Exam 1 - Lecture 2

Meninges

3 layers of tissue that provide protection to the brain and spinal cord (CNS)

Dura mater

outermost layer of meninges, tough and leathery

Arachnoid mater

“spider-like” middle layer of meninges

Subdural space

space that separates arachnoid mater and dura mater where blood can gather

Pia mater

glossy, thin, innermost layer of meninges adhering to the surface of the brain

Subarachnoid space

space separating the arachnoid and pia mater layers filled with cerebral spinal fluid

Ventricular system

a series of interconnected, ventricles filled with cerebrospinal fluid that extends the entire CNS

Structure of ventricular system

one lateral ventricle in each hemisphere of the brain, a third ventricle in the midline, and a fourth ventricle in the brainstem area

Cerebrospinal fluid

protects the brain by preventing it from getting damaged from its own weight and acting as a shock absorber

Clinical applications of ventricular system

CSF can be collected for testing and diagnosing or used to deliver drugs through

Blood-Brain barrier

protects the brain from most substances in the blood by closing pore passages in blood vessels and controlling what molecules enter and leave the brain

Blood-Brain barrier structure

formed by the tight junctions between capillary endothelial cells, which are maintained by astrocytes via their “end feet”

Superior

above; higher in position compared to another structure

Inferior

below; lower in position compared to another structure

Anterior

toward the front of the body

Posterior

toward the back of the body

Rostral

toward the front of the brain

Caudal

toward the back of the brain

Dorsal

refers to the top of the brain or the back of the spinal cord based on the axis

Ventral

refers to the bottom of the brain or the front of the spinal cord based on the axis

Coronal axis

vertical division splitting the brain into anterior and posterior sections

Sagittal axis

dividing the brain into its left and right hemispheres

Horizontal axis

splits the brain into its superior and inferior positions

White matter

myelinated axons and cells that make up the myelin

Gray matter

consists mostly of cell bodies and dendrites; un-myelinated structures

Organization of white matter in the brain

surrounded by gray matter so that myelinated axons can efficiently send signals to and between gray matter regions

Location of white matter in spinal cord

surrounding gray matter so that myelinated axons can process sensory and motor stimuli quickly and locally

Spinal cord anatomy

contains 31 pairs of spinal nerves attached to each side of the spinal cord at 31 different levels

Spinal cord

transfers information between the CNS and PNS by receiving sensory information from the dorsal roots and sending motor commands out from the ventral roots

Dorsal root ganglia

where cell bodies of neurons that make up the spinal cord live

Cranial nerves

12 pairs of nerves that are either sensory or motor or both that emerge from the brain and are responsible for motor functions in the neck and head

Brainstem

leads into the spinal cord and is divided into the medulla, pons, and midbrain

Medulla

very bottom of the brainstem that connects to the spinal cord and includes neurons that maintain normal, rhythmic breathing

Pons

bulging section of the brainstem that acts as a relay station between the cerebellum and cerebral cortex

Midbrain

section of the brainstem closest to the brain that contains two regions of nuclei responsible for processing visual and auditory stimuli

Cerebellum

responsible for planning complex movements that require multiple muscle groups, error correction when learning movements, and procedural memory

Diencephalon

comprised of the thalamus and hypothalamus, found right above the brain stem

Thalamus

located rostral to the midbrain and acts as a relay station for information going to and coming from the cerebral cortex

Hypothalamus

located below the thalamus, responsible for regulating the autonomic nervous system, motivated functions, and hormone release by controlling pituitary gland (also a part of the limbic system)

Cerebral cortex

also known as the neocortex, is the pink wrinkly part of the brain that is responsible for processing sensory input from multiple sensory areas, initiation/planning of movements, and other “higher-order” functions (memory, cognition, language)

Sulci

general grooves on the surface of the cerebral cortex

Fissures

very deep sulci on the surface of the cerebral cortex

Gyri

rounded regions (tissue) between sulci

Central sulcus

separates the parietal and frontal lobes

Lateral fissure

separates the temporal lobe from those surrounding it

Longitudinal fissure

separates the two hemispheres of the brain

Postcentral gyrus

found directly caudal to the central sulcus and contains the primary somatosensory cortex responsible for processing touch, pain, and temperature

Precentral gyrus

directly rostral to the central sulcus and contains the primary motor cortex responsible for helping plan movements and send motor signals to the spinal cord

Occipital lobe

located in the back of the brain, is responsible for early-stage vision, and contains the primary visual cortex which is the first place in the brain where visual information is processed

Parietal lobe

found rostral to the occipital lobe, contains the primary somatosensory cortex, and is responsible for late-stage vision and integrating visual information with spatial information

Temporal lobe

found ventral to the parietal lobe, contains the primary auditory and gustatory cortices, and is responsible for memory, hearing, and language comprehension

Frontal lobe

contains prefrontal cortex and is responsible for movement, working memory, impulse control, inhibition of inappropriate behaviors, and planning

Thickness of cortical layers are…

not equal in size between different cortices

Limbic system

group of interconnected structures, medially located in the brain, whose functions are all related to emotional behavior and interpretation of the world

Hippocampus

part of limbic system involved in memory consolidation and provides spatial context

Amygdala

part of the limbic system that is connected to the hypothalamus and coordinates autonomic responses with emotional states such as fear

Cerebral cortex (limbic system)

interacts with subcortical structures to guide emotional behavior

Basal ganglia structure

group of interconnected structures called the striatum, globus pallidus, and substantia nigra that are responsible for controlling voluntary, smooth movement (stimulants targeted here will increase motor activity

Corpus callosum

largest bundle of neurons in the brain that connect the two hemispheres and allow them to talk to each other