B5 Flashcards
Where is aveoli found?
In the lungs
Summarize the gaseous exchange system
Oxygen is inhaled
Oxygen from the aveoli diffuses into the blood stream
Carbon dioxide from the blood stream diffuses into the aveoli
Carbon dioxide is exhaled
What is the enzyme in saliva that breaks down carbs into sugars called?
Amylase
Where are villi found?
In the small intestine
What is the function of villi?
They absorb nutrients, and then pass them into the bloodstream
What do aveoli do?
They allow oxygen and carbon dioxide to move between the lungs and bloodstream
Summarize the digestive system
Amylase breaks down carbs into sugars
Food is mechanically churned in the stomach, and chemically broken down by gastric acids
Villi pass absorb necessary nutrients and pass them into the bloodstream
Waste is stored in the rectum, and eventually excreted
What are the two main circulatory systems?
Systemic and Pulmonary
What is the role of the systemic circulatory system?
It carries oxygenated blood away from the heart and to other parts of the body
What is the role of the pulmonary circulatory system?
It carries oxygen-depleted blood away from the heart, to the lungs (where it is oxygenated), and then back to the heart, ready for the systemic circulatory system
Summarize the excretory system
The kidneys filter out any waste from the blood
This waste is then stored until excretion
What are the 3 blood vessels?
Veins, arteries and capillaries
What are the properties of veins and why?
They have valves to prevent backflow
They have a large lumen to allow easy flow of blood
What are the properties of arteries and why?
Thick muscular wall to withstand pressure
What are the properties of capillaries and why?
One cell thick wall allows efficient and rapid diffusion in substance exchange
What does the blood contain?
Red blood cells, white blood cells and blood plasma
What is blood plasma and what does it do?
It is the liquid part of the blood, made up mostly of water
It carries blood cells and many substances like CO2, sugars, amino acids and proteins
What are red blood cells and what do they do?
Cells that are packed with a protein call haemoglobin, which binds with oxygen. Oxygen is released from the haemoglobin around the body where neccersary
What can white blood cells do?
They can engulf and destroy pathogens
They can produce antibodies to destroy particular pathogens
They can produce antitoxins that counteract the toxins released by pathogens.
What are platelets and what do they do?
They are fragments of cells
When a blood vessel is damaged, platelets send out substances that trigger a series of reactions, which creates a blood clot at the cut site.
This prevents pathogens from entering, and stops you from losing too much blood
What do the sensory neurons do?
They carry information from receptors to the CNS
What is urea?
A waste product from the breakdown of proteins in the liver
What is diffusion?
The movement of particles from an area of high concentration to an area of low concentration
What is osmosis?
The movement of solvent (e.g. water) molecules across a partially permeable membrane from an area of high concentration to an area of low concentration
What is active transport?
The movement of particles across a permeable membrane from an area of low concentration to an area of high concentration, requiring energy
How are alveoli specialised for maximising the rate of diffusion of O2 and CO2?
- Very large surface area to volume ratio
- Very thin walls
- Good blood supply
Villi has a small surface area to volume ratio (true or false)
False- villi has a very large surface area to volume ratio which allows quick transport of nutrients into the bloodstream
How are villi specialised for maximising the rate of diffusion of O2 and CO2?
- Very large surface area to volume ratio
- Single layer of surface cells
- Good blood supply
State the 2 types of chambers in the heart and where they are positioned
Ventricles- positioned at the bottom of the heart
Atriums- positioned at the top of the heart
How does the heart make sure all blood flows in the correct direction?
It has valves
What is the vena cava?
A vein carrying deoxygenated blood into the right atrium of the heart
What is the pulmonary vein?
A vein carrying oxygenated blood from the lungs to the left atrium of the heart
What is the pulmonary artery?
An artery carrying deoxygenated blood from the right ventricle of the heart to the lungs for oxygenation
What is the aorta?
An artery carrying oxygenated blood from the left ventricle to the rest of the body
Why is the wall of the left ventricle thicker than the right?
Because the left ventricle needs a greater pressure generated by the thicker muscle in order to pump to the whole body, whereas the right ventricle is only pumping to the lungs
How can hormones be used to treat infertility?
If a person is infertile, it means they can’t produce the necessary hormones naturally- this can be treated by injecting the necessary hormones
What is FSH?
