P

    F

    RT E

    ++

    ++=

    where P * ) P $a ) PCl + permeability constants for ma,or ionic species.E $a)*)Cl + equilibrium potential #volts& of the three ma,or ionsR + gas constant T + absolute temp in -elvins + araday constant

    $. Compare Acti%e and passi%e transd#cers.Acti%e transd#cer / A transducer that gives its output without the use of an excitation voltage or modulation ofa carrier signal is called an active transducer.&assi%e transd#cer ' A transducer that gives its output using an excitation voltage or modulation of a carriersignal is called a passive transducer. 0enerally the active transducer converts a non1 electrical energy intoelectrical energy and converts an electrical into non electrical energy.

    &A() * +

    2. Explain the bloc- diagram of biomedical instrument system. (3!'

    4. #a& i. Explain the structure ofC$% with neat diagram.(5'

    Central ner%o#s system #CNS &

    http://dictionary.reference.com/browse/cellhttp://dictionary.reference.com/browse/whichhttp://dictionary.reference.com/browse/whichhttp://dictionary.reference.com/browse/cell
  • 8/13/2019 Ans-bmi

    2/6

    The central ner%o#s system #CNS & is the part of the nervous system that functions to coordinate theactivity of all parts of the bodies of multicellular organisms. 6n vertebrates ) the central nervous system isenclosed in the meninges .

    6t contains the ma,ority of the nervous system and consists of the brain and the spinal cord . Togetherwith the peripheral nervous system it has a fundamental role in the control of behavior .

    The C$% is contained within the dorsal cavity ) with the brain in the cranial cavity and the spinal cord inthe spinal cavity . The brain is protected by the s-ull) while the spinal cord is protected by the vertebrae.&eripheral ner%o#s system ,&NS-

    The peripheral nervous system #P$%& resides or extends outside the central nervous system #C$%&)which consists of the brain and spinal cord. The main function of the P$% is to connect the C$% to the limbs

    and organs.7nli-e the central nervous system) the P$% is not protected by bone or by the bloodbrain barrier)

    leaving it exposed to toxins and mechanical in,uries. The peripheral nervous system is divided into the somaticnervous system) autonomic nervous system and the sensory system

    ii. Explain the function of heart with neat diagram.(4'

    #b& i. Explain the bloc- diagram of a pie8oelectricultrasonic transducer.(5'

    The conversion of electrical pulses to

    mechanical vibrations and the conversion of returned mechanical vibrations bac- into electrical energy is the basis for ultrasonic testing. The active element is the heart of the transducer as it converts the electrical energy

  • 8/13/2019 Ans-bmi

    3/6

  • 8/13/2019 Ans-bmi

    4/6

    the oral pharyn through the glottis into the trachea into the right and left bronchi ) which branches and rebranches into bronchioles ) each of which terminates in a cluster of

    al%eoli;reathing is controlled by the medulla of the brainstem. 6t repeatedly triggers contraction of the diaphragminitiating inspiration. The rate of breathing changes with activity level in response to carbon dioxide levels) andto a lesser extent) oxygen levels) in the blood. Carbon dioxide lowers the p? of the blood.

    5. #a& i. Explain the structure of a $erve Cell with neat diagram.(5'

    A nerve is an enclosed) cable1li-e bundle of peripheral axons #the long) slender pro,ections of neurons&.A nerve provides a common pathway for the electrochemical nerve impulses that are transmitted along each ofthe axons. $erves are found only in the peripheral nervous system. 6n the central nervous system) the analogousstructures are -nown as tracts. $eurons are sometimes called nerve cells) though this term is technicallyinaccurate since many neurons do not form nerves) and nerves also include non1neuronal %chwann cells thatcoat the axons in myelin.

    The synapse is the connection between nerve cells #neurons& in animals including humans. The synapse ,oins the axons in one neuron to the dendrites in another. ?ere is a diagram showing how the synapse connectsaxons to dendrites/

    The synapse consists of/@The presynaptic terminal at the end of an axon. This contains tiny vesicles which contain

    neurotransmitters 1 the small molecules which carry the nerve impulse from the sending neuron to the receivingneuron.

    @The synaptic cleft 1 a gap between the two neurons across which the neurotransmitters migrate.@The postsynaptic terminal usually in the dendrites of receiving neurons. This contains receiving sites

    for the neurotransmitters. $erve impulses are transmitted down to the presynaptic terminal in the axon of one neuron and across

    the synaptic cleft to the postsynaptic terminal in the dendrite of another neuron. %ynapses do not only ,oin axonsto dendrites #axodendritic synapses& 1 they can also ,oins axons to other axons #axoaxonic synapses& or to thesoma the neuronal cell body 1 #axosomatic synapses&.

