Frogs are found near fresh water and damp places. The common Indian frog is Rana tigrina. It moves by leaping or walking on land, and swimming using powerful hindlimbs. Frogs are carnivorous and make croaking noises. They are cold-blooded. Frogs have digestive, circulatory, respiratory, excretory and nervous systems that allow them to function on land and in water. Their morphology includes features like webbed digits and mucous glands that aid their lifestyle.
The primitive blueprint for the heart and circulatory system emerged with the arrival of the third mesodermal germ layer in bilaterians. Since then, hearts in animals have evolved from a single layered tube to a multiple chambered heart in due course of time.
The primitive blueprint for the heart and circulatory system emerged with the arrival of the third mesodermal germ layer in bilaterians. Since then, hearts in animals have evolved from a single layered tube to a multiple chambered heart in due course of time.
Sense organs are the specialized organs composed of sensory neurons, which help us to perceive and respond to our surroundings. There are five sense organs – eyes, ears, nose, tongue, and skin.
External receptors (exteroceptors): sense organs for touch, smell, taste, sight and hearing.
Internal receptors (interocepyors): these sense organs found in the body which detect the temperature, pain, hunger, thirst, fatigue and muscle position.
The chordates are named for the notochord: a flexible, rod-shaped structure that is found in the embryonic stage of all chordates and also in the adult stage of some chordate species.
It is located between the digestive tube and the nerve cord, providing skeletal support through the length of the body.
In some chordates, the notochord acts as the primary axial support of the body throughout the animal's lifetime.
The vertebrate brain
The vertebrate brain is the main part of the central nervous system. The brain and the spinal cord make up the central nervous system,
In most of the vertebrates the brain is at the front, in the head. It is protected by the skull and close to the main sense organs.
Brains are extremely complex and the part of human and animal body. The brain controls the other organs of the body, either by activating muscles or by causing secretion of chemicals such as hormones and neurotransmitters.
Muscular action allows rapid and coordinated responses to changes in the environment.
The brain of an adult human weights about 1300–1400 grams .
In vertebrates, the spinal cord by itself can cause reflex responses as well as simple movement such as swimming or walking. However, sophisticated control of behaviour requires a centralized brain.
The structure of all vertebrate brains is basically the same.
At the same time, during the course of evolution, the vertebrate brain has undergone changes, and become more effective.
In so-called 'lower' animals, most or all of the brain structure is inherited, and therefore their behaviour is mostly instinctive.
In mammals, and especially in man, the brain is developed further during life by learning. This has the benefit of helping them fit better into their environment. The capacity to learn is seen best in the cerebral cortex.
Three principles
The brain and nervous system is essentially a system which makes connections. It has input from sense organs and output to muscles. It is connected in several ways with the endocrine system, which makes hormones, and the digestive system and sex system. Hormones work slowly, so those changes are gradual.
The brain is a kind of department store. It has, all inter-connected, departments which do different things. They all help each other gather senses.
Much of what the body does is not conscious. Basically, much of the body runs on automatic (breathing, heart beat, hungry, hair growth) adjusted by the autonomic nervous system. The brain, too, does much of its work without a person noticing it. The unconscious mind refers to the brain activities which are hardly ever noticed.
Evolutionary change in heart of vertebrates
Heart is situated ventral to the oseophagus in the pericardial section of the coelom.
Heart is a highly muscular pumping organ that pumps blood into arteries and sucks it back through the veins.
In vertebrates it has undergone transformation by twisting from a straight tube to a complex multi-chambered organ.
. There has been an increase in the number of chambers in heart during evolution of vertebrates.
The heart is covered by a transparent protective covering, called pericardium. It is a single layer in fish.
Within pericardium there is a pericardial fluid, protects the heart from the external injury.
The evolution of the heart is based on the separation of oxygenated blood from deoxygenated blood for efficient oxygen transport.
Embryonic Digestive Tract:
Archenteron:
The embryonic archenteron becomes the lining of the adult digestive tract and of all its derivatives.
Splanchnic mesoderm adds layers of connective tissue and smooth muscles around the archenteron.
