Brain structures (week 1)

Behavioural Neuroscience

Study of the neural basis of behaviour in humans and animals.

Neuroscience

scoentific study of the nervous system

The Central Nervous System (CNS) is located where?

Located WITHIN the skull and the spine

sympathetic nerves

are autonomic motor nerves that project from the CNS in the lumbar (small of the back) and thoracic (chest area) regions of the spinal cord.

parasympathetic nerves

are those autonomic motor nerves that project from the brain and sacral (lower back) region of the spinal cord.

The Peripheral Nervous System (PNS) is located where?

Located OUTSIDE the skull and the spine

Neurons

cells that receive and transmit electrochemical signals

Somatic Nervous System (SNS) interacts with?

Interacts with external environment

composed of afferent nerves to send signals from skin, skeletal muscles, eyes, etc to the CNS; and efferent nerves to send motor signals from the CNS to the skeletal muscles

Autonomic Nervous System (ANS) interacts with?

Regulates the body's internal environment

composed of afferent nerves to carry sensory signals from internal organs to CNS; and of efferent nerves to send motor ignals from CNS to internal organs.

Afferent nerves

towards the CNS (approach)

Efferent nerves

from the CNS (Exit)

Anatomical Directions

are described in relation to the orientation of the spinal cord

Anterior

front

Posterior

back

Dorsal

toward top/ at back

Ventral

under/ belly/ front

Medial

towards the midline

Lateral

away from the midline

Proximal and distal are two other common directional

terms - what do they mean?

closel; far

Myelin

fatty substance

Soma

cell body

Axon

cone-shaped region

Encephalon

within the head

Golgi complex

packaging membranes

ribosomes

protein synthesis

synapses

gaps

glial cells

the forgotten cells

synaptic vesicles

neurotransmitter storage

astrocytes

largest glial cells

ganglia

In the peripheral nervous system (PNS), a cluster of neuron cell bodies

oligodendrocytes

CNS myelinators

Golgi stain colour

black

Forebrain Division

Telencephalon

Diencephalon

Midbrain Division

Mesencephalon

Hindbrain Division

Metencephalon

Mylencephalon

gray matter of spinal cord

is composed largely of cell bodies and unmyelinated interneurons

white matter of spinal cored

composed largely of myelinated axons. (It is the

myelin that gives the white matter its glossy white sheen.)

The two dorsal arms of the spinal gray matter are called the

dorsal horns

the two ventral arms are called the

ventral horns.

All dorsal root axons, whether somatic or autonomic, are sensory (afferent) unipolar neurons with their cell bodies grouped together just outside the cord to form the

dorsal root ganglia

Gyrus

Bump or ridge

Sulcus

small furrow

Fissure

large furrow; the largest of which the "longitudinal fissure" - almost seperates the 2 hemispheres → groove

Major Divisions of the Cerebral Cortex: Frontal Lobe

executive functions, thinking, planning, organising and problem solving, emotions and behavioural control, personality.

What are the 5 divisions of the adult human brain

forebrain - Telencephalon & Diencephalon

midbrain - Mesencephalon

hindbrain - Metencephalon & Myelencephalon

Myelencephalon

the myelencephalon (or medulla), the most posterior division of the brain, is composed largely of tracts carrying signals between the rest of the brain and the body.

reticular activating system (reticular formation)

the part of the brain that is involved in attention, sleep, and arousal

Metencephalon

like the myelencephalon, houses many ascending and descending tracts and part of the reticular formation. These structures create a bulge, called the pons, on the brain stem's ventral surface. The pons is one major division of the metencephalon; the other is the cerebellum (little brain)

The _______ is the large, convoluted structure on the brain stem's dorsal surface. It is an important sensorimotor structure; cerebellar damage eliminates the ability to precisely control one's movements and to adapt them to changing conditions

cerebellum

Mesencephalon

the midbrain; a region of the brain that surrounds the cerebral aqueduct; includes the tectum and the tegmentum

The ___ is the dorsal surface of the midbrain.

Tectum (roof)

The ________ is the division of the mesencephalon ventral to the tectum

tegmentum

The ____ (black substance) and the ______ are both important components of the sensorimotor system.

substantia nigral; red nucleus

diencephalon

composed of two structures: the thalamus and the hypothalamus

The _____, the largest division of the human brain, mediates the brain’s most complex functions. It initiates voluntary movement, interprets sensory input, and mediates complex cognitive processes such as learning, speaking, and problem solving.

telencephalon

The cerebral hemispheres are covered by a layer of tissue called the _____

cerebral cortex

Major Divisions of the Cerebral Cortex: Motor cortex

Movement

Major Divisions of the Cerebral Cortex: Sensory Cortex

Sensations

Major Divisions of the Cerebral Cortex: Parietal Lobe

Perception, making sense of the world , arithemetic, spelling.

