Homeostasis and Response Flashcards
What is homeostasis?
Homeostasis is the regulation of processes in your body to maintain a stable internal environment in response to changes in internal and external conditions
What are the automatic control systems in our body called?
The automatic control systems are called the nervous system and the hormonal communication systems
What do the automatic control systems control in the body?
The automatic control systems control the body’s temperature levels, blood glucose levels and water content
What are the three things that make up the automatic control systems?
The three things which make up the automatic control systems are the receptors, coordination centres and the effectors
What do receptors do?
Receptors detects change
What is the role of coordination centres?
Coordination centres interpret change
What is the role of an effector
An effector carries out the response to a change
What is negative feedback?
Negative feedback is the cycle which is carried out in the body in order to restore levels back to normal for homeostasis
What is a stimulus
A stimulus is a change in environment
What is the role of sensory neurones?
Sensory neurones carry information as electrical impulses from the recepter to the CNS
What is the role of motor neurones?
Motor neurones carry the electrical impulses from the CNS to the effector
What is a synapse?
A synapse is the connection between two neurones
Describe the process of the CNS responding to a change.
The sensory neurones are sent along the body carrying electrical impulses, triggered by the stimuli and receptor, and is transmitted to the motor neurone via a synapse. The nerve impulse is carrd by chemicals across the synapse through diffusion. The impulse then travels from motor neurone to an effector via another synapse.
What is a reflex arc?
A reflex arc is the passage of information in a reflex from receptor to effector
What are the three main parts of the brain?
The three main parts of a braina are the celebral cortex, cerebellum and the medulla
What is the role of the celebral cortex?
The celebral cortex is responsible for consiousness, intelligence, language, memory
What is the role of the medulla?
The medulla is responsible for controlling the unconscious activities such as breathing and heartbeat
What is the role of the cerebellum?
The cerebellum is responsible for muscle coordination
What are the three methods of studying the brain?
The three methods of studying the brain is electrically stimulating the brain, MRI scans, studying patients with brain damage
How does studying a patient with brain damage help with knowing more about the brain?
Studying a patient with brain damage allows neuroscientists to understand what the damaged part of the brain will do. For example, if a patient loses vision after having a stroke they can see which parts are responsible for vision
How does MRI scans help neuroscientists know more about the human brain?
MRI scans allow neuroscientists to understand which parts of the brain are active during activities such as listening to music and recalling a memory
What is the benefit to knowing more about the brain?
Knowing more about the brain has lead to the development of knowledge and treatment for disorders in the nervous system
What are the difficulties in treating the brain?
Treating the brain can lead to tumours, trauma, infection, mental health problems
What are the difficulties in treating the brain?
Treating the brain can lead to tumours, trauma, infection, mental health problems
What are the difficulties in treating the brain?
Treating the brain can lead to tumours, trauma, infection, mental health problems
What are hormones?
Hormones are chemical messengers that are produced in and secrered by glands
What are the 6 glands in the endocrine system?
The 6 glands in the endocrine system is the pituitary gland, thyroid, pancreas, ovaries, testes, adrenal gland
What hormones does the thyroid produce?
Thryoid produces thyroxine
What does thyroxine do?
Thryoxine regulates the rate of metabolism, temperature levels and heart rate
What are the hormones called which are produced by the adrenal glands
Adrenal glands produce adrenaline
What hormones does the ovaries produce?
The ovaries produce oestrogen
What hormones does the testes produce?
Testes produce testosterone
What hormones does the pancreas produce?
Pancreas produces insulin
What happens to our pupil when we face bright light?
When in bright light, our pupils get smaller because our circular muscles contract and our radial muscles relax
What happens to our pupil when in dim light?
When in dim light, our pupils get bigger as our circular muscles relax and our radial muscles contract
What happens in our eye in order to look at near objects?
To look at near objects, our cilliary muscles contract so our lens become curved and we refract more light
Why are long sighted people unable to see near objects?
Long sighted people are unable to see near objects because the lens is the wrong shape and the eyeball is too short
Why are short sighted people unable to see distant objects?
Short sighted people are unable to see near objects because their lens is the wrong shape and their eyeball is too long
What glasses do long sighted people wear?
Long sighted people wear convex lenses where lens curve outwards
What glasses do short sighted people wear?
Short sighted people wear concave lenses where the lens curves inwards
What is the optimum temperature for your body?
The optimum temperature of the human body is 37 degrees
Which area of the brain is responsible for controlling the temperature of our body?
The area of the brain which is responsible for controlling the temperature of the body is the thermoregulatory centre
How does your body respond when you are too hot?
When you are too hot, the body responds by producing sweat which means energy can be released into the environment, and also the blood vessels dilate in order to keep blood supply continuous close to the skin (this is called vasolidation) and energy is transferred into its surroundings
How does your body respond when you are too cold?
When you are too cold, the body responds by the hairs standing up in order to create an insulating layer, and also the blood vessels constrict (vasoconstriction). Shivering also means that the body will respire so that energy can be taken into the body
What happens within the first stage of the menstrual cycle?
In the first stage of the menstrual cycle, the lining of the uterus is broken down
What happens within the second stage of the menstrual cycle?
