brain and cn

What are the different parts of the brain?

Cerebrum

Diencephalon

Brainstem

Cerebellum

What components make up the Diencephalon?

Epithalamus

Thalamus

Hypothalamus

Neurohypophysis

What components make up the Brainstem?

Midbrain

Pons

Medulla Oblongata

What is rostral vs caudal?

towards the nose vs. towards the tail

How is the gray vs white matter composed within the brain and what is within these areas?

• Gray matter: contains little myelin, but mostly somas, dendrites, and proximal portions of axons; location where information is processed (synapses)

– Cerebral cortex: the outer layer of the brain

– Nuclei: deeper portions of the brain surrounded by white matter

White: highly myelinated axons called tracts, carrying information to different parts of the CNS that is deep to the cerebral cortex

What structures help support and protect the brain?

Cranium

Meninges

Cerebrospinal Fluid

Blood-brain barrier

What are meninges?

fibrous connective tissue that surrounds and protects the CNS
(include dura mater, arachnoid mater, pia mater)

What are dural sinuses? Name one dural sinus.

Veins that pools blood to be emptied out from the brain into the internal jugular veins

Superior sagittal sinus
Inferior sagittal sinus
Straight sinus
Transverse sinus
Sigmoid sinuses
Cavernous sinuses

What is the falx cerebri?

separates the right and left hemisphere within the longitudinal fissure

What are arachnoid villi and what does it do?

extensions of the arachnoid mater that passes CSF from  subarachnoid space into the dural venous sinuses

What are the different ventricles of the brain and the order that CSF flow through them?

Right and left lateral ventricles

Third ventricle

Cerebral aqueduct

Fourth ventricle

What is the central canal?

Space that runs from brain through spine to dispose of CSF.

What is the CSF’s function?

Buoyancy: reducing the weight of the brain

Protection: prevents brain from hitting cranium

Chemical stability: regulates chemical environment

How is CSF produced?

• Choroid plexus: within each ventricle has ependymal cells with capillaries to produce 30% CSF (other 30% from the lining of ventricles; 40% at subarachnoid space)

• Ependymal cells: produces CSF and also line the ventricles and central canal causing  CSF flow

• CSF from subarachnoid space goes to venous sinuses through arachnoid villi

– Superior sagittal sinus: dural venous sinus that is above the falx cerebri

How does CSF flow?

CSF from subarachnoid space goes to venous sinuses through arachnoid villi

What is the blood brain barrier?

protects brain from toxins from blood, allows water, glucose and lipid soluble substances to pass through

formed by Astrocytes

What are the structures that make up the Cerebrum?

Cerebral Hemispheres

Corpus Callosum

Cerebral Cortex

Gyri Fissure

Sulci Fissure

Longitudinal Fissure

Transversal Fissure

What is the corpus callosum?

nerve fibers (commissure tracts) that connects the right and left hemisphere

What is the cerebral cortex and what type of matter is it made of?

The outer gray matter of the brain

What are gyri vs sulci vs fissures?

Gyri: folds to increase the surface area

Sulci: shallow grooves

Fissures: deeper grooves

What is the longitudinal vs transverse fissure?

Longitudinal fissure: deep groove that separates the right and left cerebral hemisphere

Transverse fissure: separates cerebrum and cerebellum

What is made of gray matter in the brain?

Cerebral cortex

Basal nuclei

Limbic system

Where is the white matter located at?

Inside the brain, inside the cerebral cortex

What are the cerebral lobes?

Frontal lobe

Parietal lobe

Occipital lobe

Temporal lobe

Insula

What is the function of the Frontal lobe? (243)

principal area for

• motor functions

  • voluntary motor function

  • planning

• mental functions

  • motivation

  • foresight

  • memory

  • mood

• social functions

  • emotion

  • social judgment

  • aggression

What is the function of the Temporal Lobe?

principal area for

• hearing

• smell
  
  Also contains area for

• learning

• memory

• some aspects of vision and emotion

What is the function of the Parietal Lobe?

principal area that

• receives and interpreting general senses

• taste

• some visual processing

What is the function of the Occipital Lobe?

principal visual center of the brain

What are the sulci that divide the Frontal and Parietal lobes?

Central sulcus

What is motor control?

voluntary motor functions

What are the general senses?

Touch

Nociception

Pressure

Vibration

Temperature

Proprioception

What is nociception?

pain sense

What is proprioception?

positional sense

What are the special senses?

Vision

Hearing

Equilibrium

Taste

Smell

What are association areas?

integrate and store information

Which areas of the brain are for motor control?

Premotor Cortex / Somatic Motor Association

Primary Motor Cortex / Somatic Motor Area

What is the premotor cortex for?

rostral of precentral gyrus and where we

• plan our actions

• regulates eye movement for reading

What is the primary motor cortex?

precentral gyrus of frontal lobe that

• sends signals to brainstem and spinal cord for skeletal muscle contraction on the contralateral side

What does the basal nuclei and cerebellum do?

Refinement of motor control

Which areas of the brain are for general senses?

