Post basic BSC nursing 1st year question paper with answers
B.Sc. NURSING [Post Basic (Ist year)] BIOCHEMISTRY & BIOPHYSICS
Time: 3 hrs.
M.M.: 75
Note:
1. Attempt all questions.
2. No supplementary sheet shall be allowed/provided.
The Student must write Q.P. Code in the space provided on the Title Page of the respective Answer Book.
Section-A (Biochemistry)
Q.1. a. Define Enzymes.(2)
b. Write the properties of Enzymes.(4)
c. Explain the factors effecting the Enzyme activity.(4)
OR
a. Define Amino acids.(2)
b. List down the properties of Amino acids.(4)
c. Explain the functions of Amino acids(4)
Q.2.Differentiate between:
(2.5 x 4 = 10)
a. Monosaccharides and Disaccharides.
b. Glycogenesis and Glycogenolysis.
c. Saturated fats and Unsaturated fats.
d. Ribo nucleic acid (RNA) and Deoxyribo nucleic acid (DNA).
(3x2=6)
Q.3.
Describe briefly (any two):
a. Fibrous Proteins.
b. Glucose tolerence test.
c. Functions of water in human body.
d. Glycemia.
(4x3= 12)
Q.4.
Write short notes on any four of the following:
a. Precautions for handling specimens for Enzyme estimations.
b. Digestion of Carbohydrates. c. Functions of Potassium.
d. Biosynthesis of Protein in Cell.
e. Composition of Urine.
f. Polysaccharides.
Section-B (Biophysics)
Q.1. a. Define Derived units.(2)
B. Explain units of weight. (2)
C. Discuss the effects of gravitational forces on Human Body. (6)
OR
A. Define Velocity. (2)
b. Explain briefly about Vector and Scalar Motion. (4)
c. Write down the principles of Gravity.(4)
Q.2.
a. Define Centre of gravity.(2)
b. Explain the effects of Heat on Matter.
(4)
c. Discuss the Biological effects of light.(4)
Q.3. Describe briefly (any two):
(4) (2.5 x 2=5)
a. Relationship between energy, frequency, and wavelength of light.
b. ECG.
c. Instruments used for detection of lonising Radiation. d. Transer of Heat.
Q4.Write short notes on any four of the following:
(4x3=12)
a. Noise pollution and its prevention.
b. Structure of Atom.
c. CAT Scan.
d. Regulation of Body Temperature.
e. Relative Humidity.
f. Defective Vision.
Section-A Biochemistry ANSWER-1 (a)Enzymes
Enzymes are defined as soluble, colloidal, organic biocatalysts that can catalyze and speed up chemical reactions usually by lowering activation energy, without themselves being altered.
There are number of enzymes present in body of an organism which help n the digestion of carbohydrates, proteins and fats.
b.Properties of Enzymes:
There are several general properties of enzymes that you should remember when studying enzymes. Some of these are outline below:
1. Denaturation: Since all enzymes are proteins, their activity is dependent on maintaining the proper three dimensional conformation. Remember that the function of a protein is dependent on its structure so that if the structure is disrupted then its functions. From your knowledge of protein structures, you should remember that changing factors such as pH, tem- perature and ionic strength can lead to a disruption of the structure of a protein. This disruption of structure and function is known as denaturation. The activity of enzymes therefore,is usually altered by changing the pH, temperature or ionic strength.
2.Specificity: Enzymes catalyze specific reactions. This catalysis occurs in special site where, the reactants bind and react to form the products This site is known as the active site of the enzyme. The active site is specific for the substrates so that almost no other substances will bind there and subsequently react In a simplistic manner, this is similar to the relationship of a lock key. Thus, each enzyme will catalyze only one specific reaction. This specificity leads to another property - Inhibition. Some substances have similar structures to the true substrate of an enzyme. An enzyme may not be able to distinguish between the true substrate and the imposter. If the enzyme binds the imposter at the active site, usually the enzyme cannot catalyze a reaction. This imposter molecule will thus inhibit the activity of the enzyme. In such conditions, the substrate and the imposter compete for the active site and so such inhibition is known as competitive inhibition.
