Week 4: Neuroanatomy II Flashcards
Midbrain
also called masencephalon, has two parts: tectum and tegmentum
It is responsible for the coordination of muscles and responding to sensory information like sounds and lights
Hindbrain
has also two parts: metencephalon and myelencephalon
Responsible for coordination of basic and automatic tasks that are quite vital for the organism
Metencephalon
has pons and cerebellum
pons is responsible for sleep wake cycle of our body. pons is needed for communication btw cerebellum and cerebral cortex
cerebellum is responsible for our movements including standing. It is also active when recieving somatosensory, visual or auditory information. adjusting or coordinating related tasks
myelencephalon
has the medulla
medulla controls working of our vital system such as cardiovascular system and respiratory system (heart beat, breathing, vital reflexes coughing vomiting etc
Peripheral nervous system
spinal cord is kind of junction of peripheral and central nervous system, connecting the brain to the entire system. communication part.
communication in two ways
cranial nerves and spinal nerves
spinal nerves,cranial nerves
afferents from sense organs, efferents to muscles
symphathetic Branch
Spinal nerves, ganglia
parasympathetic Branc
cranial nerves, spinal nerves
ganglia
Sympathetic divison
an arouser: prapares the body to be alert. All these body parts or organs are becoming alerted when sympathetic system is activated.
norepinephrine released by neurons
salviation decreases
parasympathetic division
relaxation: acetylcholine is released by neurons
digestion urination get back to normal
other than neurons there are
glial cells in the nervous system
star shaped astrocyctes
blood supply and exchange of materials (central)
protective microglial cells
immune defense of the brain and the spinal cord (central)
Ependymal cells
create, secrete and circulate cerebrospinal fluid (central)
Oligodendrocytes
myelin sheet (central)
Satellite cells
surround and support cell bodies (peripheral)
Scwhwann cells
myelin sheet (peripheral)
3 main qualities of neurons
they live long
they dont divide so they are irreplaceable
they have high metabolic rate
Soma
cell body that has nucleus and other organelles
dendrites
listeners
axon
talker
Multipolar neurons
3 or more processes inc. one axon, bunch of dendrites
bipolar neurons
2 processes inc one axon and dendrite, rare: retina
unipolar
1 process sensory neurons
Broca’s area
to produce and process language
broca’s aphasia
some ability to understand speech but inability to produce intelligible words. Singing helps
The spinal cord and brain are protected by
bones (vertebrae and cranium/skull) and (cerebrospinal fluid)
Nociceptors
Specialized nerver receptors for pain
We all have the same
pain treshold, but individual differences in tolerances for discomfort
mechanically gated receptors
that respond to a stretch in their membranes
ligand gated receptors
that open when the damaged skin tissue releases chemicals like histamine or potassium ions
Electro Chemical messaging system
5 steps of producing reflex arc
1 receptors sense the stimulus
2 sensory neurons transmit signals up to PNS and CNS
3 Integration center decodes the signal
4 Motor neurons send directions back to the site of the stimulus
5 Effector cells respon by contracting or secreting
Innate reactions
Spinal cord: no need for much conscious processing in the brain
Learned reactions
Come from experience and becomes automatic
Reflex arcs stimulate and inhibit muscles
not related to pain only (tapping the knee)
Thalamus first reciever then send it to
somatosensory cortex (identify and localize the pain caused)
limbic system (emotional suffering)
frontal cortex (assigning the meaning)