Ectodermal invagination of the head forms the stomodaeum leading into oral cavity, and a similar mid-ventral ectodermal invagination forms proctodaeum, which leads into the hindgut.
The stomodaeum becomes the adult buccal cavity and gives rise to teeth enamel, epithelial covering of tongue, glands, e.g., mucous, poison and salivary, etc., and Rathke’s pouch of anterior pituitary gland.
The proctodaeum forms either a small terminal part of the cloaca in lower vertebrates and rectum in mammals.
Digestive Tract of Adult:
Following outgrowths arise from the digestive tract- oral glands, Rathke’s pouch, thyroid gland, gill-clefts, tympanic cavity, thymus and other glands of gill-clefts, trachea, lungs, swim bladder, liver, pancreas, yolk sac, and urinary bladder.
Histology: The wall of the alimentary canal is made of four concentric layers.
An outermost visceral peritoneum or serous coat is made of mesothelial cells and thin layer of connective tissue. It is lacking in the oesophagus.
(ii) Below this is a muscular layer formed of smooth muscle fibres arranged in outer longitudinal and inner circular muscle fibres. Between the two layers of muscles is a network of nerve cells and nerve fibres of the autonomic nervous system, known as myenteric plexus or plexus of Auerbach.
(iii) Beneath the muscle layer is a submucosa made of connective tissue having elastic fibres, fat, blood and lymph vessels, nerve cells and fibres glands.
(iv) The innermost layer is a mucosa composed of three regions:
(a) Outer-most narrow muscularis mucosa of outer longitudinal and inner circular smooth muscle fibres.
(b) Middle thin layer of lamina propria of connective tissue, blood vessels, nerves and nodules of lymphatic tissue, and
(c) A basement membrane supporting a layer of columnar epithelial cells which are often glandular and ciliated.
class 11 NEET
structural organization in animal
topic FROG
morphology ,anatomy, in detail
general characteristics
digestive system
respiratory systems
circulatory system
nervous system
reproductive system
ecological values
metamorphosis
Sense organs are the specialized organs composed of sensory neurons, which help us to perceive and respond to our surroundings. There are five sense organs – eyes, ears, nose, tongue, and skin.
External receptors (exteroceptors): sense organs for touch, smell, taste, sight and hearing.
Internal receptors (interocepyors): these sense organs found in the body which detect the temperature, pain, hunger, thirst, fatigue and muscle position.
The chordates are named for the notochord: a flexible, rod-shaped structure that is found in the embryonic stage of all chordates and also in the adult stage of some chordate species.
It is located between the digestive tube and the nerve cord, providing skeletal support through the length of the body.
In some chordates, the notochord acts as the primary axial support of the body throughout the animal's lifetime.
The vertebrate brain
The vertebrate brain is the main part of the central nervous system. The brain and the spinal cord make up the central nervous system,
In most of the vertebrates the brain is at the front, in the head. It is protected by the skull and close to the main sense organs.
Brains are extremely complex and the part of human and animal body. The brain controls the other organs of the body, either by activating muscles or by causing secretion of chemicals such as hormones and neurotransmitters.
Muscular action allows rapid and coordinated responses to changes in the environment.
The brain of an adult human weights about 1300–1400 grams .
In vertebrates, the spinal cord by itself can cause reflex responses as well as simple movement such as swimming or walking. However, sophisticated control of behaviour requires a centralized brain.
The structure of all vertebrate brains is basically the same.
At the same time, during the course of evolution, the vertebrate brain has undergone changes, and become more effective.
In so-called 'lower' animals, most or all of the brain structure is inherited, and therefore their behaviour is mostly instinctive.
In mammals, and especially in man, the brain is developed further during life by learning. This has the benefit of helping them fit better into their environment. The capacity to learn is seen best in the cerebral cortex.
Three principles
The brain and nervous system is essentially a system which makes connections. It has input from sense organs and output to muscles. It is connected in several ways with the endocrine system, which makes hormones, and the digestive system and sex system. Hormones work slowly, so those changes are gradual.
The brain is a kind of department store. It has, all inter-connected, departments which do different things. They all help each other gather senses.
