PITUITARY GLAND

*it is the smallest endocrine gland.
*it  was termed by Andrew Vesalius.
*it has pin head like shape

*pituitary gland contains mainly two parts-
Adenohypophysis
Neurohypophysis.

*in female,it helps in ovulation.
*it helps in growth and development of Corpus Luteum and other endocrine gland.
*Corpus Luteum secretes progesterone(female sex hormone)
*it helps in growth and maintenance of uterus and implanted embryo, and also helps in growth of secondary sexual character. Viz- enlargement of breast, growth of pubical hair, deposition of fat in buttock.

LUTEOTROPHIC HORMONE / LTH / PROLACTIN HORMONE-

• it is secreted from Pars distalis of Adenohypophysis.
• it has no role in male.
• in female it helps in growth and development of breast and synthesis of milk after four months of pregnancy.

MELANOCYTE STIMULATING HORMONE / MSH-

• it is secreted from pars intermedia of Adenohypophysis.
• it helps in synthesis of melanin pigment in other vertebrate except birds and mammals.
• in birds and mammal ,function is still unknown.

OXYTOCIN / PITOCIN-

• it is secreted from pars nervosa of neurohyposis.
• it is nonapeptide in structure.
• it is neurohormone.
• in male it has no role.
• in female it helps in contraction and relaxation of vagina during parturition
• it helps in ejection of milk so called as milk ejecting hormone.

ANTIDIURETIC HORMONE / ADH / VASOPRESSIN / PITRESSIN

• it is secreted from pars nervosa of neurohypophysis
• it incresace the permeability of wall of DCT to increase reabsorption of water.
• hyposecretion of ADH may cause Diabetes insipidus , which is insuline dependant diabetes.

*Hormone of hypothallamus control pituitary gland.

*hypothallamus secretes two types of factor i.e.- release factor and inhibitory factor.
*release factor stimulate release of particular hormone and inhibitory factor inhibit some particualr type of hormone as per requirement.

ENDOCRINOLOGY

*Study of endocrine glands is called endocrinology.
*endocrine gland also known as ductless gland.
*Thomas Addision is known as father of endocrinology.
*the term hormone was given by Starling
*first extracted hormone was SECRETIN.
*Types of endocrine glands;-
Pituitary gland

Thyroid gland

Adrenal gland

Thymus gland

Parathyroid gland

Ilet of Langerhan's

Ovary

Testis

Palacenta

NERVOUS TISSUE

*origin- ectoderm.
*cells of nervous tissue have least power of regeneration.
*neuron is the longest animal cell.
*length of neuron in human being- 2-3m
*total number of neuron in human being=100billion
*cell of nervous tissue also contain very less quantity of matrix.
*important cell of nervous tissue-

Neuron
Neuroglia
Schwann cell
Neurocrine cell
Amacrine cell

*Neurons

1.  DENDRON-it is thin thread like structure originated from cyton.

2.  CYTON- it is small spherical structure and considered as as main part of the neuron. it contains following structure-

• nucleus-small spherical structure present in centre.
• neuroplasm-cytoplasmic content of neuron
• neurofibrils-it is thin thread like structure present in neuroplasm, gives mechanical support and acts as endo-skeletal.
• nissl's granules-it is nucleo protein, present in cyton and dendron only.
• axon-it is long tubular structure present behind the cyton.
• myelin sheath-it is thick covering of lypoprotein formed by schwann cells. it prevents loss of energy even transmission of impulse.

3.  NODE OF RANVIER-small gap present on axon (both neurilemma and myelin sheath are completely absent. it increase the speed of impulse by jumping action.

 speed of nerve impulse in human-150-200 m/s.

MUSCULAR TISSUE

*origin- mesoderm
*muscular tissue is about 30% of total tissue.
*total number of muscles in human body are 639
*muscular tissue also contain small amount of matrix.

Types of muscular tissue-

1. Skeletal muscular tissue.

2. Smooth muscular tissue.

3. Cardiac tissue.

1.Skeletal muscular tissue-

*shape-cylindrical and unbranched

*nucleus-it is multinucleated

*sarcolema-it represent plasma membrane of muscle fibre.

*sarcoplasm-it represent cytoplasmic content of muscle fibre.

*myoglobin-it is red in colour. it is Fe++ containing pigment,it carries oxygen

*dark band and I band are alternately arranged.

*found in hind and fore limbs.

*myofibril- about 1000 in number.

2.Smooth muscular tissue-

*shape-spindle fibre.

*sarcolemma-less developed or absent.

