Homeostasis or Osmoregulation, Homeostatic Process and the Parts Involved in Homeostatis

Homeostasis is defined as the maintenance of a fairly constant internal environment in an organism. All living organisms must be able to maintain a steady environment. Body fluid such as blood, lymph and tissue fluids make up the internal environment of the organism. 

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Care of the Skin

There is need to properly take care of the skin. If the sweat and oily substances are not removed from the body on time, dust and bacteria will stick to the surface of the skin. 

Dirty skin promotes bacteria and other pathogenic growth as well as blockage of the sweat pores. Some skin diseases can even develop as well as unpleasant body odour. All these may prevent the skin from performing its normal functions. 

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Functions of the Skin

The important functions of the skin include:

1. Protection: The skin protects the body against entrance by microbes, mechanical injuries, ultra-violet rays of the sunlight and desiccation by acting as waterproof. The pigment, melani absorbs ultra-violet rays from the sun which is harmful to the body.

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The Skin and Its Structure

The skin is the outer covering of vertebrates. It forms a continuous layer over the entire body, making it the largest organ. In mammals, the skin usually bears a dense growth of hairs. Human beings, however, only have a sparse growth of hair over most parts of their bodies.

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Diseases of the Liver, their Effects and Remedies

Certain diseases can impair the functioning of the liver. 

They include:

1. Diabetes mellitus: This disease is caused as a result of the inability of the liver cells to convert excess glucose in the blood to glycogen. This is as a result of the failure of the pancreas to produce a hormone called insulin. Consequently, excess sugar is left in the blood and lost through urine.

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The Liver and Its Functions

The liver is a large reddish-brown organ with two lobes. It lies just below the diaphragm to the right side, partly overlapping the stomach. Its average weight is about 1.25kg. Each lobe of the liver is subdivided into smaller lobes 


[image credit: Bruce]

The gall bladder which stores the bile is connected to the duodenum by a short tube called bile duct. The bile duct is a soft organ with a rich and extensive blood supply.

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Diseases of the Kidneys, their Effects and Remedies

DISEASES OF THE KIDNEYS



1. Diuresis: This is a condition in which the cells of the kidney tubules are not reabsorbing water from the glomerular filtrate, and as a result, a large amount of water is  passed out in urine. Diuresis can also occur from a patient, suffering from diabetes insipidus - a condition in which the production of ADH (Anti-Diuretic Hormone) becomes reduced. Less water is reabsorbed and the patient produces a lot of urine - about 5-20 litres a day.

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Functions of The Kidneys and Conditions Affecting Them

The structure of the kidneys has already been discussed here.

FUNCTIONS OF THE KIDNEYS


[photo credit: Michal]

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Dental Formula, Adaptation of Mammalian Teeth for Feeding and Dental Care

DENTAL FORMULA

[Photo credit: Dozenist]

Dental formula can be defined as the number and types of teeth an animal has in one half of each jaw. Different mammals have different dental formulae depending on their diet. In the following formulae:

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Feeding, Digestion and Dentition in Mammals

The solid food most animals eat is usually large, and must first be broken down into small molecules in the alimentary canal before it can be absorbed in the blood stream. This is usually done mechanically and chemically in mammals. 

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Feeding Mechanism and Modifications in Some Animals

There are five modifications and mechanisms of feeding associated with some organisms. These feeding mechanisms include:

1. Biting and chewing mechanism e.g. grasshopper or cockroach: The grasshopper or cockroach has mouth parts adapted for biting and chewing. 

[Photo credit: Fir0002. License: GFDL. Released under GFDL v1.2]

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Digestive System of Rabbit and Other Herbivores

DIGESTIVE SYSTEM OF RABBIT


[Photo credit: Larry D. Moore. License: CC-BY-SA 3.0]

The teeth of herbivores are adapted for cropping grass and grinding plant matter to break down the cellulose cell walls. The incisors of a rabbit are long and chisel-shaped. They bite against each other to chop off pieces of grass.

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Digestive System or Alimentary Canal of Man

The alimentary canal is a long tube stretching from the mouth to the anus. The digestive system or alimentary canal of man includes: the mouth, oesophagus, stomach, duodenum, small intestine or ileum, caecum, appendix, large intestine or colon, rectum and anus. 

[Photo credit: Bruce Blaus]

The description and importance of the parts are as follows:

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Digestive System of Planaria, Tapeworm, Amoeba, Earthworm, Insects and Bird

DIGESTIVE SYSTEM OF PLANARIA

[Photo credit: PlanMine]

The planaria is a free-living flatworm that feeds on aquatic animals called zooplanktons. It has a simple alimentary canal with one opening - the mouth. The mouth opens into a short buccal cavity which leads into the pharynx.

