Central Nervous System

Organization

What are the 3 general functions of the CNS and PNS? Collect information (receptors) Process and Evaluate Information Respond to information

How do neurons communicate with each other? action potential propagation and

neurotransmitter release

Sensory Division

List and define the 2 subdivisions of he sensory division of the nervous system? Somatic sensory

touch, pain, pressure, vibration, temperature, proprioception, and special senses

Visceral sensory blood vessels and viscera-temperature and stretch Is “visceral sensory” part of autonomic system?

Why or why not?

Motor Division

List and define the 2 subdivisions of he motor division of the nervous system? Somatic motor

CNS to skeletal muscles Voluntary

Autonomic motor CNS to smooth muscle, cardiac muscle and glands Involuntary

We see the posterior root is sensory & anterior root is motor. Do they stay separate like this?

Flash cards only give us the following:

Neurons, which are excitable Glial cells, which are supportive

Nervous tissue cells of the CNS

Relate these structures

3-week old embryo

This process of forming a nervous system is called “_____”

The nervous system arises from which germ layer?

Do you recall?

In order for neurulation to occur there must already be 3 germ layers. Do you recall what the process was for making 3 germ layers?

Gastrulation! It resulted in ectoderm, mesoderm, and endoderm

Development

During the development of the nervous system, what longitudinal indentation forms from the neural plate? Neural groove

During the development of the nervous system, what hollow structure is formed as the neural folds meet? Neural tube

Development

What is the thickened portion of tissue over the notochord called? Neural plate

What becomes of the notochord?

Side note (not in flash cards)

Neurons grow until they reach their target organ and form a synapse. If they don’t reach the target they die (apoptosis). Even after neuromuscular connections are made, some are eliminated until each muscle fiber is innervated by only one motor neuron. For example, 20,000 motor neurons are formed in the spinal cord of the chick but ~half die.

How many neurons make up the CNS? 100 billion (mostly in brain)

What is the average volume of the human brain? 1200 cc Size matters not—you are ALL brilliant and

possess the most complex machine in the known universe

Brain Tissue Organization

What is the superficial sheet of gray matter covering most of the adult brain? Cortex

Cerebral and Cerebellar

Within the interior of the brain, what are clusters of gray matter? Cerebral nuclei

Discuss the dural septa

Name passages between ventricles

How does CSF leave the brain?

How is CSF drained?

Cerebrum

What are the functions of the cerebrum? Intelligence Reasoning Sensory perception Thought Memory Judgment Voluntary motor, visual, and auditory fcns

Cerebral Hemispheres

3 points about the cerebral hemispheres 1) it is usually difficult to assign a precise

function to a specific region 2) Usually the hemisphere receives information

from and sends motor commands to the opposite side of the body

3) The hemispheres display functional differences (lateralization)

Lobes of the Cerebrum

List the primary functions of the frontal lobe. Voluntary motor functions Concentration Verbal communication Decision making Planning Personality

Lobes of the Cerebrum

What are the functions of the lobe of the cerebrum that forms the superoposterior part of each cerebral hemisphere (Parietal)? General sensory functions

E.g. evaluating shape and texture

Understanding language Shares Wernike’s with Temporal lobe

Lobes of the Cerebrum

What are the functions of the lobe of the cerebrum that lies inferior to the lateral sulcus (Temporal)? Hearing and smell

Interpretation and storage

Lobes of the Cerebrum

What are the functions of the lobe of the cerebrum that forms the most posterior region of each cerebral hemisphere (Occipital)? Perceive visual information Store and use visual memories

Lobes of the Cerebrum

What are the apparent functions of the small, deep lobe of each cerebral hemisphere lies deep to the lateral sulcus (Insula)? Memory Taste interpretation

Functional Areas of the Cerebrum

The primary motor cortex is located within what structure of the brain? Precentral gyrus of the frontal lobe

Note motor speech area & frontal eye field in the frontal lobe

Functional Areas of the Cerebrum

What is the function of the association areas within the cerebrum? Integrate new sensory inputs with memories

Note auditory association area & visual association area

Cerebral White Matter

What are bundles of myelinated axons that lie deep to the cerebral cortex? Tracts

Projection (linking cerebrum to lower brain structures)

Association (linking multiple places in cerebrum, but on one side or the other)

Commissural (linking similar parts on the two hemispheres)

Association tracts stay within a hemisphere

Note nuclei also

Diencephalon

What part of the brain is composed of the epithalamus, right and left thalami, and the hypothalamus? Diencephalon

Diencephalon

What is the function of the thalamus? Final relay for sensory information projected to

the primary sensory cortex Filter sensory information Inform cerebrum where sensory information is

coming from

Diencephalon

What are the functions of the hypothalamus? Master control of ANS Master control of endocrine system Regulate temperature Control emotional behavior Control food intake Control water intake Regulate sleep/wake cycles

Oxytocin

ADH

Brainstem

What 3 regions form the brainstem? Midbrain Pons Medulla oblongata

Mesencephalon

Within the midbrain what are the motor tracts located on the anterolateral surfaces? Cerebral peduncles

Within the midbrain what is the “body of 4 twins”? Corpora quadrigemina

Mesencephalon

What are the “visual reflex centers” of the midbrain? Superior colliculi

What are the “auditory reflex centers” of the midbrain? Inferior colliculi

Cerebellum

What is the function of the cerebellum? Coordinate (and fine tune) skeletal muscle

movements Maintain equilibrium and posture

Cerebellum

What thick tracts connect the cerebellum to the brainstem? Cerebellar peduncles

Superior to mesencephalon Middle to pons Inferior to medulla oblongata