Brain

Basic parts of the brain

Cerebrum, cerebellum, brain stem, diencephalon, ventricles

Brain develops from

Develops from rostral end of neural tube

3 primary vesicles of brain

Prosencephalon, Mesencephalon, Rhombencephalon

Prosencephalon forms

Forebrain

Mesencephalon forms

Midbrain

Rhombencephalon forms

Hindbrain

Secondary vesicles of prosencephalon

Telencephalon, diencephalon

Telencephalon forms

Cerebrum

Diencephalon forms

Thalamus parts

Secondary vesicle of rhombencephalon

Metencephalon, Myelencephalon

Metencephalon forms

Pons, cerebellum

Myelencephalon forms

Medulla oblongata

Caudal end of neural tube forms

Spinal cord

Adult brain structures of telencephalon

Cerebral hemispheres

Adult neural canal regions of telencephalon

Lateral ventricles

Adult brain structures of diencephalon

Thalamus, hypothalamus, epithalamus, retina

Adult neural canal regions of diencephalon

Third ventricle

Adult brain structure of mesencephalon

Midbrain

Adult neural canal regions of mesencephalon

Cerebral aqueduct

Adult brain structures of metencephalon

Pons & cerebellum

Adult neural canal regions of metencephalon

Fourth ventricle

Adult brain structures of myelencephalon

Medulla oblongata

Adult neural canal regions of myelencephalon

Fourth ventricle

External protection of brain

Skull, meninges, cerebrospinal fluid

Internal protection of brain

Blood-brain barrier

Meninges

Connective tissue layers that protect CNS

3 meninges

Dura mater, arachnoid mater, pia mater

2 layers of dura mater

Periosteal & meningeal

Spaces between layers

Dural sinuses, subarachnoid space

Meningeal layer that follows contours of the brain

Pia mater

Location of dural sinuses

Between layers of dura

Location of subarachnoid space

Between arachnoid & pia mater

Dural folds

Produced by meningeal layer of dura that travel between fissures of the brain

Falx cerebri

Separates left & right cerebral hemispheres

Falx cerebelli

Separates left & right sides of cerebellum

Tentorium cerebelli

Separates cerebrum & cerebellum

Dural venous sinuses

Present between dural layers where folds occur

Function of dural venous sinuses

Carry venous blood away from brain

Superior Sagittal Sinus

In falx cerebri

Inferior Sagittal Sinus

In falx cerebri

Straight sinus

Drains ISS & great cerebral vein from brain

Confluence of sinuses

Junction of superior sagittal sinus * straight sinus

Transverse sinus

In tentorium cerebelli

Sigmoid sinus

Carries blood from transverse sinus to jugular foramen

Ventricles

Spaces in brain, continuous with central canal of spinal cord

Cerebrospinal fluid

Nourishes & protects brain, spinal cord

Lateral ventricles

Within cerebrum

Third ventricle

Within diencephalon

Fourth ventricle

Within brainstem

Connection of third ventricle

To lateral ventricles via interventricular foramina

Connection of fourth ventricle

To 2nd ventricle via cerebral aqueduct

Circulation path of CSF

Lateral ventricles → interventricular foramina → third ventricle → cerebral aqueduct → fourth ventricle → apertures → subarachnoid space → arachnoid granulations → dural venous sinuses

How CSF is returned to blood

Arachnoid granulations projecting into dural sinuses

Ridges on surface of brain

Gyri

Valleys on surface of brain

Sulci

Deep valleys of brain

fissures

Longitudinal fissure

Separates right & left hemispheres

Lateral fissure

Separates temporal lobe from frontal & parietal lobes

Transverse cerebral fissure

Separates cerebrum from cerebellum

Contents of gray matter in cerebrum

Cerebral cortex & brain nuclei

Cerebral cortex

Outer layer of gray matter

Brain nuclei

Concentrations of cell bodies

Function of gray matter in cerebrum

Perform complex neural functions

Function of white matter in cerebrum

Rapid processing between areas

5 lobes of cerebrum

Frontal, parietal, temporal, occipital, insula

Location of insula

Deep to lateral fissure

Central sulcus

Separates frontal & parietal lobes

Parieto-occipital sulcus

Separates parietal & occipital lobes

Lateral fissure

Separates temporal lobe

Precentral Gyrus

Sends motor commands

Postcentral gyrus

Receives sensory information

Sensory areas of cerebral cortex

Receive input, awareness of stimuli

Association areas of cerebral cortex

Process info from multiple sources

Motor areas of cerebral cortex

Controls motor response

General sensory pathway of cerebral cortex

Primary sensory cortex → sensory association areas → multimodal association areas → motor areas

Function of primary somatosensory cortex

Awareness of sensation from skin on opposite side of body (touch, pressure, pain, proprioception

Gyrus associated with primary somatosensory cortex

Postcentral gyrus

Lobe associated with primary somatosensory cortex

Parietal

Function of primary visual cortex

Receives visual information from retina

Lobe associated with primary visual cortex

Occipital

Function of primary auditory cortex

Conscious awareness of sound

Lobe associated with primary auditory cortex

Superior edge of temporal lobe

Function of Primary Olfactory Cortex

Conscious awareness of smell

Lobe associated with primary olfactory cortex

Medial side of temporal lobe

Function of gustatory & visceral sensory cortex

Awareness of taste, pain, pressure, hunger

Lobe associated with gustatory & visceral sensory cortex

Insula

Function of Primary motor cortex

Control skeletal muscle activity on opposite side of body

Gyrus associated with primary motor cortex

Precentral

Lobe associated with primary motor cortex

Frontal

Function of motor speech area (Broca’s Area)

Control ability to speak & write

Function of posterior association area

Integrates all types of sensory information for a unified perception of sensory input

Function of Werneke’s Area

Understanding written & spoken language

Location of Werneke’s Area

Left hemisphere

Function of Anterior Association

Receives highly processed sensory info, coordinate motor responses

Location of Anterior association area

Prefrontal cortex

Function of Limbic System

Involved in memory, emotion, fear

Location of the limbic system

Medial side of cerebral hemispheres

Homunculus

Small representation of a human

Location of motor homunculi

Precentral gyrus

Location of sensory homunculus

Postcentral gyrus