3.Regulation: A cell does not always want an enzyme to be active, For example, there is an enzyme that synthesizes glycogen from glucose, If you were starving, you would not want your cells to make glycogen- in fact, you would want to break glycogen down to form glucose. If you could not regulate the activity of enzymes, you would not be able to prevent the cell from making glycogen, For many enzymes, the cell has the ability to turn up or down the activity of the enzyme depending on the conditions in the cell and in the body. Enzyme regulation generally occurs by one of two different methods - allosteric regulation and covalent modification.
3.Factors Affecting Enzyme Activity-
Several factors affect the rate at which enzymatic reactions proceed-temperature, pH, enzyme concentration, substrate concentration and the presence of any inhibitors or activators:
1.Temperature: As the temperature rises, reacting molecules have more and more kinetic energy. This increases the chances of a successful collision
and so the rate increases.There is a certain temperature at which an enzyme's catalytic activity is at its greatest. This optimal temperature usually around human body temperature (37.5°C) for the enzymes in human cells. Above this temperature the enzyme structure begins to break down (denature) since, at higher temperatures intra and intermolecular bonds are broken as the enzyme molecules gain even more ki netic energy.
2.pH: Each enzyme works within quite a small pH range. There is a pH at
which its activity is greatest (the optimal pH). This is because changes
in pH can make and break intra and intermolecular bonds, changing the
shape of the enzyme and therefore, its effectiveness.
3.Concentration of enzyme and substrate: The rate of an enzyme-catalysed reaction depends on the concentrations of enzyme and substrate. As the concentration of either is increased the rate of reaction increases, For a given enzyme concentration, the rate of reaction increases with increasing substrate concentration up to a point, above which any further in crease in substrate concentration produces no significant change in re action rate. This is because the active sites of the enzyme molecules at any given moment are virtually saturated with substrate. The enzyme/ substrate complex has to dissociate before the active sites are free to ac commodate more substrate. Provided that the substrate concentration is high and that temperature and pH are kept constant, the rate of reaction is proportional to the enzyme concentration.
4 Inhibition of enzyme activity: Some substances reduce or even stop the catalytic activity of enzymes in biochemical reactions. They block or distort the active site. These chemicals are called inhibitors, because they inhibit reaction Inhibitors that occupy the active site and prevent a substrate molecule from binding to the enzyme are said to be active site-directed (or competitive, as they 'compete' with the substrate for the active site). Inhibitors that attach to other parts of the enzyme molecule, perhaps distorting its shape, are said to be non-active site-directed (or non competitive).
OR
A. Define Amino acids.
Amino acids are the organic compounds having both amino (-NH2) and car boxylic-COOH acid attached to same (C) carbon atom
'R'-can be a hydrogen atom/aliphatic, aromatic or heterocyclic compound. Amino acids are the building blocks of the proteins. Out of 200 different amino acids occurring in nature, 20 amino acids form the plant and animal proteins.
ANSWER - 1 (b)
General Properties of Amino Acids.
Amino Acids Act as Acids and Bases:
When an amino acid is dissolved in water, it exists in solution as dipolar ion or zwiterion. Zwitterion can act as either an acid (proton donor) or a base (proton accetor).
Such substances showing this type of nature are amphoteric and are often called ampholytes. The pH at which the molecule exists as Zwitterion is called isoelectric point (pl).
Formation of a Peptide Bond:
Most important property of amino acid is the formation of peptide bond. Two amino acid molecules can be covalently joined through a substituted amino linkage termed as peptide bond, to yield a dipeptide. This linkage is formed by removal of the elements of water from the a-carboxylic group of one amino acid and a-amino group of another.byrodnss 6
Like this, three amino acids can be joined by two peptide bonds to form a tripeptide, similarly amino acids can be linked to form tetrapeptide, pentapeptides and so forth. When a few amino acids are joined in this fashion, the structure is called an oligopeptide. When many amino acids are joined, the product is called a polypeptide. Proteins may have thousands of amino acid residues.
