Changes

Air is [[Ventilation - Anatomy & Physiology|inhaled]] and passes through the upper respiratory tract via the nares, [[Nasal cavity - Anatomy & Physiology|nasal cavity]], [[Pharynx - Anatomy & Physiology|pharynx]], [[Larynx - Anatomy & Physiology|larynx]], and [[Trachea - Anatomy & Physiology|trachea]]; it is  heated and moistened en route. It then passes to the lower respiratory tract traveling through the [[Lungs - Anatomy & Physiology|lungs]] via the [[Bronchi and bronchioles - Anatomy & Physiology|bronchi, bronchioles]] and [[Lungs - Anatomy & Physiology|alveoli]] where oxygen diffuses across the alveolar wall and into the blood, forming oxyhaemoglobin. The active process of continuous [[Gas Exchange - Anatomy & Physiology|gas exchange]] in the lungs is known as [[Ventilation - Anatomy & Physiology|ventilation]].

Air is [[Ventilation - Anatomy & Physiology|inhaled]] and passes through the upper respiratory tract via the nares, [[Nasal cavity - Anatomy & Physiology|nasal cavity]], [[Pharynx - Anatomy & Physiology|pharynx]], [[Larynx - Anatomy & Physiology|larynx]], and [[Trachea - Anatomy & Physiology|trachea]]; it is  heated and moistened en route. It then passes to the lower respiratory tract traveling through the [[Lungs - Anatomy & Physiology|lungs]] via the [[Bronchi and bronchioles - Anatomy & Physiology|bronchi, bronchioles]] and [[Lungs - Anatomy & Physiology|alveoli]] where oxygen diffuses across the alveolar wall and into the blood, forming oxyhaemoglobin. The active process of continuous [[Gas Exchange - Anatomy & Physiology|gas exchange]] in the lungs is known as [[Ventilation - Anatomy & Physiology|ventilation]].

Associated structures within the respiratory tract include the [[Paranasal sinuses - Anatomy & Physiology|paranasal sinuses]], the [[Pleural cavity and membranes - Anatomy & Physiology|pleural cavity & membranes]] and the [[Guttural pouches - Anatomy & Physiology|guttural pouches]].

Associated structures of veterinary interest within the respiratory tract include the [[Paranasal sinuses - Anatomy & Physiology|paranasal sinuses]], the [[Pleural cavity and membranes - Anatomy & Physiology|pleural cavity & membranes]] and the [[Guttural pouches - Anatomy & Physiology|guttural pouches]].

==Cardiovascular System==

==Cardiovascular System==

Blood, which has been oxygenated by the [[Lungs - Anatomy & Physiology|lungs]], flows through the pulmonary vein to the left atrium of the [[Heart - Anatomy & Physiology|heart]] and subsequently to the left ventricle from which it is ejected by the heart during ventricular systole. Oxygenated blood is then distributed to the different parts of the body via the aorta. The distribution of blood is controlled by vascular tone which dictates the degree of perfusion of capillary beds and therefore the amount of oxygen available to the various tissues. Carbon dioxide produced from cellular respiration is removed from the tissues and transported either attached to proteins, in solution or as bicarbonate via the venous system to the vena cavae and ultimately to the right atrium. The passage of venous blood is a product of blood flow, vascular valves and muscular and respiratory function. Carbon dioxide rich blood enters the right ventricle and is then pumped to the lungs via the pulmonary artery. The arteries, veins and capillaries are collectively referred to as the [[Vascular System - Anatomy & Physiology|vascular system]]

Blood, which has been oxygenated by the [[Lungs - Anatomy & Physiology|lungs]], flows through the pulmonary vein to the left atrium of the [[Heart - Anatomy & Physiology|heart]] and subsequently to the left ventricle from which it is ejected by the heart during ventricular systole. Oxygenated blood is then distributed to the different parts of the body via the aorta. The distribution of blood is controlled by vascular tone which dictates the degree of perfusion of capillary beds and therefore the amount of oxygen available to the various tissues. Carbon dioxide produced from cellular respiration is removed from the tissues and transported either attached to proteins, in solution or as bicarbonate via the venous system to the vena cava and ultimately to the right atrium. The movement of venous blood is a product of blood flow, vascular valves and muscular and respiratory function. Carbon dioxide rich blood enters the right ventricle and is then pumped to the lungs via the pulmonary artery. The arteries, veins and capillaries are collectively referred to as the [[Vascular System - Anatomy & Physiology|vascular system]].

==Integration==

==Integration==

The function of the cardiac and respiratory systems are tightly linked and regulated to maintain blood pressure, tissue oxygen delivery and carbon dioxide removal. Cardiac function is controlled by baroreceptors (pressure receptors) which result in changes to the heartrate, contractility and vascular tone. Respiratory function is controlled centrally by chemoreceptors to maintain rate and both centrally and locally to maintain bronchiolar tone.

The function of the cardiac and respiratory systems are tightly linked and regulated to maintain blood pressure, tissue oxygen delivery and carbon dioxide removal. Cardiac function is controlled by baroreceptors (pressure receptors) which result in changes to the heart rate, contractility and vascular tone. Respiratory function is controlled centrally by chemoreceptors to maintain rate and both centrally and locally to maintain bronchiolar tone.