AN INTRODUCTION TO PHYSIOLOGY|HISTORY OF PHYSIOLOGY|BRANCHES OF PHYSIOLOGY|ORGANISATION OF THE BODY

AN INTRODUCTION TO PHYSIOLOGY|HISTORY OF PHYSIOLOGY|BRANCHES OF PHYSIOLOGY|ORGANISATION OF THE BODY:

hello and welcome to high thoughts

the home of simplified tutorials

this is a human physiology series

where we aim at simplifying concepts in

the field

being the first tutorial in the series

we started an introduction to human

physiology the word physiology is derived from two greek words namely physios

which means nature and lugia which means to study therefore physiology can literally be defined as a study of nature in more specific and proper terms

physiology can be defined as a branch of

biology that deals with the normal functions of

living things as well as the chemical and physical

mechanisms behind these functions for example

the major function of the digestive

system is to ensure nutrition

the physiology of digestion explains how

food gets into the body and the various processes

by which different food types are broken

down for absorption and utilization

as well as the processes involved in the

ejection of thicker matter in another example

the major function of the genetic system is to ensure production and the physiology of the production

explains how sex results in fertilization

and how the fertilized egg divides

grows and differentiates to form a viable neonate at birth it can therefore be said that physiology reveals the mysteries behind the complicated functioning of living things ranging from the smallest viruses to the biggest trees and the most complicated humans

the study of physiology dates back to about 420 years bc in the time of hippocrates

the greek philosopher and famous father of medicine who in an attempt to explain how the

human body functions coined the theory of hemorrhaging

stating that the body consists of four fluids namely blood gild by black by and flame

these fluids were believed to exist at different temperatures

each of which was composed of one of the four basic elements air fire head and water

he noted that a balance in the volume of this fluid was necessary for one to be healthy

and an imbalance was responsible fordisease or evil helped cloudy's galenas

also known as galen was a greek physician surgeon and philosopher

who lived in the second century a.d he was basically a proponent of the

theory of hemorrhaging and is referred to as a founder of

experimental physiology as is believed to have been the first to

use experimental evidence to explain physiological processes

kalin viewed the body as consisting of three connected systems

the brain and nerves which are responsible for sensation and thoughts

the heart and arteries for energy generation

lastly the liver and veins responsible for nutrition and growth

he also added the notion of temperament

which considered imbalance in the four bodily fluids

to be the physiological basis for differences in personality

for example he believed that excess of yelubai

was responsible for the choleric temperament

expressed as excessive energy aggressiveness and short temper

in contrast excess of black by was responsible for

the melancholic temperament characterized by bipolar personality

quietness and periods of depression white excess of flame would result in a

phlegmatic temperament characterized by thoughtfulness calmness and laziness

lastly excess of blood was responsible for the sun wind temperament

expressed as happiness optimism and talkativeness gallenic theories were valid for the

next 1400 years up to the 16th century jane fennell a french physician in the 16th century

introduced the term physiology to describe the study of body functions

he was also the first to describe the spinakana william harvey an english physician

who lived between the 16th and 17th centuries is known as the founder of modern

experimental physiology he was the first known physician to

describe systemic circulation completely and in detail

a detailed understanding of systemic circulation brought to an end the

validity of the theory of the full body fluids and marked the beginning of modern

physiology the french physiologist claude bernard who lived in the 19th century is known

as the father of modern physiology among other works

he discovered the concept of the internet environment

explaining that body function requires a stable internal environment

in spite of a dynamic external environment this concept provided the basis for the

current understanding of the concept of homeostasis the physiological society was founded in

london in the year 1876 as a dining club why the american physiological society

a non-profit organization

devoted to aid education

scientific research and dissemination of

information in the field of physiology

was founded in 1887.