(c)
Functions of Amino Acids
1. Amino acids act as building blocks of proteins. All the functions performed by the proteins are actually performed by amino acids. Almost all the hormones are basically proteins.
2. Amino acids act as an important dietary source of nitrogen.
3. Many amino acids are glucogenic. Thus they act as a source of energy the body.
4. Amino acids, such as aspirate and glutamine help in the biosynthesis of nucleotides.
5. Some amino acids form important molecules, which perform important functions in the body; such as:
a Glutathione: It is an important reducing agent in the body. It reduces many harmful agents like proteins, H₂02 and other peroxides.
b. Serotonin: It is a neurochemical produced from tryptophan. It is
very important in maintaining mental equilibrium. It is a potent vasoconstrictor and stimulates cerebral activity.
c. Melatonin: It is an important hormone molecule for regulating bio logical rhythms.
d. Nitric oxide: NO is synthesized from Arginine. It acts like prostaglandins
and as a neurotransmitter. It is a potent vasodilator and maintain
blood pressure.
6. The enzymes helping in catalysing metabolic activities are also proteins formed of the amino acids.
2(a)
Monosaccharides and Disaccharides
Monosaccharides
-Monosaccharides are single sugar molecules which act as the building blocks of diasaccharides and polysaccharides.
-The structure of monosaccharides is simple, single, linear and unbranched.
-These are sugar reducing agents.
-They are sweet taste and are water soluble.
-They have single ring structure.
-For example, Aldoses and Ketoses.
Disaccharides
-Diasaccharides are sugar molecules composed of two monosaccharides.
-The structure of diasaccharides is single, linear, unbranched or branched.
-Some are reducing sugars and some are not.
-They are sweet taste and are water soluble.
-They have two ring structure.
- For example: Maltose, Sucrose, ets.
B.Glycolysis and Glycogenesis:
Glycolysis
-It is the breakdown of the complex sugar molecules to release energy.
-It is a catabolic process.
-It releases energy.
-This process results increase in the blood glucose level by releasing of glucose from the glycogen stored in muscles/liver.
Glycogenesis
-It is synthesis of glycogen.
-It is an anabolic process.
-It consumes energy.
-The process results in lowering of blood sugar level as glucose gets stored in liver or skeletal muscles.
C. Saturated and Unsaturated fatty acids
Answer 2 d
ANSWER-3 (a)
Fibrous Proteins
In these proteins the polypeptide chains are spirally bound, assuming the shape of fibres. They usually have high degree of secondary structure, which give strength and rigidity to the protein molecules. They are insoluble in water. These are special types of helices present in the two fibrous proteins a-keratin and collagen. These proteins form long fibres that serve a structural role in the human body. These proteins are usually found as structural components in cells and intercellular materials. For example, collagen and elastin of connective tissues, actin and myosin of muscle fibres and fibrin of blood clot, etc. It is generally a quaternary structure and is usually held to gether by covalent bond. It is quite different from globular proteins.
1 (c) Glucose Tolerance Test: The Glucose Tolerance Test (GTT) was the gold stan- dard for making the diagnosis of type 2 diabetes. It was first described in 023 by Jerome W.conn. It is still commonly used during pregnancy for dia nosing gestational diabetes. It is a medical test in which the person fasts overnight (at least 8 hours, but not more than 16 hours). The next morning, the fasting plasma glucose is tested. After this test, the person receives a dose of oral glucose (the dose depends upon the length of the test). This test is usually used to test for diabetes, insulin resistance, impaired beta cell function and sometimes reactive hypoglycemia and acromegaly.
(c) Glucose Tolerance Test: The Glucose Tolerance Test (GTT) was the gold standard for making the diagnosis of type 2 diabetes. It was first described in 1923 by Jerome W.conn. It is still commonly used during pregnancy for gestational diabetes. It is a medical test in which the person fasts overnight (at least 8 hours, but not more than 16 hours). The next morning, the fasting plasma glucose is tested. After this test, the person receives a dose of oral glucose (the dose depends upon the length of the test). This test is usually used to test for diabetes, insulin resistance, impaired beta cell function and sometimes reactive hypoglycemia and acromegaly.
