Central Nervous System:
(CNS)
Contains: Brain & Spinal Cord
Peripheral Nervous System:
(PNS)
Contains: Nerves -- Cranial (12 pair), Spinal Cord (31 pair)
Sensory Nerves
Afferent, start from all over the body, end up in CNS.
Motor Neurons:
Efferent, start from CNS, end up in muscles & glands.
Somatic Nervous System
Voluntary function, skeletal muscles.
Autonomic Nervous System
Involuntary function, cardiac/smooth muscles, and glands.
Sympathetic NS / Emergencies:
fight/flight, digestive & urinary system shuts down.
Parasympathetic NS / Emergencies:
Calms down the body, stimulates digestive & urinary system.
Neurons:
Main cells, makes/conducts nerve impulses.
Neuroglial / glial cells:
Support, connect, protect and provide nutritional support.
What are the 6 types of Neuroglial/ glial cells?
-Astrocytes
-Oligodendrocytes
-Schwann Cells
-Ependymal Cells
-Microglial cells
-Satellite Cells
Astrocytes:
star shaped, blood brain barrier
Oligodendrocytes:
make myelin around nerves in CNS
Schwann Cells:
make myelin around nerves in PNS.
Ependymal Cells:
have cilia, line fluid filled cavities in CNS.
Microglial Cells:
phagocytosis
satellite cell:
protect the body of the neurons.
Neurons:
Basic structural/ functional units of the nervous system.
What are the different components in Neurons?
Dendrites to body to axon.
Dendrites: short, branched, multiple
Body: Soma, contains nucleus (DNA)
Axon: Long, always one.
Synapses:
Communication, two neurons get close to communicate.
What is the gap between two neurons?
Synaptic cleft
How do two neurons communicate?
1. Nerve impulse goes from A-->B
2. End of nerve, chemical (neurotransmitter)
3. Neurotransmitter: sticks to neuron & stimulates nerve impulse.
4. After communication, NT gets sent back to nerve.
Presematic Neuron: beginning
Postsematic Neuron: aftermath
Neurotransmitter:
Chemicals which make communication between two neurons possible.
Excitatory / Stimulatory:
"green traffic light", let's nerve impulses pass.
Inhibitory:
"red traffic light", stops nerve impulses.
-enkephalines & endorphins = natural painkillers
-gaba : inhibitory neurotransmitter which brings down the mood (depression).
Meninges:
Membrane covering the brain / spinal cord for protection.
Layers of the meninges:
-Skin
-Bone
-Epidural Space
-Dura Mater: has blood vessels, outermost layer.
-Subdural Space
-Arachnoid Mater: Thin, branched, No blood vessels
-Subarachnoid space (contains CSF)
-Pia Mater: Innermost layer, attached to brain and spinal cord.
Different components in the brain:
-Cerebrum
-Cerebellum
-Diencephalon
-Brain Stem
Cerebrum:
largest highest part of brain, only part of brain that has voluntary function
-gyri: bulging areas
-sulci: depressed areas
-fissures: deep crack
Longitudinal Fissure (In cerebrum)
separates brain into L & R hemispheres.
L hemisphere:
dominant one, verbal communications & analysis
R hemisphere:
non-dominant, non verbal communications, emotions, artistic abilities (painting & music)
Cerebrum works _____, L controls R, R controls L
Contralateral
Each hemisphere has _____ lobes, ____ all together>
2 lobes, 8 all together
Frontal Lobe:
largest lobe, personality, behavior, controlling movement, problem solving,
(left frontal lobe: broca's area (speech))
Parietal Lobes:
Skin Senses
Temporal Lobes:
Hearing, memory, some emotions, sensory speech
(left temporal lobe: language comprehension)) -- Wernike's Area
Occipital Lobe:
Vision, Visual perception
Corpus Callosum:
Nerves going left/right, people who have wider ones can multitask.
Cerebellum:
2nd largest part of brain, located in the back of the brain, below occipital lobe.
helps w balance, posture, and coordination.
Cerebellum works _____. L controls L. R controls R.
*L and R lobe connected by the vermis
Ipsilateral.
Diencephalon:
contains thalamus, hypothalamus, and epithalamus.
Thalamus:
Relaying center of the brain, conscious awareness of some senses. (Pain and Temperature)
Hypothalamus:
Makes hormones, helps homeostasis: temperature, thirst, electrolytes, hunger, blood glucose, heart rate, sleep and wakefulness.
Epithalamus:
Pineal gland: melatonin, sleep hormone... melatonin goes up at night, down during the day.
Pituitary Gland
Brain Stem:
contains CN III TO XII , lowest part of brain, vital center of brain , has 3 parts: midbrain, pons, medulla oblongata
midbrain:
reflex movement of head/neck in response to sound.
Pons:
Respiration
-Respiratory rate
-Depth of respiration
Medulla Oblongata:
Heart control center
-Heart rate
Heart rhythm
-Respiratory control center: inspiration center & expiration center
-vasomotor: controls blood pressure
CN I
Olfactory Nerve: Smell
CN II
Optic Nerve: Vision
CN III
Oculomotor Nerve: moves eyeball, up, down, medial
CN IV
Trochlea: rolling eyes
CN V
Trigeminal: largest CN, sensory of face, 3 branches
CN VI
Abducens: lateral movement of the eyeball
CN VII
Facial Nerve: face movement, taste
CN VIII
Vestibulocochlear: hearing and balance
CN IX
glossopharyngeal nerve: swallowing food
CN X
vagus nerve: longest nerve, all visceral organs (chest, abdomen, and pelvic), parasympathetic
CN XI
accessory: shoulder
CN XII
hypoglossal nerve: moving tongue, speech