Major Divisions of the Cerebral Cortex: Occipital lobe

Vision

Major Divisions of the Cerebral Cortex: Temporal Lobe

memory, understanding and language.

Limbic system

regulates motivated behaviours .

Structures include mammillary bodies, hippocampus, amygdala,fornix, cingulate cortex, septum

Basal Ganglia

regulates movement.

Structures include amygdala (again); the caudate & putamen(collectively called the striatum), & the globus pallidus

Hippocamus (limbic system)

plays a major role in some kinds of memory, located at themedial edge of the cerebral cortex as it folds back on itself in the medial temporal lobe

the almond-shaped nucleus in the anterior temporal lobe

amygdala

The _______, the major tract of the limbic system, also encircles the dorsal thalamus; it leaves the dorsal end of the hippocampus and sweeps forward in an arc coursing along the superior surface of the third ventricle and terminating in the septum and the mammillary bodies

fornix

The ______ is a midline nucleus located at the anterior tip of the cingulate cortex.

septum

The _____ is located medial to the putamen between the putamen and the thalamus.

globus pallidus

Thalamus

consists of sensory relaynuclei of visual, auditory, somatosensorysystems that project information in a two-way fashion: from and to the cortex

Hypothalamus

sits below the thalamus(hypo below) implicated in motivatedbehaviour (e.g., eating, sleeping, andsexual behaviour) through hormoneregulation interacting with pituitary gland.

optic chiasm

points where optic nerves meet

Mammillary Bodies

considered to be part of the hypothalamus: recently associated with memory function

Tectum

→ Inferior Colliculi (auditory)

→ Superior Colliculi (visual+motor skills)

Mesencephalon

Tegmentum

→ Periaqueductal grey: grey matteraround aqueduct that connects 3rd and 4th ventricles; mediates analgesia → Substantia nigra

→ Red nucleus

→ Reticular formation

Pons

"Bridge"

bulge-like, contains theReticular formation (also part of the medulla and mesencephalon) - collection of nuclei withvariety of functions

Cerebellum

little brain

important sensorimotor system; likely broader functiondue to observed cognitive deficits in cerebellar damage

neurons

cells that receive and transmit

electrochemical signals

The somatic nervous system includes _______ nerves that carry motor signals from the central nervous system

to the muscles.

efferent

The _______ is the part of the peripheral nervous system that regulates the body's internal environment.

ANS

The brain and the spinal cord are the only organs that are protected with three layers of protective membranes called _______.

meninges

_______ or "tough mother" is the outer meninx.

dura mater

Immediately inside the dura mater is the fine

arachnoid membrane (spider-web-like membrane).

Beneath the arachnoid membrane is a space called the ___ which containes many large blood vessels and cerebrospinal fluid

subarachnoid space

the innermost meninx, the delicate _____, which adheres to the surface of the CNS

pia matter (piou mother)

The _______ nervous system is activated when you encounter a threatening information such as a bear attacking you. This system is essential for the initiation of fight-or-flight responses.

sympathetic

Motor nerves that project from the brain and

the lower region of the spine are called _______

nerves.

parasympathetic

The _______ nerve is a purely sensory nerve that transfers visual information from the retina of the eye to the brain.

optic

The _______ nerve is the nerve cell that extends directly from the brain to the gut.

vagus

The _______ is a channel that connects the third and fourth ventricles in the brain.

cerebral aquduct

The ventricles of patients with a congenital condition called _______ build up fluid as a result of blocked channels in the brain.

hydrocephalus

The _____is a small central channel that runs the length of the spinal cord;

Central canal

Many toxic substances that are present in the

bloodstream are prohibited from entering the brain by a mechanism called the _______ where cells of blood vessel walls are tightly packed, forming a barrier to the passage of large proteins.

blood-brain barrier

Unlike large toxic molecules, _______, which is critical for the function of the brain, is actively transported through the vessel walls.

glucose

is composed of a lipid bilayer, or two layers of fat molecules

Neuron Cell Membrane

multipolar neuron

A neuron with more than two processes extending from its cell body

unipolar neuron

A neuron with one process extending from its cell body

bipolar neuron

a neuron with two processes extending from its cell body

interneurons

Neurons with a short axon or no axon at all

In the central nervous system, bundles of axons are called ______and in the peripheral nervous system, they are called ____nerves

tracts ; nerves

Golgi Stain is used to ?

Golgi stains are commonly used to discover the overall shape of neurons.