It is released by the pituitary gland and caused a follicle (an egg and its surrounding cells) to mature
It also stimulate oestrogen production
What is oestrogen?
It is released by the ovaries and causes the lining of the uterus to thicken
What is LH?
It is released by the pituitary gland and stimulates ovulation at day 14- follicle ruptures and the egg is released.
After that it also stimulates the remains of the follicle to develop into a structure called corpus luteum which secretes progesterone
What is progesterone?
It is released by the ovaries and maintains the lining of the uterus for implantation of a fertilised egg
What does progesterone and oestrogen inhibit?
The release of FSH and LH
What occurs in stage 1 of ovulation and what is the time period of it?
From day 1-4, the lining of the uterus breaks down
What occurs in stage 2 of ovulation and what is the time period of it?
From day 4-14, the lining of the uterus builds up
What occurs in stage 3 of ovulation and what is the time period of it?
On day 14, the egg is released
What occurs in stage 4 of ovulation and what is the time period of it?
From day 14 to 28, the lining of the uterus is maintained
What does the fatty sheath surrounding axons do?
Speeds up the impulse
What is the axon?
The path on which electrical impulses travel
What does the central nervous system do?
The CNS coordinates a response and sends a message to an effector which performs the response.
Name the 3 main areas of the brain
The cerebral cortex
The cerebellum
The brain stem
What is the role of the cerebral cortex?
Responsible for consciousness, intelligence, memory and language
What is the role of the cerebellum?
Responsible for conscious movements
What is the role of the brain stem
Responsible for unconscious activities
What methods do we use to study the brain and how do they work? (3 methods)
- Study patients with brain damage characteristics (e.g. if someone damages the back of their head, and then suffers loss of vision, we can conclude that that area has something to do with vision)
- Electrically stimulate the brain: these show you what happens different areas of the brain are stimulated
- fMRI scans: these can show which parts of the brain are most active while performing activities
What is adrenaline and what does it do?
Adrenaline is a hormone released by the adrenal glands.
Adrenaline increases blood flow-faster heart rate, more aerobic respiration
What is homeostasis?
Maintaining a constant internal environment (e.g. temperature, water levels etc)
What negative feedback occurs when your body temperature is too hot?
- Hairs lie flat
- Sweat
- Vasodilation
What negative feedback occurs when your body temperature is too cold?
- Hairs stand up to insulate you
- Little sweat produced
- Vasoconstriction
What do insulin and glucagon do?
Insulin decreases the amount of glucose in your bloodstream
Glucagon increases the amount of glucose in your bloodstream
What is type 1 diabetes and how is it treated?
Pancreas stops producing insulin
- a persons glucose level can rise to a level that can kill them
- the person has to inject insulin into them to make their blood glucose levels decrease.
What is type 2 diabetes?
When a person doesn’t produce enough insulin
What does ADH do?
Makes the kidney tubes more permeable so that more water can be absorbed. This allows it to manage water levels
How is the concentration of urine controlled?
When you have gained too much water, less ADH is produced, which means that kidneys absorb less water.
When you have lost too much water, more ADH is produced, therefore the kidneys absorb more water.
What happens at the tubules?
Urine is formed
What happens when an animal cell is surrounded by a less and more concentration solution?
More concentrated - more solution outside the cell - the solution will enter the cell via osmosis - eventually could burst
Less concentrated - more solution inside the cell - the solution will leave the cell via osmosis - eventually may shrink
State the key parts of the eye and their functions
The cornea: refracts light into the eye
The iris: controls the diameter of the pupil, therefore how much light enters
The pupil: the whole in your eye in which light enters
The lens: refracts light, focusing it on the retina
The retina: receives light and sends signals on to the brain for visual recognition
The optic nerve: carries impulses from the receptors on the retina to the brain
What is accommodation in the eye?
When the lens changes shape in order to focus light on the retina
What is a cataract?
A cloudy patch on your lens causing blurred vision
How can a cataract be treated?
The cloudy lens can be replaced
What is osmoregulation?
Balancing water and salt levels
What is the relationship between water levels and ADH?
As water levels increase, ADH levels decrease, causing the kidney tubes to be less permeable, so less water is goes into cells, so more goes to the bladder.
As water levels decrease, ADH levels increase, so the kidney tubes are more permeable, so more water goes into cells, so less goes to the bladder
