Chapter 3: The Nervous System Flashcards
afferent vs efferent signals
sensory (incoming) pathways are afferent
motor (outgoing) pathways are efferent
what makes up the central nervous system?
the brain and spinal cord
what makes up the peripheral nervous system
somatic nervous system, autonomic nervous system, enteric nervous system
how does the enteric nervous system send signals to the brain?
via the vagus nerve
what affects the enteric nervous system?
stress and anxiety
what are the components of the somatic nervous system?
cranial nerves and spinal nerves
what are the components of the autonomic nervous system?
sympathetic division (arousing) and parasympathetic division (calming)
what connects the cerebral hemispheres?
the corpus callosum, which allows for communication between the hemispheres
what is dura mater?
a tough, paper-like outer covering of the brain
what is the subarachnoid space?
a space between the brain and dura mater and pia mater where cerebrospinal fluid flows
what is pia mater?
a clear covering that hugs the surface of the brain
where is cerebrospinal fluid produced?
in the choroid plexus
where is cerebrospinal fluid reabsorbed?
in the sinuses
what is hydrocephalus?
a condition marked by overproduction of cerebrospinal fluid without proper drainage/reabsorption
what is the purpose of cerebrospinal fluid?
cushions the brain and spinal cord from bumping and jostling, removes waste
what is an ischemic stroke?
a blockage of blood flow to part of the brain, resulting in a lack of nutrients and oxygen
what is a hemorrhagic stroke?
a ruptured vessel/artery that causes a bleed in the brain and produces an overactive immune response
medial
toward the brain’s midline
lateral
located toward the brain’s sides
dorsal
atop the brain
ventral
toward the bottom of the brain
histological technique for studying the brain
most precise way of examining the brain. the brain is sectioned and sliced postmortem and neuronal loss is examined
computerized tomography (CT scan)
an x-ray beam is passed through the brain at many different angles, creating many different images.
good for seeing a mass/tumour, lesion, etc
magnetic resonance imaging (MRI)
can identify specific brain tissue
diffusion tensor imaging (DTI)
detects the directional movement of water molecules to create images of nerve fibre pathways. can identify abnormalities in the pathway, such as an obstruction
positron emission tomography (PET)
a real time measure that involves injecting a radioactive tracer into the bloodstream and shows which parts of the brain are more active (have more blood flow) during certain tasks
functional magnetic imaging (fMRI)
changes in the oxygen content of the blood alter its magnetic properties. measures are taken while a task is being carried out
near-infrared spectroscopy
uses light to track blood flow in the brain based on oxygen levels. limited to more shallow areas of the brain
what makes up the hindbrain?
pons, reticular formation, medulla, cerebellum
what are the functions of the pons?
serves as a bridge to the cerebellum and allows a person to cycle through the different stages of sleep
what is the function of the reticular formation?
sleep/wake behaviour
what is the function of the medulla?
moderates heart rate and rhythm
what can damage to the medulla result in?
a person may not be able to breathe on their own
what is the function of the cerebellum?
coordination of motor movements
what can damage to the cerebellum result in?
issues with speech, movement, etc
what are the components of the midbrain?
superior colliculus and inferior colliculus
what is the function of the superior colliculus?
receives visual input
what is the function of the inferior colliculus?
receives auditory input
what structure does the superior and inferior colliculi make up? what is its purpose?
together they make up the tectum, which allows for audio-visual integration
what structures make up the diencephalon?
the thalamus and hypothalamus
what is the function of the thalamus?
serves as a relay centre for incoming and outgoing signals in the brain
what is the function of the hypothalamus?
release of the hormones into the bloodstream
what is the forebrain responsible for?
complex behaviour (problem solving, language, and thought)
what are the brainstem and midbrain responsible for?
survival based behaviours (sleeping, waking, breathing)
what are the divisions of the forebrain?
temporal lobe, frontal lobe, parietal lobe, occipital lobe
what is the purpose of the temporal lobe?
auditory processing
language and memory
taste and smell
what is the purpose of the frontal lobe?
planning and organizing
motor and impulse control (executive function)
what is the purpose of the parietal lobe?
touch
spacial awareness
what are symptoms of parietal lobe damage?
don’t know how to position the body
can’t draw shapes
what is the purpose of the occipital lobe?
visual processing
what are the symptoms of occipital lobe damage?
flashes of light, vision loss, etc
what are the functions of dendrites?
receives signals from other neurons
creates an electrical charge
what is the purpose of the myelin sheath?
conducts electrical signals more quickly
what is located in the axon terminals?
chemical signals in the form of neurotransmitters
what is the purpose of the axon?
transmits electrical signals
what is the purpose of sensory neurons?
converts environmental energy into a neural signal
what are the characteristics of motor neurons?
largest neurons with the longest axons
very well myelinated
contained in the spinal cord
synapse on muscle fibres
what are the functions of astrocytes?
help maintain the blood brain barrier
cover blood vessels
transport nutrients from the blood system into neurons
what are the functions of microglial cells?
help recover debris and waste
heavily involved in the immune response
what are oligodendrocytes?
glial cells with extensions rich in myelin that wrap around the axons of some neurons in the CNS
what is the function of schwann cells?
guide axonal regeneration after damage