Much of what the body does is not conscious. Basically, much of the body runs on automatic (breathing, heart beat, hungry, hair growth) adjusted by the autonomic nervous system. The brain, too, does much of its work without a person noticing it. The unconscious mind refers to the brain activities which are hardly ever noticed.
Evolutionary change in heart of vertebrates
Heart is situated ventral to the oseophagus in the pericardial section of the coelom.
Heart is a highly muscular pumping organ that pumps blood into arteries and sucks it back through the veins.
In vertebrates it has undergone transformation by twisting from a straight tube to a complex multi-chambered organ.
. There has been an increase in the number of chambers in heart during evolution of vertebrates.
The heart is covered by a transparent protective covering, called pericardium. It is a single layer in fish.
Within pericardium there is a pericardial fluid, protects the heart from the external injury.
The evolution of the heart is based on the separation of oxygenated blood from deoxygenated blood for efficient oxygen transport.
Embryonic Digestive Tract:
Archenteron:
The embryonic archenteron becomes the lining of the adult digestive tract and of all its derivatives.
Splanchnic mesoderm adds layers of connective tissue and smooth muscles around the archenteron.
Ectodermal invagination of the head forms the stomodaeum leading into oral cavity, and a similar mid-ventral ectodermal invagination forms proctodaeum, which leads into the hindgut.
The stomodaeum becomes the adult buccal cavity and gives rise to teeth enamel, epithelial covering of tongue, glands, e.g., mucous, poison and salivary, etc., and Rathke’s pouch of anterior pituitary gland.
The proctodaeum forms either a small terminal part of the cloaca in lower vertebrates and rectum in mammals.
Digestive Tract of Adult:
Following outgrowths arise from the digestive tract- oral glands, Rathke’s pouch, thyroid gland, gill-clefts, tympanic cavity, thymus and other glands of gill-clefts, trachea, lungs, swim bladder, liver, pancreas, yolk sac, and urinary bladder.
Histology: The wall of the alimentary canal is made of four concentric layers.
An outermost visceral peritoneum or serous coat is made of mesothelial cells and thin layer of connective tissue. It is lacking in the oesophagus.
(ii) Below this is a muscular layer formed of smooth muscle fibres arranged in outer longitudinal and inner circular muscle fibres. Between the two layers of muscles is a network of nerve cells and nerve fibres of the autonomic nervous system, known as myenteric plexus or plexus of Auerbach.
(iii) Beneath the muscle layer is a submucosa made of connective tissue having elastic fibres, fat, blood and lymph vessels, nerve cells and fibres glands.
(iv) The innermost layer is a mucosa composed of three regions:
(a) Outer-most narrow muscularis mucosa of outer longitudinal and inner circular smooth muscle fibres.
(b) Middle thin layer of lamina propria of connective tissue, blood vessels, nerves and nodules of lymphatic tissue, and
(c) A basement membrane supporting a layer of columnar epithelial cells which are often glandular and ciliated.
class 11 NEET
structural organization in animal
topic FROG
morphology ,anatomy, in detail
general characteristics
digestive system
respiratory systems
circulatory system
nervous system
reproductive system
ecological values
metamorphosis
excretion in unio and pila_poojasoni_new.pptxPooja Soni
The Bojanus organ and Keber’s organ are both part of the excretory system of Unio which belongs to the phylum Mollusca.
The organs of Bojanus or Bojanus organs are excretory glands that serve the function of kidneys in some of the molluscs. In other words, these are metanephridia that are found in some molluscs.
Keber's organ is a gland-like structure responsible for the removal of the nitrogenous wastes. It is also known as 'pericardial gland' and is a large, reddish-brown glandular mass.
Tissue-system grade
Triploblastic
Coelomate
Unsegmented
Bilaterally symmetrical
Body divisible into head,mantle,foot and visceral mass
Digestive system complete
Circulatory system closed type
Respiration direct by gills or lungs or both
Excretion by paired metanephridia
Terrestrial or aquatic
In Pila globosa, the excretory organ is a large kidney or renal organ or organ of Bojanus.
Like the gill, it is the organ of the left side, that of the right side having disappeared or modified into the gonoduct.
