nervous system: the brain by: william maldonado, francisco ruiz, esteban perez
TRANSCRIPT
Nervous system: The Brain
By: William Maldonado, Francisco Ruiz, Esteban Perez
The Brain ❖ we have about 100 billion neurons ❖ Part of the Central Nervous System
➢ Brain and spinal cord ❖ The CNS Contains:
➢ neurons ➢ neuroglia
- function is to protect and support neurons■ oligodendrocytes - make saltatory conduction possible ■ astrocytes - maintain blood brain barrier■ microglia - do phagocytosis■ Ependymal Cells - help produce cerebrospinal fluid
Function ❖ Awareness of ourselves and of our environment❖ Stream of sensory data❖ Controls muscle movements❖ Secretions of glands❖ Breathing and internal temperature❖ Every creative thought, feeling, and plan is developed by our
brain❖ Neurons record the memory of every event in our lives
Layers of the MeningesFunction is to protect CNSDura mater - outer layer lining skull
-Surrounds and supports dural sinuses carrying blood from the brain to the heart
Arachnoid mater - contains blood vessels. cushions CNS
Subarachnoid space - cerebrospinal fluid protects with central nervous system with cerebrospinal fluid
Pia mater - covers brain cerebrospinal fluid and contains the large blood vessels that supply the brain and spinal
cord.
Spinal cord reflexes - myotatic (stretch) reflex, flexor reflex,
Superficial Brain StructureGrey vs. White matterconvolution = a “wrinkle” on the surfaceGyrus = a region of the cerebrum sulcus = a shallow groove in the cerebrumfissure = a deep groove in the cerebrrumcerebral cortex = the outer few mm of the cerebrum
Brain Development ❖ In utero, the brain starts out as a hollow cylinder in the neutral tube❖ develops sense of touch
❖ At 3 weeks By 3 weeks the neural plate thickens first at the head end of the embryo and folds into the neural tube which will form the brain
and the spinal cord. By 3 weeks, the 3 primary sections of the brain are identifiable. These sections are called the forebrain, midbrain, and hindbrain
Sections of the Brain1. Cerebrum Frontal lobe
Parietal lobe Occipital lobe Temporal lobe Limbic lobe Insular cortex
Function of cerebrum The cerebrum is the center of the of sensory perception, memory, thoughts, judgment, and also the center of voluntary motor activityIt encompasses about two-thirds of the brain mass
Cerebrum cont.Frontal lobe- responsible for conscious thought Parietal lobe- plays an important role in integrating sensory information from various senses
Cerebrum cont.Occipital lobe- responsible for sense of sightTemporal lobe- responsible for senses of smell, sound, and processing of complex stimuli Insular cortex- responsible for pain, and some other senses
Limbic system
2. Limbic system- it supports adrenaline flow, emotion, behavior, motivation, long-term memory, olfaction, our emotional life, and has a large part in the formation of memoriesLocated on both sides of the thalamus, under the cerebrum
Cerebellum3.cerebellum- a region of the brain that plays an important role in motor controlIt is located underneath the cerebral hemispheres attached to the bottom of the brain
Brainstem4. Brainstem- responsible for allowing the nerve connections of the motor and sensory systems from the main part of the brain to the rest of the body It also regulates heart rate, sleeping, breathing, eating, the central nervous system, and helps maintain consciousness
Cranial Nerves- 12 Different Nerves
- Medial
- Motor skills and Senses
OlfactorySmell: Sensory-CN1-branch through cribriform plate-Olfactory mucosa, signal sent to olfactory bulb
OpticVision: SensoryCN2Transfers visual info to the brain.
OculomotorEyelid/Eyeball movement:MotorConnects to eye musclesand relays info from thebrain.
TrochlearControls superior Obliquemoves eye downward andlaterally.Motor
TrigeminalChewing/ face & mouth touchSensory & Motor
3 branches
AbducensTurns eye laterally motor
Connects from pons to lateral rectus muscle
Facialmost facial expressions/secretionsMotor & sensory
Many branches, each targeting a different area.
Vestibulocochlearhearing/equilibrium/sensations Sensory
Cochlea- hearingPeripheral nerves-balance
GlossopharyngealTaste/blood pressure/senses carotidsensory & motormany branches, taste ⅓ of tongue, attaches tostylopharyngeus muscle
Vagus-Slows heart rate-stimulates digestive system-Taste-Senses aortic B.P.Motor & Sensory
Spinal Accessorycontrols trapezius and sternocleidomastoid controls swallowing movementsMotor
Allows movement of head and thoracic.
Hypoglossalcontrols tongue movements.MotorHelps with digestion and the swallowing of food.
ReflexesSensory info normally travels from nerves through the spine to the brain. With reflexes, the action potential loops sooner to give outa mechanical response.Potential harm avoided