Biology Std 10-Function and location Study notes
Plant Physiology
Organ
Lenticels
Cuticle
Mesophyll Cells
Location
On the surface of old, woody
stems
Wax like covering on
epidermis of leaves & green
stems
Between the epidermal cells
of the leaf.
Below the bark of the tree
Xylem
Veins of leaf, stem and leaves/
Innermost part of Vascular
bundles
Found in the veins of leaf,
stem and leaves /Periphery of
the Vascular Bundles
Special openings on the leaf
margin
Between the epidermal cells
of the leaf/ On either side of
stoma.
In the cytoplasm of green
plant cells
In the chloroplast
Colourless ground substance
present in the chloroplast
Minute openings(surrounded
by guard cells) occurring in
large number on the lower
surface of leaf
JN
Phloem
Hydathodes
Guard Cells
Chloroplast
Thylakoids/ Grana
Stroma
Stoma
Traps light energy with the
chloroplast present in them
for photosynthesis
Increases the girth of the
stem
Conducts water from the
roots to the aerial parts of
plant.
Translocates the prepared
food in the leaves to the
storage organs.
Guttation
Cambium
Function
Exchange of photosynthetic
and respiratory gases
Prevent Transpiration
Regulate the opening and
closing of the stoma
Photosynthesis
Site of Light Reaction
Site of light independent
reaction
Diffusion of photosynthetic
and respiratory gases ,
Transpiration
Circulatory System
Structure
1) Heart
Function
Pumps oxygenated blood to the
different parts of the body.
Protects the heart from
mechanical injury and shock.
Acts as a lubricant and reduces
friction for the beating of the
heart.
Keeps the tissues of the heart
moist.
3) Sino atrial node
Upper wall of right atrium.
Initiates the heart beat.
(S A node) or
Regulates the contraction of the
Pacemaker.
auricles.
4) Atrio Ventricular Bottom of the right auricle.
Regulates the contraction of the
node. (AV node)
ventricles.
5) Bundle of His
Arises from the A V node and It receives an impulse from the A V
consists of a left and right
node and transmits it to the Purkinje
branch which extends upto
fibres.
the apex of the heart.
6) Bicuspid valve or Between the left auricle and
Allows the blood to flow from the left
mitral valve.
ventricle of the heart.
auricle to the left ventricle and
prevents it from going back into the
auricle.
7) Tricuspid valve.
Between the right auricle and Allows the blood to flow from the
ventricle of the heart.
right auricle to the right ventricle and
prevents it from going back into the
auricle.
8) Chordae
Extend from the papillary
Keeps the tricuspid and bicuspid
tendinae.
muscles to the pointed ends of valves in position and prevents them
the cuspid valves.
from upturning.
9) Pulmonary
At the opening of the
Prevents backflow of deoxygenated
semilunar valve.
pulmonary artery which arises blood into the right ventricle.
from the right ventricle.
10) Aortic semilunar At the opening of the aorta
Prevents backflow of oxygenated
valve.
which arises from the left
blood into the left ventricle.
ventricle.
11) Coronary artery Arises from the aortic arch,
Supply oxygenated blood to the walls
near its base as it emerges
of the heart.
from the heart.
JN
2) Pericardial fluid
Location
Situated between the two
lungs in the thoracic cavity.
The apex is tilted towards the
left side.
Found in the pericardial
cavity, between the two
membranes of pericardium.
Excretory System
6) Proximal
convulated tubule
Location
Lie along the posterior
abdominal wall one on either
side of the vertebral column.
They arise from the renal
pelvis of the kidneys at the
hilum and the other end opens
into the urinary bladder.
Sac like structure situated in
the lower end of the abdomen
into which the other end of the
ureter opens.
Short, muscular tube arising
from the neck of the urinary
bladder and leading to the
outside.
Knot of capillaries present in
the cup of the Bowmans
capsule.
Lies in the cortex of the
kidney.
7) Loop of Henle
Present in the renal medulla.
8) Distal convulated
tubule.
9) Collecting duct
Present in the cortex of the
kidney.
Formed by the union of
collecting tubules passes
through the cortex , medulla
and opens into the pelvis of the
kidney.
2) Ureters
3) Urinary bladder
4) Urethra
JN
5) Glomerulus
Function
Excretion .
Osmoregulation.
Transports urine from the pelvis of
the kidney to the urinary bladder.
Temporary storage of urine.
Allows the passage of urine outside
the body.
Brings about ultrafiltration of urine.
Reabsorbs most water and much of
glucose and sodium and chloride
ions.
Absorption of water and sodium
ions.
Tubular secretion, Reabsorption of
remaining chlorides and some water.
Pours urine into the pelvis of the
kidney.
Structure
1) Kidney
Endocrine System
Structure
1) Adrenal gland
Adrenal
Cortex.