It communicates with the exterior on one hand and with the pericardial cavity representing coelom on the other; it is, thus, of the nature of a coelomoduct.
It consists of two chambers, a right anterior and a left situat posterior.
Anterior renal chamber :
It is more or less an oval organ, reddish in colour and lies anterior to the pericardium.
It opens into the branchial chamber of the mantle cavity through a slit- like opening near the epitaenia.
At the other end, it communicates with the posterior renal chamber through an internal opening.
Internal cavity of the anterior chamber is very much reduced due to the presence of many triangular leaf like processes or lamellae, those arising from the roof alternating with those from the floor.
Dorsal surface of the chamber is marked by numerous transverse grooves, corresponding to these internal lamellae.
Lamellae on the roof are arranged on either side of a median longitudinal axis, or the efferent renal sinus.
Lamellae on the floor are arranged on either side of a similar median axis, the afferent renal sinus, which is the right branch of the peri-intestinal sinus.
It breaks up into the numerous branches to supply the lamellae on both the sides.
Posterior renal chamber :
It is a broad, brownish to grey and hook-shaped chamber, situated behind the anterior renal chamber, in between the rectum on the right and the pericardium and the digestive gland on the left.
The ventral glandular portion of the kidney extracts guanin and other nitrogenous waste products of metabolism from the coelomic pericardial fluid as well as the blood supplied to the kidneys.
The walls of the pericardial sinus are also glandular, and supposed to secrete waste materials from the blood into the coelomic cavity.
The ciliated epithelial lining of the bladder produces an outgoing current, thus conveying excretory fluid from the glandular part of the kidney to the suprabranchial chamber which leads to the excurrent siphon.
There is reabsorptio
Physiology of Respiration in InvertebratesPRANJAL SHARMA
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Development of Chordata: From Embryogenesis to Morphogenesis"mishisajjad566
This topic explores the developmental processes that shape the Chordata phylum, including embryogenesis, morphogenesis, and organogenesis. It covers the formation of the notochord, nerve cord, and post-anal tail, as well as the development of chordate characteristics such as gill slits and pharyngeal pouches.
This topic delves into the developmental biology of Enteropneusta, a subphylum of Chordata that includes acorn worms. It examines the embryonic development of Enteropneusta, including gastrulation, neurulation, and organogenesis, and discusses the unique features of their developmental processes, such as the formation of the proboscis and the development of their distinctive body shape.
Note: Enteropneusta is a subphylum of Chordata that includes acorn worms and other related species. They are marine animals that belong to the phylum Hemichordata
Earliest Galaxies in the JADES Origins Field: Luminosity Function and Cosmic ...Sérgio Sacani
We characterize the earliest galaxy population in the JADES Origins Field (JOF), the deepest
imaging field observed with JWST. We make use of the ancillary Hubble optical images (5 filters
spanning 0.4−0.9µm) and novel JWST images with 14 filters spanning 0.8−5µm, including 7 mediumband filters, and reaching total exposure times of up to 46 hours per filter. We combine all our data
at > 2.3µm to construct an ultradeep image, reaching as deep as ≈ 31.4 AB mag in the stack and
30.3-31.0 AB mag (5σ, r = 0.1” circular aperture) in individual filters. We measure photometric
redshifts and use robust selection criteria to identify a sample of eight galaxy candidates at redshifts
z = 11.5 − 15. These objects show compact half-light radii of R1/2 ∼ 50 − 200pc, stellar masses of
M⋆ ∼ 107−108M⊙, and star-formation rates of SFR ∼ 0.1−1 M⊙ yr−1
. Our search finds no candidates
at 15 < z < 20, placing upper limits at these redshifts. We develop a forward modeling approach to
infer the properties of the evolving luminosity function without binning in redshift or luminosity that
marginalizes over the photometric redshift uncertainty of our candidate galaxies and incorporates the
impact of non-detections. We find a z = 12 luminosity function in good agreement with prior results,
and that the luminosity function normalization and UV luminosity density decline by a factor of ∼ 2.5
from z = 12 to z = 14. We discuss the possible implications of our results in the context of theoretical
models for evolution of the dark matter halo mass function.
