neurological system

nervous system

• body’s command center

• made up of the brain, spinal cord, and nerves that sends highly complex sensory information to different parts of the body

• divided into 2 regions: central nervous system and peripheral nervous system

central nervous system

• made up of the brain and spinal cord

• primary functions:

  • command center for processing information

  • motor response or regulate body mechanisms

• categorized into 3 main regions:

  • hindbrain

  • midbrain

  • forebrain

hindbrain composed of 3 main regions:

• medulla oblongata

• pons

• cerebellum

medulla oblongata

• regulation of breathing, blood pressure & heart rate

• “medulla manages”

  • essential bodily functions with motor control, monitoring heart rate, and modulating breathing

pons

• transmit signals between forebrain and cerebellum

• “pons passes”

  • passes messages between the brain and body, plays a critical role in the patterns of breathing and sleep cycles

cerebellum

• balance and movement coordination

• cerebellum coordinates

  • coordinates complex voluntary movements, controls balance, and calibrates muscle activity to ensure smooth and balanced motion

midbrain

• alertness, sleep/wake cycle, motor activities

• “MID controls”

  • Movement

  • Involvement in the sleep/wake cycle

  • Detection of auditory & visual reflexes

movement

• midbrain is involved in motive movements and coordination, particularly eye movement and other reflective responses

involvement in the sleep/ wake cycle

• crucial role in maintaining alertness and regulating sleep/wake cycle

detection of auditory & visual reflexes

• midbrain processes that audit and visual signals contributing to the reflective responses we get whenever we’re introduced to a stimuli

forebrain

• contains primary motor & sensory cortices (&cerebrum)

• association areas allow for complex analysis of internal/external environment

• limbic system

• highest aspects of cognitive function

• substrate for conscious experience

contains primary motor & sensory cortices (& cerebrum)

• the primary motor cortex, located in the frontal lobe is the area that is crucial for initiating voluntary or conscious motor movements (ex: if you decide to start walking, this initiation actually occurs where labeled, marking it as the highest level of which motor activity is controlled), similarly, the sensory cortex process incoming information from both our external and internal environments enabling us to consciously be aware of what’s going on, this area represents the highest level of sensory information integration (ex: touching a hot surface)

• frontal lobe

associations areas allow for complex analysis of internal/external environment

• although the primary motor and sensory cortices initiate basic actions, like walking, its really the association area that enhances the capability by allowing the sequencing & planning of more intricate tasks

  • ex: dancing ballet

• sensory cortices play a crucial role when it comes to interpreting the type of sensory information that we encounter

• parietal lobe

limbic system

• memory & emotional aspects of behavior

• is integral to the highest level of cognitive function in the cerebral hemisphere

  • cognitive function encompass activities like planning, making judgments, experiencing emotions, reasoning, and behavior, most occurs in frontal lobe, specifically the prefrontal cortex and damage in this area will significantly impair functions listed

substrate for conscious experience

• cerebral hemispheres serve as the foundation of our conscious experience when consciously aware of something its because that sensory information or thought processes have reached our cortex

• cerebellum & brain stem

left & right hemisphere

• most developed part of brain

  • the cerebral hemispheres house the primary motor and sensory cortices

• has a fissure that runs down the middle of the brain, dividing it into 2 hemispheres

cortices

• plural form of cortex - the cerebrums outer layer

• about 1-5 mm thick and composed of gray matter

• critical layer that our consciousness emerges

axon terminal

• typically connects to another neuron

axon

• is enclosed in a myelon sheath (made up of fats & lipids, appear white, therefore in the brain we have gray matter) where the synapsing actually occurs

grey matter

• site of integration of information, essentially where the brain makes sense of incoming data

• consists of neuron cell bodies

white matter

• signals highways facilitating the rapid transmission of signals from one area of the brain to another

• primarily composed of the axons in the myelon sheaths

frontal lobe

• think “forehead” for deep thought and decision making

parietal lobe

• think “parachute” covering top of head; sensory information

occipital lobe

• think “optics” & “ocular” focusing on vision

temporal lobe

• think “tempo” for hearing and rhythm in speech & memories

peripheral nervous system

• everything outside of the brain and spinal cord (nervous system elements like the nerves distributed throughout the body)

• primary function: sensory information for CNS

• categorized into 2 main parts:

  • autonomic nervous system

  • somatic nervous system

autonomic nervous system

• internal temperature, regulating GI functions, excretory & endocrine systems, cardiac muscle activity

• categorized into 2 main parts:

  • sympathetic

  • parasympathetic

sympathetic

• fight or flight response

  • increase in heart rate and respiratory rate & slow digestion

parasympathetic

• rest and digest

  • decrease in HR & digestion occurs

somatic nervous system

• motor functions of skeletal muscles (voluntary & somatic)

PNS and CNS

• work together by PNS gathering sensory information and the CNS processes the data and coordinates motor responses and regulates bodily functions

primary types of cells found in the nervous tissue of both CNS & PNS

• neurons

• glial

neurons

• composed of 3 parts:

  • dendrites

  • axon

  • synapse

dendrites

• branch-like structures that receive signals from other cells

axon

• long body made of fibers that carry signals away from the neuron to other cells

• “axon away”

synapse

• uses axon terminal to communicate with other neurons

glial

• originate from Greek word, meaning glue

• help maintain the chemical balance necessary for signaling between our cells

• help sustain that blood-brain barrier, which prevents many substances in the body from entering from our nervous system

• produce myelin sheath (a protective coating that wraps around our neurons axons, insulting them & enhancing signaling transmission)

• generate cerebrospinal fluid, protects our brain & maintains homeostasis

• immune function

afferent

• sensory neurons input straight to our CNS

• admission afferent arrives

• ex: after touching a hot stove, afferent “sensory” neurons signal brain that something it hot

efferent

• motor neurons output away from the CNS

• efferent = exit

• once the brain processes the information, efferent “motor” neurons tell the muscles to pull hand away