Nervous System🧠 Flashcards
What are the different sense receptors?
- Auditory
- Somatosensory
- Olfactory
- Gustatory
- Visual
What are the different types of receptors?
- Chemoreceptors
- Thermoreceptors
- Mechanoreceptors
- Photoreceptors
What are the three types of neurons?
- Sensory neuron- responsible for transmitting impulses from sensory organs to the central nervous system (CNS)
- Motor neuron - send impulses from the CNS to specific muscles or organs
- Interneuron - transmit impulses between sensory and motor neurons within the brain or spinal cord
What is the structure and function of the eyelid?
1.structure- fold of skin which covers the eye
2. Function- cleaning and protecting the eye
What is the structure and function of the cornea?
- Structure- transparent covering on the eye
- Function- protecting the eye; helping converge (bend and join) light rays that enter the eye
What is the structure and function of the sclera?
- Structure- white part of the eye made of tough collagen fibres
- Function- providing protection and support
What is the structure and function of the retina?
- Structure- layer of light-sensitive cells (photoreceptors) at the back of the eye
- Function- detecting light rays that are focused by cornea and lens
What is the structure and function of the choroid?
- Structure- layer of blood vessels with a black pigment
- Function- nourishing the eye and absorbing light
What is the structure and function of the iris?
- Structure- ring of muscles around the pupil, coloured which provides eye colour
- Function- controlling the amount of light entering the eye
What do the structure and function of the lens?
Structure- transparent, flexible and can change shape due to cilliary muscles
2. Function- focusing the light onto the retina and focusing on objects
What is the structure and function of the ciliary body?
1.Structure - attached to the underside of the lens
2. Function- producing aqueous humour and helping with focusing by altering the shape of the lens
What is the structure and function of the aqueous humour?
1.structure- Found behind the lens
2. Function- helping to keep the rounded shape; providing nutrients to the cornea and lens
What is the structure and function of the lateral rectus muscles?
- Structure- found on the lateral side of the eye
- Function- helping orientate the pupil away from the body
What is the structure and function of the medial rectus muscle?
- Structure- found on the medial side of the eye
- Function- helping orientate the pupil away from the centre of the body
What is the structure and function of the fovea?
- Structure- spot located in the macula, which has a high density of cone cells
- Function- giving sharp central vision; light is focused onto this spot by the lens
What is the structure and function of the optic disc?
- Structure- blind spot where there are no photoreceptors
- Function- where the optic nerves leave the eye
What is the structure and function of the optic nerve?
- Structure- bundle of fibres
- Function- relaying information from the retina and fovea to the brain
What are the two divisions within the autonomic nervous system?
- Parasympathetic (rest and digest)
- Sympathetic (flight or fight)
What happens within parasympathetic?
Eyes- constrict pupil
Salivary glands - stimulates salivation
Heart- slows heartbeat
Lungs- constrict bronchi
Stomach- stimulates digestion
Liver- stimulates bile release
Intestines- stimulates peristalsis and secretion
Bladder- contracts bladder
What happens within sympathetic
Eyes- dilate pupil
Salivary glands- inhibits salvation
Heart- accelerates heartbeat
Lungs- dilate bronchi
Stomach- inhibits digestion
Liver- stimulates glucose release
Kidneys- stimulates epinephrine and norepinephrine release
Intestines- inhibit peristalsis and secretion
Bladder- relaxes bladder
What is the different between rods and cones?
- Rods contain rhodopsin which cannot detect colour
- Cones contain iodopsin which detects colour
What is the structure and function of the nervous system?
- Structure;
•surrounded by shock-absorbing cerebrospinal fluid (CFS)
•Brain
•spinal cord- long bundles of nerves that branch out between each vertebrae connecting to PNS
Function- controls most of the functions and responses in the body
•Receive (stimuli from external and internal environments)
•Analyse (interpret the stimuli and information)
•Respond (bring about the necessary response)
What is the structure and function of the peripheral nervous system?
Structure; nerves that connect the spinal cord to the rest of the body, made up of sensory and motor neurons
Function; parts of the PNS form the somatic nervous system which detects and responds to external stimuli, when receptors are triggered, a message is sent to CNS
What two receptor cells (photoreceptors) are within the layers of the retina?
- Rods
- Cones
What is the role of a reflex arc?
- A reflex arc is a neural pathway that controls a reflex
- Allows for faster reflex actions - activating spinal motor neurons
- Control involuntary reflexes (do not require the brain)
- Quicker response rate- protecting ourselves from harms stimuli
What is the function of a dendrite?
- Receive communications from other neural cells through their tree-like projections
What is the function of the cell body/soma?
1.Encapsulates the nucleus
What is the function of the nucleus?
- Contains genetic information that controls the neuron
What is the function of the myelin sheath
- Outer coating of the axon, protects and maintains health of the axon. Acts like an electrical insulator.
What is the function of node ranvier?
- Allow impulses to jump by a process called ‘saltatory conduction’- this means that impulses can jump through gaps in the axon and speed up responses.
What is the function of schwann cells
- Helps form the myelin sheath and speeds up transmission of nerve impulses
What is the function of axon terminals
- Connects the neuron to target cells, such as effector and nerve cells
What is the function of gilial cells?
- Provide protection and support to nerve cells
- Surround and are in direct contact with neurons
What is a synapse?
1.The junction between two neurons
What are the names of the two divisions within the peripheral nervous system (PNS)
- Sympathetic
- Parasympathetic
What is the function of sympathetic (fight or flight)?
- Prepares the body for physical activity
- Inhibits all ‘normal’ body functions
- Noradrenaline (NA) - neurotransmitter
What is the function of parasympathetic (rest and digest)?
- Restores ‘normal’ body functions
- Acetylcholine (Ach) - neurotransmitter
What is the role of tapetum lucidum?
- Bounces light back
- Improving night vision in nocturnal animals