Primary somatosensory cortex, Somatosensory association area

What is the primary somatosensory cortex?

postcentral gyrus that detect general senses on contralateral side

What is the somatosensory association area?

caudal of postcentral gyrus of the parietal lobe; makes sense of sensation

Which part of the brain is for vision?

Primary visual cortex

Visual association area

Which lobe is primarily for vision?

Occipital

What is the visual association area?

anterior of occipital,
posterior part of the parietal lobe,
inferior temporal lobe

recognize faces and familiar objects

Which part of the brain is for hearing?

Primary auditory cortex

Auditory association area

Which lobe is primarily for hearing?

Temporal lobe

What is the auditory association area?

inferior to temporal lobe to recognize spoken words, familiar music and voice

Which part of the brain is for equilibrium?

Cerebellum and brainstem nuclei

Which part of the brain is for taste?

inferior part of the postcentral gyrus of parietal lobe and anterior region of insula

Which lobe is primarily for taste?

Insula

Which part of the brain is for smell?

medial surface of temporal lobe and inferior surface of frontal lobe

What lobe is primarily for smell?

Temporal Lobe

Functions of the Wernicke area and Broca area?

recognizes spoken and written language

inferolateral part of frontal lobe, which transmit signals to the precentral gyrus to eventually cause muscles to help us speak

Which hemisphere are the Wernicke and Broca area usually found?

left cerebral hemisphere

What is the function of the opposing hemisphere?

emotional aspect of language

What is the function of the basal nuclei?

lateral to the thalami contain many brain centers for motor control

What is the function of the limbic system?

• center of emotion and learning

• center for gratification and aversion

What are the functions of the components in the limbic system?

Hippocampus: memory role

Amygdala / Amygdaloid Body: emotion and mood role, especially fear

Olfactory bulbs, tracts, and cortex: odors producing emotions/memories

Mammillary bodies: nuclei in diencephalon that interconnect other parts of the limbic system, may have a memory role

What are the functions of the components of the diencephalon? (- thalamus)

Epithalamus: hosts pineal gland, endocrine gland that secretes melatonin which regulates circadian rhythm

Thalamus: processes most information (except olfaction) and relay them to cerebral cortex; also for motor control and memory

Hypothalamus

Neurohypophysis: stores hormones

What is the function of the hypothalamus?

Hormone secretion
Autonomic effects
Thermoregulation
Food and water intake
Sleep and circadian rhythms
Memory
Emotional

What structure is also related to the hypothalamus?

Infundibulum / Neurohypophysis

What is the infundibulum?

stalk that connects the hypothalamus to pituitary gland

What is the neurohypophysis?

Posterior pituitary gland; stores hormones made by the hypothalamus

What hormones does the posterior pituitary gland secrete?

oxytocin and ADH

Where do the hormones from the posterior pituitary come form?

Hypothalamus

Why isn’t the anterior pituitary part of the neurohypophysis?

anterior pituitary gland is not derived from nervous tissue

What is the function of the midbrain?

connects hindbrain to forebrain, connects third and fourth ventricles

What is the function of the pons?

Transmit signals from forebrain to cerebellum

• Trigeminal Nerve (V) (44)

• Abducens Nerve (VI) (43)

• Facial Nerve (VII) (50)

Autonomic respiratory centers

What is the function of the medulla oblongata?

Manages heart, circulation and breathing

Pyramid body (swaps sides of control)

Cardiac center

Vasomotor center

Respiratory centers

• Vestibulocochlear Nerve (VIII) (45)

• Glossopharyngeal Nerve (IX) (47)

• Vagus Nerve (X) (51)

• Accessory Nerve (XI) (42)

• Hypoglossal Nerve (XII) (Hypoglossal)

What structures form the corpora quadrigemina?

Superior colliculi

Inferior colliculi

What are the functions of the colliculi?

Superior colliculi:

• for visual attention

• tracking moving objects

• reflexes (blinking, focusing, pupillary dilation and constriction)

Inferior colliculi:

• receive signal from inner ear and relay to other parts of brain like the thalamus

• reflexive turning to sound

What space divides the cerebrum from the cerebellum?

Transverse Fissure

What are the different structures of the cerebellum?

Cerebellar hemispheres

Vermis: motor control, balance, and emotional regulation, connects cerebellum hemispheres

Folia: small folds on cerebellum, increase surface area

Arbor vitae: white branches on the cerebellum, Signal Conduit, Connection and Communication with brainstem

Are cranial nerves part of the CNS?

No!

List the Cranial Special Sensory Nerves

special sensory nerves

CN1 olfactory: smell

CN2 optic: vision

CN8 vestibulocochlear: hearing and equilibrium

List the Cranial Motor Nerves

motor nerves

CN3 oculomotor: eyeball and eyelid movement, accomidation

CN4 trochlear: superior eyeball movement

CN6 abducens: lateral eye movement

CN11 accessory: head and shoulder rotation

CN12: hypoglossal: tongue movement

List the Cranial Multiple Use Nerves

multiple use nerves

CN5 trigeminal: face and chewing

CN7 facial: face expressions and 2/3rd of the tongue taste, tears

CN9 glossopharyngeal taste 1/3rd of tongue, swallowing and salivation

CN10 vagus: heart rate reduction and digestion