A&P Flashcards
Thoracic cavity?
Thoracic cavity?
.In the mammals, the thoracic cavity, located cranially is enclosed by the ribs. Its boundaries are considered to be the thoracic inlet (cranial location) and the diaphragm (caudal location).
Also considered as being parts of the boundary are: the thoracic vertebrae (posterior location), the sternum (anterior location), obviously the ribs and, the intercostal muscles. The vertebrae are included because certain thoracic vertebrae also hold the ribs! Usually though diagrams of the thoracic cavity do not show the sternum or ribs.
Parts of the oesophagus and trachea lie within the thoracic cavity. For veterinary directions, the thoracic cavity is divided into right and left pleural cavities. The mediastinum divides these sides.
.House and protect the lungs and the heart whilst also helping to maintain what is known as thoracic pressure. Should the lungs be punctured by a rib for example, thoracic pressure falls and the animal cannot breathe effectively.
Abdominal Cavity?
Abdominal Cavity?
.The abdominal cavity in mammals is located caudally and is described very differently to the thoracic cavity and its function is also different.
.The abdominal cavity is not enclosed by bones of the skeleton although it is backed by some of the vertebrae. Its boundaries are said to be the diaphragm for mammals, the pelvic inlet, lumbar vertebrae, ventral abdominal muscle and lateral abdominal muscle describe the rest of the abdominal cavity’s boundary in the body.
.The abdominal cavity is to house many more organs than that of the thoracic cavity. It houses the liver, spleen, stomach, pancreas, small and large intestines, urinary bladder, reproductive organs (of the female), peritoneum, peritoneal cavity, mesentery and, the kidneys.
In terms of animal health therefore, injury to with the abdominal cavity has the potential to affect many organs.
Pelvic cavity?
Pelvic cavity?
.Not separated from abdominal cavity.
.The pelvic girdle provides the main support mechanism for the body as a whole as it is joined to the vertebral column and the hind limbs.
.A fractured pelvis means an animal cannot support the rest of the body.
The pleural cavity?
The pleural cavity?
.A membrane surrounding the lungs
.The pleural cavity lies between the diaphragm and the pleural membrane that covers the lungs.
.Is the first layer of protection. The pleura is like a thin bag in which pleural fluid lubricates and supports the spongy lungs.
.The pleural cavity contains a substance called the pleural fluid that helps maintain thoracic pressure and protects the lungs.
.The pleural cavity is divided into the right pleural cavity and the left pleural cavity.
.Should the pleura be punctured, pressure drops and fluid is lost.
.The mediastinum divides the pleura. Some protection is given to the lungs as a whole because of the mediastinum.
.The pleural fluid function is to lubricate and support the spongy lungs.
The thoracic inlet?
The thoracic inlet?
.Is said to be part of the boundary of the rabbit’s thoracic cavity.
.The inlet is like a circle at the top of the rib cage.
Intercostal muscles?
Intercostal muscles?
.There are external intercostal and internal intercoastal muscles.
.They help in the breathing mechanism because they raise the ribs and expand the chest cavity helping with inhalation and exhalation.
What is a serous membrane?
What is a serous membrane?
.A serous membrane is a single layer of epithelium which makes a watery lubricating fluid because of this it acts as a lubricant between cavities, organs and structures.
.The serous membrane that surrounds the abdominal cavity in mammals is the peritoneum.
The Skeleton?
The Skeleton?
.An internal skeleton provides structure, support, locomotion (movement) and protection plus, it carries out certain physiological processes (blood cell manufacture).
.The skeleton is constructed of bones and joints – the joints permit an animal to move whilst the whole skeleton provides structure and support to the body as a whole.
.The skeleton is divided into two parts: the axial skeleton and the appendicular skeleton.
Axial skeleton parts?
Axial skeleton parts?
.The skull, vertebral column and the rib cage
Appendicular skeleton parts?
Appendicular skeleton parts?
.Fore and hind limbs and the limb girdles.
What are thecodont teeth?
What are thecodont teeth?
.They are teeth that are set in the jaw, in tooth sockets (as in mammals).
Circulation during disease/Illness?
Circulation during disease/Illness?
.When there is disease or illness of some sort, the heart’s rate can increase or decrease and there may also be an abnormal heart rhythm.
.The heart’s rhythm is controlled by a particular structure within the heart called the sinoatrial node (SAN). Sometimes, this structure is called the heart’s “pacemaker”.
Circulation process?
Circulation process?
.The heart at rest, the sinoatrial node (SAN) fires electrochemical impulses across the atria (the upper chambers), the atria contract, this pushes blood out of the atria and into the ventricles, the atrioventricular node fires now, electrochemical impulses are fired into the ventricles (the lower chambers) and they contract, blood is now pushed out of the ventricles either to the heart from the right ventricle or into the Aorta to be sent around the body.
Sinoatrial node?
Sinoatrial node?
.The SAN should fire its signals at a regular, consistent rate but when it does not, sinus arrhythmia occurs and a phenomenon called tachycardia is detected.
.Tachycardia means an abnormally fast or slow heart rate that is, outside the normal range for the species.
.As a result of tachycardia, blood flow (circulation) will be affected too. Sinus arrhythmia can indicate a heart disease (cardiac disease) or, it may happen under certain conditions that are not “normal” for a rabbit, a bird or a reptile.
.Abnormal conditions under which sinus arrhythmia can occur in the rabbit, the bird and the reptile include being anaesthetised and, a temporary illness or, disease.
Blood being able to transport effectively?
Blood being able to transport effectively?
.As the heart is responsible for ensuring an effective circulation, it is also key to the blood being able to transport effectively: oxygen to cells and carbon dioxide away from cells; the absorbed products from the digestive system to cells and, hormones around the body. Blood transports heat too, so the whole body can experience an almost equal temperature.
