contents - record.pdf4 study of diffusion using kmno4 objective to demonstrate the phenomenon of...

Contents

1 Study of Mitosis in plants 1

2 Study of Osmosis by Potato Osmoscope 4

3 Study of Osmosis by istle Funnel Experiment 5

4 Study of Diffusion using KMnO4 7

5 Study of Absorption of Water 8

6 Study of Transpiration by Bell jar method 9

7 Study of Transpiration by cobalt chloride 11

8 Study of Transpiration by Ganong’s potometer 12

9 Study of necessity of light for Photosynthesis 15

10 Study of necessity of CO2 for Photosynthesis 16

11 Study of necessity of Chlorophyll for Photosynthesis 18

12 Study of photosynthesis—Inverted funnel experiment 19

13 Structure of Human Urinary system 21

14 Structure of Human Heart 22

15 Structure of Human Kidney 24

16 Structure of Human Blood Cells 25

17 Structure of Human Blood Cells 27

18 Structure of Human Ear 29

19 Structure of Human Eye 32

20 Structure of Adrenal gland 35

21 Structure of Pancreas 36

22 Structure of Pituitary gland 37

23 Structure of yroid gland 39

1 STUDY OF MITOSIS IN PLANTS

Objective Observation of permanent slides of stages of mitosis.

Requirements

1. Prepared permanent slides of different stages of mitosis. 2. Compound Microscope.

Procedure

1. Different stages of mitosis are focused under the low and high

power of compound microscope. 2. Make labelled diagrams of different stages of the cell division—Mitosis.

Observation A. Interphase (phase between the two successive division)

1. e slide shows the interphase of mitosis. 2. e nucleus is large and prominent. 3. Nuclear membrane, nucleolus present. 4. Chromatin network is distinct.

CELL MEMBRANE

CYTOPLASM

NUCLEAR MEMBRANE CHROMATIN THREADS

NUCLEOLUS NUCLEOPLASM

MITOSIS — INTERPHASE STAGE

B. Prophase (First phase of Karyokinesis) 1. e slide shows prophase of mitosis. 2. e nucleus is slightly bigger in size.

1

3. e nuclear membrane starts disappearing. 4. e nucleolus starts disappearing. 5. Prominent, dense, long, cylindrical chromosomes are seen. ey

later split into two chromatids.

NUCLEAR MEMBRANE DISAPPEARING CENTROMERE

CHROMOSOMES

NUCLEOLUS DISAPPEARING

MICROTUBULES FORMING

MITOSIS — PROPHASE STAGE

C. Metaphase 1. e slide shows metaphase of mitosis. 2. e nuclear membrane and nucleolus disappear. 3. e chromosomes arrange themselves at the equator. 4. e chromosomes appear to be short, thick and ‘X’ shaped. 5. e spindle is formed by the fibres given off from the opposite poles. 6. e chromosomes get attached to the spindle fibres at the centromere.

SPINDLE FIBRES

CHROMOSOMES LIE ALONG THE EQUATORIAL PLANE OF THE CELL

MITOSIS — METAPHASE STAGE

2

D. Anaphase 1. e slide shows the anaphase of Mitosis. 2. e spindle fibres shorten and pull apart the chromatids. 3. e centromere splits into two. 4. e chromosomes are pulled towards the opposite poles as

the spindle fibres shorten. 5. e chromatids are towards the poles with their arms

towards the centre of the cell.

SISTER CHROMATIDS SEPERATE TO OPPOSITE POLES

MITOSIS — ANAPHASE STAGE

E. Telophase

CELL PLATE

NUCLEAR MEMBRANE REAPPEAR CHROMOSOMES BECOMES INDISTINCT

NUCLEOLUS REFORMS

MITOSIS — TELOPHASE STAGE

1. e slide shows the Telophase of mitosis. 2. e spindle fibres disappear. 3. e nucleolus and nuclear membrane reappear.

3

4. e chromosomes lose their dense appearance and form the

chromatin network. 5. Cell-plate formation starts and division of cell takes place.

2 STUDY OF OSMOSIS BY POTATO OSMOSCOPE

Objective To demonstrate the phenomenon of osmosis through live

membrane using ‘potato osmoscope’.

Requirements

1. A large sized, uniformly textured potato tuber 2. 10% sugar solution 3. Stain to colour water 4. Beaker 5. Water 6. Scalpel 7. Pin

Procedure

1. Take a large sized potato tuber and peel off its skin with the

help of scalpel. 2. Make it flat at the base by cutting a portion at one end. 3. Now, scoop off the centre of the potato from the other end to

make a cavity in the tuber upto the base. 4. Pour some coloured sugar solution till half of the hollow cavity

is filled up. 5. Mark the initial level of water by inserting a common pin in the

wall of the potato as shown in the figure. 6. Put the potato in a beaker containing water. 7. e level of water in the beaker should be less than the level

of sugar solution in the potato tuber. 8. Let the apparatus stand undisturbed for some time.

Observation e level of the sugar solution in the potato tuber rises a er sometime.

