Brain & Skull Flashcards
PNS
Peripheral Nervous System
Sensory (affarent) Division
PNS, attracting information to the brain
Motor (efferent) Division
PNS, going away from the brain
PNS Function
Receptors detect internal or environmental change, information is sent to the CNS (central nervous system) to promote movement in the muscle.
SNS
Somatic nervous system, part of the motor division of the PNS
ANS
Autonomic nervous system, part of the motor division of the PNS
Cells in Nervous Tissue
Neurons & Neuroglia (several kinds of supporting cells; also called glial cells)
Neurons
Communicate between brain regions, made up of 3 parts; cell body - nucleus & other organelles, dendrites - receive the stimuli internally or from environmental changes, axon - transmits/conducts information to other cells in the form of electrical pulses, axon terminals - site of communication/contact with other cells
Neuroglia
Different types with different functions; protection, support, repair nervous system, nutrient supply to neurons
Astrocytes
First line defence to protect the brain, regulate blood flow
Oligodendrocytes
In the CNS, insulate the axons (produces myelin) to ensure strong electrical communication, supports nerve fibres
Schwann Cells
In the PNS, support nerve fibres, repair after injury, form myelin sheath around peripheral nerves)
White Matter
Regions filled with myelinated axons
Grey Matter
Regions where the axons are less dominate
Synapse
The region of space between cells, cells can communicate with each other, neurotransmitter is released from the presynaptic membrane
Nervous Cell Mutation
E.g. Amyotrophic lateral sclerosis - progressive degenerative disorder that affects motor neurons in the CNS, causes atrophy of the associated skeletal muscle fibers
Structure of the Brain (not the lobes)
Cerebrum, divided into 2 hemispheres, highly folded surface - gyrus (ridge) & sulcus (trough), superficial layer of grey matter is called the cerebral cortex
Functions of the Brain
Conscious thought, memory storage & processing, sensory processing, regulating skeletal muscle contractions
Cerebellum (functions)
Partially hidden by the cerebral hemispheres, coordinating and modulating motor commands from he cerebral cortex, coordinates motor function, balance & memory
important to protect the cerebellum
Brainstem (3 structures)
Midbrain - processes visual and auditory (sound) information & controls reflexes, pons - tracts and relays centres & visceral motor control (if a stroke were to occur, it would cut off transmission to the rest of the body and there would be no communication), medulla oblongata - relays sensory information to the thalamus & integration centres that regulate heart rate and blood pressure
Lobes of the Brain
Frontal, Parietal, Temporal, Occipital, Precentral Gyrus, Postcentral Gyrus
Frontal Lobe
Motor, emotions - 1/3 of cortical surface, divided into 2 key areas, controls motor function, high order functions, e.g. emotion, memory, learning
Parietal Lobe
Sensory - receives and processes stimuli, cutaneous, e.g. touch, pain, kinaesthetic , e.g. body position
Temporal Lobe
Auditory
Occipital Lobe
Vision
Precentral Gyrus
Contains primary motor cortex
Postcentral Gyrus
Contains primary somatosensory cortex; receives sensory information
Corpus Callosum
Communicates between the left & right hemispheres of the brain
Association Fibers
Connections between the gyri in the same hemisphere
Projection Fibers
Connect the cerebral cortex with the brainstem and spinal cord (= motor + sensory)
Skull Bones
Frontal, Temporal x2, Parietal x2, Occipital, Sphenoid, Ethmoid
Facial Bones
Mandible, Zygomatic Arch x2, Maxilla x2
Sutures
Joints where the cranial bones and facial bones connect
Coronal Suture
Straight down, attaches the frontal and parietal bones
Sagittal Suture
Attaches parietal bones
Squamous Suture
Attaches temporal and parietal bones
Lambdoid Suture
Attaches occipital and parietal bones