In the second stage of the menstrual cycle, the lining of the uterus is built back up again
What happens within the third stage of the menstrual cycle?
In the third stage of the menstrual cycle, the egg is released from the lining of the uterus
What happens within the fourth stage of the menstrual cycle?
Within the fourth stage of the menstrual cycle, the lining of the uterus is maintained
How many stages are there of the menstrual cycle?
There are four stages of the menstrual cycle
What are the four hormones which are involved in the menstrual cycle?
The four hormones involved in the menstrual cycle is the FSH, LH, Oestrogen and Progesterone
What is the role of the FSH?
The FSH causes the egg to mature
Where is the FSH and the LH released from?
The FSH and LH are released from the pituitary gland
What is the role of the LH?
The LH stimulates the release of an egg
What is the role of oestrogen?
Oestrogen makes the lining of the uterus grow
What is the role of progesterone?
Progesterone maintains the lining of the uterus
What are the main roles of the kidneys?
The main role of the kidneys is filteration, such as removing waste substances from your blood and converting it into urine. The kidneys are also responsible for controlling water and ion levels.
What is selective reabsorption?
Selective reabsorption is when the kidneys reabsorb useful substances such as water and ions back into the blood after filtration
What happens to excess amino acids in the blood?
The excess amino acids is stored as fats and carbohydrates which produces ammonia, which then the ammonia is converted into urea so it can be removed from the blood during filtration in the kidneys
What is deamination?
Deaminatino is the process where excess amino acids are broken down and urea is eventually produced
What happens if there is an imbalance of water and ions in the body?
If there is an imbalance of water and ions in the body, the rate of osmosis is affected
Which hormone controls the concentration of urine?
ADH controls the concentration of urine, which is released by the pituitary gland
What are the two treatments for kidney failure?
The two treatments for kidney failure is dialysis and kidney transplants
Why is dialysis done regularly?
Dialysis is done regularly in order to keep levels of concentration of dissolved substances in the blood at normal levels and also so waste substances are filtered out as urine by the kidneys
What is the process of dialysis in a dialysis machine?
For dialysis, blood flows between a semi-permeable membrane which is surrounded by dialysis fluid
What is the purpose of dialysis fluid in a dialysis machine?
Dialysis fluid has the same concentration of glucose and ions as healthy blood, and so the right amount of ions and water is lost or gained, and large molecules such as protein cant enter
How often are dialysis sessions and how long for?
Dialysis sessions are done 3 times a week for 3-4 hours per session
What can dialysis lead to?
Dialysis can lead to blood clots and/or infection
What is the risk of kidney transplants?
The risk of kidney transplants is that they can be rejected by the patient’s immune system
Which two hormones are used to reduce fertility?
Oestrogen and progesterone are used to reduce fertility
How can progesterone reduce fertility?
Progesterone can be used to reduce fertility by releasing mucus to slow the movement of sperm
What are the negatives of using the pill to reduce fertility?
The negatives of using the pill to reduce fertility is that it can have side effects such as nausea and vomiting, and it also doesn’t prevent STI’s
Which two ways are used to reduce fertility which involves oestrogen?
The two ways which involve using oestrogen to reduce fertility is contraceptive patches and contraceptive implants
How does IUD reduce fertility?
IUD kills sperm when implanted into the uterus, therefore, reducing fertility
What are two forms of barriers which reduce fertility?
The two forms of barriers that reduce fertility include condoms and diaphragm contraceptives
How does a diaphragm contraceptive help reduce fertility?
By placing a plastic cup in the cervix which includes spermicide, sperm are killed
How does sterilisation reduce fertility?
Sterilisation involves cutting the fallopian tubes or the sperm duct
What is a natural way of reducing fertility?
A natural way to reducing fertility is having sex when a female is the least fertile during her menstrual cycle
What is an auxin?
An auxin is a plant hormone which controls the growth of the tips and roots of plants
What is phototropism?
Phototropism is when the shoot grows towards the light
What is geotropism?
Geotropism is when plants grow towards gravity
What happens when a shoot is exposed to light?
When a shoot is exposed to light, more auxin grows on the shaded side. This means that the shoot elongates more on the shaded side causing the shoot to grow upwards
What happens when a shoot grows sideways?
When a shoot grows sideaways, the auxin grows at the bottom where it is shaded due to the pull of gravity. This means the lower side grows faster and so the shoot grows upwards
What happens when a root grows sideways?
When a root grows sideways, more auxin grows on the lower side however the cells ontop grows faster because the roots inhibit growth meaning the root grows downwards towards gravity
What are the three commercial uses of auxin?
The three commercial uses of auxin include killing weeds, making rooting powders and tissue culture
How does auxin stimulate tissue culture?
Auxin stimulates tissue culture as it is added to the growth medium meaning the cells divide to form roots and shoots and clones can be grown
What are the three commercial uses of giberellin?
The three commercial uses of giberellin includes controlling dormancy, flowering and growing larger fruit
How does giberellin alter dormancy?
Giberellin alters dormancy because some plants usually require certain conditions to grow however giberellin means plants grow at time where they wouldn’t usually
What does dialysis fluid contain?
Dialysis fluid contains glucose, concentration of ions similar to those in plasma and no urea
