Define Respiration?

Answer :

RESPIRATION

:

Definition :

The stepwise and enzymetic complex oxidation reduction processes by which food is broken down into simple materials to release energy at the cellular level is called respiration.

IMPORTANCE OF RESPIRATION :

a) In aerobic respiration , organisms break down their food with the help of oxygen into simple compounds like water and low to release energy.

b) Such energy is stored in the form of ATP which is used in other metabolic activities .

c) In respiration Co2 is produced which is waste product and the organisms must get rid of Co².

Question :

Write the properties of respiratory surfaces?

Answer : -

PROPERTIES OF RESPIRATORY SURFACES:

Definition :

" The surface or area of organism body where respiratory gaseous exchange with the environment or surrounding takes place is called respiratory surface . " Respiratory surfaces are the sites where gaseous exchange takes place by simple diffusion process for effective diffusion of respiratory gases , the respiratory surface must have the following properties .

a) THIN EPITHELIUM :

    The surface through which exchange of gases takes place must Be very thin walled , so the distance through which difusion takes place may be minimum

b) MORE PERMEABLE :

The surface through which exchange of respiratory gases takes place must be permeable..so more gases will be diffused.

c) LARGE SURFACE AREA:

    Respiratory surface should have lange Sarface area , so that maximum air is taken in and maximum CO2 is given out .

d) WET SURFACE :

    The respiratory surface should be kept moist so that gaseous exchanges occur easily because gases cann't Pass through dry surface easily.

e) CAPILLARY NETWORK:

The respiratory surface should possess extensive network of blood capillaries through which blood can pass at an adequatic speed. In this way complete diffusion gradient is maintained which helps in rapid diffusion of oxygen.

f) VENTILATION:

There should be a good ventilation mechanism to maintain steep ( High ) diffusion gradient across the respiratory surface.

Q - 3 : Describe the structure of human respiratory system?

Answer :

HUMAN RESPIRATORY SYSTEM:

Definition: A system of organs functioning in respiration is respiratory System. "

Explanation : - Human respiratory system consists of lungs and air passage to carry air to and from lungs. i.e Air passage:

AIR PASSAGE:

Definition : " The respiratory tract / tube in which gases are passed toward lungs for exchange is called air passage.

PARTS OF AIR PASSAGE:

Air passage way consiste of the following parts .

NOSE:

introduction : " The nose is only external part of the respiratory system which links the respiratory system with the environment for exchange of respiratory gases ."

STRUCTURE OF NOSE :

Nose is external visible part of respiratory system which is slightly different ( External feature ) in each individual depending upon the ethmoid bone and the catilages . But each nose structure consists of bones , cartilage and Fibro fatty tissue . 

NOSTRILS :

" It is the openings of nose in which air enters to respiratory tract or tube. 

NASAL CAVITIES:

 Each nostril open to cavities called nasal cavity , which then open into pharynx. 

MUCOS AND HAIR :

Each nasal cavity is lined by cilliated - epithelial cells which secrete mucous and also bear hair .

 FUNCTIONS OF NOSE : ( Mucous and Hair)

1) Through nose respiratory gases is enter to respiratory tube .

2) The hair of nose acts as a filter to trap large dust particles defense mechanism against the harmful pathogens and solid particles present ,

3) The mucus and cilia filter the air and prevent the entry of foreign particles such as microorganisms , dust , etc.

4) Nose hair also serve as a in the air .

5) The mucus also helps in moistening the air.

6) Underneath the mucos membrane , there are blood capillaries that help to warm the air ( at about 30C° ).

PHARYNX : ( 4.5 inch )

introduction : - " The nasal cavities open into cone shaped muscular passage called pharynx . "

FUNCTIONS:

Pharynx also linned with muscous membrane .

1- The mucus of pharynx moisturized the air warm the air and trap dusts and solid particles .

2. It regulate the air and food to Trachea and oesophagus .

LARYNX ( sound box / voice box ): 

Introduction :

It is a cartilagenous structure present on the upper end of the trachea.It is also lined with mucous membrane . Cartilagenous: The Larynx is composed of an external skeleton of cartilage plates that prevents collapse of the structure .

 GLOTTIS AND EPIGLOTTIS:

The opening of larynx is known as glottis which is gaurded by lid called epiglettis. The epiglottis prevents entry of food or liquid into larynx .

 VOCAL CORD:

Inside the larynx there are two fibrous bands called vocal cords which help in voice production . As air passes through lungs the vocal stretch and produce sound. Sound is changed into word by tongue and lips .

 VOCAL PITCH :

Men and women have diferent vocal cord sizes . This differences in vocal cord size causes a difference in vocal pitch. Adult males have large vocal cords and usually produce Low pitched voices , while adult females have smaller vocal cord and produce high pitched voices . 

FUNCTIONS OF LARYNX :

1. Larynx is a small air passage which linned with mucous membrane , helps in filteration of air.

2). Larynx is also called sound box because it produces sound . -

TRACHEA :

Introduction : - It is a tubular cartilagenous structure which is also called wind - pipe , lies below the larynx . it is internally lined by ciliated epithilium which bears mucous secreting cell .

Length : Trachea is about 10-12 cm long , and 2 cm wide . 

CARTILAGENOUS RINGS: 

The Treachea bear 16-20 " C " or shoe shaped cartilage rings which prevent the trachea from collapsing and keep it open .

FUNCTION OF TRACHEA:

1. The mucous of Trachea - moist and warmth the air .

2. Trachea provide a passage for air to move toward lungs.

3. mucous and cilia of Trachea filter the air and protects the respiratory surface from an accumulation , of foreign particles.

BRONCHI:

Introduction : - " The Trachea is divides into right and Left bronchi which enters to each lungs. Bronchi are cartilagenous air - passage , which lined with mucous membrane. 

RIGHT AND LEFT BRONCHI:

The right bronchus has larger diameter and is shorter , while the left bronchus has smaller diameter and is longer.

 FUNCTION BRONCHI:

1- Bronchi ( right + left bronchi ) divided the air for each lung

2. Bronchi also lined with mucous membrane which filter , moisturized and warmth the air .

MUCUS:

Mucus is a viscous fluid composed of water , epithelial cells , dead leukocytes , mucin ,and inorganic salts. 

AIR SACS AND ALVEOLI:

The bronchioles continue to divide and subdivide deep into the lungs and finally open into a large number of air - sacs . In fact air - sac is the functional unit of the lungs . Each air - sac is like a cluster of grapes and consists of several microscopic single layered structures called alveoli . The alveoli are surrounded by a rich network of blood capillaries to produce an excellent site for the exchange of gases . There are about 700 million alveoli present in the lungs of a mammal.

LUNGS:

The lungs are closed sacs that are connected to the outside by the way of the trachea and the nostrils or mouth . Lungs are spongy because of the presence of millions of alveoli . Lungs are placed in the chest cavity . Chest cavity is bounded by ribs and muscles on the sides . The floor of the chest is called diaphragm which is sheet of skeletal muscles . Lungs are covered with double layered thin membranous sacs called pleura .

Pre-medical Ist year Biology Notes.