*sarcoplasm-present in very less amount.

*myofibril- very less in number.

*nucleus- single nucleate.

*complete absence on A-band and I- band.

*complete absence of myoglobulin.

3. Cardiac tissue

*shape-cylindrical and branched

*nucleus-multinucleate/ uninucleate.

*presence of well developed sarcolemma.

*presence of sarcoplasm.

*presence of myofibril in between 4 -1000

*alternately arranged A-band and I-band are present.

*presence of myoglobin.

*it is formed by fusion of two adjecent muscles fibre.

*it is found in heart.

FLUID CONNECTIVE TISSUE

*fluid connective tissue contain maximum amount of water and it doesn't contain fibrous matrix.
*Blood and Lymph are its example.

LYMPH

*it is colourless fluid contain WBC & Platelets and complete absence of RBC.

BLOOD - CELL  =  PLASMA

BLOOD - RBC  =LYMPH

PLASMA  - FIBRINOGEN PROTEIN  =  SERUM

*lymph also contain blood plasma protein but in less amount than blood.

*it stores fat and adipose tissue.

*it clots like blood.

*it circulate through lymphatic vessel.

BLOOD

*colour- bright red

*total volume- 6-7 Lt  [body wt/ 13 in adult]

*pH-7.4(arterial blood)

        7.3(venous blood)

*specific stain-Leishman stain

*components- liquid component -blood plasma

                       solid component-blood cell

BLOOD PLASMA

water

*85-92% of tatal volume of blood

albumin

*it is the smallest blood plasma protein

*it is about 4% of blood volume

*it maintain osmotic pressure of blood.

*decreased albumin causes -Oedema

increased albumin causes- Albuminaria

globulin

* it is of three types alpha (α), bita(β ), and gama(γ)

*first two helps in transportation of nutrients and the last one acts as immunoglobulin.

fibrinogen and prothrombin

*it helps in blood clotting

BLOOD CELL

RBC / ERYTHROCYTES

*size-7.5-8.5 micro meter in diameter in human

          largest RBC-Amphuma,79 micrometer.

          smallest RBC- Muskdeer, 4 micro meter.

*shape- biconcave in human

*nucleus-newly formed RBC has nucleus,but as their size increses, RBC looses their nucleus .

*life span-120 days in human

*site of formation-liver, spleen and bone marrow.

rate of formation-2-3 million /sec

*site of distruction-liver, bonemarrow and spleen, but mainly spleen.

*spleen is also called the graveyard of blood.

*RBC contain haemoglobin, hence it is red in colour.

WBC / LEUCOCYTE

*total count-4000-12000/cubic mm of body

*it nucleated colourless blood cell.

*life span-48 hours to 14 days.

*it is of two types-

1. granulocyte-Basophil, Eosinophil and Neutrophil
2. agranulocyte-Lymphocyte and Monocyte

*Basophil-it helps in secretion of heparin, histamine and serotonin chemicals.

*Eosinophil-it secretes antitoxic substance.

*Neutrophil-it helps in killing disease causing substance and paracite.

*Lymphocyte-it synthesise antibodies or immunoglobulin and provide immunity

*Monocyte-phagocytic in nature.

PLATELETS

*it is non-nucleated blood cell.

*it is the fragment of megakaryotic cell of bone marrow.

*function-helps in blood clotting

                 helps in repairing of damage of blood vessel.

THROMBOCYTES

*it is nucleated blood cell found in non-mammals

*it also helps in blood clotting.

*it help in repairing of blood vessel

SKELETAL CONNECTIVE TISSUE

*it is hard connective tissue, due to presence of mineral like calcium & phosphorus in their matrix.
*it is further classified into two groups-

1. Cartilage

1. Bone

1. Cartilage
-study of cartilage is called chondrology.
-perichondrium- it is outer most covering and it gives shapes to cartilage. it is elastic in nature and made up of yellow fibre.
-matrix- it contains water as main component and chondriodin sulphate and also some mineral like calcium.
-lacunae- it is small open space and it contains cartilage-forming cells, chondrocytes. chondrocytes forms chondrin protine and chondrin protine combines with water,chondriotic-sulphate and mineral to make cartilage. this process is called chondrogeesis. cartilage contains white fibre for mechanical support.
-chondroplast cell- it is cartilage digesting cell, develops in old age and it is multi-nucleated.

*cartilage is called avascular connective tissue, because it does not contain distribution of blood vessel.
*the growth of cartilage is unidirectional,i.e. always towards peripheri.

