◊ Body fluid

◊ Types of fluid

◊ Compositon of fluid

◊ Functions of body water

◊ Water balance

◊ Osmoconformers

◊ Osmoregulators

◊ Types of environment

◊ Osmoregulation in different enviroment

◊ Types of osmoregulatory organs in invertebrates

60% of body weight of young male51% of body weight of young female 40% in obese persons 72 kg weighted youn male contain 42 liters

body fluid

Body fluid

۞Two types of body fluid is present in humans

1)Interacellular fluid

2)Extracellular fluid

Types of body fluid

water inside the cell is called intracellular fluid

Constitiute about 2/3 of total body fluid

About 28 liters in young 40% of total body weight

Intracellular fluid

Main Cation:- K+ , Mg2+ , Na+ along with small

amount of Ca2+

Main Anion:-

HPO4 2- and protein along with small amount of Cl-, HCO3- and SO42-

pH:-

almost 7 pH.

Composition of ICF

Ж Fluid outside the cells Ж Found in blood, in lymph, in body

cavities lined with serous membrane, in the cavities and channels of the brain and spinal cord, and in muscular and other body tissues.

Ж 20% of body weightЖ constitute about 1/3 of total body

fluid

Extracellular Fluid

¥ Main Cation:-

Na+ , K+ and small amount of Ca2+ and Mg2+

¥ Main Anion:-

Cl- , HCO3-, protein and small amount of HPO42- and SO42-.

¥ pH:-

is about 7.4

Composition of ECF

It can be subdivided into two following types:

a)Intravascular fluid

b)Extravascular fluid

Subdivisions of ECF

☼ Fluid within blood vessels

☼ Made up of blood, serum (water, clotting factors, chemicals and electrolytes)

☼ Normally ¼ of ECF volume

☼ about 5% of body weight

Intravascular Fluid

₢ Fluid outside the blood vessels

₢ Normally about ¾ of ECF volume

₢ 15% body weight

₢ It includes:

i. Interstitial fluid( tissue fluid)

ii.Transcellular fluid(cerebrospinal and intraocular fluids)

Extravascular fluid

Medium for chemical and enzymatic reactions

Medium for physical reactions, filtration and diffusion

Ionizing medium Regulates the body temp.Lubricant in joints and pleura

Functions of Body Water

Refractive medium in eyeMechanical buffer in cerebrospinal fluid to

protect the brain Medium for exchange of gases in lungs

and tissues.

Balance b/w daily water gain and water loss

Under normal condition, both are equal (2300 ml/day each)

So body fluid remains in balance.

Water Balance

Normally about 2300ml/day.Gain from 2 sources:

1.Exogeneous water:-

by oral route (by drinking and eating)

averages about 2000 ml/day

Water Gain

2. Endogeneous water:-

formed inside the body

It is as a result of oxidation of H2 .

Normally about 300ml/day.

o Normally lose 2300 ml/day as follows:

a)1400 ml in urine

b)100 ml in feces

c)350 ml by evaporating from respiratory tract

d)450 ml from skin

Water Loss

Maintance of osmotic pressure by control of water and salt conc.

Types of Animals on the Basis of Osmoregulation:-

a)Osmoconformers

b)Osmoregulators

Osmoregulation

Osmoconformers

which maintain body osmotic conc. To external environment.

Examples:-

 marine invertebrates such as echinoderms (such as starfish), mussels, marine crabs, lobsters, jellyfish, ascidians (sea squirts

Osmoregulators

Which regulate body osmotic conc. To external environment.

Examples:-

Cartilagnious fishes, bony fishes, fresh water protozoa, Ameoba, Paramecium, almost all vertebrates including humans.

Types of Environment

• Hypertonic Environment:-

Contain large amount of solutes

• Hypotonic Environment:-

Contain small amount of solutes

• Isotonic Environment:-

Amount of solutes balanced

Osmoregultion in Marine Envir.Marine fish hypotonic to their environment Blood has high level of water to their

surroundings Water molecules diffuse out by osmosisMust replace water which lose by osmosisProduce small amount of urine Brings large amount of salt

To replace water they drink sea water Have low rate of filtration in their kidney

tubules Have small glomerulus Salts are removed by rectal glands

Osmoregulation in fresh water environment

๏ hypertonic to their surroundings

๏ blood has a lower water concentration than the surrounding fresh water.

๏ Water molecules diffuse from the fresh water into the blood by osmosis.

๏ must produce a very large volume of urine

๏ large volume of urine carries salt with it

๏ remove a large volume of water from the blood by having a high rate of filtration into thekidney

๏ having many large glomeruli

๏ salt replacement is solved by chloride secretory cells

Osmoregulatory organ in Invertebrates

following osmoregulatory structures are present

Contractile vacuoles ProtonephridiaMetanephridiaGreen & Maxillary glandsMalphigian tubulesCoxal Glands

Contractile vacuoles

Need energy Expel excess water from individual cell to

hypo osmotic environment Present in fresh water species like

protozoan and sponges

Protonephridia

Present in annelids, larval molluscs and some flatworms

Primitive Nephridia Composed of network of excretory canals Flame cell system present on execratory

canals Flame cells filter surrounding interstitial

fluid

Cilia propels the fluid through excretory canals

Then it moves out from body through excretory pores

Primarily eliminates excess water Nitrogenous waste are simply diffuse

across the body surface

Metanephridia

Present in many annelids, earthworms and many molluscs at their adult stage

Advanced type of excretory system Begins with a ciliated funnel

“nephrostome” Opens in body cavity Beating of cilia moves the fluid into

tubules

Network of capillaries surrounds the tubule

Reabsorbs ions Tubules open in enlarged bladder Bladder opens outside the body through

nephridiopore

Excretory organs in crustaceans

They have following structures:

¶ Gills

¶ Green glands or Antennal glands

¶ Maxillary glands

Gills remove nitrogenous waste by diffusion in some crustaceans

Green glands are present in crayfish & crabs

Located near antenna and green in color Fluid filters from hemocoel Hemolymph pressure cause filtration Nephridial canals also present

Malphigian tubules Present in insects Attached with gut K ions moves in tubules through active

transport Water follows osmotically Some water and ions are reabsorbed Tubules open into gut &all uric acid

passes to gut

Coxal Glands Present in spiders, scorpions & mites Spherical sacs Collect waste from Hemolymph Discharge it through pores Pores are present on appendages &

these are present near proximal part of joint of leg

Also secret pheromones