4

Inference and Conclusion

1. e rise in the level of the sugar solution in the potato tuber is

due to the movement of water molecules from the pure water

into the beaker (Endosmosis). 2. is demonstrates the phenomenon of osmosis. 3. ‘Osmosis is the phenomenon of movement of water

molecules from their higher concentration to their lower

concentration through a semi-permeable membrane’. 4. Here in this experiment the living cells of potato tuber collectively,

act as semi permeable or differentially permeable membrane.

PIN BEAKER

NUCLEAR MEMBRANE

10% SUCROSE

POTATO WATER

POTATO OSMOSCOPE

3 STUDY OF OSMOSIS BY THISTLE FUNNEL EXPERIMENT

Objective To demonstrate the phenomenon of osmosis by ‘ istle Funnel

method’.

Requirements

1. istle funnel 2. Cellophane paper or goat’s bladder 3. Water 4. read or rubber band 5. Sugar solution (10%) 6. Beaker 7. Stand.

5

Procedure

1. Take a thistle funnel and close its wide mouth with goat’s

bladder or cellophane paper and tie it securely with the thread

or rubber band as shown in the figure. 2. Pour 10% sugar solution in the inverted funnel till it reaches

upto the middle of the vertical tube. 3. Dip the inverted funnel in a beaker containing water. 4. Fix the funnel on a stand holding the vertical tube in position. 5. Mark the initial level a solution in the tube. 6. Leave the apparatus as such for a while and then observe.

STAND WITH HOLDER THISTLE FUNNEL

BEAKER

PURE WATER SUGAR SOLUTION

CELLOPHANE

PAPER OR GOAT'S BLADDER

THISTLE FUNNEL EXPERIMENT


1. A er sometime the level of solution in the vertical tube of the

thistle funnel starts rising. 2. is explains that the water molecules from pure water of the

beaker move into the solution in the thistle funnel due to the

phenomenon of osmosis through a semi permeable

membrane (goat’s bladder or cellophane paper).

6

4 STUDY OF DIFFUSION USING KMnO4

Objective To demonstrate the phenomenon of ‘diffusion’.

Requirements

1. Beaker 2. Water 3. Potassium permanganate (KMnO4) or copper sulphate (hydrated).

Procedure

1. Take a beaker and fill the beaker more than half with distilled water. 2. Place a small crystal of potassium permanganate of copper

sulphate at the bottom of the beaker and observe.

Observation

1. e crystal starts dissolving immediately and colour the water slowly. 2. A er the whole of the crystal is dissolved, the water gets

uniformly coloured.


1. e above experiment demonstrates that when there is no

intervening partition, most molecules mix (diffuse) into each

other till they thoroughly make homogenous mixture. 2. Here it shows the diffusion of solid into the liquid medium. 3. In living processes, this phenomenon of diffusion

holds great importance for the movement of solutes. 4. It is a passive process without involvement of metabolic energy.

LOW PARTIAL PRESSURE OF DYE PURE WATER

HIGH PARTIAL PRESSURE OF DYE

DEMONSTRATION OF DIFFUSION

7

5 STUDY OF ABSORPTION OF WATER

Objective To demonstrate the phenomenon of absorption of water.

Requirements

1. Potted plant of tomato or balsam 2. Knife 3. Rubber tubing 4. A narrow glass tube 5. Stand 6. Water

Procedure

1. Take a plant of balsam or potato and water it thoroughly. 2. Cut off the top of the plant just above the soil a er the excess

of water has drained off. 3. Connect the cut stump to a narrow glass tube with the help of

rubber tubing. 4. Seal the joints with gra ing wax. 5. Pour a little water in the tube and mark the initial level. 6. e upper surface of water in the tube should be covered with

oil drop to avoid surface evaporation. 7. Keep the apparatus as such for sometime to make the observation.

Observation e water level rises in the glass tube.


1. e water level rises due to absorption of water from the soil through the

roots which create a hydrostatic pressure called as root pressure.

2. e phenomenon of absorption due to root pressure can also be

demonstrated by fitting a manometer instead of the vertical tube.

8

Precautions

1. e potted plant should be well watered. 2. e plant should be cut with a sharp knife a few centimeters

above the soil. 3. e whole set up should be made air tight by applying wax at the joints.

STAND WITH HOLDER

GLASS TUBE

RUBBER JOINT STUMP

PHENOMENON OF ABSORPTION OF WATER

6 STUDY OF TRANSPIRATION BY BELL JAR METHOD

Objective To demonstrate the phenomenon of Transpiration by bell jar method.

Requirements

1. A bell jar 2. A glass plate 3. Oil cloth 4. Grease 5. read and 6. A small potted plant.

Procedure

1. Take a well watered potted plant. 2. Cover the area of the soil which is open with an oil cloth or

cellophane paper to prevent evaporation of water.

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3. Place the pot on the glass plate and cover it with a bell jar. 4. Leave the apparatus as such for sometime and then observe.

Observation Small drops of water start appearing on the inner side of the bell jar.


1. e drops of water are the condensed water vapours which

have been transpired through the stomatal openings from the

ventral side of the leaf of the potted plant. 2. Transpiration is a phenomenon of loss of water from the aerial

parts of the plant in the form of water vapour.