Classification of cartilage on the basis of their properties-

• Hyline cartilage(transparent like glass)- it is most primitive and most abundant found in animal body. it contains small white fiber in matrix.. it is found in endings of long bones, in larynx, in ending of ribs, in hyoid etc
• Elastic cartilage- it is elastic in nature, their matrix contain long elastic fibres. it is found in nose- tip, ear pinna,vertebrae of shark
• Fibrous cartilage- it is the strongest cartilage,it contain long white fibrous matrix. it is found in inter-vertebral disc, in pectorial girdle
• Calcified cartilage- it is the hardest cartilage, because calcium is present in there matrix. it is found in pubis and pelvis girdle.

2.Bone

-study of bone is called osteology

-periostium-it is outer most covering of bone, it is made up of white connective fibre. it is tough, rigid and inelastic in nature. it gives shape to bone.

-osteoblast cell-it is bone forming cell, present just inside the periostium and also found in bone marrow

-osteocyte- it is also bone forming cell, present inside lacunae, it is formed by osteoblast. both osteoblast and osteocyte forms ossein protein.

-matrix- matrix of bone contain maximum amount of water, calcium phosphate and calcium hexose metaphosphate enzyme.

-lamellae- it is circular plate of bone matrix.

*Haversian canal-it is found in long bones of mammals.it contain longitudinal canal(Hervasian camal) and transverse canal(Volkman's canal) and the branched process is canal culi.

*process of formation of bone is called osteogenesis.

*Calcification-deposition of calcium on bone is called calcification.

*Decalcification-desolution of calcium from bone is called decalcification.

*Bone marrow- it is the central cavity of bone, which is filled with two types of cells-yellow bone marrow and red bone marrow.

-white bone marrow stores fat and red bone marrow helps in formation of blood.

-in children bone is completely filled with red bone marrow

Types of bone on the basis of formation-

• Cartilaginous/ replacing/endochondral bone-these bones are formed from deposition of calcium on cartilage.it is found in every limbs, bones of girdle, roof of the cranial vertebrae etc.
• Membranous/ dermal/investing bone- these bones are formed by deposition of calcium on mesenchyme. it is found in jaw bone, pectorial girdle, bone of floor of cranial etc
• Sesamoid bone- these bones are formed by the deposition of calcium on tendon. e.g.- patella. 

CONNECTIVE TISSUE PROPER

AREOLAR TISSUE

*It contains air in its space, hence it is called areolar connective tissue or spongy tissue.
*it contains following types of cells having specific function-

1. Mast cell-it is small spherical cell scattered in matrix..

                         it secretes following types of chemical-

     (A) Heparin-natural anticoagulant.

     (B) Histamin- vasodialator, Antiallergic

     (C) Serotonin-vasoconstricter  

     2. Histiocytes cell-it is phagocytic cell, it engulfs disease causing.

    

    3.Plasma cell-it is small spherical cell,which secretes antibodies.

    4. Fibroblast cells- these cells forms animal fibrous tissue. it is divided into two groups-

             (A)white fibrous/collagen/inelastic tissue- unbranched collagen protein. 

 

             (B)yellow fibrous/ elastic tissue-thin and branched and made up of elastin protein

FIBROUS TISSUE

* these connective tissue contains fibroblast cells and animal's fibre

*fibrous connective tissue classified into two groups-

1. White fibrous connective tissue-it is made up of white fibre, e.g.- tendon.
2. Yellow fibrous connective tissue- it is made up of yellow fibre. e.g.- ligament

ADIPOSE TISSUE

* it contains fat and fat forming cells.

*it is further classified into two groups-

      White adipose tissue

      Brown adipose tissue.

*in children, brown adipose tissue is present in excess amount , hence children less suffer from cold.

*brown adipose tissue contain excess amount of mitochondria and very less amount of ATPs.

*as age increases, brown adipose changes into white adipose tissue.

*Blubber- it is thick pad of adipose tissue found in blue whale.

*Hump-it is found in camel and ox, it is accumulation of adipose tissue.

RETICULAR CONNECTIVE TISSUE

*it is thin thread like structure of reticulin protein.

*reticulin protein is generally store in lymphatic tissue. e.g. lymph, vermiform appendix, spleen.

CONNECTIVE TISSUE

*It helps in connection and binding of cells, tissue and different organ.

*it helps in transportation of nutrients.

*it gives mechanical support to body.

*it also helps in transportation of hormones and enzymes.

*it helps in hearing(malleus, incus, stapes)

*it also helps in production of sound.

