Brain and spinal cord

Cranial Nerves, Spinal Nerves, Ganglia

• Insulate, support and protect the neurons. • "Nerve glue" • Do not carry nerve impulses.

Transport nutrients to neurons and restrict what substances can enter the brain, forming the blood - brain barrier. • It provides structural support, regulates ion, nutrients and dissolved gases Concentrations • It absorbs and recycle neurotransmitters • Form scar tissue after injury

Remove cellular debris, wastes and pathogens by phagocytosis from the nerve tissues.

• CNS structures that wrap around the neuronal axons, forming the myelin sheath. • It provides the structural framework of the body.

• It is line ventricle (Brain) and central canal (Spinal Cord) • It assists in producing, circulating, and monitoring of cerebrospinal fluid.

• PNS structures that wrap around the neuronal axons to form the myelin sheath.

• It surrounds neuron cell bodies in ganglia • It regulates Oxygen, Carbon Dioxide, nutrients, and

TYPES OF GLIAL CELLS (CNS)

TYPES OF GLIAL CELLS (PNS)

- Cells within the nervous system that transmit information to other nerve cells, muscle, or gland cells. - Basic functional unit of brains

process of reacting through a certain stimuli

wiring that coordinates how your body runs and the signals travel quickly through the nervous system, and the ability of nerves to transmit impulses

TYPES OF NEURONS: Carry messages from the CNS to the effectors

TYPES OF NEURONS: Carry impulses from the sensory neurons to motor neurons.

TYPES OF NEURONS Receive stimuli from receptor sites in the sensory organs (skin, eyes, ears, nose and taste buds) that can be perceived by the five senses. Carry messages or impulses toward the CNS.

PARTS OF A NEURON • Are treelike extensions at the beginning of a neuron that receive information from other neurons and transmit electrical stimulation to the soma (cell body). • Threadlike extensions of the cytoplasm of a neuron. • Compose most of the receptive surface of a neuron • Function as an antennae • Segments of a neuron that receive stimulation in order for the cell to become active

PARTS OF A NEURON • is the archivist and the architect of the cell. • As archivist it contains the genes, consisting of DNA • As architect, it synthesizes RNA from DNA and ships it through its pores to the cytoplasm for use in protein synthesis. • Central part of most cells that is enclosed in a membrane • Contains majority of the cell’s genetic material in the form of multiple linear DNA molecules organized into structures called chromosomes

PARTS OF A NEURON • Also called the "soma" • spherical part of the neuron that contains the nucleus. • connected to the dendrites which bring information to the neuron, which sends information to other neurons. • produces all the proteins for the dendrites, axons and synaptic terminals • contains specialized organelles such as the mitochondria, Golgi apparatus, endoplasmic reticulum, secretory granules, ribosomes and Polysomes • to provide energy and make the parts • a production line to assemble the parts into completed products

TYPES OF NEURON • long threadlike part of a nerve cell along which impulses are conducted from the cell body to other cells. • Main conducting unit of the neuron • Capable of conveying electric signals along distances that range from as shirt as 0.1mm to as long as 2m • Primary transmission lines of nervous system • Passes messages away from cell body to other neurons or glands

TYPES OF NEURON • Are the spaces between the myelin coating on the neuron's axon • act like electric wires • electricity will be conducted within the cell's environment, and this signal will be propagated down to the axon. • Periodic gap in the insulating/myelin sheath on the axon of certain neurons that serves to facilitate the rapid conduction of nerve impulses.

TYPES OF NEURON • a fatty white substance that surrounds the axon of some nerve cells, forming an electrically insulating layer • essential for the proper functioning of the nervous system. It increases the speed at which impulses propagate along the myelinated fiber.

TYPES OF NEURON • Also called neurilemmal cell • produces the myelin sheath around neuronal axons • also responsible in repairing damaged nerves and generating them.

gap between adjacent neurons

junction between nerves

• Where the messages go from one cell to the next cell. • Messages go from the axon of one cell to the dendrite of another; they never touch • The space between them is the synaptic cleft. • The conduction is accomplished through neurotransmitters. • Neurotransmitters • are chemical substances that make it possible for messages to cross the synapse of a neuron to target receptor

• Chemicals responsible for signal transmission between the individual neurons • Most neurons make two or more transmitters, which are released at different stimulation frequencies • 50 or more neurotransmitters have been identified by chemical structure and function

• Also known as the “Epinephrine” • Important part of body’s ability to survive but sometimes will release the neurotransmitter when it is under stress, but not facing real danger • Can create feelings of dizziness, light-headedness, and vision changes • When no danger is present, that extra energy has no use, and this can leave the person feeling restless and irritable • Excessively high levels of the adrenaline due to stress without real danger can cause heart damage, insomnia, and a jittery, nervous feeling

