This document summarizes respiration in animals. It begins with an overview of the topics to be covered, including the anatomy of the respiratory system, external respiration (gas exchange between the lungs and environment), and internal respiration (gas exchange between blood and body tissues). It then defines respiration and describes the modes. The anatomy section details the structures of the airways, lungs, and respiratory muscles. External respiration involves inhaling oxygen and exhaling carbon dioxide between the lungs and air. Internal respiration is gas exchange between blood in the pulmonary capillaries and tissues via diffusion. The cycle of respiration continuously supplies oxygen to tissues and removes carbon dioxide.

1. ANIMAL PHYSIOLOGY
SEMINAR PRESENTATION
BY
U.ID

2. ON:
RESPIRATION
...journey of O2 from environmet to body tissues….

3. TOPICS COVERED
RESPIRATION
Anatomy of respiratory system
Phases of respiration physiology
*External respiration
*Internal respiration

4. RESPIRATION…..
DEFINITION:
The major physiological process in all
living organism, involves the production of
energy, typically with intake of oxygen and the
release of carbon dioxide from the oxidation of
complex organic substances.
*Performed by special respiratory modes,
which differs from species to species.
O2 CO2

6. MODES OF RESPIRATION

7. ANATOMY OF RESPIRATORY
SYSTEMAnatomically respiratory system is composed of 3
major parts..
the airway the
lungs,
the
muscles of
respiration.
includes
nose, mouth,
pharynx, larynx,
trachea, bronchi, and
bronchioles, carries
air between the
lungs and the
body’s exterior.
functional units of
the respiratory
system by
passing oxygen
into the body and
carbon dioxide out
of the body.
includes the
diaphragm and
intercostal muscles,
work together to
act as a pump,
pushing air into
and out of the
lungs during
breathing.

8. Nose and Nasal Cavity
-Main external opening for the respiratory system
-Function - nasal cavity = warm, moisturize, and filter air
entering the body before it reaches the lungs.
-
Mouth/ORAL CAVITY
-Secondary external opening for the respiratory tract.
- Oral cavity can be used to supplement or replace the nasal cavity’s functions
when needed.
- Lacks the hair and sticky mucus that filter air passing through the nasal cavity.
- One advantage of breathing through the mouth is that its shorter distance and
larger diameter allows more air to quickly enter the body.
Pharynx - also known as the throat
-Muscular funnel that extends from the posterior end of the nasal cavity to the superior end of
the esophagus and larynx.
-divided into 3 regions:
the
AIRWAY
nasopharynx, oropharynx ,
laryngopharynx

9. Nasopharynx - is the superior region of the pharynx found posterior
to nasal cavity.
- Inhaled air from the nasal cavity passes into the nasopharynx and
through the oropharynx, located in the posterior of the oral cavity.
-The inhaled air then descends into the laryngopharynx, where it is
diverted into the opening of the larynx by the epiglottis.
flap of elastic cartilage that acts as a switch
between the trachea and the esophagus
Because pharynx is also used to swallow food, epiglottis ensures that air passes into
the trachea by covering the opening to the esophagus. During swallowing, epiglottis
moves to cover the trachea to ensure that food enters the esophagus and to prevent
choking.

10. Larynx: also known as the voice box.
-short section of airway that connects laryngopharynx &
trachea.
-located in anterior portion of neck, just inferior to the hyoid
bone and superior to the trachea.
-Several cartilage structures make up the larynx and give it
its structure.
-posterior to epiglottis- thyroid cartilage, often referred - Adam’sapple
-posterior to thyroid cartilage is ring-shaped cricoid cartilage ,
-contains special structures, vocal folds, which allow the
body to produce the sounds of speech &
singing.
folds of mucous membrane that vibrate to
produce vocal sounds. The tension and vibration speed
of the vocal folds can be changed to change the pitch that
they produce

11. Trachea:
-windpipe ,5-inch long tube made of C-shaped hyaline cartilage rings lined with
pseudostratified ciliated columnar epithelium.
-connects larynx to bronchi & allows air to pass through neck & into thorax.
- main function -to provide a clear airway for air to enter & exit the lungs.
-epithelium lining the trachea produces mucus that traps dust & other contaminants
& prevents it from reaching lungs.
-Cilia on surface of the epithelial cells move the
mucus superiorly toward the pharynx where it can be
swallowed & digested in the gastrointestinal tract.

12. Bronchi and Bronchioles: At posterior end of the trachea, the airway splits into left and
right branches known as the primary bronchi.
run into each lung before
branching off into smaller secondary bronchi
carry air into the lobes of the lung
split into many smaller tertiary bronchi within each lobe.
# split into many smaller bronchioles that
spread throughout the lungs.
Each bronchiole further splits into many smaller
branches less than a mm in diameter- terminal bronchioles.
*Finally,millions of tiny terminal bronchioles conduct air to
alveoli of lungs.
*Main function = carry air from the trachea into the lungs.
alveoli form clusters, called alveolar sacs, that resemble bunches of grapes.
many tiny air sacs in
lungs.Aprox 300,000,000 alveoli
at the ends of the bronchiolesalveoli form clusters, called alveolar sacs, that resemble bunches of grapes.

