B5: Coordination & Control Flashcards
What happens when your heart beat increases? [3]:
- High blood pressure which can cause…
- General fatigue of the heart
- Weaker blood vessels to rupture
Homeostasis [definition]:
The automatic regulation of internal conditions in an organism
Endocrine system [definition]:
A system of glands that release chemical messengers, like hormones, into the bloodstream
The nervous system [definition]:
A system of nerves that carry electrical impulses
What are the different types of neurones in the reflex arc? [3]:
- Sensory neurone
- Relay neurone
- Motor neurone
Sensory neurone:
Carries electrical impulses to the central nervous system
Relay neurone:
Relays electrical impulses from sensory neurones to the appropriate motor neurone
Motor neurone:
Carries electrical impulse from the central nervous systemto an effector
What are factors that effect reaction time ? [2]:
- Caffeine consumption
- Excercise
Components of the nervous system [3]:
- Brain
- Spinal cord
- Neurones
Synapses [definition]:
Gaps between neurons which can be found at each junction of a reflex arc
Reflexes [definition]:
Rapid and automatic movements that allow us to respond to dangerous situations
Examples of reflexes [3]:
- Blinking
- Sneezing
- Dropping hot objects
Components of the Reflex Arc [5]:
- Stimuli
- Receptors
- Neurons
- Effectors
- Response
The Brain [definition]:
A complex organ that controls all concious and unconcious thoughts in order to keep an organism alive
What makes brain damage/disease difficult to treat? [2]:
- The brain is delicate
- Thebrain is not well understood
Medulla [definition]:
The part of the brain responsible for unconscious thoughts
Cerebellum [definition]:
The part of the brain responsible for muscle control
What is the Cerebellum important for? [4]:
- Movement
- Balance
- Posture
- Speech
Cerebral Cortex [definition]:
The part of the brain responsible for conscious thoughts
What is the Cerebral Cortex important for? [3]:
- Memories
- Languages
- Intelligence
Methods of learning about the Brain [3]:
- Studying brain damage
- MRI scanning
- Electrical system
How does studying brain damage works? [2]
- It helps mapping in structure and related functions
- studying people with different types of brain damage and then comparing them
In a reflex action…
the nerve impulse follows a pathway called the reflex arc.
Spinal reflexises do not…
involve the brain
Spinal reflexes do not…
involve the brain
How do nerve impulses travel across the synapses?
Nerve impulses pass across a synapse with the help of chemical transmitter molecules.
What are the components of the human eye? [9]:
- Retina
- Iris
- Pupil
- Optic nerve
- Cornea
- Lens
- Ciliary muscles
- Suspensory ligaments
- Sclera
Retina [definition]:
Made up of light-sensitive receptors
Optic nerve [definition]:
Carries impulses from the retina to the brain
Cornea [definition]:
Transparent region of the sclera located at the front of the eye
Lens [definition]:
Focuses light rays on the retina
Pupil [definition]:
The hole in the centre of the iris that allows light to pass through
Iris [definition]:
The coloured bit of the eye; has sets of muscles that control the size of the pupil and regulate the light reaching the retina
Suspensory ligaments [definition]:
Change the shape of the lens to focus light on the retina
Ciliary muscles [definition]:
Ring of smooth muscles that change the shape of the lens that focuses the eye
What is the name of the receptor cells in the eye that percieve colour?
Cones
What is the function of the cones?