Location
Cap like structure above each
kidney.
Outer region of the adrenal
gland.
Adrenal
medulla.
3
Function
Secretes corticoidsGlucocorticoids.
mineralocorticoids.
Sex corticoids.
Secretes adrenaline which
Inner region of the adrenal
gland.
2) Thyroid gland
Situated on the lateral and
ventral sides of the trachea, just
below the larynx.
3) Pancreatic gland Below the stomach, at the loop
of the duodenum.
THE NERVOUS SYSTEM
Parts of a neuron
LOCATION
2.
NAME OF
STUCTURE
Perikaryon
1
/ cyton /
cell body
Dendrites
Axon
4.
Myelin sheath
Covering /surrounding the
axon
.5.
Nodes of Ranvier
6.
7.
Neurilemma
Terminal branches
/axon terminals
Unmyelinated gaps between
the myelin sheath.
Surrounding the myelin sheath
Posterior end of the axon.
8.
Synaptic bulb
Distal end of the terminal
branches
9.
Neurotransmitters
Found in the synaptic bulb.
Proximal part of a neuron
JN
SL.
NO
Secretes hormones like Glucagon
and insulin.
Glucagon increases blood sugar level
by converting glycogen into glucose.
Insulin controls the blood sugar level
by converting glucose into glycogen.
Attached to the hypothalamus or Anterior lobe of pituitary secretes
below the hypothalamus.
hormones like growth hormone and
tropic hormones such as TSH,
ACTH, LH, FSH.
Posterior lobe of pituitary secretes
hormones like Oxytocin and
Vassopressin.(ADH)
4) Pituitary gland
prepares the body in an
emergency situation for fight
or flight response.
Secretes thyroxine which regulates
the basal metabolic rate of the body.
Cytoplasmic projections of
cyton/ perikaryon
Long process of the cell body
FUNCTION
Typical cellular structure.
Centrosome absent.
Receives nerve impulses and
conducts it to the cyton.
Conducts nerve impulses away
from the cyton.
Prevents the mixing of nerve
impulses.
Increases the speed of nerve
impulse conduction.
Increases the speed of nerve
impulse conduction.
Protects the axon.
Receives nerve impulses
conducted through the axon and
transmits it to the next neuron.
Contains chemicals called
neurotransmitters (eg.
acetylcholine).When the nerve
impulse reaches the terminal
branches, neurotransmitters are
released by the synaptic bulb,
Neurotransmitters are released
10.
Synapse
Is the junction between the
terminal branches of one
neuron and the dendrites of the
adjacent neuron.
into the synapse by the synaptic
bulb. Hence these chemicals are
responsible for transmission of
nerve impulses from the
terminal branches of one neuron
to the dendrites of the next
neuron.
Neurotransmitters are released
in to the synapse, which sets off
a wave of excitement in the next
neuron.
Types of neurons
2.
Motor neuron
Association neuron
Extends from receptors( sense
organs) to Central Nervous
System
Extends from the Central
Nervous System to the
effectors (muscles and glands)
Found in the spinal cord and
brain
Transmits nerve impulses of
stimuli received from the sense
organs to brain or spinal cord
Transmits nerve impulses for
response from CNS to the
muscles and glands.
Interconnect the sensory
neuron and the motor neuron.
1. Sensory neuron
JN
THE BRAIN
A. Protective layers of the brain
1.
Meninges
Outer protective layer of the
brain
2.
Cerebro spinal fluid
(CSF)
Found between the layers of
the meninges.
Tough layer, hence protects the
internal delicate parts of the
brain.
It contains blood vessels and
so nourishes the brain
Serves as a shock absorber
Maintains constant pressure in
and around the brain.
Helps in exchange of nutrients
and waste products between
nerve tissue and blood.
B. Parts of the brain
1.
Cerebrum
Forebrain
Part of the fore brain and is
5
It is the seat of intelligence,
the largest part of the brain.
2.
Corpus callosum
Transverse band of nerve
fibres, internally joining the
two cerebral hemispheres.
3.
Diencephalon made
up of the
Hypothalamus and
the Thalamus
Between the two cerebral
hemispheres, just superior to
the mid brain.
Mid brain.
It relays sensory impulses from
the spinal cord to the thalamus.
It relays motor impulses from
the thalamus to the Spinal
cord.
1.
Mid brain
Between the anterior and
posterior part of the brain
memory, thinking, reasoning
and emotions
Centre for perception of
stimuli for vision, smell, taste
and hearing.
All voluntary activities are
initiated in the cerebrum.
Transmits nerve impulses from
the right cerebral hemisphere
to the left hemisphere and vice
versa.
Hypothalamus: Controls
pituitary gland, sleeping and
waking patterns, hunger and
thirst. Also regulates body
temperature.