Preparation: Preparation for the oral glucose tolerance test involves fasting overnight (from 8 to 16 hours) and participating normally in activities of daily living. The individual should eat and drink as they normally do prior to the test. The morning of the test, the person should not consume caffeine or
smoke.
Procedure:
1 A zero time blood sample is with drawn.
2 The patient is then given measured dose of glucose solution to drink
within 5 minutes.
3. Blood is drawn at intervals for measurement of glucose and sometimes insulin. For simple diabetes screening, the most important sample is the 2 hour sample and 0 and 2 hour samples may be the only one collected.
Evaluation of Results of Test:
1. Normal response: A person is said to have a normal response when the two hour glucose level is less than 140 mg/dl and all values between 0 and 2 hours are less than 200 mg/dl.
2. Impaired Glucose Tolerance (IGT): A person is said to have impaired glucose tolerance when the fasting plasma glucose is less than 126 mg/dl and the two hour glucose level is between 140 and 199 mg/dl. This is sometimes referred to as "prediabetes" because people with IGT have a higher risk of developing diabetes.
3. Diabetes: A person has diabetes when two diagnostic tests done on different days show that the blood glucose level is high. This means either the two hour levels is greater than 200 mg/dl or the fasting glucose is noted as greater than 126 mg/dl. A glycosylated hemoglobin (HbA1c) level of 6.5% or more also supports a diagnosis of diabetes mellitus.
4. Diabetes during pregnancy: A pregnant woman has diabetes if she has a fasting plasma glucose of over 92 mg/dl or a two hour glucose level greater than 153 mg/dl.
Reliability of Test: For the glucose tolerance test to give reliable results, the person must be in good health (not have any other illnesses, not even a common cold). Also, the person should be normally active (not lying down, for example, as inpatient in a hospital) and should not be taking medicines that could affect the blood glucose. In preparation for the oral glucose tolerance test, the person should eat and drink as they normally would. The morning of the test, the person should not smoke or consume caffeine.
C. Role of water in the body:
1. water is required for various process like digestion, transport and excretion.
2. Water being good solvent dissolve nutrients and salts.
3. Water act as medium for all metabolic reactions that takes place in body.
4. Water help in removal of waste products.
5. Water regulates the temperature of our body by process of sweating.
ANSWER-3 (d)
Glycemia
Glycemia means the presence or level of glucose in blood. Normally i 60-100 mg/100 ml in fasting and 100-140 mg/100 ml following ingestion os a carbohydrate containing meal. However, any alteration in blood sugar may lead to hyperglycemia and hypoglycemia. Blood sugar is one of the important blood parameters to measure, as abnormal levels can Cause severe complications.
Glycemia is one of the important parameter in homeostasis, since
glucose is needed to provide the metabolic energy required for many cell functions.Several important hormones are involved in the regulation of blood sugar. One is insulin,which promotes the uptake of glucose from cells when the glucose level is raised. Another is glycogen, which has the opposite effect and increased the blood glucose level when it has dropped too low.
It has two types:
Hyperglycemia: An elevated blood glucose level is called hyperglycemia. It is caused by overproduction and under utilization of glucose, as a result of which glucose is synthesized more.
2. Hypoglycemia: Hypoglycemia is the medical term for a state produced by lower than normal level of blood glucose. It is defined as serum glucose level below 70 mg/ml.
Answer 4 (a)
Precaution for Handling Specimens for Enzyme Estimation: The main factors, which must be considered for assaying enzymes, are temperature, pH, ionic strength and the proper concentrations of the essential components like substrates and enzyme. Many enzymes, especially those from mammalian sources, possess a pH optimum and temperature so pre- cautions are taken to store these enzymatic specimens at their optimum conditions. Buffers serve to adjust and stabilize the desired pH during the enzyme assay. Due to the divergent features of enzymes a general estimation of enzyme is not possible, rather special rules can be given as follows:
1. pH: Preferentially the pH of the pH optimum of the respective enzyme is chosen, as far as possible at or near the physiological pH (~7.5)
2. Buffers and ionic strength: To stabilize the pH, buffers are used, and their pK, value should correspond to the pH optimum of the enzyme assay Buffer concentrations of about 0.1 M are suitable for most enzyme . estimations.