*WHARTSON JELLY - an undifferentiated connective tissue, which is only found in umbilical cord of foetus.

*MESENCHYME- undifferentiated connective tissue found everywhere except umbilical cord.

*CLASSIFICATION OF CONNECTIVE TISSUE-

STRATIFIED EPITHELIUM (COMPOUND EPITHELIUM)

*cellls arranged in more than one layer.
*basal layer of the tissue are either cuboidal or columnar , never squamous, so it is further classified into three types on the basis of cells present on its upper surface-

1. Compound squamous epithelium/ pavement
2. Compound columnar epithelium
3. Compound squamous epithelium

1. Compound squamous epithelium-this type of epithelium contains, squamous cells on free surface, it is further classified into two group on the basis if Keratin protein.

#Compound keratinised squamous epithelium-it contains keratin protein, hence it is hard and dead. e.g.-epidermis of skin.

#Compound non-keratinised squamous epithelium-it does not contain keratin protein, so it is relatively soft. it is present at all opening of the body which communicate with environment like mouth, anus ,nasal opening,ear opening, urinogenital opening.


2. Compound cuboidal epithelium-this type of epithelium contains cuboidal cells on free surface.
e.g.-testis, ovary

3.Compound columnar epithelium-this type of epithelium contains columnar cells on its free surface.
e.g.- epiglottis, gullet, larynx,pharynx,oesophagus(all parts are of food track).

SPECIAL TYPE OF EPITHELIAL TISSUE

A. Pseudo-stratified epithelium- cells arranged in single layer, but it apopears like arranged in more than one layer. e.g.-it is found near pharynx.

B. Transitional epithelium-these epithelium do not contain basement membrane. in this type of epithelium cells are arranged in 4-5 layers, and cells of each layer have different function. e.g.- urethra, urinary bladder.

SIMPLE EPITHELIAL TISSUE (EPITHELIUM)

*first animal tissue found in coelentrata.
*cells arranged in single or more than one layers, but the upper end of the layer is always free, means not covered.
*presence of basement membrane, which is made up of gylcoprotein and polysaccharide.
*epithelium divides throughout life.
*cell of epithelium are avascular
*Types of  epithelium on the basis of layer of the cell-

1. Simple epithelium
2. Compound/ Stratified epithelium

1. Simple epithelium-cells are arranged in single layer. it is further classified into three different group-

• Simple squamous epithelium/ Pavement
• Simple cuboidal epithelium/ Germinal epithelium
• Simple columnar epithelium

Simple squamous epithelium- cells are arranged like tiles or scales of fish.
-it contain very less quantity of matrix.
-cells are smaller in size.
-nucleus is at center of the cell.

-distribution- (a) Pericardium (covering of heart)- parietal pericardium, visceral pericardium, pericardial fluid.
                      (b)Bowman's capsule-it is a part of nephron in kidney.
                      (c)Pleura of lungs- it is covering.

Simple cuboidal epithelium- it contain very less quantity of matrix.

-it is also known as germinal epithelium.
-thyroid follicle of thyroid gland are made up of cuboidal epithelium.

Simple columnar epithelium- cells are column like or row like.
-nucleus present towards the base.
-it contain less quantity of matrix.

Modification of simple columnar epithelium

(1) Ciliated epithelium- presence of small hairy structure on free surface of the cell, called cilia.
-it performs specialised function.
-it present in neck of nephron.
-cilia of nephron helps in movement of filtrate from anterior end to posterior end.
- it is also found in alveoli of lungs.

-it also conduct egg in fallopian tube.

(2)Sensory epithelium- cells of columnar epithelium modified to receive stimulus.
-it is found in taste bud of tongue.
-it is also found in organ of corti.
-also present in rod and cones of retina of eye.
-schnederian membrane of nasal tube.

(3)Glandular epithelium- cells of columnar epithelium modified to form glands and gland specialised for secretion of substance.
               Types of glands on the basis of number of cells present in gland.-
#Unicellular glands- these gland contains only one cell. e.g.- goblet cell( found in intestine of human and secretes mucus), ebner's gland(present in tongue and secretes lipid digestive enzyme).

#Multicellular glands-these gland contain more than one cells. e.g.- salivary gland, ovary, testis, liver, pancreas,thyroid, pituitary gland, lacrymal gland, mammary gland, sweat gland, parotid gland etc

              Types of glands on the basis of transportation-

#Exocrine gland-it has duct to transport their product. e.g.-salivary gland, lacrymal gland, mammary gland, liver etc.