They convert light into the electrical energy of a nerve impulse
In dim lighting…[2]:
- Ciliary muscles contract, making the pupil larger
- This is to allow the retina to receive as much light as possible
In bright light…[2]:
- Ciliary muscles relax, leaving the pupil small
- This is so that the retina does not receive too much light
Accommodation [definition]:
The process by which the eye lens changes shape to better see objects at different distances
Focusing on objects up close [4]:
- Ciliary muscles contract
- Causes suspensory ligaments to loosen
- Causes lens to become thicker and rounder
- Results in significant refraction of light rays
Focusing on a Close object [4]:
- Ciliary muscles contract
- Suspensory ligaments loosen
- Lens becomes thicker and rounder
- Resulting in significant refraction of light rays
Focusing on a distant object [4]:
- Ciliary muscles relax
- Suspensory ligaments tighten
- Lens becomes flatter and thinner
- Minor refraction of light rays
Hyperopia [definition]:
- Happens when rays of light focus behind the retina
- long-sightedness
Myopia [2]:
- When rays of light focus in front of the retina
- short-sightedness
Thermoregulation [definition]:
- Control of the body temperature
Focusing on distant objects [4]:
- Ciliary muscles relax
- Causes suspensory ligaments to tighten
- Causes lens to become thinner and flatter
- Results in minor refraction of light rays
Hyperopia [2]:
- long sightedness
- When rays of light focus behind the retina
Myopia [2]:
- Short-sightedness
- When rays of light focus in front of the retina
Endocrine glands [6]:
- Adrenal glands
- Thyroid glands
- Pituitary gland
- Pancreas
- Testes
- Ovaries
Adrenal glands [3]:
- Two glands located above the kidney
- Produce adrenaline
- Triggers the ‘fight or flight’ response
Thyroid glands [3]:
- In the neck
- Releases thyroxine
- Thyroxine regulates metabolism, heart rate and temperature
Testes [2]:
- Produce testosterone
- Testosterone controls puberty and sperm production
Pituitary gland [4]:
- Main endocrine gland found in the brain
- Linked to hypothalamus region of the brain
- Releases hormones in response to changes detected by the hypothalamus region
- Hormones mostly trigger glands to release more hormones
Pancreas [2]:
- Produces insulin and glucagon
- These are involved in regulating blood glucose levels
Ovaries [3]:
- Produce oestrogen
- Oestrogen controls puberty
- Main hormone in regulating the menstrual cycle
Menstruation…
only lasts for the time a person is bleeding
Progesterone [3]:
- Produced in the ovaries after ovulation
- Maintains the lining of the uterus from day 14-28 of the
menstrual cycle - Inhibits the release of LH and FSH
Follicle Stimulating Hormone (FSH)
[3]:
- Secreted by the pituitary gland
- FSH stimulates the ovaries to produce Oestrogen
- FSH causes the eggs to mature in the ovaries
Oestrogen [3]:
- Produced in the ovaries
- It Causes the development of the thick, spongy uterus
lining - Inhibits futher release of FSH and stimulates the release of LH
Luteinising Hormone [2]:
- Produced in the pituitary gland
- It stimulates the release of a mature egg on day 14 of the menstrual cycle
What happens when Progesterone levels drop?
- It triggers the breakdown of the uterus lining
- This marks day 1 of the Menstrual cycle
Menstrual cycle Stage 1
(Day 1-4):
The uterus lining breaks down, resulting in bleeding
Menstrual cycle Stage 2
(Days 4-14):
The uterus lining starts to build up again into a thick, spongy layer full of blood vessels
Menstrual cycle Stage 3
(Day 14):
Ovulation happens. This is when an egg is released from one of the ovaries
Menstrual cycle Stage 4
(Days 15-28):
The uterus lining is maintained, which means that it is now ready for the arrival of a fertilised egg
What happens if the egg is not fertilised during the menstrual cycle?
If not fertilised, the egg is attached to the uterus lining, the lining breaks down and the cycle begins again
The combined pill [2]:
- Contains both Oestrogen and Progesterone
- By taking it every day, enough oestrogen builds up in the female body to inhibit the production of FSH so that no eggs mature.
Progesterone-only pill [3]:
- Stimulates the production of thick, sticky mucus, which is very difficult for any sperm to penetrate.
- Inhibits the release of FSH, so that eggs don’t mature.
- Has fewer side effects then the combined pill but equally effective
The contraceptive injection [2]:
- Contains progesterone
- Lasts up to 3 months
The contraceptive implant [3]:
- Inserted under the skin
- continually releases small amounts of progesterone
- can last for 3 years
Contraceptive patch [3]:
- The woman places a small contraceptive patch on her skin
- steadily releases progesterone
- Has to be changed 1 a week
Intrauterine device IUD [3]:
- They are small t-shaped devices that are inserted into the uterus.
- They work by preventing implantation of an embryo (fertilised egg).
- Some intrauterine devices also release progesterone.
Diaphragms [3]:
- A diaphragm is a shallow plastic cup, which is inserted into the vagina prior to sexual intercourse and sits at the entrance to the uterus.
- It is designed to prevent the sperm from reaching the egg.
