1. Brain & Body Flashcards
3 major subdivisions of the brain
Forebrain
Midbrain
Hindbrain
5 subdivisions of the brain
Telencephalon
Diencephalon
Mesencephalon
Metencephalon
Myelencephalon
Subdivisions of the Forebrain (2)
Telencephalon
Diencephalon
Subdivision of the Midbrain (1)
Mesencephalon
Subdivisions of the Hindbrain (2)
Metencephalon
Myelencephalon
Division of the Cerebral Cortex (4 lobes)
Frontal lobe
Parietal lobe
Temporal lobe
Occipital lobe
Frontal Lobe
Executive functions
Cognitive functions
Motor cortex (control over skeletal muscles)
Parietal lobe
Sensations from the environment
Sensory cortex (sensations)
Temporal lobe
Memory
Auditory information
Auditory cortex
Occipital lobe
Visual information
Visual cortex
Gyri & Sulci
Gyri are the ridges of the brain
Sulci are the fissures/valleys
They increase the brains surface area & separate lobes
Postcentral gyrus
Contains the sensory cortex - sensations
Precentral gyrus
Contains the motor cortex - fine movement
Central sulcus
Separates the frontal & parietal lobe
Lateral sulcus
Separates the frontal & parietal lobes from the temporal lobe
The Limbic System (function)
Fight or Flight (influences the autonomic nervous system & endocrine system)
Feeding & Reproduction
The Limbic System (contains)
Amygdala
Hippocampus
Fornix
Cingulate cortex
Septum
Amygdala
Evaluation of emotional information, fear in particular
Located in the anterior temporal lobe
Hippocampus
Memories
Monitoring direction
Thalamus
Sensory information is received by nuclei in the thalamus which is sent to the cerebral cortex and back with certain aspects of the stimuli highlighted for attention
The Binding Problem
The question of how the brain combines activity in different brain areas to produce unified perception and coordinated behaviour
Neurons - Dendrites
Receive electrical impulses from other neurons
Specialised in receiving information
Surface is lined with synaptic receptors where information is received
Greater surface area = more information received
Dendritic spines - growths that increase surface area
Neurons - Soma
Genetic material is localized
Nucleus, ribosomes and mitochondria
Metabolic work occurs
Often covered with synapses like the dendrites
Neurons - Axon
Long projection fibre specialised in transmitting information over a large distance to other neurons, organs or muscles
Electrical impulses (aka action potential) travel along the axon
There can only be one axon, but it may have branches
Efferent axon
carries information from a structure
Motor neurons are efferent from the nervous system as they transfer information to other body cells like muscles
E for Exit
Efferent axon
carries information from a structure
Motor neurons are efferent from the nervous system as they transfer information to other body cells like muscles
E for Exit
Neurons - Myelin Sheath
Insulation that helps enhance the speed of the electrical impulse
Not in invertebrate axons
Interruptions called nodes of Ranvier
Neurons - Terminal buttons/presynaptic terminal
Neurotransmitters are released, conveying a message to the receiving cell
Neurons - Synapse
Where the message is transmitted between two cells from terminal button to other cell
Intrinsic neuron
when a cell’s axon and dendrites are contained within a single structure
Likely to have shorter axons as they have to be contained within one place
Glia
These + neurons make up the nervous system
Non-neuronal cells of the nervous system
Interneuron/Relay neurons
send messages between each other. Can be either motor or sensory
Sensory neurons
Soma is on a stalk off of the main body
Motor neurons
soma in the spinal
Multipolar neurons
more than two dendrites, most neurons are multipolar
Unipolar neurons
one dendrite
Bipolar neurons
two dendrites
Blood-Brain Barrier
Protection of the brain from molecules from chemicals
Blood vessels are more densely packed around the brain
Oxygen, glucose can pass the barrier
Peripheral Nervous System (PNS)
- located in the periphery of the body
- connects the brain and spinal cord (effectively linking it to the rest of the body)
Autonomic NS:
Sympathetic NS
Parasympathetic NS
Central Nervous System (CNS)
- Brain and spinal cord
- Also consists of blood vessels and stuff (both of them do)
Somatic NS
Autonomic NS
Regulates the body’s internal environment like heart rate. In control of the heart, intestines and other organs
Contains
Sympathetic NS
Parasympathetic NS
Sympathetic NS
Active during psychological arousal. Mobilizes energy to perform well
- Norepinephrine released
- Chains of ganglia (connections between spinal cord
- Physiological changes like heart rate and breathing
Parasympathetic NS
Active during psychological relaxation. Helps to conserve energy
- Opposite actions to the sympathetic nervous system like decreased heart rate and breathing. Increased digestive activity
- Acetylcholine
Somatic NS
Regulates the body’s interaction with the external environment. Axons convey messages from sensory organs to the CNS. From the CNS they travel to the muscles
Comparison to other primates
Primates (humans, monkeys, apes) have a proportionally larger cerebral cortex, more folds & a higher density of neurons
Other animals have bigger cerebral cortexes, but not proportionally to the rest of their brain
Endocrine
Releases hormones
Youngest lobe
Forebrain
Oldest lobe
Hindbrain
Medulla oblongata
An extension of the spinal cord
12 pairs of cranial nerves connect the head and other organs to the medulla
- These control crucial reflexes like heart rate, breathing, coughing, sneezing etc.
Hindbrain
The pons
Anterior and ventral to medulla
Also has cranial nerves
- A bridge
- Axons cross from one side of the spinal cord to the other
- Hemispheres control the opposite side of the body
Hindbrain
Cerebellum
- Control of movement
- Balance and coordination
- Learning & conditioning
- Shifting attention between auditory and visual stimuli
- Timing
- Rhythm
4 Ventricles
- Filled with CSF (cerebrospinal fluid)
- This provides buoyancy and protects the brain from injuries
- Also goes into the spaces between the brain and the meninges (membranes surrounding the spinal cord & brain)
- Swollen blood vessels in the meninges cause migraines
- Subarachnoid space - CSF is reabsorbed into the blood
- Reserve supply of hormones for the brain and spinal cord