#Endocrine gland-these are duct less gland, they circulate their product through blood. e.g.- thyroid, pituitary,thymus etc.

#Heterocrine gland-in this type of gland one part has duct and another is ductless. e.g.- pancreas.

            Types of glands on the basis of mode of secretion-

#Holocrine gland-in this type of gland their total cytoplasm releases in the form of secretory material.e.g- sebaceous gland.

#Apocrine gland-in this type of gland, small amount of cytoplasm releases in the form of secretory product. e.g.-mammary gland.

#Merocrine gland-in this type of gland the secretory product releases through diffusion.e.g.- mammary gland.

ANIMAL TISSUES, INTRODUCTION

*group of cells having similar origin and function but their structure may or may not be similar , is commonly called TISSUE.
*study of tissue is called Histology.
*father and founder of Histology - Marcello Malpighi
*Matrix- it is secretory product of cell in tissue. The quantity of matrix and chemical composition varies in different cell.
*first of all tissue appeared in animals of phylum coelentrata.

*on the basis of function tissues are classified into four types-

1. Epithelial tissue- FUNCTION- absorption, secretion, protection etc.
2. Connective tissue- FUNCTION- connection, binding, joining, attachment etc.
3. Muscular tissue- FUNCTION- contraction and relaxation, movement and locomotion.
4. Nervous tissue- FUNCTION- to receive stimulus and transport the transport the stimuli from one place to another.

MAMMALIA CLASS, VERTEBRATA.

*these animals are warm blooded, hairy and have mammary or milk producing glands.
*there are about 4.000 species of mammals found in world.
*they are the only animals which nourish their young once with milk.
*sebaceous glands(oil gland) and sudoriferous glands(sweat gland) are present in the skin.
*teeth are heterodont and thecodont(embedded in the shocket of jaws). they develop twice in a life hence it is diphyodont
*they possess a muscular diaphragm dividing trunk into thorax and abdomen.
*mammals possess seven cervical vertebrae, except few.
*the skull is dicondylic.
*the heart is four chambered.
*the coelom is divided into four cavities- a pericardial cavity, two pleural cavities and an abdominal cavity.
*12 pair of cranial nerve.
*each consists of three parts,external, middle and internal. pinna is a part of external ear
*a copulatory organ is always present.
*fertilization is internal.
*except egg laying animal they are viviparous.
*sub-class are Prototheria and Theria
*e.g.-kangaroo, opossum, human etc

OPOSSUM

HUMAN

KANGAROO

AVES-CLASS, VERTEBRATA

*about 9000 species of aves are found
*they are warm blooded animal.
*they have bipeadal feather.
*their fore-limbs are modified into wings.
*the hind limbs are adapted for perching, walking or swimming.
*only preen gland(oil gland) present on tail, and no other gland present on skin.
*Ostrich and parrot lack oil glands
*upper and lower jaws modified into beak,which lack teeth
*legs bear horny epidermal skin.
*respiration occurs in lungs.
*syrinx produces voice in birds not larynx.
*heart is four chambered, sinus venosus is absent.
*renal portal system is very much reduced.
*kidney is metanephric, which directly drain uric acid into cloca through ureter. urinary bladder is absent
*Reha americana (South American Ostrich ) is the only bird which has urinary bladder.
*cerebrum, cerebellum and optic lobes are developed organ of brain.
*birds have 12 pair of cranial nerves.
*bones are pneumatic,means they have air cavity to reduce weight , which helps in flying.
*skull is monocondylic.
*female has well developed single left ovary and oviduct.if right ovary and oviduct are present then they are non-functional.
*sexual dimorphism is found in many birds.
*fertilization is internal
*birds are oviparous, means they lay eggs.
*e.g.-Ostrich, Kiwi. Penguins, Parrot, Duck

OSTRICH

KIWI

PENGUINS

REPTILIA CLASS, VERTEBRATA

*they are about 6000 species
*reptilia are creeping and burrowing cold blooded animals.
*they bear scales
*skin is dry, rough and without scales.
*respiration is by lungs.
*skull is monocondylic.
*except in snake there are two pair of pentadactyl limbs, each with 5 digits bearing claws.
*heart bear two auricles and partly divided ventricles
*kidneys are metanephric
*12 pairs of cranial nerves are present
*ear consists of three parts- internal, middle anr wxternal.
*snake do not possess ear.
*all reptiles are carnivorous/insectivorous, only tortoise feed entirely on vegetation.
*a typical cloaca is present.
*fertilization is internal
*e.g-Chelone(turtle), Testudo(tortoise), Chameleon(tree lizard),Naja(cobra),Bangarus(karait) etc