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The return of a sample of near-surface atmosphere from Mars would facilitate answers to several first-order science questions surrounding the formation and evolution of the planet. One of the important aspects of terrestrial planet formation in general is the role that primary atmospheres played in influencing the chemistry and structure of the planets and their antecedents. Studies of the martian atmosphere can be used to investigate the role of a primary atmosphere in its history. Atmosphere samples would also inform our understanding of the near-surface chemistry of the planet, and ultimately the prospects for life. High-precision isotopic analyses of constituent gases are needed to address these questions, requiring that the analyses are made on returned samples rather than in situ.
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As consumer awareness of health and wellness rises, the nutraceutical market—which includes goods like functional meals, drinks, and dietary supplements that provide health advantages beyond basic nutrition—is growing significantly. As healthcare expenses rise, the population ages, and people want natural and preventative health solutions more and more, this industry is increasing quickly. Further driving market expansion are product formulation innovations and the use of cutting-edge technology for customized nutrition. With its worldwide reach, the nutraceutical industry is expected to keep growing and provide significant chances for research and investment in a number of categories, including vitamins, minerals, probiotics, and herbal supplements.
Professional air quality monitoring systems provide immediate, on-site data for analysis, compliance, and decision-making.
Monitor common gases, weather parameters, particulates.
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3. Habit and habitat
Class : Amphibia
Phylum : Chordata
Kingdom : Animalia
• Frogs in general are found in or near fresh
water and in very damp places on land.
• The most common species of frog in India is
Rana tigrina.
• It moves in two ways by leaping or walking on
land and by swimming in water.
• The frogs swims in water by powerful thrusts of
its hindlimbs which act like propellers.
• Adult frogs are carnivorous.
4. • The characteristic noise or sound made by frogs is
known as croaking.
• Frog is a cold-blooded or poikilothermous animal
i.e., the temperature of its body fluctuates with
that of the environment.
• Frogs have the ability to imitate other organism for
their protection purpose. This protective property
is known as mimicry.
• Frogs exhibit sexual dimorphism.
14. Digestive system mainly consists of Alimentary
canal and Digestive glands.
Alimentary canal :
The alimentary
canal is short because frogs
are carnivores and the
length of intestine is
reduced but it is complete
ie. from mouth to cloaca.
15.
16. IT CONSISTS OF FOLLOWING PARTS :
MOUTH :
mouth is a wide anterior opening leading
to a spacious buccal cavity that leads to the
oesophagus through Pharynx
OESOPHAGUS :
Because of absence of neck in the
Frog, the oesophagus is only a short tube that
leads to the stomach
17. STOMACH :
It lies on the left side of the body cavity
Its large anterior part is called cardiac stomach
Its short posterior part is called pyloric stomach
It also contains,
multicellular gastric glands which secrete the
enzymes pesinogen.
unicellular oxynticglands which secrete
hydrochloric acid
Its posterior end opens into small indestine
18. INTESTINE :
It is the longest part of alimentary canal
and it is divisble into :
DUODENUM :
It recieves bile from gall bladder and
pancreatic juice from the pancreas through a
common bile duct (hepato pancreatic duct)
19. ILEUM :
The internal lining of ileum is also thrown
into a large number of finger like branched
projections known as villi which increases the
absorptive surface area.
RECTUM :
The ileum leads into a broad ,thin walled
,short but wider tube known as rectum or large
indestine.
It opens outside by cloaca.
20.
21. DIGESTIVE GLANDS :
LIVER :
= It is a reddish brown, multilobed gland located close
to heart and lungs.
= Liver secretes a alkaline fluid ,the bile.
= The bile is transferred to the gall bladder for storage .
PANCREAS :
• It is a branched flat elongated pale-yellow gland .
• It secretes pancreatic juice containing several enzymes.
24. Digestion of food
take place by the
action of HCl and
gastric juices
secreted from the
walls of the
stomach
CHYME – Liquified semi digested acidic food
25. In Duodenum, Chyme is mixed with Bile and
Pancreatic juices for futhur digestion to take place.
Bile neutralizes the acidity of Chyme and
Emulsifies the Fat.