3. Temperature: One of three favoured temperatures should be chosen:
a. 25°C, the most frequently used one, easy to maintain, but giving relatively low enzyme activity.
b. 30°C, a compromise between 25°C and the physiological temperature,
especially for temperature sensitive enzymes.
c. 37°C, the physiological temperature, relatively high enzyme activity, but more difficult to maintain.
Different temperatures are needed for special cases (e.g. thermophilic
enzymes).
4.Concentrations of substrates and cofactors: Should be saturating, as far as possible 100Km, but at least 10Km
5.Concentration of the enzyme: As low as possible, but enough to observe
the progressing reaction.
6. Concentrations of additives: (Stabilizers, antioxidants, thiol reagents,
protease inhibitors, complexing reagents) as required for efficiency.
7. Conditions of the particular enzyme assay must accurately be specified in the protocol.
ANSWER-4 (b)
Digestion of Carbohydrates: In this, various enzymes are involved as:
1. Salivary amylase: It hydrolyzes starch, glycogen like polysaccharides to monosaccharides like glucose and galactose.
2 Pancreatic amylase: It acts on polysaccharides and splits them into smaller units.
3. Intestinal amylase hydrolyzes: Polysaccharides and splits them into smaller units, i.e. monosacchrides.
Intestinal juice also contains several enzymes that digest disaccharides
and
Enzymes.
Absorption of Carbohydrates:
Monosaccharides are end product of digestion of carbohydrates. They are completely absorbed in small intestine. Some disaccharides enter intestinal cells by pinocytosis and get hydrolysed and absorbed.
Mechanisms of Absorption:
Almost all the monosaccharides formed are absorbed from intestinal lumen into blood stream of portal venous system through mucosal epithelial celle by following processes:
1. Simple diffusion: Glucose, galactose and all other monosaccharides are absorbed to some extent by diffusion process. Diffusion is a process by which these substances are absorbed along their concentration gradi ent without any expenditure of energy.
2. Facilitated diffusion: Fructose and maltose are absorbed by process of facilitated diffusion, in which a carrier protein is required. It is also an energy independent process and takes place along concentration gradi ent. The carrier protein is called GLUT-5.
3. Active transport: The glucose and galactose are absorbed very rapidly by an active process which is a sodium dependent process. It requires ATP and occurs by expenditure of energy.
Glucose is polar in nature. So, it cannot diffuse through lipid bilayer of cell. It occurs with help of a carrier protein
Present in brush border of intestinal mucosa. The carrier protein has 2 binding sites (for Na+ and glucose). It is mobile and is dependent on Na+ and ATP. It occurs against concentration gradient. The process is called as Co-transportation by sodium dependent glucose transporter (SLGT-1).
Sodium independent transporter GLUT-2 facilitates transport of sugars out of mucosal cells into portal circulation.
Functions of Potassium:
1. Potassium helps in maintaining normal osmotic pressure of body fluids and maintains water and electrolyte balance.
2. It helps in maintenance of normal excitability of nerves and ensures smooth conduction of nerve impulses.
3. The potassium concentration has a significant influence on hydrogen ion concentration in the blood.
4. Potassium alongwith sodium is involved in active transport of many substances.
5. Potassium acts as cofactor for several enzymes such as pyruvate kinase Na+ -K+ ATPase.
6. Potassium salts form buffer system and thus plays important role in
maintenance of pH of body fluids.
ANSWER-4 (d)
Biosynthesis of Protein in Cell:
ANSWER
Biosynthesis of Proteins in the Cells: Protein biosynthesis is the process new proteins. It is the assembly of where by biological cells generate aminoacids by ribosome along with generation of mRNA, aminoacylation of tRNA, co-translation transport and post translational modification:
The cistron DNA is transcribed into variety of RNA intermediates. Proteins are synthesized directly from genes by translat ing mRNA.