• Also known as the Norepinephrine • Promotes alertness • Strongly associated with bringing our nervous system into “high- alert” • Associated with awake-arousal • Also important for forming memories • Healthy humans feed fish oil rich in the omega-3 fatty acids EPA and DHA show reduced plasma levels of the stress-associated hormone

Inhibitory neurotransmitter • when it finds its way to its receptor sites, it blocks the tendency of that neuron to fire • involved with motivation, decision-making, movement, reward processing, attention, working memory, and learning • Vitamin B6 is essential in converting __ • Produce arousal • Thought to play an important role in motivation, by attaching cognition of incentive significance to stimuli

• Short for endogenous morphineǁ • Inhibitory, it is involved in pain reduction and pleasure • It is structurally very similar to the opioids (opium, morphine, heroin, etc.) and has similar functions • Allows bears and animals to hibernate

• major inhibitory neurotransmitter of the brain, occurring in 30-40% of all synapses • Acts like a brake to the excitatory neurotransmitters that lead to anxiety • Caffeine has an effect of inhibiting GABA release • Commonly inactivated after release into the synapse

• Responsible for much of the stimulation of muscles, including the muscles of the gastrointestinal system. • Also found in sensory neurons and in the autonomic nervous system, and has a part in scheduling REM (dream) sleep • Linked to Alzheimer’s disease

• Most excitatory neurotransmitter in the cortex • Plays an important role in learning and memory long term potentiation (LTP) • molecular processes believed to help form memories, occurs in glutamatergic neurons in the hippocampus and cortex • Actually toxic to neurons, and an excess will kill them. • Sometimes brain damage or a stroke will lead to an excess and end with many more brain cells dying that from original trauma

• Intimately involved in emotion and mood • Too little _____ has been shown to lead to: • Depression • problems with anger control • obsessive-compulsive disorder • suicide • also leads to an increased appetite for carbohydrates (starchy foods) and trouble sleeping, which are also associated with depression and other emotional disorders

• ○ Nerve impulses have a domino effect. • Each neuron receives an impulse and must pass it on to the next neuron and make sure the correct impulse continues on its path • Through a chain of chemical events, the dendrites (part of a neuron) pick up an impulse that’s shuttled through the axon and transmitted to the next neuron. • The entire impulse passes through a neuron in about seven milliseconds — faster than a lightning strike.

• presence of neurotransmitters • it is open when an appropriate chemical lands

• open and closes in response to changes in membrane potential

open in response to physical deformation of the receptors

Depolarization – a stimulus depolarizes the neuron’s membrane • A deploarized membrane allows sodium (Na+) to flow inside the membrane • The exchange of ions initiates an action potential in the neuron

• If the action potential (nerve impulse) starts, it is propagated over the entire axon • Potassium ions rush out ofthe neuron after sodium ions rush in, which repolarizes the membrane • The sodium-potassium pump restores the original configuration • This action requires ATP

• The impulse continues to move toward the cell body • Impulses travel faster when fibers have a myelin sheath

GROSS STRUCTURES OF BRAIN

DIENCEPHALON

BRAINSTEM

An intricate mass of soft nervous tissue

- Gray matter • is the outer cortex and considered the highest center of reasoning and intellect. - White matter • located in the deeper part of the cerebral cortex, consists of myelinated nerve tracts.

is the outer cortex and considered the highest center of reasoning and intellect.

located in the deeper part of the cerebral cortex, consists of myelinated nerve tracts.

Process of storing “old” information we have learned and packaging and storing of new information by the brain.

acts like a receptionist, deciding the significance of the event and determining where in the brain the information should be stored.

Coverings of the Brain (Meninges) - Outer brain covering, which lines the inside of the skull. - A tough, dense membrane of fibrous connective tissue containing an abundance of blood vessels.

Coverings of the Brain (Meninges) The middle layer, resembling a fine cobweb with fluid-filled spaces.

Coverings of the Brain (Meninges) • Covers the brain surface itself • consisting of blood vessels held together by fine areolar connective tissue.

Spaces in between meninges - between the dura mater and arachnoid mater.

Spaces in between meninges • between the arachnoid and pia mater • filled with cerebrospinal fluid • produced within the ventricles of the brain.

- Acts as a liquid shock absorber and source of nutrients for the brain. - A substance formed inside the brain ventricles from the blood vessels of the choroid plexus. - Protects the delicate brain and the spinal cord. - removes metabolic waste products from the brain cells. - Can be used for detecting selected brain diseases.

is the removal of cerebrospinal fluid for diagnostic purposesis the removal of cerebrospinal fluid for diagnostic purposes

• Includes the least permeable capillaries of the body • Excludes many potentially harmful substances • Useless against some substances • Fats and fat soluble molecules • Respiratory gases • Alcohol • Nicotine • Anesthesia

• Largest part of the brain • Covers the whole upper part of the skull • Divided into 2 sections called cerebral hemispheres • by a deep groove known as longitudinal fissure • The cerebral cortex is the outermost layer of the cerebrum. • composed of gray matter formed into raised convolutions/ridges called gyri • the deeper furrows or grooves are the fissures • the shallow grooves between the gyri are called sulci.