several discoveries were made in the

field of physiology between the 19th and

20th centuries

some of which include

the demonstration of conditioned reflex

in dogs by the russian physiologist evan

parlov

the development of the cell theory by

matthias clayden and theodosium

the discovery of the ionic mechanism of

nerve impulse transmission

by andrew huxley and alain hodgkin in

the year 1952

as well as the discovery of the sliding

filament in skeletal moses in 1954

by andrea huxley and hill huxley amongst

others

due to advancement in knowledge and

technology over time

the study of physiology has evolved

from hypothetical theories in ancient

days

to advanced laboratory techniques in

modern days such as molecular imaging

which enables the visualization of

physiological processes taking place at

cellular and subcellular levels in

intact subjects including humans

animal physiology investigates the

life-supporting processes in animals

examples of such processes include

feeding

blood circulation respiration courtship

etc

plant physiology a sub-discipline of

botany deals with the functioning of

plants

explaining concepts such as

photosynthesis tropism transpiration etc

eco-physiology

also known as environmental physiology

studies the responses of an organism's

normal functioning to changes in

environmental conditions such as

temperature humidity pressure etc

comparative physiology investigate the

diversity in functional characteristics

of living things for example

how the process of respiration

differ between fishes and birds

or how the process of digestion

differs between birds and reptiles

evolutionary physiology investigates how

the functional features of organisms

develop and diversify from older worlds

for example

how the functional processes in human

have evolved from those of apes

human physiology a branch of interest

explains the mechanisms that keeps the

human body alive and functioning

including life-supporting processes such

as nutrition respiration excretion reproduction etc.

the organization of the human body

attempts to answer the question

what is the human body made up of

like every other matter

the human body essentially consists of

indivisible building blocks known as

atoms

atoms combine to form molecules

a collection of molecules form

organelles which work to ensure and

maintain life at the cellular level

a combination of organelles forms the

cell

why a collection of cells performing a

function is known as a tissue

tissues combine to form organs

a collection of organs performing a

given function is known as an organ

system

a combination of organ systems form a

whole human body such as ears and mind

the atom is the least level of body

organization structurally

each atom consists of protons and

neutrons in the nucleus

as well as revolving electrons in the

orbits the body consists of atoms of elements

such as hydrogen oxygen carbon nitrogen and etc

a combination of atoms linked together

by chemical bonds

forms a molecule

molecules can be formed from atoms of

the same or different elements oxygen water

and glucose for example

are molecules found in the body

each of which consists of various atoms

various molecules combine to form

organelles such as nucleus mitochondria

ribosomes cell membrane etc

the cell membrane for instance majorly

consists of molecules of protein

carbohydrates and fat the nucleus on the other hand consists

of molecules of nucleic acids and

proteins plain principle rules in gene expression

the cell is a structural and functional

unit of life composed of organelles

cells define structure with function

for example

the nerve cells are modified for impulse

generation and conduction why muscle cells are modified for

contraction whereas red blood cells are structured for

oxygen transport a collection of cells performing a

particular function is known as a tissue

examples of body tissues include

lung tissues muscle tissues brain tissues etc

a combination of tissues performing a

function is known as an organ

there are 78 major organs in the human

body each of which is specialized in carrying

out the particular function examples include the heart lungs liver brain etc.

A system of connected organs

playing a specific role in the body is

known as an organ system

there are nine major organ systems in

the human body these include

the digestive system nervous system

endocrine system respiratory system etc

the digestive system for example

consists of the mouth its phagos stomach

pancreas intestine anus amongst others

why the respiratory system in another

instance consists of the nose pharynx trachea

bronchi and lungs the various organ systems constitute the

whole human body such as yours and mind capable of carrying out the virus

activities of life physiologist is science that

investigates the normal functioning of living things

the study of body functions dates back

to about 420 years bc and has transformed over time from

ancient theories to advanced laboratory

techniques there are six main branches of

physiology this includes animal physiology

plant physiology comparative physiology

evolutionary physiology human physiology

and eco-physiology the body essentially consists of atoms

which combine to form molecules

organelles cells tissues organs and organ systems.