The pumping action of the pharynx sucks in pieces of food which enter the pharynx and pass into the small intestine. The small intestine has three branches - one leading to the head and the other two towards the tail. The branches give off numerous side branches.

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Digestion, Digestive System and Feeding Mechanism

Digestive System includes the alimentary tract or canal and all the organs and glands associated with the digestion and assimilation of food in animals.The digestive system varies from one animal to another, Organisms from simple to complex ones have different types of digestive systems or alimentary tract.


Animals have different types of alimentary tracts which vary in size, complexity, mode of feeding or type of diet. However, there is no definite alimentary canal in plants.

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Excretory System of Plants

Plants have no special excretory organs because their metabolic waste products are minimal. Plants manufacture their own food, i.e they are autotraphic. The waste materials are disposed off through various parts of the plant. 

[Photo credit: Estreya]

Plant wastes products include water, carbon dioxide oxygen, acids, resins, mucilage, latex, alkaloids, crystals of salts, oils, gum and anthocyanin.

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EXCRETORY SYSTEM OF MAMMALS: Structure and Mechanism of Excretion of the Kidney and Urinary Tubule

EXCRETION IN MAMMALS

[Photo credit: Jordi March i Nogué]

In mammals, there are four excretory organs:

• lungs, which excrete water vapor and carbon dioxide;
• skin, which excretes water, salts and urea through sweat;
• liver, which excretes bile pigments called bilirubin; and
• kidneys, which excrete water, mineral salts, urea, uric acid, and creaunine.

EXCRETORY SYSTEM OF MAMMALS

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Excretory System and Mechanism of Excretion in Earthworm, Flatworm, Insects and Amoeba

EXCRETORY SYSTEM OF EARTHWORM

[Photo credit: KDS444. Earthworm_head.svg from wikipedia commons. License: CC-BY-SA 3.0]

An earthworm has a segmented body. Each segment of the body except the first three and the last segment has a pair of tubes called nephridia. The nephridia are the excretory organs of the earthworm.

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EXCRETION: Definition, Importance, Need for Excretory Systems, Organisms and Their Excretory Organs, Excretory Organs and Their Waste Product

Excretion can be defined as the process by which metabolic waste products are removed from the body of living things. Waste product from metabolic activities are always produced by the bod and their removal are carried out by special excretory systems or organs. 


[Photo credit:  Hämbörger. License: GNU Free Documentation License]

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Respiratory System in Plants

Plants carry out gaseous exchange for: photosynthesis and cellular respiration.


[Photo credit: Yvan Lindekens]

Photosynthesis is the process by which green plants manufacture their food, making use of carbon dioxide and water in the presence of sunlight.

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Respiratory System in Mammals

The  most complex respiratory system is found in mammals. Most vertebrates, including birds, lizards and mammals use the lungs as their only respiratory organs where gaseous exchange takes place.

LUNGS

[Photo credit: Patrick J. Lynch, medical illustrator]

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Supporting Tissues in Plants, Their Mechanisms and Their Functions

SUPPORTING TISSUES IN PLANTS


[Photo credit: Emmanuel]

Plants generally are known to possess supporting tissues which give them definite shape, strength, rigidity and resistance against external forces such as wind and water to which they are continuously subjected.

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JOINTS: Definition, Types, Structure, and their contribution to movement

A joint is a place or region where where two more more bones meet or articulate. Movement is made possible with the aid of joints and muscles. Joints are always held together by strong ligaments which prevent dislocation during movement. Ligaments join bones together.

[Photo credit: Madhero]

TYPES OF JOINTS

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Appendicular Skeleton

Appendicular skeleton, together with axial skeleton, makes up the skeletal system.

The Appendicular skeleton is a skeletal system, which consists of the girdles and the bones of the limbs. The girdles consist of: 

• pectoral girdles and
• pelvic girdles 

while the limbs consists of:

• fore limbs and 
• hind limbs

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Axial Skeleton

The skeletal system in mammals are grouped into two parts: Axial skeleton and Appendicular skeleton.


The axial skeleton is a skeletal system, which consists of the skull, vertebral column, the ribs and sternum.



THE SKULL

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SKELETON: Forms, Components, Types and others you need to know

Skeleton can be defined as the bony framework of the body, which provides support, shape and protection to the tissues and organs in animals. It enables movement in animals. Without skeleton, movement or other life processes may not be possible in animals.