Precautions

1. e apparatus should be air tight. 2. e potted plant should be thoroughly watered. 3. e open soil surface should be well covered.

o

o

o o

o o

o

o o

o o o

o o o

o o o

o

WATER DROPLETS

BELL JAR

PLANT

OIL CLOTH

GLASS PLATE

BELL JAR EXPERIMENT

10

7 STUDY OF TRANSPIRATION BY COBALT CHLORIDE

Objective To compare the rate of Transpiration from the two surfaces of

dorsiventral leaf of a plant by cobalt chloride method.

Requirements

1. A potted plant with dorsiventral leaves 2. Filter paper 3. Cobalt chloride solution (5%) 4. Glass slides 5. read.

Procedure

1. Dip a filter paper in slightly acidic 5% cobalt chloride solution. 2. Dry it thoroughly. 3. Now, take a plant and select a healthy dorsiventral leaf. 4. Clean both dorsal and ventral surfaces with dry cotton. 5. Carefully place the dry cobalt chloride strips on both upper

and lower surfaces of the leaf and immediately cover them

with dry clean glass slides. 6. Press them together and tie the slides with thread or rubber band. 7. Leave the set up as such for some time and observe.

Observation It is observed a er sometime that the dry blue coloured cobalt chloride

strip which was put on the lower side turns pink faster as compared

with one on the upper surface which takes a longer time to do so.


1. e observation infers that the loss of water from the lower surface

is comparatively much higher than from the upper surface. 2. It is due to the presence of higher number of stomata per unit

area on the lower surface than those on the upper surface.

11

3. More water vapours are released from the lower surface which hydrates the dry cobalt chloride strip and it turns from

blue to pink (CoCl2 2 H2O or CoCl2 4 H2O). 4. On the upper surface only cuticular transpiration takes place.

Precautions

1. e cobalt chloride paper should be securely placed under

the glass slides so that it is not in direct contact with air. 2. e experimental setups should not be placed in too windy or

humid surroundings which will hinder the rate of transpiration.

SLIDES HOLDING CoCl2 PAPERS

STUDY OF TRANSPIRATION

8 STUDY OF TRANSPIRATION BY GANONG’S POTOMETER

Objective To demonstrate the rate of transpiration by Ganong’s potometer.

Requirements

1. Ganong’s potometer 2. A leafy shoot cut under water 3. Vaseline or melted wax 4. Beaker 5. Water coloured with a drop of saffranine.

12

Apparatus—Ganong’s potometer

1. ‘Ganong’s potometer’ consists of a horizontal glass tube

which is graduated. 2. It is connected to a wide vertical tube and a reservoir on one

side, whereas it is bent downwards on the other end having a

small hole on the lateral side. 3. ere is a glass stopper below the reservoir. 4. e whole apparatus is fixed on a wooden stand.

PLANT TWIG

WATER RESERVOIR

AIR BUBBLE

BEAKER

HOLE

STAND

GANONG'S POTOMETER EXPERIMENT

Procedure

1. Fill the Ganong’s potometer completely with coloured water. 2. Choose a healthy leafy twig of a plant and cut it under water. 3. Fix the twig in the wide vertical tube through a hole in the cork. 4. Dip the other end of horizontal tube in a small beaker containing water.

5. e whole apparatus is to be made air tight by applying

vaseline or melted wax. 6. To start the experiment, bring the bent tube end above water

level in the beaker and introduce a single air bubble in the

tube with the help of the finger. 7. Place back the tube in the beaker. 8. Keep the whole set up in bright sunlight and observe.

13

Observation

1. In a short while, the introduced air bubble starts moving

towards the cut end of the twig. 2. Repeat this procedure two to three times and take out the

average rate of transpiration.

Calculations

e readings can be put in a tabulated form and the rate of

transpiration can be calculated.

S.N Distance Travelled Time Taken Rate of Transpiration

‘d’ ‘t’ ‘d/t’

1. 13 cm 5 sec. 13/5

2. 14 cm 5 sec. 14/5

3. 16 cm 5 sec. 16/5 e rate of transpiration will be about 14.33 cm in 5 sec.


1. As the plant twig is in direct sunlight, it starts transpiring

water through the stomata. 2. is results in creation of a suction force and water is sucked in

the cut end. 3. e water moves thereby in the horizontal tube taking the

bubble along with it. 4. is gives us the readings in the Ganong’s potometer.

Precautions

1. e twig should always be cut obliquely under water. is increases the

surface area of the cut surface and also no air bubble enters the twig. e apparatus should be absolutely air tight.

14

9 STUDY OF NECESSITY OF LIGHT FOR PHOTOSYNTHESIS

Objective To demonstrate that light is necessary for photosynthesis.

Requirements

1. A potted plant 2. Petri dish 3. Test tube 4. Alcohol (70%) 5. Iodine solution (KI) 6. Black papers 7. Spirit lamp.

Procedure Destarching

1. Take a healthy potted plant and place it in dark for about 72

hours so that the leaves become free from starch. 2. Choose a broad, healthy leaf on the plant and cover a portion of it on

both sides with black paper as shown in the figure with cello tape.

