Lecture 1: How do our body systems keep us alive? Flashcards
What is the average turnover of red blood cells?
~120 days
What are the 4 basic types of tissue?
Epithelia
Connective tissue
Muscle
Nervous tissue
How do cells use ATP?
They “cash it in” to carry out their specific functions.
Where does the GI tract start and finish?
Mouth to Anus
Where does venous blood from the absorptive part of the GI tract go first and why?
To the liver, to detoxify the blood.
What is the cardiovascular system made up of?
The heart and the blood vessels.
What is the difference in function between arteries and veins?
Arteries- Pump oxygenated blood away from the heart around the body (with the exception of the pulmonary artery).
Veins- Pump deoxygenated blood from the tissues to the heart.
Describe the path of blood through the blood vessels through the body
Heart–>Arteries–>Arterioles–>capillaries–>Venules–Veins–> Back to the heart
What happens at the capillary bed?
Nutrients, oxygen, hormones and drugs etc. pass in and out of the cells from the blood through diffusion, though gaps between cells that form the capillary wall.
What are alveoli?
Small balloon-like structures that allow oxygen and CO2 exchange with surrounding capillaries by diffusion.
How is oxygen transported around the body?
By reversibly binding to haemoglobin within red blood cells which are transported through the blood vessels.
What causes anaemia?
Low haemoglobin count, which leads to low oxygen carrying capacity, and can cause breathlessness as a result.
What is tissue fluid?
Fluid that is squeezed out of capillaries due to the pressure of blood, and as a result surrounds the tissues in the body.
If tissue fluid was left in the tissues, what would it cause?
Swelling of the tissues and reduced blood volume.
What are the functions of the lymphatic system?
- To return tissue fluid (lymph) back into the veins of the neck.
- Fights infections
What are lymph nodes?
Glands located all around the body that fight infection from infected lymph.
What happens to lymph nodes when infection is present?
They swell up and are palpable.
Name tissues that form lymphatic tissue and help fight infection?
- Tonsils at the back of the nose, mouth and tongue
- The spleen
- Lymphoid tissue located in the walls of the intestines
How are waste products excreted? Name some of these waste products.
- In the faeces (Indigestible foodstuff such as fibre, Cellular debris, GI bacteria, commensals and pathogens)
- In the urine (Digested drugs such as alcohol or other medications), Urea
- In the respiratory tract (CO2)
What is the skin’s function?
Physical, waterproof barrier (mainly to keep fluid inside)
Defence against trauma
Defence against UV rays
What comprises the Central nervous system?
The brain and spinal cord.
What comprises the Peripheral nervous system?
All aspects of the nervous system except the brain and spinal cord.
What is the difference between the endocrine system and the nervous system?
The Nervous system acts more quickly in controlling the body processes, The endocrine system acts more slowly.