- It can also be covered in a spermicide to kill the sperm.
Which pill has the fewest side effects?
the progesterone only one
Which STIs are condoms effective agianst:
Condoms are effective in protecting against sexually transmitted infections (STIs), such as chlamydia, gonorrhoea and HIV.
Sterilisation in women:
For a woman, this involves having the fallopian tubes (ducts which connect the ovaries to the uterus) cut so that an egg cannot reach the uterus.
Sterilisation in men:
For a man, this involves having the sperm ducts (the tubes between the testes and the penis) cut so that the sperm are not released on ejaculation.
Sterilisation:
Sterilisation is a permanent procedure to remove any chance of getting pregnant.
Timing [2]:
- Since a female’s body temperature usually rises during ovulation, some women choose to avoid sexual intercourse on days when they know (or feel) that they are ovulating.
- However, sperm can last up to six days inside the woman’s body, so this is not a very reliable or effective method of contraception.
Abstinence
- The only truly effective way (apart from sterilisation) to avoid pregnancy is abstinence.
- This simply means that a couple chooses to not have sexual intercourse unless they are ready for a baby.
Puberty effects on males [3]:
- The amount of the hormone testosterone rises. This stimulates sperm production.
- Underarm, facial and pubic hair grow.
- Voice deepens.
Puberty effects on females [3]:
- The amount of the hormone oestrogen rises and triggers the menstrual cycle.
- Underarm and pubic hair grow.
- Breasts enlarge.
Diabetes type 1 [5]:
- In type 1 diabetes, sufferers are unable to produce enough insulin.
- Type 1 diabetes develops during childhood.
- We do not know what causes Type 1 diabetes, but we think that the body’s immune system attacks the pancreas cells.
- The main treatment is to inject insulin when blood glucose levels rise too high.
- Sufferers can also manage their diet and exercise regularly to keep blood glucose levels as steady as possible.
Diabetes type 2 [3]:
- In type 2 diabetes, sufferers can still produce insulin, but their body no longer responds to it.
- Type 2 usually develops in later life
- sufferers must manage their diet and exercise regularly to keep blood glucose levels steady.
Too little glucose
If there is not enough glucose, an organism cannot produce enough energy.
Too much glucose
If blood glucose levels are too high, this can have a negative impact on osmosis (movement of water between cells) by affecting concentration gradients.
Which hormone is released when glucose is too high?
insulin
Which hormone is released when glucose is too low?
glucagon
When too little glucose is detected [5]:
- Low concentration of blood glucose is detected
- This triggers the pancreas to release glucagon into the blood stream
- glucagon is detected by the liver
- the liver converts stores of glucagon into glucose and releases it into the bloodstream
- process continues until pancreas detects normal glucose levels
Water leaves the body if…[5]:
- sweating
- Urinating
- breathing
- too much salt
- illness
kidneys:
The kidneys are important for homeostasis. They control the water and ion levels in the blood.
excess water is …
monitored by the hypothalamus in the brain
Production of urea [3]:
- digestion of protein results in excess amino acids
- in the liver the amino acids undergo deamnation
- produces urea
Light investigation [4]:
- Place the seeds in petri dishes with damp cotton wool, and leave them in a warm place to germinate (develop).
- Randomly divide the petri dishes into three groups and assign each group to Full sunlight in a windowsill, Darkness, Partial light
- Measure the height of the plants daily for a week.
- Draw and label biological drawings to show the effects.
Ethene [definition]:
Ethene is a gas that controls cell division and the ripening of fruits.
Auxins [2]:
- Auxins change growth patterns to allow roots and shoots to move either towards or away from a stimulus
- Responses to stimuli that involve directional growth are called tropisms.
Gibberellins:
Gibberellins are important in starting off the seed germination (sprouting) process.
Phototropism:
+ growth towards a light source
- growth away from a light source
gravitropism [2]:
+ growth towards the direction of gravity
- growth away from the direction of gravity
Why is homeostasis important in organisms?
Organisms must regulate their body’s internal conditions to make sure their enzymes and cells function well.
What internal conditions are regulated in the human body? [5]:
- Carbon dioxide levels
- Water levels
- Urea concentration
- Body temperature
- Blood sugar levels
Dialysis [definition]:
The artificial removal of urea and excess materials from the blood
Water reabsorbtion
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