The Brain Flashcards
What is Casual explanation ?
Link between biology and psychology - how things work
What does TMS stand for ?
Transcranial Magnetic Stimulation - cause and effect
What are the 2 main parts of the nerves system?
- Central Nerves System
2. Peripheral Nerves System
What does the CNS contain ?
Brain and Spinal Cord - located in skull and spine
Within the PNS what are the 2 main nerves systems?
- Somatic Nerves System
2. Autonomic Nerves System
Whats the difference between the Somatic and Autonomic Nerves System ?
Somatic - external environment - enters the body
Autonomic - internal environment - internal organs
Within the Somatic nerves system, what 2 types of nerves are there ?
Efferent - motor signals from CNS to muscles
Afferent - sensory signals from environment to CNS
Within the autonomic NS, there are both efferent and afferent. What are the 2 types of afferent nerves ?
Sympathetic and Parasympathetic
What are the functions of the sympathetic nerves system ?
- connect neurons far away from the organs
- energise them in threating situations
- psychological arousal
What are the functions of the parasympathetic nerves system?
- connect neurons close to target organs
- conserve energy
- psychological relaxation
Each autonomic organ recives opposing sympathetic and parasympathetic input. Controlled by regulating the activity levels of these.
TRUE OR FALSE
TRUE
What does the cranial nerve involve?
- 12 pairs from the brain
- purely sensory nerves but can contain both sensory and motor fibres
- longest are the vagus nerves
Roughly how long can neurones be in the body?
- about 1 meter long
How many protective membranes are there protecting organs?
- 3 meniges
- dura mater, arachnid membrane and pia mater
What is the subarachnoid space ?
- below the dura mater
- contains blood vessels and cerebrospinal fluid
What does the cerebrospinal fluid contain ?
- supports and cushions the brain
- produces by CHORID PLEXUSES (network of capillaries)
- excess fluid goes to a vein within the neck
- the flow can be blocked by a tumor - causes hydrocephalus
What is a blood brain barrier ?
- stops certain molecules from entering the brain via the bloodstream
- cerebral blood vessels - tightly packed
- therapeutic and recreational drugs though this
What are the main purpose of neurons?
- fundamental units of the NS
- cells which are specialised
- reception, conduction and transmission of electrochemical signals
What does a typical neuron look like ?
SEE NOTES
What does the cell membrane do ?
- only allows certain molecules in
- made up of fat that is embedded in protein molecules. Either channel (certain molecules) or signal (inside the neuron)
What does the…
- Cell Body (soma)
- Dendrites
do?
CELL BODY (SOMA) - metabolic centre - contain nucleus (DNA) DENDRITES - info from synaptic contacts - other nerurons
What does the…
- Axon
- Axon Hillock
do?
AXON
- away from the body of the cell - can be long or short
AXON HILLOCK
- junction where cell body and axon meet
- conveyance of electrical signals
What does the…
- Myelin Sheath
- Nodes of Ranvier
do?
MYELIN SHEATH/ MYELIN - insulates axon - assists in the conduction of signals NODES OF RANVIER - gaps between sections of myelin
What does the…
- Terminal Buttons
- Synapse
do?
TERMINAL BUTTONS - release chemicals - communicate with other cells SYNAPSE - point of communication, gap
Whats the difference between MULTIPOLAR, UNIPOLAR and BIPOLAR neuron?
MULTIPOLAR = 2 or more process from the cell body UNIPOLAR = 1 process from the cell body BIPOLAR = 2 process from the cell body
What are the 9 parts inside a neuron ?
ER, C, R, GC, N, M, MT, SV and Neuro
Endoplasmic Reticulum - folded membranes, helps proteins
Cytoplasm - fluid
Ribosomes - protein synethis
Golgi Complex - system of membranes
Nucleus - DNA
Mitochondria - aerobic
Microtubes - transport of molecules
Synaptic Ventricles - store neurotransmitter
Neurotransmitter - released across synapses
Within both the CNS and the PNS, what are the cells of bodies called ?
CNS - nuclei
PNS - ganglia
Within both the CNS and the PNS, what are bundles of axons called?
CNS - tracts
PNS - nerves
What are the 4 main types of Glia cells?
- Oligodendrocytes
- Schwann cells
- Microglia
- Astrocytes
What do the Oligodendrocytes involve ?
- in the CNS
- wrap around axons
- extensions - got myelin (fatty substance) and myelin sheaths (help conduction of energy)
What do the Schwann Cells involve ?
- in the PNS
- similar to Oligodendrocytes
- only have one myelin segment
- guide axonal regeneration after damage
Microglia involve…. what ?
- small
- respond to injury and diseases
- multiplying and engulfing the debris or the cells
The Astrocytes involve…..