2. A succession of tRNA molecules charged with appropriate aminoacids are brought together on mRNA molecules and matched by base-pairing through the an ticodons of tRNA with succes sive codons of mRNA. The amino acids are linked to extend the growing chain when the required protein is formed, further growth of the chain is terminated and rRNA is released.
Composition of urine:
ANSWER-4 (f)
Polysaccharides: Polysaccharides are polymeric carbohydrate molecule composed of long chains of monosaccharide units bound together by glycosidic bonds. They range in structure from linear to highly branched. examples include storage polysaccharides such as starch and glycogen, and structural polysaccharides such as cellulose and chitin.
Polysaccharides are often quite heterogeneous, containing slight modifications of the repeating unit. Depending on the structure, these macromolecules can have distinct properties from their monosaccharide building blocks. They may be amorphous or even insoluble in water.[1][2] When all the monosaccharides in a polysaccharide are the same type, the polysaccharide is called a homopolysaccharide or homoglycan, but when more than one type of monosaccharide is present they are called hetero-polysaccha rides or heteroglycans.
Functions: Nutrition polysaccharides are common sources of energy. Many organisms can easily break down starches into glucose, however, most organisms cannot metabolize cellulose or other polysaccharides like chitin and arabinoxylans. These carbohydrates types can be metabolized by some bacteria and protists. Ruminants and termites, for example, use microorgan isms to process cellulose.
Even though these complex carbohydrates are not very digestible, they may comprise important dietary elements for humans called dietary fiber, these carbohydrates enhance digestion among other benefits. The main action of dietary fiber is to change the nature of the contents of the gastrointestinal tract, and to change how other nutrients and chemicals are absorbed. Soluble fiber binds to bile acids in the small intestine, making them less likely to enter the body; this in turn lowers cholesterol levels in the blood. Soluble fiber also attenuates the absorption of sugar, reduces sugar response after eating, normalizes blood lipid levels and, once fermented in the colon, produces short-chain fatty acids as byproducts with wide-ranging physiological activities (discussion below). Although insoluble fiber is associated with reduced diabetes risk, the mechanism by which this occurs is unknown.
Not yet formally proposed as an essential macronutrient (as of 2005), dietary fiber is nevertheless regarded as important for the diet, with regulatory authorities in many developed countries recommending in creases in fiber intake.
Section-B Biophysics Answer a. Derived units: These are the units which can be derived from the fundamental units.
For eg. unit of speed is meter per second. This means that to cover a distance of 1 meter, the time required is 1 second.Speed
Commonly, we use the term mass and weight in the same sense. However in physics, the concept of both are different.
B.Units of weight
1. Mass is the measure of quantity of matter contained in the body.
2.Weight of the body is gravitational pull on it due to Earth. It is given by weight W=mg.
Where W denote the weight, m is its mass and g is the acceleration due to gravity.
British System
27.34 grains = 1 dram
6 drams = 1 ounce
16 ounces = 1 pound
2240 pounds = 1 long ton
Metric System
10 mg = 1 centigram
10 centigram = 1 decigram
10 decigram = 1 gram
10 grams = 1 decagram
10 decagrams = 1 hectogram
10 hectograms = 1 kilogram
100 kilograms = 1 quintal
1000 kgs = 1 metric ton
1.b differentiate between speed and Velocity.
Velocity
Velocity is the rate of displacement of an object.
It is measured in m/s.
Velocity refers to how a particular object changes position from point A to B.
Velocity is concerned with how long it took for an object to travel between two points.
Dimensional formula is : [V] = [M°LT-1]
Speed
Speed is the rate of change of position of an object in any direction.
It is measured in ms-1
Speed refers to as proportion of total distance travelled by the object to the total time taken.
Speed is concerned with how an object covers equal distance in equal intervals of time.
