Week 2: Nervous System & Cerebral Cortex

Central Nervous System

Brain and Spinal Cord

• controls all basic bodily functions and responds to external changes

Peripheral Nervous System

The part of the nervous system that lies outside the central nervous system, responsible for transmitting sensory and motor signals between the central nervous system and the rest of the body.

Somatic Nervous System

The component of the peripheral nervous system that controls voluntary movements of skeletal muscles and contains motor and sensory nerves.

Autonomic Nervous System

The portion of the peripheral nervous system that parallels the spinal cord and regulates involuntary bodily functions (smooth muscles and glands) such as heart rate, digestion, and respiratory rate.

Enteric Nervous System

A subsection of the ANS that governs the function of the gastrointestinal system and is involves in the gut-brain axis

Sympathetic Nervous System

A division of the autonomic nervous system that prepares the body for stressful or emergency situations, commonly known as the "fight or flight" response, and is activated when encountering a stressor (fear).

Parasympathetic Nervous System

A division of the autonomic nervous system that promotes rest and digestion, often referred to as the "rest and digest" response. It inhibits arousal/activation and maintains homeostasis

Reflexes

simple responses to the environment

• one stimulus = one response

• no cerebral cortex or PNS involvement

• fight/flight/freeze/fawn response

Instincts

• more complex

• more than a single stimulus and response

• inbuilt system

• not learned

Encephalisation Quotient (EQ)

• emotional intelligence

• more capable of intelligent behaviours = higher EQ (exception - Chihuahua)

• log of average brain mass divided by log of average body mass

Cerebral Cortex

outermost layer of the brain

• wrinkly to increase surface area of the brain —> more functions

• contains higher-order abilities (language, complex thinking, etc)

gyri

bulges of cerebral cortex

sulci

small grooves of cerebral cortex

fissures

large grooves of cerebral cortex

corpus callosum

connects hemispheres and shares information with contralateral side

• split brain surgery - cuts it

Frontal Lobes

• Primary Motor Cortex

• Dorsolateral Prefrontal Cortex

• Broca’s Area

Primary Motor Cortex

• behind dlpfc, from top of skull to ears

• initiation of voluntary motor movements

• frontal lobes

Dorsolateral Prefrontal Cortex

• midpoint of frontal lobes, in front of M1

• executive functions

• frontal lobes

Broca’s Area

• above left temporal lobe

• language processing and speech production

• broca’s/nonfluent aphasia

• frontal lobes

Parietal Lobes

processing of sensory info and spatial awareness

• primary somatosensory cortex

• visuospatial processing

primary somatosensory cortex

• strip next to M1

• processes incoming sensory info

• parietal lobes

Occipital Lobes

near base of spine and involved in visual processing

• cortical blindness

• primary visual cortex

• visual agnosias

cortical blindness

• impaired visual functioning despite healthy eyes

• occipital lobe

primary visual cortex

• intercept visual info

• occipital lobes

visual agnosias

• apperceptive - familiar objects

• achromatopsia - colour

• akinetopsia - motion

Temporal Lobes

below temples on side of skull, auditory processing, object recognition, facial perception, memory processes

• primary auditory cortex

• fusiform face area

• wernickes area

primary auditory cortex

• auditory processing - understanding it and locating where sound comes from

• temporal lobes

fusiform face area

• recognition of human faces

• right temporal lobe

• damage —> prosopagnosia - can’t recognise faces

Wernicke’s Area

• language processing and speech comprehension

• Wernicke’s (fluent) aphasia

• temporal lobes