The Nervous System Flashcards
name the three protections of the nervous system
- bone (cranium)
- meningeal layers –> DURA, ARACHNOID, PIA
- cerebrospinal fluid
where is the cerebrospinal fluid produced, where does it go, and what does it do?
- it is formed in the blood
- it circulates in the brain, providing nutrients (glucose, protein, urea, salts)
where is the cerebrum located?
it is the outer section of the brain, the largest part
what are the four lobes of the cerebrum?
frontal, temporal, occipital, parietal
why is the cerebrum folded?
to increase surface area
what is the difference between a sulcus and a fissure?
a fissure is a deep down fold that occurs in the brain whereas a sulcus is a small, shallow down fold
what are the three areas of the cerebral cortex?
sensory –> interpret impulses from receptors
motor –> control muscular movements
association areas –> intellectual and emotional processes
what is the corpus callosum and where is it located?
the corpus callosum is a bundle of nerve fibres that is located underneath the cerebrum at the base of the longitudinal fissure. It connects the right hemisphere of the brain to the left.
what are the functions of the cerebral cortex?
thinking, reasoning, learning, memory, intelligence, sense of responsibility
what is the main characteristic of the left side of the brain?
language ability
what is the main characteristic of the right side of the brain?
music and artistic ability
where is the cerebellum located?
it is located underneath the rear part of the cerebrum
where is grey and white matter located in the cerebellum?
outer = grey matter inner = white matter
what is the function of the cerebellum?
posture, balance, coordination of voluntary muscle movement
where does the cerebellum receive information from?
inner ear and receptors in skeletal muscles
where is the hypothalamus located?
middle of the brain
what is the hypothalamus concerned with?
homoeostasis
what types of functions does the hypothalamus regulate?
autonomic nervous system: regulation of HR, BP, digestive juices, pupil diameter
body temperature, food and water intake, sleep and wake patterns, contractions of urinary bladder, emotional responses, secretion of hormones
where is the medulla oblongata located?
it is a continuation of the spinal cord, so it located at the base of the neck
which centres does the medulla oblongata contain?
cardiac centre: rate and force of heart beat
respiratory centre: rate and depth of breathing
vasometer centre: diameter of blood vessels
involuntary centres: swallowing, coughing, sneezing, vomiting
what is the central canal?
runs the length of the spinal cord, located in the centre of the spinal cord
what is the difference between ascending and descending tracts?
ascending tracts: sensory axons that carry impulses upwards
descending tracts: motor axons that conduct impulses downwards
what is the difference between the peripheral nervous system and the central nervous system?
CNS: consists of brain and spinal cord
PNS: connects CNS with muscles, receptors and glands
in which direction do dendrites carry nerve impulses
towards the cell body
in which direction do axons carry nerve impulses
away from cell body
what is the difference between myelinated and unmyelinated nerve fibres?
myelinated: contain myelinated fibres, are white in colour
unmyelinated: do not contain myelinated fibres, grey in colour
what are Schwann cells?
cells that wrap around a nerve fibre and produce the fatty myelin sheath
what are Nodes of Ranvier?
gaps in the myelin sheath that enable the transmission of impulses to occur at a fast rate
what is the role of neurilemma?
it is a sheath that surrounds a nerve fibre to help prepare injured fibres
what are the three functional types of nerve cells?
receptor, motor and inter
what is the function of receptor neurons?
messages are carried from receptors in sense organs to CNS, sensory neurons
what is the function of effector neurons?
carry messages from CNS to muscles and glands, motor neurons
what is the function of interneurons?
link between sensory and motor neurons, relay neurons
what are the three structural types of neurons?
multipolar, bipolar, unipolar
what are the characteristics of multipolar neurons?
one axon, multiple dendrites, includes interneurons and motor neurons
what are the characteristics of bipolar neurons?
one axon, one dendrite, found in the nose, ear, eye
what are the characteristics of unipolar neurons?
single axon, cell body located on one side, carry messages to spinal cord
what is a synapse?
junction between branches of adjacent neurons
what is the definition of a nerve impulse?
eletrical message that travels along a nerve fibre
what are the two divisions of the peripheral nervous system and what are their functions?
Afferent: carry information into the CNS
Efferent: carry information away from the CNS
what are the two divisions of the afferent nervous system and what are their functions?
somatic sensory neurons: skin and muscle
visceral sensory neurons: internal organs
what are the two divisions of the efferent nervous system and what are their roles?
somatic division: carry messages to skeletal muscles
autonomoic division: carry messages to involuntary muscles and glands and heart muscle
what are the two divisions of teh autononic division and what are their roles?
sympathetic division: fight or flight response
parasympathetic division: rest and digest
what are some examples of neurotransmitters?
adrenaline, noradrenaline, acetylcholine, histamine
how are nerve impulses transmitted across a synapse?
vesicular transport from the nerve ending across the synapse to another nerve
