The Nervous System Flashcards
What is the peripheral nervous system?
the nervous system outside the brain and spinal cord.
What is the central nervous system?
brain and spinal cord
What is the brain protected by?
scalp, skull, three layers of meninges and cerebrospinal fluid
What are the two hemispheres of the brain, what do they control?
right hemisphere: left side of the body and left hemisphere: right side of the body
What two types of matter make up the brain? What are they responsible for?
Grey matter: found outside the brain, responsible for information prosessing. White matter: found inside the brain responsible for information transfer.
How are the two hemispheres connected?
corpus callosum
What are the functions (overall) of the brain
Responsible for memory, logic and judgment, Analyzes and interprets the nerve impulses sent from the sensory organs
Produces nerve impulses to stimulate muscles to move and glands to secrete
substances.
What are the lobes of the brain?
frontal, parietal, occipital, temporal
What is the limbic system?
The limbic system is the internal portion of the brain that controls our behavioural and emotional responses
What makes up the limbic system?
hippocampus, amygdala, hypothalamus, thalamus, olfactory bulb
What is the olfactory bulb responsible for
processing the sense of smell
What is the amygdala responsible for
emotion
What is the thalamus responsible for
information relay
What is the hippocampus responsible for
memory
What is the hypothalamus responsible for
homeostasis
What is the cerebellums functions
coordinating movement and balance, Determines the required force and speed needed for a certain movement
What is the brain stems function?
connects the brain to the cerebellum and spinal cord Regulates respiratory rate, heart rate, blood pressure
and reflexes (coughing, swallowing, hiccupping,
vomiting and sneezing)
What are the three parts of the brainstem?
midbrain, pons, medulla oblongata
What is the spinal cord?
the main communications link between the brain and body
What is the function of the spinal cord?
Transport electrical nerve impulses from the encephalon to the motor nerves
Transport electrical nerve impulses from sensory nerves to the encephalon
What is a neuron?
a nerve cell; the basic building block of the nervous system
What does a neuron admit and why?
electrical nerve impulses (electrical currents) between each other to communicate with one another and to bring messages to the brain.
What are the three parts of the neuron
dendrites, cell body, axon
What is a dendrites?
receive information, extendable part of neuron (communicator)
What is the cell body of a neuron?
nucleus and cytoplams
What is the axon
Longest part of the neuron, Tipped with nerve endings, Surrounded by Myelin Sheath
What is a synapes?
this is where there are gaps between two neurons and a electrical impulse is trying to pass through to get to where it is needed so the side that has the electrical impulse releases chemicals across the gaps and this then stimulates the other neuron to release a electrical impulse
What are the nerve endings tiny sacs filled with?
neurotransmitters.
What are the three types of neurons
sensory, motor, association
How does the sensory neuron work?
receive and transmit, information from the senses (sight, hearing, smell, touch, taste) to the encephalon (brain)
How does the motor neuron work?
Transmit information from the encephalon (brain) to muscles in order for them to contract (or to glands to secrete)
How does the association neuron work?
transmit information between neurons
What is amitotic?
If they die they cannot be replaced, they cannot divide by mitosis AKA: NEURON
What is cranial nerve
nerves in the brain/encepolon
What is a spinal nerve
nerves branching off of the spinal cord to the rest of the body.
What is a involuntary reflex?
A reflex done involuntarily, muscles contract and relax without us having to consciously think about it.
What is a voluntary relfex
Reflexes we control: muscles contract and relax on command (like holding an apple), however sometimes they contract and relax without us having to consciously think about it (like moving our hand away from a hot stove after touching it)
What is a spinal reflex
spinal cord makes the decision of creating the involuntary reaction to deal with a particular stimulus.
Describe process of reflex arc
Start off with a Sensation, A Processor transforms the sensation into an electrical nerve impulse.
A Sensory Nerve carries the electrical nerve impulse to the Integration Center.
The Integration Center (either the brain or the spinal cord) decides on what the
reflex will be.
A Motor Nerve carries the reaction of the brain/spinal cord in the form of an
electrical nerve impulse.
A Muscle transforms the electrical nerve impulse message into an action.
What is the eye?
receptor organ of light
What is the sclera of the eye?
white part of the eye - protects and determines shape
What is the choroid?
contains many blood vessels, supplies with nutrients
What is the retina?
contains nerve cells that convert light into electrical nerve impulses (the first step of visual processing).
What is the cornea?
membrane which allows light rays through it - a bump of the eyes
What is the aqueous humor?
made of water, maintains the structure of the cornea
What is the vitreous humour?
made of gelatinous water, maintains the structure of the eyeball
What is the iris?
colored part of the eye that controls the size of the pupil (theirs a hole)
What is the pupil?
opening in middle of the iris. opens and closes due to iris contraction.
