Post on 26-Mar-2015
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Brain Spinal cord
Spinal Cord
Sensory Nerves: Afferent Motor Nerves: Efferent
Afferent: stimuli both internal and external
Internal: ◦ Stretch Receptors
External: ◦ Integumentary receptors
Messiner corpusle: touchPacinian corpusle: pressureNociceptor: painThermoreceptor: heat
Efferent: Response to effectors
Two functional divisions
Somatic:◦ Skeletal muscle
Autonomic:◦ Cardiac & Smooth
muscles◦ Glands
Sympathetic Parasympathetic:
Fight or FlightIncrease
◦ HR, RR, BP, BSDecrease blood flow
digestiveAdrenaline (Stress Hormone)
◦ released for the Adrenal glandsPupils DilateIncrease Blood Flow to MusclesSenses HeightenRelease of glucagon
◦ stimulates liver to release glucose increase BS
Homeostasis: CalmingSelf-Maintenance Activities
◦ Balance the Sympathetic response
◦ Decrease HR, RR, BPIncrease blood flow
◦ Digestive system
Adrenals stop releasing Adrenaline
Release of glycogen ◦ Stimulates liver to store BS
Fight or Flight: Sympathetic
Homeostasis: Parasympathetic
Cerebrum Cerebellum Meningies Ventricles Medulla Oblongata Corpus Callosum Pons Midbrain Spinal cord
Largest part of the brain Divided into hemispheres Each hemisphere has four lobes (F,T,P,O) Connected by the CORPUS CALLOSUM
Thick band of nerve fibres◦ connect the brain cells in one
hemisphere to those in the other hemisphere
◦ allows for constant communication
Aids motor coordination of left and right side
Left : Logical words logic numbers analysis lists linearity and
sequence
Right: Creative creative brain rhythm spatial awareness colour imagination daydreaming holistic awareness
and dimension
◦ planning ◦ organizing◦ problem solving◦ personality ◦ reasoning◦ Intuition or
perception ◦ behavior and
emotions
Frontal lobe
visual processing color recognition vision recognition
Occipital Lobe
◦ cognition (acquiring knowledge by the use of reasoning, intuition, or perception)
◦ information processing
◦ pain and touch sensation
◦ spatial orientation ◦ speech and visual perception.
Parietal Lobe
◦ emotional responses◦ hearing◦ speech. ◦ differentiate smells and
sounds
Memory (Hippocampus & Amygdala)◦ information sorting short and
long term memory. right lobe visual memory left verbal memory
Temporal lobe
Hippocampus
Motor Sensory
3 Layers◦ Dura Mater-toughest and outermost layer◦ Arachnoid Mater (resembles a spider web) middle
layer◦ Pia Mater-inner layer and most delicate sits
directly on top of the brain and spinal cord
Space between Arachnoid and Pia Mater has cerebrospinal fluid (CSF)
What is inflammation of the Meningies called?
Why is it serious?
What covers the Brain and the Spinal Cord?
What will this swelling cause?
In the Brain? In the Spinal Cord?
Cavities within the center of the brain filled with CSF
This fluid is found in the space around the Meningies and the central canal of the spinal cord
Fluid protects and cushions the CNS
Pituitary Gland:Master Gland
ThalamusHypothalamus: Homeostasis
CerebrumCorpus Callosum
Ventricles
Cerebellum
Spinal Cord: sensory impulses upMotor impulses down
Inferior to the Occipital lobes
Posterior to the Pons and Medulla Oblongata
Co-ordinates complex skeletal muscle contractions and relaxation necessary for body movement and balance
Connects the brain to the brain stem
Pituitary gland
Cerebellum
Hypothalamus
Thalamus
Inferior part of brain stem
Contains the vital reflexes◦ Cardiovascular center: force
and rate of the heart rate and changes in smooth muscle of the arteries to regulate Blood Pressure
◦ Respiratory centers: controls diaphragm
◦ Vomiting, hiccupping, swallowing, coughing, sneezing
Medulla Oblongata
Bulging brain stem region
Bridge between the cerebellum and the cerebrum
Works with the medulla oblongata to control breathing (respiration)
Pons
Form important connections between the cerebral cortex and the brainstem and spinal cord to control sensory processes such as vision and movement.
Midbrain
Electrical impulses (messages) travel back & forth between from the PNS to the CNS and then back to the PNS through bundles of neurons which are called nerves
1 Dendrites:◦ Extends out from the
cell body picks up message from synaptic terminal of adjoining neuron
2 Cell Body:◦ Directs all activity of
the neuron
3 Axon:◦ long single fiber that
transmits electrical impulse from cell body to the synaptic terminals
4 Synaptic terminals or axon terminals:◦ Release neurotransmitters
that allows electrical message to travel to the next neuron’s Dendrites or gland or muscle cells
5 myelin sheath covers most
neurons
insulates the axon and helps nerve signals travel faster and farther.
Movement of neurotransmitters
from synaptic terminal of one neuron:
to the dendrites of another neuron◦ Muscle cell : cardiac,
skeletal, smooth◦ gland
For a synapse to occur you need to have a
1.Pre-synaptic cell2.Post-synaptic cell
Acetylcholine – ◦ stimulates muscle contraction
Monoamines - Norepinephrine & Dopamine ◦ sense of feeling good, ◦ low levels = depression
Serotonin◦ Sleepiness◦ Depression
Endorphins◦ reduce pain by inhibit receptors
Neurons in the CNS Brain Spinal cord
White matter: Cell Body
Gray Matter: Axons
Spinal nerve
Central canalGray matter
White matter
Meninges
Spinal nerve
Meningies
Sensory: afferent stimuliDORAL ROOT
Motor: efferent responseVENRAL ROOT
Reflex Arc requires:1.Sensory neuron to
provide afferent input (stimuli) (Dorsal root)
2. Interneuron to process (Gray matter)
3.Motor neuron to send efferent output (response) (Ventral Root)
Nerve messages are sent through the spinal cord to the brain to be processed
Link between brain and rest of body (PNS)
31 pairs of spinal nerves
Reflexes processed directly by spinal cord
Reflex – quick, automatic, involuntary responses
Result of reflex arcs – shortest nerve pathways