3. Keep the potted plant with the covered leaf in sunlight for a few hours. 4. Detach the covered leaf from the plant and test it for the

presence of starch.

Starch Test

1. e leaf to be tested is transferred into boiling water to kill all the cells. 2. Now boil the leaf in alcohol in a water bath till it becomes

dull-white due to the removal of chlorophyll. 3. Transfer it back to water, wash it thoroughly and add iodine solution.

Observation

e portion of leaf which was covered does not change colour,

whereas the portion which was uncovered turns blue-black.

15


e portion of the leaf which was not covered received all the factors

necessary for photosynthesis. erefore, that part could only

photosynthesis whereas, the one which was covered could not

manufacture food. e presence of starch gave the positive test with

iodine, i.e., turned to blue-black colour. Photosynthesis is the process of manufacture of food by the green parts of the plant (especially the leaves) in the presence of sunlight

and chlorophyll with the help of CO2 and water.

6CO +6H O Sunlight C H 12

O 6 + 6 O 2

" 2

2

Chlorophyll

6

! BLACK PAPER

BLUE BLACK

BROWN

EXPERIMENTAL LEAF LEAF AFTER STARCH TEST

10 STUDY OF NECESSITY OF CO2 FOR PHOTOSYNTHESIS

Objective

To demonstrate that CO2 is essential for the process of

photosynthesis (Moll’s half leaf experiment).

Requirements

1. A potted plant with healthy leaves 2. A wide mouthed bottle 3. A split cork 4. KOH solution 5. Iodine solution (KI) 6. Beaker 7. 70% alcohol 8. Spirit lamp

16

9. Test tube 10. Wax or vaseline.

Procedure

1. Take a potted plant and destarch the leaves by placing it in

dark for about 72 hours. 2. Put a little KOH solution in the wide mouthed bottle. 3. Now, insert one half of a leaf of the potted plant still attached to

the plant into the bottle with the help of the split cork and mark the

apparatus air tight with wax or vaseline as shown in the figure. 4. Keep the set up in sunlight for few hours. 5. A er the given time, detach the experimental leaf and boil in

alcohol till it decolorises. 6. Wash it in water and then test with iodine.

POTTED PLANT

BLUE-BLACK STARCH FORMED

NO STARCH

KOH

MOLL'S HALF LEAF EXPERIMENT


1. e portion of the leaf which was outside the bottle turned blue-black,

whereas the portion inside the bottle did not show colour change.

2. is demonstrates that CO2 is necessary for photosynthesis as enclosed portion of the leaf got all the factors necessary for

photosynthesis except CO2 and, thus, did not produce starch, resulting in negative test with iodine solution.

17

3. e portion outside got all the factors necessary for photosynthesis

including CO2, therefore, produced starch and turned blue-black.

4. is proves that CO2 is necessary factor for photosynthesis.

Precautions

1. e apparatus should be made air tight so that outside CO2

may not enter the bottle. 2. e leaves must be destarched properly before starting

with the experiment.

11 STUDY OF NECESSITY OF

CHLOROPHYLL FOR PHOTOSYNTHESIS Objective To demonstrate that chlorophyll is essential for photosynthesis.

Requirements

1. A potted plant with variegated leaves like coleus and croton 2. Water bath 3. Alcohol or methylated spirit 4. Iodine solution 5. Petridish

Procedure

1. Take a plant with variegated leaves, having some green and

non-green areas. 2. Destarch the leaves by placing the potted plant in dark for 2–3 days. 3. A er 2–3 days, place the plant in the sunlight for 2 hours. 4. Pluck a leaf from the plant and make its sketch on a paper. 5. Carefully mark the distribution of chlorophyll in the leaf. 6. Test the leaf for the presence of starch.

Test for Starch

1. e leaf to be tested is transfered into boiling water to kill all the cells.

18

2. Now, boil the leaf in alcohol in a water bath till it becomes

dull-white due to the removal of chlorophyll. 3. Transfer it back to water, wash it throughly and add iodine solution.

Observation Green portions of the leaf turn blue-black indicating the presence

of starch while the non-green portions of the leaf turn brown

indicating that starch has not been formed.

WHITE

GREEN

BROWN

BLUE-BLACK

NECESSITY OF CHLOROPHYLL FOR PHOTOSYNTHESIS

Inference Since only green portions of the plant show blue-black colour, it is

inferred that chlorophyll is essential for photosynthesis.

12 STUDY OF PHOTOSYNTHESIS—

INVERTED FUNNEL EXPERIMENT Objective

To demonstrate the evolution of O2 during photosynthesis by

inverted funnel method.

Requirements

1. Beaker 2. Funnel with a short stem 3. A test tube

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4. Hydrilla plant 5. Pond water 6. Pyrogallol.

Procedure

1. Fill the beaker more than half with pond water. 2. Put some Hydrilla plant twigs at the bottom of it and cover

them with inverted funnel. 3. Cut ends of the plant should be introduced into the stem of the funnel. 4. It should be seen that the water level in the beaker should be

above the upper end of the funnel. 5. Invert a test tube filled with water over the stem of the funnel. 6. Mark the level of water in the test tube and keep it in bright

sunlight for observation.