CEREBRAL FEATURES It is composed of gray matter formed in raised convolutions or elevated ridges “winding” around the brain.

CEREBRAL FEATURES Small grooves dividing the gyri

CEREBRAL FEATURES Divides the Frontal Lobe from the parietal lobe

Deep grooves, generally dividing large regions/lobes of the brain

FISSURES Divided the two cerebral hemisphere (left and right)

FISSURES Separates the cerebrum from the cerebellum

FISSURES Divides the temporal lobe from the frontal and parietal lobes

Both right and left hemispheres interpret sensory data, store memories, learn and form concepts.

• ○ Language and logical operations • ○ Number skills • ○ Written language • ○ Reasoning • ○ Spoken language • ○ Scientific skills • ○ Right-hand control

• ○ Emotions, artistic and spatial skills • ○ Insight • ○ Forms • ○ Art awareness • ○ Imagination • ○ Music awareness • ○ Left- hand control

LOBES OF THE BRAIN - Controls the voluntary motor activity - Expressive (motor) speech - Both right and left hemispheres interpret sensory data, store memories, learn and form concepts. • ability to speak clearly • Broca’s area • Damage to the area leaves the client unable to speak clearly • Expressive aphasia • but the client still knows and understands what to say

LOBES OF THE BRAIN • Sensory perception • tactile sensations like temperature, touch, pain and pressure) • Concept formation and abstraction •● Right ___ lobe Spatial orientation and awareness of size and shapes (stereognosis) and body position (proprioception) •● Left ___ lobe Right-left orientation and mathematics

Spatial orientation and awareness of size and shapes (stereognosis) and body position (proprioception)

Right-left orientation and mathematics

LOBES OF THE BRAIN • Auditory receptive area • ability to hear • Auditory association areas ○ Left ____ lobe ability to store spoken language memories ○ Right ____ lobe sound memories that are not language like music, various animal sounds, other noises

facilitates understanding speech & language. Damage may result to : • Receptive Aphasia difficult to language • Auditory Aphasia difficulty music or sounds

difficult to language

difficulty music or sounds understand music or sounds

LOBES OF THE BRAIN Visual (receptive) interpretation areas • Visual Association Areas storage of visual memories contributes to the ability to visually recognize & understand the environment. • Visual speech center enables a person to read Damage to this area leaves the client unable to read (Alexia).

LOBES OF THE BRAIN • Located at the center of the brain beneath the other four lobes. • Center for feelings and control of emotion (fear, anger, pleasure and sorrow) • Influences unconscious and instinctive behaviors that relate to survival • The temporal lobe component of the limbic system plays essential role in the interpretation of smell

WHERE IS WERNICKE’S AREA ____ LOBE

WHERE IS BROCA’S AREA ____ LOBE

PARTS explains why the sense of smell is associated with emotions (think of smells that recall happy memories).

influences behavior appropriate to meet the body’s needs and is associated with emotional reactions especially fear, anxiety and aggression.

• involves in memory and learning, recognizes new information and recalls spatial relationships.

helps monitor strong emotions like rage and fright

pathway of nerve fibers from hippocampus to mammillary body

nucleus that transmits messages between the fornix and the thalamus

area that comprises the limbic cortex, and modifies behavior and emotion.

connect the fornix to the corpus callosum.

- controls the conscious thought, judgment, memory, reasoning and will power • The high degree of development makes the human the most intelligent of all the animals.

• Located between the cerebrum and midbrain • Sits on top of the brain stem • Composed of the thalamus and Hypothalamus

• Acts as a relay station for incoming and outgoing nerve impulses • Receives and direct nerve impulses from the various sense organs of the body (except the olfactory sensations). • Also receive nerve impulses from the cerebral cortex, cerebellum and other areas of the brain.

• Lies below the thalamus • A bundle of nerve fibers connects it to the pituitary gland, thalamus and the midbrain. • Part of the limbic system • considered as the brain of the brain.

- Composed of gray and white matter • Controls balance (equilibrium) and posture. • Controls voluntary (purposeful) motor activities, muscle movements, and position of body parts. • It is also known as the second largest part of thebrain

- Attaches to the spinal cord - Composed of midbrain, pons and medulla oblongata

Contains two (2) respiratory centers that promote normal rhythm of breathing.

prolonged inhalation