TESTUDO

CHELONE

NAJA

AMPHIBIA CLASS, VERTEBRATA

*It includes 3000 species.
*they are first evolved cold blooded land living animals.
*they can live on both land and water
*glands present on skin which keep it moist.
*two pairs of limbs for locomotion.
*skull is dicondylic.
*respiratory organs are lungs,buccopharyngeal cavity , skin and gills.
*heart are three chambered.
*kidneys are mesonephric.
*ear consists of internal and middle ear.
*10 pairs of cranial nerves are present.
*they breed in water.
*e.g.-Bufo (toad), Rana (frog),Hyla(tree frog), Salamandra (salamander), Ichthyophis(limbless amphibia).

BUFO

RANA

HYLA

SALAMANDRA

OSTEICHTHYES CLASS, VERTEBRATA

* habitat-both marine and fresh water fishes
* endoskeleton is cartilaginous in the embryonic stage, but in the adult forms it is replaced by bones.
*they are ectothermic( cold blooded)
* there body is streamlined
*the mouth is terminal, digestive tract leads into an anus.
*a swim bladder is usually present,helps in floating
*they have four pair of gills which are covered by an operculum
*the exoskeleton, if present comprises cycloid, ctenoid and ganoid scales.
*the heart is 2- chambered and has sinus venous and anteriosus.
* lung fishes have three chambered heart.
*kidneys are mesonephric.
*there are 10 pairs of cranial nerves.
*fertilization is generally external.
*e.g.- Labeo(rohu), Catla (katla), Muraena(eel)

CHONDRICHTHYES CLASS, VERTEBRATA

*they are marine animals with streamlined body.
*they have cartilaginous endoskeleton
*mouth is located ventrally
*notochord is persistent throughout life
*gills slit are separate and without operculum(gills cover)
*skin is tough and have placoid scales
*teeth are modified placoid,and very strong jaws
*they lack air bladder, hence the have to swim constantly
*heart is two chambered
*some of them have electric organ
*some possess poison sting
*they are cold blooded.
*sexes are separate
*fertilization is internal

*e.g.-Scoliodon, Prestis,Trygon

CYCLOSTOMATA CLASS, VERTEBRATA

*habitat- fresh water and marine water.
*mouth is jawless and they are called jawless fishes.
*body is eel like and tail is compressed
*skin is soft and scale less
*head and brain is poorly developed
*unpaired fins are present
*paired fins and associated girdles are absent
*endoskeleton is cartilaginous
*stomach is absent.
*respiratory organs are gills
*heart is two chambered
*there are 10 or 8 pairs of cranial nerves
*lateral line sense organs are present
*fertilization is external.
*they are mostly parasite on some fishes
*e.g.-Lamprey, Hag fish

CHORDATA PHYLUM

*presence of eal gilnotochord, dorsal hollow nerve cord and paired pharyngeal gill slit are the characterised feature of chotdata.
*habitat- found everywhere
*symmetry- bilateral
*body form- triploblastic
*body cavity- coetomate
*level of organisation-organ system level
*circulatory system- closed type
* phylum chordata is divided into three subphylua-

1. Urochordata /Tunicata
2. Cephalochordata
3. Vertebrata 

*Urochordata and Cephalochordata are comes under protochordates.
*protochordates are exclusively  marine.
*in urochordata the notochord is present only in larval tail.
*in cephalochordata , notochord  extends from head to tail region, throughout life
*e.g.-Urochordata-Ascidia, Salpa,Doliolum
         Cephalochordata-Branchiostoma
*in vertibrata the notochord is replaced by a cartilaginous or bony vertebral column. thus all vertibrates are chordates but all chordates are not vertebrates.

ASCIDIA

BRANCHIOSTOMA 

HEMICHORDATA PHYLUM

*habitat-lives in borrow and are exclusively marine
*body form-soft body and divided into proboscis,collar and trunk
*germ layer-triploblastic
*level of organisation- organ system level
*body wall-single layered epidermis
*coelom-enterocoelous
*digestive tract- it is complete
*gills slit- gills are present
*blood vascular system-open type
*excretory organ-glomerulus
*nervous system-primitive type, consists of nerve plexus
*sense organ-sensory cells are present on epidermis
*reproduction-mostly sexual
*development- except some most of them have indirect development
*e.g.- Balanoglossus, Rhabdopleura

BALANOGLOSSUS

RHABDOPLEURA