OXYGEN

TEST TUBE

AIR BUBBLES

BEAKER

FUNNEL

HYDRILLA PLANT TWIG

INVERTED FUNNEL EXPERIMENT

Observation

1. Air bubbles start coming out from the cut end of the Hydrilla twigs. 2. e bubbles collect at the top of the water level in the test

tube as a result water level falls down.

20

3. On dissolving pyrogallol in water, the level of water rises, as it

absorbs the gas collected above the water level in the test tube.


1. e above observation shows that gas produced is oxygen

which came out of the plant due to photosynthesis. 2. Oxygen is produced due to photoxidation of water in the

presence of sunlight, chlorophyll and CO2.

6CO +6H O Sunlight C H 12

O 6 + 6 O 2

" 2

2

Chlorophyll

6

! 13 STRUCTURE OF HUMAN URINARY SYSTEM

Objective To study the structure of the urinary system of human.

Requirements Model or chart showing external structure of human urinary system.

Procedure and Observation Study the given chart or model carefully. Observe each part, draw,

label and write comments on the structure.

Structure Urinary system consists of the following organs

1. A pair of kidneys 2. Ureters 3. Urinary bladder 4. Urethra

Kidney Kidneys are a pair of reddish brown bean-shaped structures

found in our abdomen.

21

Ureter A tube arises from the notch (hilum) in the median surface of each kidney. Ureters carry the urine from kidneys to the urinary bladder.

Urinary bladder e ureters, in turn, are connected to a large sac called the urinary bladder.

Urethra Leading from the bladder is another muscular tube called the

urethra, which works as the outlet passage.

ADRENAL GLAND KIDNEY RANAL ARTERY RENAL VEIN

URETER

URINARY BLADDER

HUMAN EXCRETORY SYSTEM

14 STRUCTURE OF HUMAN HEART

Objective To study the structure of human heart.

Requirements Model or chart showing internal structure of human heart.

22

Procedure and Observation Study the given model or chart. Observe each part, carefully. en

draw, label and write comments on the structure.

SUPERIOR VENA CAVA

AORTA

PULMONARY ARTERY

PULMONARY VEIN

LEFT ATRIUM BICUSPID VALVE RIGHT ATRIUM

SEMILUNAR VALVES TRICUSPID VALVES

LEFT VENTRICLES

RIGHT VENTRICLES

INFERIOR VENA CAVA

HUMAN HEART INTERNAL STRUCTURE

Internal Structure

1. Heart has four chambers—two auricles and two ventricles. 2. Auricles are two upper chambers (le and right), thin

walled and separated by inter auricular septum. 3. e walls of auricles are thin. 4. Right auricle receives deoxygenated blood from the body by

two large veins. 5. Ventricles are two lower chambers thick walled and separated by thick

interventricular septum. Right ventricle however has thinner walls.

6. e right ventricle pumps blood to lungs through pulmonary

artery and le ventricle supplies blood to the body through aorta. 7. e heart has four valves. ey permit the flow of blood in

one direction only. So they prevent back flow of blood.

23

15 STRUCTURE OF HUMAN KIDNEY

Objective To study the structure of human kidney.

Requirements A model or chart showing internal structure of human kidneys.

Procedure and Observation Observe carefully each part of the structure in the given model or chart. Study and then draw the labelled diagram and write comments on the same.

RENAL CORTEX

RENAL MEDULLA

RENAL PAPILLA

RENAL ARTERY

RENAL VEIN

RENAL PELVIS

URETER

RENAL PYRAMIDS

HUMAN KIDNEY INTERNAL STRUCTURE

Internal Structure L.S. of a kidney shows three main regions

1. Outer cortex 2. Medulla in the middle

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3. Internal renal pelvis 4. Outer Cortex

(a) e cortex is dark red in colour which is covered by a

fibrous capsule. (b) It looks granular due to the presence of nephrons. (c) Nephrons are structural and functional unit of the kidney.

5. Medulla (a) It is light-red in colour, subdivided into many conical

renal pyramids. (b) e apex of each renal pyramid forms the renal medulla

deep to the renal cortex. (c) ese renal pyramids are aligned with their bases

towards the cortex. 6. Renal Pelvis

(a) Renal pelvis is the funnel like dilated proximal part of the

ureter in the kidney. (b) e major function of renal pelvis is to act as a funnel for

urine flowing to the ureter, i.e., urine flows from the

kidney to the urinary bladder through it.

16 STRUCTURE OF HUMAN BRAIN

Objective To study the structure of human brain.

Requirements Model or a chart showing external structure of human brain.

Procedure and Observation Study the given chart or model carefully. Observe each part, draw,

label and write comments on the structure.

Structure

1. Human brain is most developed as compared to all other

animals in the animal kingdom. 2. It is located in the head protected by bony cranium and its coverings.

25

3. e meninges, which are continuous with the spinal cord are (a) Outermost duramater (b) Middle arachnoid and (c) Innermost piamater.