What is the lens?
focuses light into the retina
What is the optic nerve?
carries electrical nerve impulses from the sense receptors on the retina to the brain
What role does the occipicle lobe of the brain have with the eye?
interpret visual stimuli received from the eyes and to create a coherent visual perception
What is the lacrimal Glands?
tear glands, found just below eyebrow
Why do tears have antibodies?
to help protect the eyes from infections, layer of protection
What is the conjunctiva?
thin layer of cells that lines the inside of your eyelids from the eye
Which structures of the eye are opaque (light cannot pass thorough)
Sclera, chorid, retina
What is biconcave lens?
a lens that curves inward on both sides, like the inside of a bowl, and in the eye, it helps to focus light onto the retina for clear vision, creates a larger image, light gets farther and farther
What is a biconvex lens?
bulges outward on both sides, makes light interprested closer and closer to eachother, inverses images, brain makes it right side-up
What is emmetropia?
normal vision 20/20
What is myopia?
can see well close up, but far away images are blurry, caused by an elongated eyeball, the light rays merge in front of the retina, can be corrected with a biconcave lens
What is hypermetropia?
can see distant objects well, but nearby objects are blurry, caused by a shortened eyeball, the light rays try to merge behind the retina, can be corrected with a biconvex lens
What is presbyopia?
similar to hypermetropia but the cause is different, caused by a loss of flexibility in the lens usually due to aging, can be corrected with a biconvex lens
What is astigmatism?
makes it difficult to see both near and far away objects, caused by an irregularity in the curvature of the cornea or lens, can be corrected with thick cylindrical lenses that concentrate light rays and limit refraction
What is the difference between perception and sensing?
Sensing is what actually is, its what you can sense while perception is what you think you see (what you interoperate)
What is the outour ear responsible for, what structures are in it?
- Captures sound and directs into the middle ear
Prevents foreign objects from entering the ear
- Pinna
- Cerum gland
- Cillia
Pinna
Outer ear part that captures sounds
Cerumen Gland
Produces ear wax to protect eardrum from bacteria
Cilia
Tiny hairs that trap dust particles
Auditory Canal
Passageway that carries sound to the eardrum
What is the middle ear responsible for, what structures are in it?
- Amplifies/tones down sound if necessary - Balances air pressure on both sides of the eardrum
- Eardrum
- Ossicels
- Estachian tube
Eardrum
Membrane that vibrates the ossicles (mallus, incus, stapes) when stimulated by sound waves
Ossicles
Bones (mallus, incus, stapes) that transmit, amplify and increase vibrations from eardrum to the cochlea
Eustachian Tube
Connects to the pharynx, balances air pressure on both sides of eardrum
What is the inner ear responsible for, what structures are in it?
- Converts sound into nerve impulses that are sent to the brain - Detects movement and sends the information to the brain
- Vestibule
- Semicircular cannals
- Cochlea
Vestibule
Area with nerve cells detecting body movements for balance
Semicircular Canals
Fluid-filled rings detecting movement
Cochlea
Snail shaped and converts vibrations into nerve impulses for hearing
How does the cochlea convert vibrations into nerve impulses?
The sound vibrations make the fluid in the cochlea rippel, inturn making the hair bundles move, those movments create electricle nerve impulses which are transmitted to the auditory nerve through the bottem of the hair cell. The cell carries the single to the temporal lobe of the brain.
Auditory Nerve
Sends nerve impulses from cochlea to the brain
Skin
Receptor organ for pressure, heat, and pain sensations with 3 layers: Epidermis, Dermis, Hypodermis
Epidermis
Outer layer of skin composed of dead skin cells, keratin, and melanocytes producing melanin
Dermis
Layer of skin containing blood vessels, sweat glands, hair follicles, muscles, sebaceous glands, and nerve endings
Hypodermis
Layer of skin made up of adipose tissue, thicker in areas like hips and abdomen
Melanocytes
They produce a brown pigment called melanin which absorbs the harmful UV rays from the sun.
Non-sensory functions of the skin
- Protects the body from bacteria, water, UV rays - Regulates body temperature
- Excretes waste (sweat, excess water and minerals)
- Produces vitamin D
What happens to. capillaries when hot vs cold?
When hot, the capillaries dilate (get bigger) which causes the sweat glands to secrete sweat. When cold, the capillaries contract (grow smaller) to limit heat loss.
Name the Receptor, Processor, Signal, Conductor and Analyzer for the skin
Receptor: Skin Prosessor: nerve endings
Singal: Nerve impulses
Conductor: Sensory nerve, spinal cord and brain stem
Analyzer: Somatosensory cortex
Tongue
Receptor organ for taste
Gustatory Papillae
Small bumps on the tongue containing taste buds
Taste Buds
Detect flavors; convert taste into nerve impulses sent to the brain
To be perceived as taste, substances must be:
- Sapid (have flavour) - Soluble (can be dissolved in saliva)
- Concentrated enough to be detected by the taste buds
- In contact with a taste bud
How is favour processed and where?
Taste buds act as the processor turning taste into nerve impulses, sending it to the brain stem and or to the gustatory complex of the brain.
Name the Receptor, Processor, Signal, Conductor and Analyzer for the tongue
Receptor: Tongue Prosessor: Taste buds
Singal: ENI
Conductor: Cranial nerves and brain stem
Analyzer: Gustatory cortex
For a smell to be smelled substances must be:
- Odorant (have chemical smell properties) - Gaseous (can move through the air)
- Concentrated enough to be detected
- In contact with the olfactory receptors
What are non-Smell Functions of the Nose
Mucus and nose hair act as non-specific immunity to trap dust, bacteria and viruses
What are olfactory receptors?
Detect fragrances and convert smells into nerve impulses
Name the Receptor, Processor, Signal, Conductor and Analyzer for the nose
Receptor: Nose Prosessor: Olfactory receptors
Singal: ENI
Conductor: Olfactory nerve
Analyzer: Olfactory cortex
