Topic 5 Flashcards
What is Homeostatis?
The regulation of the conditions inside your body to maintain a stable internal environment in response to changed.
What are the 3 steps of Negative Feedback?
- Receptor detects levels of x are too low/high
- The co-ordinarion centre recieves and processes this information & organises a response
- Effector produces a response, which counteracts the change snd restores the optimum level. (level increases/decreases)
What are the three types of neurons?
Sensory neuron
Relay neuron
Motor neuron
What is a Receptor?
What is an Effector?
A receptor detects stimuli
An effector responds to the stimuli
What is the reaction time practical?
- Person 1 sits with their arm resting on the table.
- Person 2 lets go of the ruler from zero, without warning.
- Person 1 trues to catch the ruler as fast as they can.
- The reaction time is measured by the number on the ruler when its caught, the higher then number the slower the reaction time.
- Repeat
- Repeat having given person 1 caffeine
What are the 3 parts of the brain and what do they do?
Cerebral Cortex - responsible for consciousness, intelligence, memory and language.
Cerebellum - responsible for muscle coordination.
Medulla - responsible for unconscious activitylike breathing.
How do we learn about the brain?
Studying patients with brain damage.
Electronical stimulation.
MRI scans.
What are the 6 parts of the eye?
- SCLERA - suppoting wall of the eye
- CORNEA - transparent outer layer at the front of the eye, it refracts light into the eye.
- IRIS - contains muscles and controls the diameter of the pupil
- LENS - focuses the light onto the retina
- CILIARY MUSCLE & SUSPENSORY LIGAMENTS - control the shape of the lens
- OPTIC NERVE - carries impulses from the receptors to the brain
Why does the size of the pupil change?
To repond to low/high light levels.
How do we look at nearby objects?
The ciliary muscles contract, the suspensory ligaments slacken.
The lens becomes fat.
This increases refraction of light.
How do we look at distant objects?
The ciliary muscles slacken which causes the suspensory ligaments to pull tight.
The lens becomes thinner.
It refracts light less.
Why are people Long Sighted?
Their Lens is the wrong shape and doesn’t refract the light enough or the eye is too short.
Why are people short sighted?
The lens is the wrong shape and refracts too much light or the eyeball is too long.
How does the body control it’s temperature?
TOO HOT
1. Sweat
2. Blood vessels dilate (Vasodilation)
TOO COLD
1. Hairs stand up to create an insulating layer
2. Blood vessels constrict (Vasoconstriction)
3. Shivering
What are the 6 parts if the Endocrine system?
- Pituitary Gland
- Thyroid
- Adrenal Gland
- The Pancreas
- Ovaries
- Testes
What’s the difference between nerves and hormones?
NERVES
1. Fast action
2. Short term changes
3. Very specific area
HORMONES
1. Slower action
2. Long term changes
3. More general area
What is the difference between diabetes type 1 and diabetes type 2?
TYPE 1
1. No insulin produced by the pancreas.
2. Blood glucose levels are uncontrolled.
3. Often take insulin injections and watch their diet.
TYPE 2
1. Resistant to insulin.
2. Blood glucose levels are uncontrolled.
3. Obesity is a major risk factor for Type 2
4. Regular excersise and watching diet.
What does the kidney do?
The kidneys make urine by taking waste products out of the blood. Substances are filtered out (filtration) as they pass through in the blood. Some useful things are reabsorbed (selective reabsorbtion)
What is urea?
Urea is created when excess amino acids are turned to fats and carbohydrates (deamination).
This process creates Ammonia, which is toxic, so is converted to urea in the liver.
What is ADH?
It controls the concentration of urine.
The brain monitors water levels in the blood and instructs the pituitary gland on how much ADH to release.
It is a process of negative feedback.
How does dialysis work?
It is done regularly to replace the kidneys. (3-4 times a week for hours at a time)
- The blood flows through partially permeable membranes, surrounded by dialysis fluid.
- These permeable membranes allow ions and waste products through but not big molecules like proteins (like the kidneys)
- The dialysis fluid concentration is specific to that of healthy blood.
- This means dissolved ions and glucose dont diffuse out of the blood.
- Only waste substances diffuse across the barrier.