4. e spaces between the membranes are filled with cerebro-spinal fluid. 5. In most parts of the brain, the grey matter containing the nerve

cells is outside the white matter made up of fibres of nerve cells.

e brain can be studied in 3 parts 1. Fore brain 2. Mid brain and 3. Hind brain 4. Fore brain: It consists of

(a) Cerebrum (b) Olfactory lobes and (c) Diencephalon. (d) Cerebrum

i. It is the largest part of the brain divided into right

and le cerebral hemispheres. ii. ese are connected together by a sheet of nerve

fibres called corpus callosum. iii. e grey matter which is outside is highly

convoluted with ridges and furrows. iv. is part of the brain is seat of intelligence, thinking,

memory, reasoning, perception and stimulus interpretation. (e) Olfactory lobes

i. ese are a pair of small club shaped solid structures

lying on the lower surface of cerebral hemisphere.

ii. ese are related with the sense of smell. (f) Diencephalon

i. It is concealed by the cerebrum. ii. It has two parts— alamus and hypothalamus.

iii. alamus relays some of the sensory impulses, whereas

hypothalamus coordinates autonomic activities.

5. Mid Brain: It connects the fore brain to hind brain and

controls muscle toning, some motor activities. 6. Hind Brain: It consists of

(a) Cerebellum (b) Medulla oblongata.

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(c) Cerebellum i. It lies below cerebrum and above medulla oblongata. ii. e white matter appears like branching tree. iii. It has numerous furrows but no convolutions. iv. It maintains posture, equilibrium and muscular toning.

(d) Medulla oblongata i. It is the lowest part of the brain. ii. Oblongata continuing into spinal cord. iii. It has white matter on the outer side and grey matter

on the inner side. iv. e roof of medulla contains a choroid plexus

where cerebrospinal fluid is formed. v. Medulla oblongata has cardiac centre,

respiratory and vasomotor centre.

CEREBRUM

CEREBELLUM PONS

MEDULLA OBLONGATA

HUMAN BRAIN EXTERNAL VIEW

17 STRUCTURE OF HUMAN BLOOD CELLS

Objective Identification of different types of blood cells under the microscope.

Requirements Permanent slide of the cells of blood, microscope.

27

Observation and Comments e permanent slide of blood shows the following features

1. Erythrocytes (Red blood corpuscles or RBCs) (a) Red in colour. (b) Larger in number (c) Biconcave disc-like structures (d) Anucleated.

2. Leucocytes (White blood corpuscles or WBCs) (a) Fewer in number as compared with RBCs. (b) Bigger in size than RBC. (c) Colourless, irregular or oval in shape. (d) ey are of two major kinds

i. Granulocytes—having distinct granules in the cytoplasm. ii. Agranulocytes—do not have granules.

Granulocytes Granulocytes are of three types

1. Eosinophils (a) ey have bibbed nucleus. (b) Cytoplasmic granules stain orange red with acid dye (Eosin) (c) Engulf particles. (d) 60–300 per ml of blood.

2. Basophils (a) Nucleus has two or more lobes. (b) Affinity for basic dyes and stain blue black with them. (c) Found in small numbers, 35–100 per ml of blood.

3. Neutrophils (a) Nucleus is polymorphic, with three to five lobes. (b) Found in large number, 400–500 per ml of blood. (c) Stain with neutral dyes. (d) Phagocytic in nature.

Agranulocytes Agranulocytes are of two types

1. Lymphocytes (a) Small blood cells with large indented nucleus. (b) Number ranging from 1500–2000 per ml of blood. (c) ey are irregular in shape. (d) Migrate through the walls of the blood capillaries into the

tissues by the process of diapedesis.

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2. Monocytes (a) ey are bigger cells having larger cytoplasm. (b) Nucleus is kidney shaped. (c) 200–700 per ml of blood in number. (d) Phagocytic in nature.

3. Patelets (a) ey are colourless, non-nucleated and irregular

fragments of cells. (b) ey have a very short life-span of 3–5 days. (c) In an adult, these number from 200,000 to 400,000 per cu

mm of blood. (d) ey help in the clotting of blood.

RBC PLATELETS

EOSINOPHIL BASOPHIL NEUTROPHIL

MONOCYTE LYMPHOCYTE

HUMAN RBC AND WBC CELLS

18 STRUCTURE OF HUMAN EAR

Objective To study the structure of human ear.

Requirements Model or a chart showing the structure of human ear.

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Procedure and Observation Study the given chart or model. Observe, draw, label and write

comments upon the structure.

Structure Ear is the organ for hearing and equilibrium. e ears in human

beings are present on the two lateral sides of the head. Each ear is

divided into three parts—the external, middle and the inner ear.

External Ear

1. is is the outer part of the ear consisting of trumpet-shaped

ear lobe, pinna which is carlilagenous and skin covered. 2. It is meant to collect the sound waves and direct them to the

middle ear through a canal called the auditory meatus. 3. e canal is lined with cerumenous glands which secrete a waxy

material called cerumen which entangles the foreign bodies.

4. Fine hair are also present throughout the inner lining of the

auditory canal which also trap the unwanted material to enter

into the middle ear. 5. A thin obliquely placed membrane called the tympanic

drum or membrane lies between the external and middle

ear. Sound waves striking against it cause it to vibrate.

