Nervous System Flashcards
Outline three adaptions of a predator (a cat)
Tapetum Lucidum
Slit Pupils
Near-sighted
Describe the tapetum lucidum
Layer at the back of the eye
High concentration of cones
More photoreceptors stimulated to allow the cat to see in the dark
Why are slit pupils important for cats?
Allows them to focus on prey
Allows varying amounts of light to enter the eye from different areas
Why is being near-sighted an issue for cats?
Unable to focus on distant objects
State two advantages of cats being near-sighted
Cats have a 200 degree field of vision which allows them to pick up on subtle movements
They have more rods which allows them to see in low light
State three adaptions of a prey animal (Duck)
Control curvature of cornea & lens
Blood vessels concentrated in pectum
Mallards lateral viewing window is 360 degrees
Rapid head movement
State the structure of the retina
Outer pigmented layer
Inner neutral layer
Name the layers of the retina
Bipolar neurones
Axons of ganglion cells
Optic nerve
What is a reflex?
A fixed response to a stimulus
What is a stimulus?
A detectable change in the physical or chemical environmental of an organism
How are stimuli detected?
Receptors within sense organs
Pain stimuli
State the two types of reflexes
Voluntary
Involuntary
What is a voluntary response?
A reflex that involves the brain
What is an involuntary reflex?
A reflex that does not involve the brain
Name some reflex responses
Kicking
Flinching
Blinking
Pain responses
Coughing
Sneezing
Shivering
Define neuron
Specialised cells that conducts electrical impulses
What is the autonomic nervous system regulated by?
Hypothalamus
What is peristalsis?
Clenching of oesophagus to move large food molecules to stomach
State the types of the autonomic nervous system
Sympathetic
Parasympathetic
What is the response that is related to the sympathetic nervous system?
Fight or flight
Which response is related to the parasympathetic nervous system?
Rest & digest
State three functions of rods
Light sensitive & functions in dark
Single pigment known as rhodopsin
Share connection with optic nerve
State five features of cones
Higher intensity than rods
Contain iodopsin (photo pigments)
Range of colour depends on type of cone cell present
High level of visual sharpness
Each cone has connection with optic nerve