Pancreatic juices contain various types of enzymes
to digest carbohydrates and protiens.
26. The digestion is completed in the intestine only
This completely digested food is absorbed by
numerous finger like folds in the inner wall
intestine[ileum]
The undigested solid waste moves into rectum
[where water reabsorption occurs ] and finally passes
out through cloaca
28. Being amphibious in nature, frogs can utilize the
oxygen present both in atmospheric air and water.
Types of respiration in frogs:
1. Using gills-Tadpole /larval stage
2. Cutaneous respiration- adult frog
3. Pulmonary respiration- adult frog
4. Bucco-pharyngeal respiration- adult frog
29. 1.RESPIRATION THROUGH GILLS
• Takes place in the larval stage ,where the
tadpole are present only in water
• 4 pairs of gills are present for respiration.
• Water containing oxygen is taken through the
mouth ,diffusion takes place at the gills and
co2 is given out.
30. 2.CUTANEOUS RESPIRATION(water)
• Adult frogs use this mode of respiration when
they are in water.
• The skin of the frog provides an extensive surface
for the exchange of gases
It shows certain features:
1. The skin is thin.
2. It is vascular (richly supplied with blood
capillaries)
3. It is kept moist (mucus and water)
31. • Dissolved oxygen in water is exchanged through
the moist surface of the skin by diffusion.
• It is practically the only mode of respiration when
the frog is in water.
• This mode of respiration mostly takes place
during hibernation and aestivation.
32. 3.PULMONARY RESPIRATION(land)
• Adult frogs use this type of respiration when
on land.
• Breathing takes place through the usage of
lungs and respiratory tract ( nostrils, buccal
cavity and glottis).
33. • The lungs are a pair of elongated, thin-walled,
elastic, pink-coloured sacs present in the
upper part of the trunk region. i.e., the thorax
• The inner surface of each lung is divided by a
series of partitions, the septa and further into
many small cavities known as alveoli.
34. • Air enters the nostrils into the buccal cavity
and then into the lungs.
35. 4.BUCCO-PHARYNGEAL
RESPIRATION(land)
• Adult frogs fill its bucco-pharyngeal cavity
with air through the nostrils when on land
• Gaseous exchange takes place through the
moist lining of the buccal cavity and then
expelled out.(similar to cutaneous
respiration).
36. • It brings oxygen to the bloodstream by
dissolving it and diffusing it into the blood
capillaries.
• Mucous membrane blood capillaries
38. HEART:
It is a muscular structure which lies mid-ventrally, inside the
anterior trunk region
It is enclosed within a thin, transparent, two layered sac
called the pericardium. It protects heart from friction or
mechanical shocks.
Heart is a three chambered structure in frog, made of two
anterior aria(right and left) and a single posterior ventricle.
The heart of frog has 2 additional chambers –sinus venosus
and truncus arteriosus(=conus arteriosum).
Sinus venosus is a thin –walled, triangular chamber attached
dorsally to heart. It opens into the right larger atrium
through an aperture.
39.
40. BLOOD CIRCULATION:
• The right atrium receives deoxygenated blood through
sinus venosus which in turn receives blood from the major
veins called vena cava. While the left atrium receives
oxygenated blood from pulmonary veins. Both right and
left atrium pump blood into single ventricle which opens
into truncus arteriosus. The circulation of blood is achieved
by the pumping action of heart. Various chambers of heart
are separated by valves to keep the blood flowing in one
direction.
• ARTERIAL SYSTEM: Arteries carry blood from the heart. The
arterial system in frog begins with the truncus
arteriosus(=conus arteriosus). The truncus divides into left
and right branches each of which sub-divided into vessels.
41.
42. VENOUS SYSTEM
• It includes veins an or those blood vessels
which carry the blood to the heart. In frog it
can be studied in four parts:
PULMONARY VEINS: They collect
oxygenated blood from two lungs and open
directly into left auricle.
VENA CAVA: They carry deoxygenated blood
from the body parts towards heart .
43. RENAL PORTAL VEIN: Renal portal vein carrying
deoxygenated blood from lower part of the body like
hindlimbs, gonads, etc… enters kidney. The blood from
hind parts of the body contains urea and uric acid are first
filtered in the kidneys before the blood goes to the heart.