14. Lungs:
- a pair of large, spongy organs found in thorax lateral to the heart and superior to the
diaphragm.
-Each lung is surrounded by a pleural membrane that provides the lung with space to
expand.
- both are slightly different in size and shape due to the heart pointing to the left side of
the body.
- left lung is therefore slightly smaller than the right lung and is made up of 2 lobes while
the right lung has 3 lobes.
-The interior of the lungs is made up of spongy tissues containing many capillaries and
around 30 million tiny sacs known as alveoli
cup-shaped structures found at the end of the terminal
bronchioles and surrounded by capillaries
alveoli are lined with thin simple squamous epithelium
that allows air entering the alveoli to exchange its
gases with the blood passing through the capillaries.

15. Muscles of Respiration:
-Surrounding the lungs are sets of muscles that are able to cause air to be inhaled or
exhaled from the lungs.
- principal muscle of respiration in the human body is the diaphragm
When diaphragm contracts, it moves inferiorly a few inches into the abdominal cavity,
expanding space within thoracic cavity & pulling air into lungs.
Relaxation of diaphragm allows air to flow back out the lungs during exhalation.

16. Between the ribs are many small intercostal muscles that assist the diaphragm with
expanding and compressing the lungs.
-divided into 2 groups:
the internal intercostal muscles and the external intercostal muscles
-the deeper set of muscles
-depress the ribs to compress the thoracic
cavity and force air to be exhaled from the
lungs.
found superficial to the internal
intercostals and function to elevate ribs,
expanding the volume of the thoracic
cavity , causing air to be inhaled into the
lungs.

17. PHYSIOLOGY OF RESPIRATION:
Is divided into two phases
EXTERNAL
RESPIRATION
INTERNAL
RESPIRATION
EXTERNAL RESPIRATION
# processes by which external air is drawn into the body in order to supply the lungs
with oxygen, and (used) air is expelled from the lungs in order to remove carbon
dioxide from to body.
-gases are exchanged between the lungs and the 'external' environment.
Specifically –
- gases exchange between air in alveoli & blood with in pulmonary capillaries
Normal rate of respiration =10-20 breaths/min

18. #Inhaled , your lungs are filled with air.
pulmonary gas exchange in play, takes place in
lungs between alveoli & blood
-Gas exchange occurs down a pressure gradient, via a
process called ‘diffusion’.
-When breathe in we inspire air consisting of a mixture
of gases including O2 & CO2.
-These gases each have a pressure related to their
conc. within the gas mixture. These individual pressures
are
termed partial pressures (PP)
-Diff in PP between gases in alveoli and blood create a
pressure gradient across the respiratory membrane.
- pressure same on each side of membrane =no gas
exchange = no movement of O2 and CO2.

19. -Both exchanges of O2 and CO2 occur until the
equilibrium of each gas is established.
-Final PO2 is 100 mmHg & PCO2 is 40 mmHg in
the blood which leaves the lungs
(oxygen-rich blood),
- To absorb O2 into blood it binds to
haemoglobin (Hb),[a compound sits on
RBC]. Oxygenated blood (carried in arteries) is
bright red due to binding of HB & O2.
-Deoxygenated blood (carried in the veins) is
much darker red due to lack of available O2 to
bind to HB.
- blood comes from body tissue to the alveoli is
high in CO2. so CO2 from ‘deoxygenated’ blood
diffuses across respiratory membrane into alveoli
, area of low CO2 conc, is subsequently expired
(breathed out) from the lungs.

21. INTERNAL RESPIRATION(peripheral gas exchange)
-process by which the respiratory gases are exchanged between the blood in
capillaries and the body tissue.
-Capillary blood = higher PP of O2 & lower of CO2 than tissues through which it
passes.
-Diff in PP leads to diffusion of gases along their pressure gradients from high to
low pressure through the endothelium lining of the capillaries.
- Net result of internal respiration = diffusion of O2 into the tissues and the
diffusion of CO2into the blood.
- cardiovascular system capillaries deliver O2 rich blood to the tissues of body.
-O2 then diffuses across thin capillary walls from the high conc. in the blood to the
low conc. in the tissues.(FOLLOWED BY CELLULAR RESPIRATION)

22. - CO2 - waste product from cellular respiration
diffuses from tissues through thin capillary
walls into blood where it is transported back
to the alveoli.
-Once the de-oxygenated blood from internal
respiration reaches the alveoli the whole
process repeats.

23. -This cycle of respiration works continuously in order to ensure the supply of
O2 to the tissues of the body and the removal of CO2 is sufficient.
- Increases and decreases in respiratory (breathing) rate will occur
automatically to meet the changing demands that we place on the body.

24. ……………………………………………………………………………………………………..
Inside the mitochondria, cellular respiration occur , which produces energy in the form of
ATP , which requires O2 ……and cO2 is produced as a waste.
Thus, in order to maintain cellular processes in a balanced condition, continuous flow
of oxygen should be maintained by blood.
.Main diff between internal & external respiration =
in the direction of gas exchange and in the location where each of the processes
occur.

28. TRANSPORTATION OF GASES