The brain (and some cranial stuff) Flashcards
Brain
Complex organ that allows complex sensational, intellectual and nervous activity to occur.
Cranial Nerves
Neural extensions that send signals to and from the face, neck and torso
-5 senses
Meninges
3 layers of protection for the brain.
Pia Mater
Adheres to brain
Areolar CT
Arachnoid Mater
Medial layer.
Arachnoid trabeculae extend to pia mater through subarachnoid
space.
Subarachnoid space contains CSF.
Dura Mater
Tough, outermost membrane.
Dense Irregular CT
Composed of 2 layers:
-Meningeal layer (deeper layer)
-Periosteal layer (superficial layer)
Epidural space
Between dura and skull; contains arteries and veins
Dural extensions
Form partitions between brain areas; provide support.
There are 4
Falx Celebri
Located on midline; separates R & L cerebral hemispheres
Tentorium cerebelli
Separates occipital and temporal lobes from cerebellum
Falx cerebelli
Separates left and right cerebellar hemispheres
Diaphragma sellae
Forms “roof ” over sella turcica of sphenoid bone
Choroid Plexus
a network of blood vessels in each ventricle of the brain. It is derived from the pia mater and produces the cerebrospinal fluid.
Blood-brain Barrier
Regulate what substances enter the brain.
Composed of specialized capillaries
-wrapped by astrocytes
-tight junction connection
4 Functional Regions of the Brain
-Brainstem
-Diencephalon
-Cerebrum
-Cerebellum
Gyri
Outer fold (top of bumps)
Sulci
Inner folds
Fissures (deep sulci)
Medulla
Inferior regions of the brainstem
Pyramids
Crossing of somatic motor axons
Cardiac centers
Regulate heart rate and force
Respiratory centers
Regulates respiratory rate
Vasomotor centers
Regulates blood pressure
Pons
Bulging regions on anterior brainstem.
Controls the rate of involuntary respiration.
Midbrain
Superior portion of the brainstem
Substantia nigra
Part of midbrain, releases dopamine to control movement
-provide excitatory/inhibitory stimuli.
Periaqueductal gray
modulation of pain
-inhabitation/facilitation of pain
Diencephalon
A region of the brain that includes:
-Pineal gland (epithalamus)
-Thalamus
-Hypothalamus
Pineal gland
Sleepy time section of the brain
Secretes melatonin
Thalamus
Receives all sensory information excluding smell.
Sends information to all appropriate cerebral centers.
Hypothalamus
Controls the autonomic nervous system (ANS)
Regulation of body temperature
Control over the pituitary gland
Regulation of thirst and hunger
Cerebrum
In charge of intellectual function. Includes:
-Intelligence and reasoning.
-Thought, memory, judgement
-Voluntary movement
-Visual + auditory function
Gray matter
In charge of processing sensation, perception, voluntary movement, learning, speech and cognition.
White matter
Enables communication of the different pieces of the brain.
Comprised of myelinated axons.
Tracts in the CNS
Nerves in the PNS
Longitudinal fissure (sulcus)
Splits right and left hemispheres
Central sulcus
Boundary between the frontal and parietal lobes.
Corpus collosum
200 million axons that connect both hemispheres.
Cerebral lobes
Frontal
-Central sulcus
-Lateral sulcus
Temporal
Parietal
-Parieto-occipital sulcus
Occipital
Insula
Frontal lobes
Handles executive function
-in control of analysis, judgement, planning and personality
Contains somatomotor cortex and Broca’s area
Broca’s area
Control muscles of speech production
Temporal lobes
Primary auditory cortex
Contains Wernicke’s area
Primary olfactory cortex
Wernicke’s area
In charge of language comprehension
Parietal lobes
Sensation from body
Somatosensory area
Tactile sensation (detect pressure)
Occipital lobes
Primary vision cortex
Insula
Involved in:
Memory
Consciousness
Emotion
Additionally is the primary gustatory complex (taste)
Postcentral gyrus
Primary sensory cortex
Found within the parietal lobes
Receives sensory info from the proprioceptors, touch, pressure, pain and temperature receptors
“Sensory homunculus”
Precentral gyrus
Primary motor cortex
Frontal lobes
“Somatic motor area”
“Motor homunculus”
Cerebral lateralization
Functional specialization of the 2 cerebral hemispheres
Left hemisphere specializes in language production
Right hemisphere specializes in visuospatial abilities
-depth and distance perception
Cerebral nuclei
Centers deep in the cerebrum
The striatum does subconscious movement and regulates muscle tone
CNS tracts
Myelinated axons that create neural pathways between different parts of the brain and spinal chord
Associated tracts
Same hemisphere
Short tracts connecting neighboring nuclei called arcuate fibers
Tracts connecting nuclei in different lobes are called longitudinal fasciculi (fibers)
Commissural tracts
Connect regions in different hemispheres
Projection tracts
Connect cerebral cortex to inferior brain regions
Cerebellum
Folia (folds)
Vermis (connect left and right hemispheres)
Primary fissures separates anterior and posterior cerebellar lobes
Helps with coordination and balance
Stores memories of previously movements
Adjusts movements initiated by cerebrum
Helps with balance
Cerebellar regions
Cerebellar cortex
-outer gray matter
Arbor vitae
-inner white matter “branches”
Peduncles
-Connect brain to cerebellum
Limbic system
Emotional brain
Composed of multiple centers that process emotion
Hippocampus
Forms long term memory
Parahippocampus gyrus
encoding and retrieving memories
Amygdala
Integration of emotions and emotional behavior
Cingulate gyrus
Integration center
Olfactory centers
Evoke memory from smell
Memory
Characterized in terms of stages: the length of time information
remains available to us.
Information processing begins in sensory memory, moves to short-term memory, with practice and retrieval moves to long-term memory.