Thus, the blood going to the heart contains comparatively
less impurities.
HEPATIC PORTAL VEIN: A large hepatic portal vein
confluence of several branches from stomach, intestine,
spleen and pancreas. It carries blood of alimentary canal
and its glands laden with digested foodstuffs, to the liver
into which it breaks as capillaries.
44.
45. BLOOD
• Blood carries nutrients ,gases and water to the
respective sites in the body. Hence it is the
chief circulatory fluid of the body. It contains a
clear liquid, called plasma, in which are
suspended various types of free cells, called
blood substances.
I. Plasma: it is composed of water(dissolved
mineral salts)absorbed foods, excretory
wastes and other soluble substances.
II. Corpuscles: three types of blood corpuscles
are present In the plasma :RBC,WBC OR
PLATELETS.
48. • The prominent endocrine glands found in frog
are pituitary ,thyroid, parathyroid , thymus,
pineal body , pancreatic islets adrenals and
gonads
49.
50. • Well developed excretory system .
• It is ureotelic organism.
• Excretory system consists of namely:
1. A Pair of kidneys
2. Ureters
3. Urinary bladder
4. cloaca
51. A pair of kidneys
The two mesonephric kidneys, situated one on
either side of the vertebral column in the posterior
part of the body cavity.
Each kidney is a compact mass of innumerable highly
twisted microscropic uriniferous tubules or nephrons
and blood vessels embedded in connective tissue.
Ureters
It is a fine, white tube extends backwards to open
into the dorsal wall of cloaca. In male frog , the
ureters are called urinogenital ducts.
52. Urinary bladder
A large transparent, bilobed, thin walled elastic. It
opens into the ventral wall of cloaca.
Cloaca
Small median chamber into which the anus ,
urinogenital apertures and urinary bladder.
53.
54. PROCESS OF EXCRETION
• Blood is filtered by nephrons in kidney. All the
wastes is filtered out and useful substances
are reabsored into blood. The remaining fluid
forms urine which is carried out in kidney by
collecting vessels into ureter and passes into
cloaca.
56. INTRODUCTION :
• The frog has a highly developed nervous
system. It consists of a brain, a spinal cord, and
nerves.
• The important parts of the frog brain
correspond to comparable parts in the human
brain. The medulla regulates automatic
functions such as digestion and respiration.
Body posture and muscular co-ordination are
controlled by the cerebellum.
57.
58. NERVOUS SYSTEM OF A FROG
• The nervous system of a frog is well developed and is
represented by :
1. Central nervous system comprising brain and spinal cord.
2. Peripheral nervous system including cranial and spinal
nerves.
3. Autonomic nervous system comprises sympathetic and
parasympathetic nervous system .
CENTRAL NERVOUS SYSTEM :
i. Brain : it is enclosed in the cranial cavity of the skull called
brain box. The brain is divisible into three parts.
a) Forebrain :it comprise two olfactory lobes, two cerebral
hemispheres and unpaired diencephalon.
59. b) Mid-brain : It consists of optic lobes and cura cerebri.
c)Hind brain :the posterior part of brain includes cerebellum
and medulla oblongata.
ii)SPINAL CORD:
The spinal cord extends posteriorly from medulla
oblongata through foramen magnum and lies protected
within neural canal of its vertebral column. It is short,
thick, cylindrical somewhat flattened and white in
colour.
60. 2) PERIPHERAL NERVOUS SYSTEM :
i. Cranial nerves : There are 10 pairs of cranial nerves which
originate from brain of the frog.
ii. Spinal nerves : Frog has 10 pairs of spinal nerves. Every
spinal nerves on either side arises from spinal cord.
3)AUTONOMIC NERVOUS SYSTEM :
It is a system of nerve fibres and ganglia which controls and
coordinates the involuntary activities of the visceral organs,
such as secretion of digestive fluid, action of heart etc.
62. SENSE ORGANS
• Sense organs receive stimuli from inside or outside of the
animals and pass impulses to the nervous system.
