Nervous System Flashcards
The brain
Communication and control centre of the body, it receives, processes and evaluates many kinds of input, decides on response needed and acts
Involuntary activity
Autonomic Nervous System
Voluntary activity
Somatic Nervous System
What is the brain protected by
The skull, meninges and CSF
What is the meninges made up of
DAP
Dura mater, Arachnoid mater, Pia mater
The cerebral spinal fluid
Provides a cushion for brain and spinal cord.
Formed in ventricles, circulates around brain and returns to venous blood
Important to maintain normal pressures
What are the arachnoid villi
Small protrusions through the dura mater, they allow CSF to exit sub-arachnoid space and enter the blood stream
Blood brain barrier
Protective mechanism provided by relatively impermeable capillaries
Cerebral hemispheres
Largest portion of the brain, separate by a fissure
How is each hemisphere divided
4 major lobes
Frontal, parietal, occipital, temporal
Each has specific function and is responsible for OPPOSITE SIDE of the body
Sensory and association areas
These areas are responsible for recognizing and then interpreting the received data
Dominate hemisphere
It controls language, commonly the left
Broca’s area
Motor or expressive speech area, controls the output of words and ensures they are coordinated in an appropriate and understandable way
Wernicke’s Area
Integration centre that comprehends language received
Example of impaired broca area
A stroke victim may be able to make sounds but not functional sentences
Example of impaired Wernicke’s area
You ask what colour the wall is and they reply with bookstore
Limbic system
Responsible for emotion reactions and feelings, linked to hypothalamus - responsible to autonomic emoticons responses (nausea)
Diencephalon
Contains thalamus and hypothalamus
the thalamus
Main nerve bodies that serve as a sorting and relay stations for incoming sensory impulses
The hypothalamus
Key role in maintaining homeostasis, regulation of body temperature, intake of food, sleep cycle, libido
Brain stem
Connects brain to spinal cord contains pons, medulla oblongata, RAS
What are pons
Contains afferent and efferent fibres
What is the medulla oblongata
Vital control centre that regulates respiratory and cardiovascular functions
What is the RAS
Reticular Activating System, determines the degree or arousal or awareness of the cerebral cortex
- decides which of incoming sensory impulses the brain ignores and notices
Cerebellum
Responsible to coordinate movement and maintain posture and equilibrium
Blood supply to brain
Supplied by internal carotid and vertebral arteries which are branches of the carotid and subclavian
Venous blood then collects in dural sinuses and drains into left jugular veins
What does anastomosis mean
Different branches that supply the same area with blood
Circle of Willis
Inside the brain and ensures blood flow remains unimpeded in case any supplies are damaged
How many cranial nerves are there
12 pairs, originate from brain stem to skull
Mnemonic for the cranial nerves
Ooh, Ooh, Ooh to touch and feel very good velvet. Such Heavenly
Mnemonic for what the nerves do
Some say marry money but my brother says big brains matter more
Parts of cervical spine
C1-C7
Parts of thoracic spine
T1-T12
Parts of Lumbar spine
L1-L5
Parts of sacral spine
S1-S5
Spinal nerves
31 pairs in spinal column, carry motor and sensory fibres to and from organs and tissues, innervate at skin level called DERMATOMES
What is a neuron
Highly specialized cells that conduct impulses through CNS and PNS
How are impulses transmitted
Cell to cell via chemical neurotransmitters
Types of neurotransmitters
Acetylcholine (Ach)
Norepi/epi
Dopamine
Serotonin
Acetylcholine
Present at neuromuscular junction and in the Autonomic Nervous System and Peripheral Nervous System
Norepi/Epi
Neurotransmitter in the SNS
- causes vasoconstriction and increases in HR
- stimulates alpha and beta receptors
Autonomic Nervous System
Involuntary control, incorporates the SNS and PNS
- typically have antagonistic effects to maintain homeostasis
SNS of Autonomic nervous system
increases the level of activity including cardio, respiratory and neurological functions
Releases Ach, EPi
PNS of autonomic nervous system
Dominates digestive system and aids in recovery after sympathetic stimulation
Slows, largely innervated by vagus nerve
Somatic Nervous System
Stretches to nearly every part of body, carry out commands from brain to your muscles so you can move
What do all neurons have
Dendrite, cell body, axon and myelin sheath
Dendrite
Receptor site, conducts impulses towards the cell body
Cell body
Contains the nucleus
Axon
Conductions impulses away towards effector site or connection neuron
Frontal Lobe
Thinking, emotions, personality, self control, muscle movements
Occipital Lobe
Vision, visual processing
Temporal Lobe
Hearing, processing information from all 5 senses, storing memories, understanding language
Parietal
Processing sensory (cold, hot, pain), coordination with visual and auditory
