Body Cavities and Water Content Flashcards
(26 cards)
Define Parietal
Serous membrane that lines the boundaries of the cavity
Define Visceral
Serous membrane that covers the organs in the body
What is the name of the serous membrane in the thoracic cavity?
Pleura
What is the name of the serous membrane in the abdominal cavity?
Peritoneum
What are the boundaries of the thoracic cavity?
Dorsal - vertebral column Ventral - Sternum Lateral - ribs and intercostal muscles Cranial - thoracic inlet Caudal - diaphragm
What is the pericardial cavity and where is it found?
It is in the mediastinum. It contains the heart.
What is the structure of the thoracic cavity?
Divided into 2 pleural cavities by a continuation of the parietal pleura. Each cavity contains one lung and serous fluid.
The thorax is divided into two halves by the mediastinum (connective tissue).
What is the name of the membrane covering the lungs?
Pulmonary pleura
What does the pleural cavity contain and why?
Pleural fluid. Helps lubricate the lungs and allows friction-free movement and prevents the membranes sticking together
What are the contents of the thoracic cavity (including the pericardial cavity)?
Lungs Trachea Thymus Lymph Nodes Oesophagus Arteries Veins Nerves Heart
What are the boundaries of the abdominal cavity?
Dorsal - Vertebral column
Ventral and Lateral - muscles of the abdominal wall
Cranial - Diaphragm
Caudal - pelvic inlet
Describe the lining of the abdominal cavity?
Parietal peritoneum lines walls and visceral peritoneum lines the organs and between these is the peritoneal cavity which contains peritoneal fluid. The visceral peritoneum is folded around the organs called mesentery and is named according to its location. E.g. Mesovaruim, mesoduodenum, omentum
What are the 3 openings of the diaphragm and what passes through it?
Aortic hiatus - aorta
Oesophageal hiatus - oesophagus and vagus nerve
Caval foramen - transports caudal vena cava
What are the contents of the abdominal cavity?
Stomach Kidney Intestines Pancreas Liver Spleen Gall Bladder Urethra Bladder Uterus Ovaries Prostate Glands Arteries and Veins
What are the boundaries of the Pelvic Cavity?
Continuation of the abdominal cavity- no physical separation
Cranial - Pelvic inlet
Caudal - Pelvic outlet
Dorsal - Sacrum
Ventral - Pelvic floor (ischium and pubis)
Lateral - Pelvic walls
What are the contents of the pelvic cavity?
Rectum
The peritoneum extends in and covers the organs that lie in both cavities:
Bladder
Reproductive organs
What is the Interstitial Fluid (ISF)?
Water found in between the cells
What is the Plasma Water (PW)?
Intravascular water in plasma (in the blood vessels)
What is transcellular fluid (TCF)?
e.g. gastrointestinal secretions, saliva, tears etc.
Describe the make up of the total body water
Water (60% of total body weight)
Divided into Intracellular Fluid (40%) and Extracellular Fluid (20%)
ICF is divided into Blood cells and other body cells
ECF is divided into ISF (15%), PW (5%) and TCF (<1%)
Describe the exchange of fluid between the capillaries and the ISF
There is high hydrostatic pressure at the arterial end of the capillary which forces water and solutes out of the capillary and into the ISF.
Large proteins remain in the plasma of the capillary, maintaining osmotic pressure. The water and solutes in the ISF bathes the tissues and is then drawn back into the capillary by the osmotic pressure at the venous end (where hydrostatic pressure is low due to the reduced fluid volume)
What are the characteristics of intracellular and extracellular fluid?
ICF
- High concentration of protein anion
- Main cation is K+
ECF
- Low concentration of protein anion
- Main cation is Na+
- Main anion is Cl-
Define Osmotic Pressure
The pressure required to stem the flow of water across a semi-permeable membrane.
The greater the osmotic pressure of a solution, the higher the concentration of molecules in that solution and the greater the potential influx of water
Define
Isotonic
Hypotonic
Hypertonic
Isotonic - Equal OP to plasma
Hypotonic - Lower OP to plasma
Hypertonic - Higher OP to plasma