• Frog has five types of sense organs . They are :
i. Organs of touch : Also known as tangoreceptors. These are
cellular aggregates around nerve endings, found in the skin as
sensory papillae.
ii. Organs of smell : Also known as olfactoreceptors. They are
also cellular aggregates found in the nasal epithelium of the
nasal chambers.
iii. Organs of taste : Also known as gustato receptors. These are
found as taste buds which are present in the epithelium of the
tongue.
63. iv) Eyes are organs of sight.
v) Ears are organs of hearing and balancing.
Out of these, eyes and internal ears are well – organised.
They are described below :
a) EYE : There are two large eyes. Each eyeball is roughly
spherical and lodged inside an orbit in the dorso- lateral side
of head protected by eyelids.
b) EAR : A pair of ears are attached to skull, posterio-laterally
in all vertebrates. They are statoacoustic organs as they help
in both hearing and balancing of body. The ear of a frog
mainly consists of two parts – middle and internal ear.
64.
65. REPRODUCTIVE SYSTEM ..
Frogs have well defined male and female reproductive system.
MALE REPRODUCTIVE SYSTEM ..
• Consists of two testes
• Several vasa efferentia
• And two urinogenital ducts
TESTES.
• It is an elongated and ovoid light yellow body attached to the upper part
of kidney by a double fold peritoneum called mesorchium .
• Seminifereous tubules are coiled within the testes.
VASA EFFERENTIA .
• 10-12 Fine tubes connecting the testes on each side of the kidney
• The vasa efferntia run transversely through the mesorchium and opens
into the bidder’s canal .
• And passes through the urinogenital duct..
66. URINOGENITAL DUCT..
• Arising from the kidney acts as both urinary
and sperm duct .
• Finally opens into the cloaca and passed out
through the cloacal aperture …
67.
68. FEMALE REPRODUCTIVE SYSTEM..
• Comprises a pair of ovaries , oviduct .
OVARIES ..
• Irregular shape ,lobulated structures near the kidneys.
• They have no internal functions and connections with
kidney
• Ovary contains dark round ova in different stages
developments .
• Ovum releases through the oviduct ..
OVIDUCTS..
• Paired ,white , glandular and long coiled tubes on sides of
body cavity
• Posterior ends posses an ovisac where eggs are stored
temporarily..
• Mature female frog lay 2500-3000 ova at a time .
71. FERTILISATION …
• Onset of rainy season ,frogs emerge out of
aestivation and starts breeding ..
• Male frog starts croaking to attract the female
frog for mating ..
• Male mounts upon the female and grasps with
the help of copulatory pads called amplexus .
• Female release (2500-3000) ova into the water
and sperms discharges over the eggs for
fertilisation .
• exhibits external fertilisation .
72. DEVELOPMENT AND
METAMORPHOSIS .
• Exhibit indirect development
• Within two weeks fertilised eggs develop into
free swimming larvae called tadpoles
• It swims freely on the water and feeding on
planktonic foods .
• Tadpoles has external gills which become
replaced into an internal gills later ,after
metamorphorsis
73.
74. CHANGES THAT CONSTITUTE THE
METAMORPHOSIS …
• Limbs appears and tail shortens .
• Quick growth and movement of the eyes to
higher up the skull
• formation of eyelids , skin glands
• Thickening of skin and development of an
eardrum to lock the middle ear .
• These changes make them into an young adult
frogs.
• finally they disperse into the terrestrial habitat.
75. DID U KNOW ?
• Frogs cannot live away from the aquatic
environment because no means to control the
evaporative water loss through the skin ..
IMPORTANCE TO THE MANKIND …..
• It eats insects and they are harmful to crops
• Saves expenditure on insecticides
• Maintain ecological balance and food chain
• Muscles of frog used as food in other countries
and some parts of india ..
• As an experimental material for teaching nad
researches……..
76. REFERENCE
BOOKS :
NCERT CLASS 11
THE ANATOMY OF FROG BY ALEXANDER ECKER
UNCOVER A FROG BY AIMEE BAKKEN
WEBSITES :
WIKIPEDIA
WWW.ALPHACODERS.COM
https://www.britannica.com