    A typical neuron in the central nervous system #C$%& has around 3!!)!!! synapses. The effect of therelease of neurotransmitters across the synapse may either be excitory 1 ma-ing the triggering of a nerveimpulse #action potential& in the receiving neuron more li-ely 1 or inhibitory 1 ma-ing it less li-ely. An action

    potential is an on1off event and is always 1BB millivolts 1 there are no grades of nerve impulse. $eurotransmitters) on the other hand) are additive 1 if the net effect of all the excitory neurotransmitters minus

    all the inhibitory ones achieves this threshold then an action potential will be initiated.ii. Explain the characteristics of resting potential.(4'

    http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/P/Pulmonary.htmlhttp://users.rcn.com/jkimball.ma.ultranet/BiologyPages/P/Pulmonary.html
  • 8/13/2019 Ans-bmi

    5/6

    The value of the resting potential is maintained as aconstant until some -ind of the disturbance will upset the equillibrium.

    6t strongly depends on temperature. The range of resting potential is 12! to 13!! m". The resting potential is derived by gold sman equation.

    '('('('('('(

    ln))out Cl in Nain K

    inCl out Naout K Cl K Na

    Cl P Na P K P

    Cl P Na P K P

    F

    RT E

    ++

    ++=

    whereP* ) P $a ) PCl + permeability constants for ma,or ionic species.E $a)*)Cl + equilibrium potential #volts& of the three ma,or ionsR + gas constant T + absolute temp in -elvins + araday constant

    " R +152.5m"

    #b& i. Explain any one application of fibre optic transducer with neat diagram.(5'

    ii. ;riefly discuss the structure of

    a cell. (4'

  • 8/13/2019 Ans-bmi

    6/6

    C0 / The fundamental unit of every animal or plant is cells. Combination of cells is called T6%%7E%. Every:R0A$ in the body is made up of combination of many tissues.C0 S / All cells are same and they contain a gelatinous substance made up of or composed of water) protein)acids) fats) and various minerals.C0 0 +(AN0' Cell membrane protects the cell and surrounds it that passes into and out of the cell.N C 0 S / The nucleus controls the structure of the cell. Cell reproduction process is directed by the nucleusonly and which determines the function of the cell and the structure of the cell.

    C (5 5S5 0S / These are rod1li-e structures inside the cell. ?uman body cells #other than sex cells) theegg) and sperm cells& contain < pairs of chromosomes. %ex cells) such as sperm and egg cells have < singlechromosomes only. 9hen one egg cell unites with a sperm cell to for an embryo) then the embryonic cell has>2 chromosomes i.e. < pairs...understand the difference... Chromosomes contains the regions called 0E$E%.

    Thousands of genes are in an orderly sequence on each chromosome. 0ene is made up of a chemical substancecalled =$A #deoxyribonucleic acid&. =$A is an important compound that regulates the activities of the cell in asequential order on each chromosome. The =$A is a series of codes. 9hen =$A activity carries out of thenucleus to other parts of the cell) the activities of the cell i.e. cellular reproduction and the manufacture of

    proteins are controlled by =$A.

    C6)5& AS ' 6t means cyto means cell) plasm means formation.Cytoplasm carries the wor- of a cell i.e.nerve cell conducts stimulation) muscle cell contracts. Cytoplasm contains D6T:C?:=R6A andE$=:P A%D6C RET6C7 7D.

    7)5C 5ND(7A / 6t is called power center of the cell. This is small and sausage1shaped bodies produceenergy by burning food in the presence of oxygen. This process is called catabolism #cata1down) bolto cast)1ism1process&. This process ma-es complex food particles into simpler substances and energy is released afterthis action to do the wor- of the cell0ND5& AS 7C (0)7C / These li-e canal1li-e structures1this is a networ- within the cell. Thesecanals contain a very small structures called R6;:%:DE% li-e a tunnel system in this proteins are produced for

    the use of the cell. This process is called A$A;: 6%D #ana1up) bolto cast) 1ism1process&. After this process)complex proteins are made up from the simpler parts of food.

    %maller proteins lin-ed li-e a chain to become complex proteins in this process. ;oth these catabolismand anabolism in combination is called DETA;: 6%D #metachange) bol1to cast) 1ism1 process& i.e totalchemical activities that occuring in a cell. 6n this process) the sugars and fat in the food are used up and burnedquic-ly and so the E$ER0F is released