Module 8 Flashcards
(47 cards)
what is homeostasis
Homeostasis is the maintenance of a stable internal metabolic environment (set point). This is necessary for optimal enzyme function
3 types of neurones?
Sensory neurones detect stimuli such as pain, pressure, temperature, taste, sound, sight, smell etc. using receptors at the ends. They store their nuclei in cell bodies attached to the side of the axon.
Motor neurones are responsible for moving; they send electrical impulses to electors (mainly muscles) to carry out voluntary and involuntary action so
Relay neurons (a.k.a. connector neurones, interneurons) carry information between motor and sensory neurons, and make up the spinal cord and brain
type of sensory
Chemoreceptors detect the presence of chemicals.
Thermo receptors detect changes in temperature.
Mechanoreceptors detect mechanical forces.
Photoreceptors detect light during vision.
pancreas role
The pancreas is one of the most important organs of homeostasis as it controls blood glucose. It contains two types of endocrine cells – alpha cells (which produce glycogen)and beta cells (which produce insulin)
what is negative feedback
Negative feedback is where the body recognises that it is not at set point and corrects the imbalance in the opposite
what is positive feedback
Positive feedback is where the stimulus is reinforced and leads to an amplified response, e.g. labour during childbirth,
what happens when BGL are to high
cells in the pancreas release insulin, causing the body to absorb glucose, from the blood, the liver turning it to glycogen and stores it and lowering the blood sugar level to normal.
what happens when BGL are to low
- alpha cells in pancreases release glucagen
- liver breaks down glyogen to glucose
- bgl increases
plants water balance
-Plants in hot climates thus have a wide variety of structural and physiological adaptations to prevent excess water loss
deep root systems, thin needle-like, curled, or vertically hanging leaves with thick waxy cuticles, sunken stomata with stomatal hairs which only open in the morning, hard fruit and small flowers, water storage in trunks, and loss of leaves/limbs in very dry periods
Mechanisms and Adaptations
Structural adaptations such as ear size, fur, etc. (anatomical), physiological adaptations such as hibernation, sweating etc. (metabolic), and behavioural adaptations such as burrowing
eh artic foxes
Outline the function of the Cochlea (snail)
-> filled with a fluid that moves in response to the vibrations from the oval window.
fluid moves= 25,000 nerve endings are set into motion= transform the vibrations into electrical impulses = travel along the eighth cranial nerve (auditory nerve) to the brain.
outline the function of the organ of the corti (hearing)
three rows of outer hair cells and one row of inner hair cells
Vibrations caused by sound waves bend the stereocilia on these hair cells via an electromechanical force.
outline 2 types of hearing loss
- Conductive hearing loss
- Sensorineural hearing loss
outline conductive hearing loss
caused by a problem with the mechanical conduction of vibrations
through the outer and middle ear
could be from trauma
outline Sensorineural hearing loss
- permanent
- caused by damage to, or malformation of, the inner ear, including parts
of the cochlea, the hair cells or the auditory nerve. - from excessive noise exposure, heredity, birth defects, infections, tumours,
medication and ageing.
name 3 technologies for hearing loss
- hearing aids
- bone conduction implant
- cochlear implant
name 3 technologies for hearing loss
- hearing aids
- bone conduction implant
- cochlear implant
what does hearing aids do
magnify the sound vibrations to better enable their transmission to the
middle ear and then the inner ear.
for conductive
what does hearing aids do
magnify the sound vibrations to better enable their transmission to the
middle ear and then the inner ear.
for conductive
what does bone conduction implant do
Microphone that detects the sound and transforms it into
Vibrations - there is a risk of infection and inflammation at the implant site after surgery.
what does cochlear implant do
external speech processor and transmitter coil - conversion of sound into electrical impulses that stimulate an
electrode array implanted in the cochlea, which in turn stimulates electrochemical impulses in
the auditory nerve.
outline processes of eye focussing light
- light passes through the cornea
- convex nature of the cornea bends the light
- enters pupil
- light passes through the lens. The lens works together with the cornea to focus light correctly on the retina.
- light hits the retina, photoreceptors turn the light into electrical signals.
- electrical signals travel from the retina through the optic nerve to the brain
outline the role of rods
are evenly distributed over most of the retina,
→ Contain “rhodopsin” = extremely sensitive to low levels of light = responsible for vision at low light levels
outline role of cones
contain 3 pigments = light of one particular wavelength may stimulate more than one type of cone. By comparing the rate at which various receptors respond, the brain is able to interpret these signals as intermediate COLOURS