SEMI CIRCULAR CANALS

MALLEUS INCUS STAPES AT OVAL WINDOW ROUND WINDOW CHOCLEA

EAR DRUM

EUSTACHIAN TUBE

PINNA

HUMAN EAR INTERNAL STRUCTURE

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Middle Ear

1. It is represented by a ‘tympanic cavity’ which lodges three

tiny bones called the ear ossicles. 2. e ear ossicles are the malleus (hammer shaped), incus (anvil

shaped) and stapes (stirrup shaped). 3. e malleus is placed close to ear drum while stapes lies

against small membrane covered oval window—fenestra

ovalis opening into the inner ear. 4. Another opening, the round window connects the middle ear

and the inner ear. 5. A tube called Eustachian tube connects the middle ear to the pharynx of

the mouth to equalise the air pressure on both sides of the ear drum.

Internal Ear Membranous Labyrinth

1. It consists of a membranous labyrinth enclosed within

a bony labyrinth. 2. Membranous labyrinth consists of three semi circular canals,

vestibule and cochlea. 3. Semicircular canals are a set of three fluid filled canals

arranged at right angles to each other in three different

planes, so that one is horizontal and two are vertical. 4. One end of each canal enlarges into a swelling called the

ampulla containing sensory cells to maintain body balance. 5. Nerve fibres from them join the auditory nerve.

Vestibule

1. Vestibule consists of utriculus and succulus. 2. It joins the semi circular canals to the cochlea. 3. is is concerned with static balance.

Cochlea

1. e cochlea arises from the lower side of the sacculus. 2. It is spiral shaped tube with two and a half turns. 3. Its inner cavity is divided into three parallel tubes,

separated by membranes.

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4. e outer and inner canals are filled with perilymph,

whereas the middle one is filled with endolymph. 5. e middle canal has the sound sensitive system called the ‘organ of

Corti’ containing receptor cells which transform sound vibrations into

nerve impulses which are sent to the brain via the auditory nerve.

19 STRUCTURE OF HUMAN EYE

Objective To study the structure of human eye.

Requirements Model or a chart showing the structure of the human eye.

Procedure and Observation Study the given chart or model carefully. Observe, draw, label

and write comments upon the structure.

Structure Human beings are provided with two eyes which are situated in

the deep bony cavities called the orbits in front of the skull. Each

eye consists of the eye ball and accessory structures like the 1. eyelids 2. eyebrows 3. eyelashes 4. lacrymal glands etc.

Eyelids Upper and lower eyelids are protective movable parts which protect

the eye from excessive light, foreign particles and their blinking

spreads lubricating secretion over the eyeball.

Eyebrows A row of hair is present above the eyes to protect sweat, etc., from

falling into the eye.

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Eyelashes

ey are a row of short thick hair on the margin of the upper and lower

eyelids. ey protect the eye from foreign particles from falling into the eye.

Lacrymal Glands Each eye has a set of lachrymal glands at the upper, outer end of

the eye. ey produce a secretion-the lacrymal fluid which is spread

evenly on the eye ball, thus, lubricating it. Excessive lacrymal

fluid—the tears wash away dust particles. ey also have antiseptic

property as they contain enzyme—lysozyme.

SCLERA CHOROID

RETINA

CONJUNCTIVA VITREOUS

AQUEOUS HUMOR HUMOR

PUPIL YELLOW SPOT

IRIS

LENS

SUSPENSORY BLIND SPOT

LIGAMENT OPTIC NERVE

HUMAN EYE INTERNAL STRUCTURE

Structure of Eye Ball

1. Eye ball (a) Eye ball is embedded in a bony socket and is

suspended to the bones by six muscles. (b) Only the front, one sixth portion of the eye ball is exposed. (c) It is covered by three layers

i. Conjunctiva ii. Sclera and iii. Choroid

(d) Conjunctiva

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i. A thin membrane which covers the entire part of the eye. ii. It is continuous with the inner lining of the eyelids. iii. It is transparent, thin epithelial layer over the cornea.

(e) Sclera i. It is the outermost fibrous layer. ii. It is thick, white, non elastic covering of the eye ball

leaving the anterior most portion, the iris where

Sclera bulges as non-vascular, transparent, fiberous,

coat, covering the coloured part of the eye. iii. is is called the cornea.

(f) Choroid i. e middle layer of the eyeball is so , vascular and

thin which nurishes the eye, called the choroid.

ii. is layer completely encloses the eye ball leaving a

circular opening in front called the pupil. iii. Colour of the eye refers to the colour of the pupil. iv. e contraction and relaxation of circular and radial muscles

of the iris constrict or widen the diameter of the pupil

regulating the amount of the light entering into the eye.

v. Ciliary Body is the part of choroid arising from the

point just behind the junction of sclera and cornea. It

consists of ciliary processes and ciliary muscles. 2. Retina

(a) It is the innermost thin layer which is sensitive in nature

having senory cells—the rods and cones. (b) It receives the images of the objects focused by the lens. (c) e retina thins off and terminates behind the ciliary muscles. (d) Rods are sensitive to dim light are meant for night or dark vision. (e) ey contain a pigment called Rhodopsin. (f) Cones are sensitive to bright light and colour vision. (g) ey contain pigment Iodopsin.