- largest, star shaped
- some - cover blood vessels - make contact
- these - some chemicals into the CNS via the blood others are blocked
- relax or constrict blood vessels
What are the 3 main neuroanatomical techniques ?
Golgi stain - stain meninges - black neurons
Nissal stain - bind to the structure of cell bodies
Electron Microscopy - slices of neuron tissue
Anterior vs Posterior
A = towards nose end. P = towards tail end
Dorsal vs Ventral
D= back/top. V= towards chest
Medial vs Lateral
M= towards midline. L = away
Superior vs Inferior
S = top. I = bottom
Proximal vs Distal
P= close . D= far
What are the 3 planes and there cuts ?
Horizontal, Sagittal and Frontal
Midsagittal - cut down centre
Cross Section - right angle
What is grey matter within the spinal cord ?
- largely cell bodies
- unmyelinated interneurons
- 2 dorsal arms: dosal horns and ventral horns
- white matter is the opposite
The axons are attached to the spinal cord via 2 roots. What are these roots ?
Dorsal - unipolar, sensory, dorsal root ganglia
Ventral - motor, multipolar
What are the 3 main parts of the brain and what is in each section ?
Forebrain = Telencephalon, Diencephalon Midbrain = Mesencephalon Hindbrain = Metencephalon, Myelencephalon
What does the Myelencephalon involve ?
- medulla oblongata
- composed - efferent and afferent
- tracts - signals - brain and body
- function - keep balance
- involved in - sleep, attention, muscle tone, cardiac function and respiration
- reticular formation
What is the reticular formation ?
complex network of nuclei, central core system, network like appearance
What does the Metencephalon involve ?
- many efferent and afferent neural tracts
- 2 major divisons: cerebellum and pons
Whats the difference between the cerebellum and pons ?
CERBELLUM (little bridge): sensorimotor structure, sensory info and movement, damage - eliminates the ability to control movements.
PONS (bridge): swelling in the brain stem, postural relaxes
What does the Mesencephalon involve ?
Tetcum: - roof
- consist: colliculi (little hills)
- superior - visual. Inferior - auditory
Tegentum: - below (inferior) to tetcum
- red nucleus and substantia nigra (sensorimotor)
- periaqueductal grey (pain relief function)
What are the 4 main sections of the Diencephalon ?
- one either of 3rd ventricle - by massa intermedia
1. Thalamus
2. Hypothalamus
3. Optic Chiasm - optic nerves, x shapes, decussate
4. Mammillary Bodies - spectral nuclei
Whats the difference between Thalamus and Hypothalamus ?
THALAMUS: - at the top - different nuclei - protects cortex - links to it - SENSORY RELAY NUCELI (signals from sensory receptors transmit to sensory cortex) HYPOTHALMUS - below - pituitary gland - releases hormones - key roles in endocrine
What does the Telencephalon involved ?
- largest and newest
- cerebral hemispheres
- movements, psychological processes (thoughts, emotions), sensory world
- makes us humans
What is the telencephalon characterised by ?
- cerebral cortex = layer of tissue, small unmyelinated neurons
- convolutions: gyri (peaks), fissures (deep valleys), sulci (small valleys)
- have these due to evolutions and brain development
There are 2 main hemispheres within the brain and what are the 4 lobes ?
- connected by commissures (large tracts)
- largest is the corpus callous
1. FRONTAL
2. PARIETAL
3. TEMPORAL
4. OCCIPTAL
Whats the difference between the Frontal and Parietal Lobe ?
FRONTAL
- precentral gyros and adjacent frontal cortex (motor)
- frontal cortex anterior (complex cognitive function)
- superior to lateral fissure and anterior to central fissure
PARIETAL
- postcentral gyros (sensations), posterier (direct attention)
- posterior to central fissure
Whats the difference between the Temporal and Occipital lobe ?
TEMPORAL - superior gyros (hearing and language) - inferior cortex (visual patterns) - media cortex (certain kinds of memory) - inferior to lateral fissure OCCIPITAL - vision - posterior to temporal and pariteal
What does the Neocortex involve ?
- 6 layered cortex
3 important characteristics
1. many cortail (pyramidal - multipolar - apical dendrite - small)
2. size and density of cell bodies and proportions
3. many long axons and dentries course vertically
What does the Limbic system involve ?
- circuit midline structure - thalamus
- regulation of motivated behaviour
- amygdala: almod shaped nucleus, emotion
- hippocampus
- cingulate cortex: large strip in cingulate gyrus
- fonix: major tract - encircles dorsal
What does the basal ganglia involve ?
- amygdala - out of each - caudate - complete circuit - connect fibre bridges in putamen - striatum
- voluntary motor response and decision making - Parkinson disease
- Nucleus acumenus - rewarding effect of addictive drugs and other reinforces
