Body systems Flashcards
What are the levels of organisation?
Chemical >Cellular>Tissue>Organ>Body system
What are cells?
Basic structural and functional units of our body
Why do cells require energy?
- to carry out the common metabolic processes that keep them all alive (e.g maintenance of internal cell pH for cell enzyme function)
- to perform their specific functions (e.g cardiac muscle cell contraction to make the heart pump)
What is the ‘cellular currency” of energy?
ATP (adenosine triphosphate)
What are the 4 basic tissue types?
- muscle
- epithelia
- nerves
- connective cells
What is an organ ?
Group of tissues acting together to perform a specific function(s)
How do systems work?
Collections of organs that have related functions and work together to carry out a common ‘goal’ and are essential for survival
Describe the gastrointestinal (GI) system?
- The GI tract runs from mouth to anus
- large molecules are digested into smaller molecules which can then be absorbed into the veins (and lymphatic vessels ) of the small intestine
- The venous blood from the absorptive parts of the GI tract drains to the liver first
- the liver is one of the associated organs of the GI tract that combine to make the GI system (the spleen and the pancreas included)
- the liver stores some nutrients , makes other products from them, or returns them into the venous system
What does the liver do to venous blood?
Metabolise/detoxify potentially harmful substances absorbed from the GI tract putting (partially ) “cleaned” blood back into the blood
How are nutrients derived to the cells?
-absorbed nutrients first pass in the veins of the GI tract to the liver and then venous blood from liver drains back to the heart
What type of blood does the right and left side of the heart carry?
Right pump- deoxgenated blood
Left pump- oxygenated blood
How does blood circulate (through what vessels)?
Heart- artery - arteriole- capillaries-venue- vein - Heart
How do we get oxygen into the blood?
- air travels down ‘respiratory tree’
- surface of the very thin walled alveoli is covered with many thin walled capillaries and this allows oxygen to be transferred by diffusion into the blood
How is oxygen delivered to the cells?
The haematological system- Haemoglobin within red blood cells reversibly binds to oxygen in the lungs and carries it to all the capillary beds where it is released to the cells
What is tissue fluid?
When fluid is squeezed out of the capillaries by blood pressure, the fluid that is not reabsorbed in the tissues is tissue fluid
What happens when tissue fluid is taken up by the lymphatic vessels?
Its called lymph
What are the features of the thoracic duct?
- major lymphatic vessel in the body
- returns lymph to large veins in the root of the neck
What systems help the removal of waste and what do they remove?
- respiratory system- removes CO2 quickly
- Renal system excretes acids more slowly
What are the 2 by-products of ATP formation and what do they combine to form?
- Carbon dioxide and water
- carbonic acid
What forms can waste come in/
- Cellular debris
- Indigestible foodstuffs
- GI tract bacteria,commensals and pathogens
- Ingested drugs
- foreign bodies
what is the body’s first line of defence and why?
Our Skin (integument)
- physical defence against trauma
- waterproof barrier
- helps to regulate body temp
- to a degree protect us against UV radiation
What is the difference clinically of normal lymph nodes and lymph nodes fighting infection?
Normal lymph nodes cannot be palpated but due to enlargement during infection, infected lymph can be palpated
What is the purpose of the nervous system?
-allow us to sense our environment and to effect an appropriate response
What is the endocrine system and what does it do?
- number of organs called endocrine glands
- secrete hormones directly into their capillary blood
