Module 8 Flashcards
Define homeostasis
The process of maintaining a stable internal environment despite changing external conditions
Process of temperature homeostasis
Change in external temperature detected by thermo-receptors —> message sent to hypothalamus via nerve —> message sent to effectors to either dilate blood vessels and sweat or constrict blood vessels and shiver.
Process of Glucose homeostasis
Change in blood glucose levels detected by pancreatic cells—> liver breaks down glycogen or takes up glucose —> blood glucose rises/declines to a set point and homeostasis is restored.
Process of water homeostasis
Water levels change —> hypothalamus detects change —> pituitary glad stops/starts releasing ADH —> ADH stops/starts acting on the kidney by increasing/decreasing the permeability of the nefrons.
What are the behavioural adaptations to maintain homeostasis?
- movement to different environments (shade/sun)
- deliberate use of muscles (metabolic heat)
- sunbaking (radiation)
- licking (evaporation of saliva)
- drinking water
How does genetic engineering help/fix non infectious diseases
Gene therapy: inserting corrected gene sequencing into a cell where a defect has occurred - techniques used to do this include insertion of viral vectors, gene gun and inorganic particles
CRISPR: point mutations to dysfunction cells this alters the genomes resulting in a lasting somatic cell edit
Embryo screening or editing: screening allows implanting embryos without genetic defect editing within embryos allows while organism changes
The ear (sections)
The outer ear: pinna (ear lobe ect) and ear canal
The middle ear: ear drum and ossicles (hammer, anvil and stirrup)
The inner ear: cochlea, semicircular canals (balance) and auditory nerve
The pathway of sound through an ear
Sound enters the ear in the form of waves the EAR DRUM vibrates this movement causes the the OSSICLES to move in a chain like fashion. This movement knocks on the membrane window of the COCHLEA the cochlea is filled with fluid which moves in response hair cells lining the cochlea are bent in response which creates an electrical impulse to be sent along the AUDITORY NERVE and to the brain
Conductive hearing loss and what can cause it
Occurs when there is damage to outer or middle ear resulting in ineffective sound transfer
The cochlea may still be functional but does not recievce sufficient signal to create an auditory impulse
May be a result from infections, abnormal bone growth in middle ear or perforation of the eardrum
Sensorineural hearing loss and what can cause it
Occurs when there is damage to inner ear, sound may arrive at cochlea but is not properly passes to auditory nerve or the nerve itself may be damaged
Damage may be congenital as a result of genetic factors or disease or acquired due to factors such as age, noise exposure, physical trauma or diseases such as meningitis
Pathway of light through the eye
Light-> cornea -> pupils (can dilate and contract iris to change how much light entered the eye) -> lens (focused light) -> through vitreous gel-> light rays come to a focal point image is focused at the retina-> as light hits the retina light energy is converted into electrical impulses by the rods and cones which sends the messages onto the optic nerve -> brain
What is it called when light does not focus properly in the eye due to incorrect shaping of the cornea
Refractive errors
What is myopia and what lens shape assists
(Near sightedness) occurs when the cornea is too curved or the eyeball is too long resulting in light refracted at an angle which places the focal point in front of the retina
Concave lenses allow light to focus on retina
What is Hyperopia and what lens assist
(Far sightedness) occurs when the cornea is too flat or the eyeball is too short resulting in light being focused beyond the retina ( objects close up are blurry)
Convex lenses allow light to focus properly on retina
Astigmatism, glaucoma and cataracts
Astigmatism: disorder where vision is blurred at all distances as a result of misshapen cornea
Glaucoma: blindness due to build up of pressure in the eye causing optic nerve damage
Cataracts: clouded areas in the lens causing blurry or tinted vision
List the causes of genetic diseases
- gene or chromosome abnormalities caused by point or chromosomal mutations ( may result from errors during gamete formation or exposure to mutagens)
- inherited from parents
- acquired changes to pre- existing genes