Thalamus: interprets sensory
impulses such as pain, touch
and pressure.
JN
Hind brain
Located under the cerebrum
1.
Cerebellum
2.
Pons
Between the two lobes of the
cerebellum on the ventral
side.
3.
Medulla oblongata
Below the cerebellum
1. Tear glands
EYE
Under the upper eyelids, at the
upper, outer corner of the orbit
of the eye.
6
Maintains the body balance.
Coordinates the movements of
the skeletal muscles.
Transmits nerve impulses
across the two lobes of the
cerebellum, thus ensuring a
coordination of muscular
movements on both sides of
the body.
Controls the involuntary
activities such as breathing and
heart beat.
Also controls peristaltic
movements of the alimentary
canal.
Secretes tears- cleanses the eye
by washing away foreign
substances that may enter the
eye.
Contains lysozymes- this
protects the eye from infections.
Protects the surface of the eye.
Conjunctiva
Covering of the entire front
surface of the eye, continuous
with the inner eyelids.
3.
Sclera
4.
Cornea
Outermost white layer of the
eyeball.
Anterior, bulging and
transparent part of sclera.
Provides and maintains the
shape of eyeball.
Refracts the light rays as they
pass through it.
5.
Choroid
Middle layer of the eye, inner
to the sclera.
As it is pigmented, it absorbs
light rays and prevents total
internal reflection of the light
rays.
Blood vessels present here,
nourish the eye.
6.
Iris
Located between the lens and
the cornea.
It regulates the amount of light
entering the eyeball, by
increasing or decreasing the
diameter of the pupil.
It gives colour to the eye.
7.
Pupil
Opening seen in the center of
the iris.
8.
Ciliary body
Swollen portion of the choroid, Ciliary processes secrete
at the junction of the choroid
aqueous humour.
Ciliary muscles alter the shape
and iris.
of the eye lens for
accommodation.
9.
Suspensory ligaments
Extends from the ciliary
muscles to the eye lens.
Holds the eye lens in position.
Along with ciliary muscles alter
the shape of the eye lens for
accommodation.
10..
Retina
Innermost layer of the eyeball,
adhering to the choroid and
ending at the edge of the ciliary
body.
It is the photosensitive layer of
the eye.
Provides the screen for image
formation.
Rods
(contain a pigment
called Rhodopsin)
Present at the periphery of the
retina.
Respond to low light intensity
and so enable vision in dim
light.
Cones
(contain a pigment
Present mainly at the yellow
spot.
Are specialized for colour vision
and for vision in bright light.
JN
2.
It admits light rays into the
eyeball.
11.
called Iodopsin)
Optic nerve
12.
Lens
Located behind the iris and
pupil, supported by the
suspensory ligaments.
Refracts and focuses the light
rays on the retina.
Clear vision of both far and near
objects is obtained due to its
ability to change its focal length
with the help of the ciliary
muscles and suspensory
ligaments.
13.
Aqueous humour
In the anterior chamber,
between the lens and the
cornea
Keeps the cornea moist.
Protects the lens from
mechanical shocks
Helps in refraction of light rays.
14.
Vitreous humour
In the vitreous chamber,
Maintains the shape of the
between the lens and the retina. eyeball.
It refracts the light rays before it
reaches the retina.
It protects the retina.
15.
Yellow spot
On the retina, in line with the
horizontal axis of the eyeball.
It is the region of brightest and
sharpest vision as it contains the
highest concentration of cones.
16.
Blind spot
Opening lateral to the yellow
spot, where the optic nerve
leaves the eyeball.
This is an area of no vision,
since rods and cones are absent
here.
1.
JN
Leaves the eye at the blind spot Transmits nerve impulses from
and reaches the occipital centre the sensory cells (rods and
of the brain.
cones) of the retina to the visual
area (occipital region) of the
cerebrum for interpretation.
Ear pinna
2.
Auditory canal
3.
Tympanum / ear
drum
1.
Ear Ossicles
EAR
External ear
Either sides of the head.
Extends from pinna to the
tympanum.
Stretched tightly between the
external and middle ear.
Collects sound waves and
directs it into the auditory
canal.
Directs sound waves to the ear
drum / tympanum.
When sound waves strike its
surface, it vibrates. These
sound vibrations are then
transmitted to the middle ear.
Middle ear
Made up of three small bones. The 3 ossicles form a leverage
system. They amplify the
a. Malleus is hammer
8
shaped. Its handle rests on the
tympanum and the head rests
on the incus.
b. Incus- is the central small
bone and is anvil shaped.
c. Stapes- is stirrup shaped
and its base is attached to the
oval window.
Extends from the pharynx to
the cavity of the middle ear.
sound waves received from the
external ear and transmit these
sound vibrations to the internal
ear.