[Photo credit: Skimsta]

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Transport System in Plants

As I discussed in an earlier post about means of transport system, the medium or means of transport in plant is latex or cell sap and the materials transported are water, carbon dioxide, oxygen, amino acids, e.t.c. Plants require sufficient quantities of several minerals and other substances which are transported in them.

[Photo credit: Smartse]

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The Heart and Blood Vessels

The movement of blood in the body is made possible with the aid of the heart and blood vessels. The heart is responsible for the pumping of blood around the body and the blood circulates through the blood vessels.


BLOOD VESSELS


[Photo credit: Kelvin Song]

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Circulatory System in Mammals

Circulatory system refers to the organs and tissues involved in the continuous movement of blood round the body. It involves the heart and the blood vessels - veins, arteries and capillaries.


[Photo credit: Mariana Ruiz Villareal]

Types of Circulatory Systems

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Transport System in Man

Materials are efficiently distributed in mammals, especially man is provided by the transport system. The blood and lymph are the means of transport in man.


THE BLOOD

Components of the Blood


[Photo credit: Messer Woland]

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Transport Systems

Transport systems refer to the systems of organs and tissues involved in the movement of materials, from where they are produced to where they are needed  within various parts of an organism. This transport occurs in plants and animals.

[Photo credit: Foobar]

Importance of Transportation

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Respiratory System in Unicellular Organisms, Insects, Fish, Tadpole and Toad

RESPIRATORY SYSTEM IN UNICELLULAR ORGANISMS


[Photo credit: Dr.Tsukii Yuuji]


Unicellular organisms have no special respiratory organs, as well as aquatic animals such as Amoeba and Paramecium. Oxygen that dissolves in water diffuses into the body while carbon dioxide goes out of the body through the

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RESPIRATION: Meaning, Stages, Conditions Required, Characteristics

Respiration can be defined as biochemical activity of the cell, in which glucose is broken down by a series of reactions, controlled by enzymes, to release energy.


[Photo credit: Regis Frey]

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Reproductive System in Flowering Plants

The flower is known as the reproductive structure of flowering plants. It consists of the male sex organ and female sex organ which makes it possible for them to reproduce sexual. Seeds, which are capable of germinating into new plants are produced, often as a result of the fertilization that occurs internally.

THE STRUCTURE OF A FLOWER


[Photo credit: Amada]

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Reproductive System in Reptiles, Fish and Birds

REPRODUCTIVE SYSTEM IN REPTILES

The reproductive system in Agama lizard is as follows.


[Photo credit: Sajjad Fazel]

The male Agama lizard possess two testes. The testes are located in the abdomen. One testis is found at the right side and the other at the left side.

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Reproductive System in Mammals

Mammals generally reproduce sexually. They are generally unisexual. Reproduction in mammals is usually viviparous - their offspring are born alive, and not eggs that need to be hatched. Reproductive system in mammals is majorly divided into two - male reproductive system and female reproductive system.


[photo credit: Zephyris]


MALE MAMMALIAN REPRODUCTIVE SYSTEM

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Pollination in Plants

Pollination can be defined as the process by which mature pollen grains are transferred from the anthers of one flower, to the stigma of the same or another flower, hence making fertilization occur. It is a required process in reproduction in plants.


[Picture credit: Brocken Inaglory]

Types of Pollination

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Courtship Behavior In Animals

Courtship behavior of an animal is the collection of instinctive behavior the animal exhibits, in response to some external stimuli. It precedes mating and reproduction. It is carried out by male and female animals, and usually carried out in sequence. One step leads to another.


[photo credit:  U.S. Fish and Wildlife Service]

Significance of Courtship Behavior in Animals

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EVOLUTION: Explanation, Evidences, Theories, Modren Theory, Trends

EVOLUTION

Evolution, also known as organic evolution, can be defined as the total adaptive changes in the inheritable genetic make-up of organisms, which results in the diversity of functions, forms and structures among the organisms. It usually takes a long period of time.

[Photo credit: Волков Владислав Петрович.]

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MENDEL'S WORK IN GENETICS: His Experiments, His Reasons, His Laws

Gregor Mendel (1822-1884) is often regarded as the father of genetics.This is because his work formed the foundation for scientific study of heredity and

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GENETICS: Biology of Heredity

Genetics can be defined as the scientific study of inheritance or heredity and variations in living things (plants and animals).

Heredity: This can be defined as the transfer of traits(characters) in organisms, from parents to offspring. Living things (plants and animals) offspring usually

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