Dimensional formula is :
[S]=[M°LT-1]
Ans.1.C Energy is defined as the capacity of the body to do work. Units of Energy:
S.I unit = joule (J)
C.G.S unit = erg
Biochemistry
The Types of Energy are:
1.Light energy: It produces the sensation of vision in human body.
2.Sound energy: Sound energy produces the sensation of hearing in human body.
3.Heat energy: It produces the sensation of warmth .
4.Electric energy: It is the energy constituted by the flow of electric charges.
5.Mechanical energy: It is the sum of kinetic energy and potential energy of the body.
a.Kinetic energy: Energy possessed by an object due to the virtue of its motion.
b. Mechanical energy: Energy possessed by an object by the virtue of
its position.
C. Chemical energy: It is the energy stored in the chemical bonds of an atom/ molecules.
Transformation of Energy:
1.All the forms of energy are interconvertible.
2The convertion of one form of energy to another form is called as "trans-
formation of energy".
"The transformation of energy is based upon the law of conserva-
tion of energy which states."
"Energy can neither be created nor be destroyed. However, it can be transfused from one form to another form."
3.One form of energy can never be fully transformed into another form.
Some amount of energy is lost as heat energy.
Example: Chemical energy stored in food is converted into heat and kinetic energy in the muscles of body.
Answer -(C)
Effects of gravitational force on human body- Everybody in the universe attract every other body with a force is directly proportional to the product of their masses and universally proportional to the square of the distance between their centres. This force attraction between 2 bodies is called as gravitational force.
1.Effect of gravitational force on the human body:-
The circulation of the blood in the body takes place under the effect of gravity it has following applications:
A. The return of Venous blood from the legs takes place against the gravitational force therefore long standing hours may cause a edema in legs due to the gravitational pull.
B. During fainting or shock the elevation of legs may facilitate the Venous return of the blood from legs and facilitate the circulation of blood to head. it is beneficial because the sensitive tissues of head get required oxygen and damage is avoided.
C. postural drainage of the fluid from the lungs utilizes the effect of gravity. In this patient lie on his abdomen across the bed with his chest and had Is hanging down over the side of bed.
D. The post operative patient is placed with one side. It helps in the dropping down of patient's tongue to one side under the effect of gravity. It makes a larger passage way for the air to enter.
E. Brain surgery is frequently done with the patient in sitting or semi siting position. The blood from the region of head is drained down under the effect of gravity. It reduces the chances of haemorrhage.
2. Effect of gravitational forces on the equilibrium of human body:-
Every This body is made up of large number off particles. Each particle is attracted toward the Centre of earth by gravitational force. The resultant of all these forces is considered to be acting at fixed point "called centre of gravity" or "centre of mass" of human body. For human body to be in equilibrium, it should be supported at its centre of gravity.
While standing erect, the center of gravity is in front of the body of 2nd sacral vertebrae and run from vertex, through the plane of external ear, through the mid of vertebrae and mid o plane of hip joints and femoral joint in pelvis.
Any movement of body parts tend to disturb the equilibrium of the body by altering the position of centre of gravity. However, human body immediately adjusts to these change to maintain it's equilibrium.
For example:-
a. A man carrying a load on his back bends forward. In this way, the centre of gravity falls in between his feet.
b. A man climbing up a hill bends forward, to keep his body supported by the changed position of centre of gravity.
In this way, there are various movements in the body parts to keep the body is equilibrium.
Or
Answer-1 (a)
Velocity:- it is the rate of change of the displacement, the difference between the final and initial position of an object. Velocity is equivalent to a specification of its speed and directions of motion, e.g. 60km/h to the north.
Answer-2 (b)
Motion
This motion is defined as an act of change in position of an object with time with respect to some fixed position, which is taken as the reference point.
Scalar Motion
The physical quantities, which have a magnitude but no direction are called scalars. For example mass, length, temperature, work, charge, specific heat, time, density, etc. It may be positive or negative.
Vector Motion
The Physical quantities, which possess both magnitude and directions are called vectors. for example displacement, velocity, acceleration, force weight, momentum etc.
Answer 1 (c)
Principles of Gravity:
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