Eustachian tube
It equalizes the air pressure on
either sides of the ear drum.
3.
Oval window
On the inner boundary of the
middle ear and inner ear
The sound vibrations from the
stapes (middle ear) is
transmitted through the oval
window to the cochlea of the
inner ear.(this in turn sets the
fluid in the cochlea to vibrate)
4.
Round window
Below and a little behind the
oval window.
When the stapes transmits
vibrations to the oval window,
the round window moves
outwards. This enables the
fluid in the cochlea to move
freely.
2.
Inner ear (Membranous
labyrinth)
Bony canal made of two and
half spirals in the inner ear.
Found in the lower portion of
the labyrinth.
In the middle canal / median
canal/cochlear canal of the
cochlea.
Cochlea
2.
Organ of Corti
3.
Semi circular canals
Set of three fluid filled canals
arranged at right angles to
each other. Found in the
upper portion of the labyrinth.
4.
Vestibule
5.
Auditory nerve
Forms the central portion of
the labyrinth. It is made up of
two sacs called the Utriculus
and the Sacculus
Extends from the inner ear to
the temporal lobe of the
cerebrum.
JN
1.
Contains the Organ of Corti
which is responsible for
hearing.
Contains receptor cells which
transform sound vibrations
into nerve impulses. (It has
different areas suited to
interpret sounds of different
frequencies.)
Contains sensory cells
responsible for dynamic
balance.
Contains sensory cells
responsible for static balance.
Transmits nerve impulses from
the Organ of Corti to the
cerebrum.
Male Reproductive System
Organ
Location
Function
Contained in the thin walled
scrotum
Produces sperms & Hormone
Testosterone.
Seminiferous Tubules
Present in the lobules of the
testes
Spermatogenesis (Produces
sperms)
Interstitial Cells / Leydig Cells
Present as packing tissue in the
lobules of the testes, between
the seminiferous tubules.
Produces the male hormone
Testosterone
Epididymis
Fitting like a cap on the upper
pole of each+ testis.
Stores the sperms till they
mature & become motile
Vas Deferens
Connects the epididymis to the
urethra
Transports sperms from the
epididymis to the urethra.
Penis
Lies in front of the scrotum
Serves for passing out of both
semen and urine.
Seminal Vesicles
Between posterior surface of
urinary bladder & rectum.
To produce a sugary secretion
which provides energy to the
sperms.
Prostate Gland
Surrounds the Urethra, at the
base of the Urinary Bladder.
To produce an alkaline secretion
to neutralises the acidic vagina.
Bulbo urethral Gland or
Cowpers gland
Located beneath the prostrate
gland on either side of the
urethra.
Its secretion lubricates the end
of the penis during coitus.
JN
Testes
Female Reproductive System
Organ
Ovaries
Location
Upper pelvic cavity, one on
10
Function
Oogenesis, Ovulation &
each side of uterus
Secretion of Hormone
Progesterone & Oestrogen.
Extends laterally on each side of Site of fertilization /Picks up &
the uterus
transports the released ovum
into the uterus.
Oviducal Funnel
Mouth of oviduct, with finger
like projections called fimbriae
& just above the ovary.
Receives the released ovum and
pushes it into the oviduct.
Uterus
Pear shaped , hollow ,
muscular organ situated
between urinary bladder and
rectum.
Protects & nourishes the
developing embryo.
Endometrium
Innermost vascular layer of the
uterus
Thickens to receive the
fertilized egg and gets
discharged during the Menstrual
Phase.
Cervix
A small lower constricted part
of the uterus.
Enlarges during parturition
Vagina
A muscular tube starting from
lower end of the uterus to the
outside
Receives the penis during
coitus (intercourse)
JN
Oviduct / Fallopian Tube/
Uterine Tube
Corpus Luteum
Yellow remnants of the Graafian Produces hormones after
follicle after ovulation.
releasing the ovum.
Amnion
Surrounds the embryo except at
the thick umbilical cord.
Contains the foetus and the
amniotic fluid.
Amniotic Fluid
A fluid within the amnion ,
surrounding the foetus
Protects the embryo against
mechanical jerks, Keeps even
pressure around the embryo,
Prevents sticking of the foetus
to the amnion.
Chorion
Second layer of the foetal
membranes.
Supports the amnion
Allantois
Forms the Villi of the placenta
from the foetal side.
Helps in diffusion of substances
from the mother to the foetus &
foetus to mother .
Placenta
A disc like structure attached
to the uterine wall
Diffusion of substances from the
mother to the foetus & foetus to
mother /Also acts as an
11
endocrine gland
Umbilical Cord
A cord containing blood vessels
connecting the placenta to the
foetus.
The only blood vascular
connection between foetus and
uterine wall. Hence transports
substances from mother to
foetus and vice versa.
JN
***************************************************************
12