3. Lens (a) It is transparent, biconvex, crystalline structure situated

behind the pupil. (b) e suspensory ligaments of the ciliary body hold this in position. (c) e contraction and relaxation of ciliary muscles change the

shape of the lens of viewing objects at different distances.

(d) e presence of lens divides the cavity of the eyeball into two

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chambers: i. Aqueous Chamber: Situated between cornea and

lens, filled with aqueous humour which supplies

oxygen and nutrients in addition to removal of wastes.

Keeps the lens moist and gives protection to the eye. ii. Vitreous Chamber: Lies behind the lens and is

filled with jelly—like vitreous humour. It maintains

the shape and protects the retina. 4. Yellow Spot: is is a small area on the retina which has

maximum number of cone cells. is is also called as Macula or

Fovea centralis. is is the region of best vision. 5. Blind Spot: It is the region on retina which is devoid of sensory

cells, therefore, no image is formed here. is is the point, where

the nerve fibres from all the sensitive cells of retina converge and

together leave the eyeball as optic nerve to reach the brain.

20 STRUCTURE OF ADRENAL GLAND

Objective Identification of the given endocrine gland with the help of a model

or chart and comment on it.

Requirements Models or charts.

Procedure

1. Observe the structures in the charts or in the form of models. 2. Draw labelled diagram. 3. Write comments on the given endocrine gland.

Observation

External structure

1. It is also known as suprarenal gland. 2. e paired adrenal glands are in the form of small, yellowish-

brown, flattened and wrinkled triangular cap-like structure. 3. Adrenal glands are located on the top of each kidney.

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Internal structure

1. Each adrenal gland enclosed in a connective tissue capsule. 2. Capsule comprises of two functionally distinct plants: a

superficially yellowish part called Suprarenal Cortex and

deeper brownish part, suprarenal medulla. 3. e volume of cortex is about ten times the medulla.

SUPRARENAL CORTEX

SUPRARENAL MEDULLA

HUMAN ADRENAL GLAND

21 STRUCTURE OF PANCREAS




Procedure


Observation Pancreas (Endocrine as well as exocrine gland)

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External structure

1. e gland consists of a head, neck, body and tail. 2. e head of the pancreas fit into the ‘C’ of curve of duodenum. 3. Its body extends to the le and its tail touches the spleen. 4. It appears in the form of a serious compound tubulo-alveolar gland. 5. Endocrine part of pancreas is in the form of numerous rounded

collection of cells that are embedded in within the exocrine cells. 6. Collection of cells are called pancreatic islets of Langerhans. 7. Each islet is separated from the surrounding alveoli by a thin

layer of reticular tissue.

Internal structure

1. e islets are richly supplied with blood vessels. 2. ree main types of cells can be distinguished in an islet:

a. Alpha cells, b. Beta cells and c. Delta cells 3. Alpha cells are arranged towards the periphery (cortex, beta cells near the

centre (medulla) and the delta cells are also placed at the periphery.

PANCREATIC ACINI ALPHA CELLS BETA CELLS

DELTA CELLS PANCREATIC ACINI

PANCREATIC ACINI AND ISLETS OF LANGERHANS

22 STRUCTURE OF PITUITARY GLAND




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Procedure


Observation Pituitary gland (Master gland)

HYPHOTHALAMUS NERVE FIBRE

BLOOD VESSELS

ANTERIOR PITUITARY

POSTERIOR PITUITARY

HUMAN PITUITARY GLAND

External structure

1. Pituitary is a small pea-shaped 1.5 g gland hanging from the

base of the brain. 2. It forms a link between the nervous system and the endocrine system.

3. It has three lobes—anterior lobe, intermediate lobe and posterior

lobe. Posterior pituitary is actually an outgrowth of the hypothalamus.

Internal structure

1. Histologically, the anterior pituitary is a highly vascular and

cellular structure. 2. Intermediate lobe of pituitary is poorly developed in the

human hypophysis. 3. Posterior pituitary is whitish lobe comprising about 1/4 of pituitary.

Histologically it consists of nerve fibres and neurological cells.

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23 STRUCTURE OF THYROID GLAND




Procedure


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HUMAN THYROID GLAND

FOLLICLE CELLS

COLLOID

BLOOD

CAPILLARY CONNECTIVE

TISSUE

Observation

External structure

1. yroid gland is a bilobed structure. 2. It is situated in the neck below the larynx on either side of

trachea ventrally. 3. Both lobes are connected by isthmus. 4. It is the largest endocrine gland weighing about 20g in an adult. 5. e gland consists of about three million spherical or oval

sac-like follicles.

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6. Each follicle about 200 mm in diameter, is lined by epithelial

cells.

Internal structure

1. Each follicle is lined by epithelial cells and contain a jelly-like

structure less material called colloid. 2. Occasionally, in between the basement membrane of follicle

and the lining of the follicular epithelium, some special large

cells occur called parafollicular cells. 3. Follicles are bound together by connective tissue that

contains blood vessels, lymphatics and nerve fibres.

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