MedTech - Psychology

Nervous system three main functions

• To RECEIVE information​

• To PROCESS information​

• And to coordinate a RESPONSE to information​

Neurons

• The nervous system is made up of neurons.​

• Neurons are individual nerve cells​

• They carry electrical messages

• They do not touch each other (there is a gap in between)​

• Impulses only travel in one direction​

axon

carries the neural impluse to the cell body to the axon terminals

dendrites

receives neural information from other neurons

soma

cell body. controls the maintenance and metabolism of the neuron

synapse

the junction between two neurons.

axon terminals

the end of an axon. releases neurotransmitters

myelin

improves speed of transmission of the electrical impulse down the axon

neurochemicals

chemical released by axon terminals to communicate with the next neuron

structure of a neuron

• cell body

• axon

• dendrites

• neural impulse

• terminal branches of axon

• myelin sheath

sensory neurons

• They receive information from our sense organs (ie. Skin, eyes, ears, tongue and nose) and our internal organs (e.g. stomach, lungs, heart) ​

• ​

• They then transmit this information to the brain​

motor neurons

• Motor neurons make the connection between the brain and muscles throughout the body. ​

• These neurons transmit electrical impulses containing information to skeletal muscles and smooth muscles.

• carry information from the brain​

interneurons

• Found in the spinal cord or brain​

• Responsible for processing information from the external environment and internally, within the body. They integrate the information and generate a response.​

reflex arc

A reflex arc is a neural pathway that controls an action reflex. In most animals, sensory neurons do not pass directly into the brain, but to the spinal cord

central nervous system (CNS)

• CNS consists of the brain and spinal cord​

• It is responsible for integrating and coordinating all incoming information and initiates outgoing messages to be sent to the body​

• These include conscious commands such as controlling voluntary movements and unconscious commands such as change in heartbeat​

three different areas of the brian

Cerebral Cortex​

Brain Stem

Cerebellum​

cerebral cortex

• Divided into two hemispheres, each of which has four lobes.​

• The left hemisphere controls the right half of the body, and the right hemisphere controls the left half.​

The four lobes of the brain

Parietal

Temporal

Occipital

Frontal

PTOF

frontal lobe

• Planning and organising​

• Located behind the forehead, the frontal lobes are the largest lobes of the brain. They are prone to injury because they sit just in front of the skull.​

temporal lobe

The temporal lobes, located on the sides of the brain near the ears, are crucial for processing auditory information, language, memory, and emotions, with the left lobe often dominant for verbal functions and the right for non-verbal ones. 

parietal lobe

These lobes are particularly important in integrating information from the body’s senses to allow us to build a coherent picture of the world around us

occipital lobe

• The occipital lobes are vital regions located at the back of the brain responsible for processing visual information. They receive and interpret visual stimuli from the eyes.​

brain stem

The brain stem, located at the base of the brain, connects to the spinal cord and is essential for survival, controlling breathing, heart rate, blood pressure, and sleep. All information from the body passes through it, and damage can cause severe issues like breathing difficulties, trouble swallowing, or even death.

spinal cord

It transmits sensory information to the brain and motor commands from the brain to the body, linking to the skin, muscles, and internal organs.

somatic nervous system

The spinal cord transmits sensory information from the five senses to the brain and sends motor commands to skeletal muscles for voluntary movement.

autonomic nervous system

The spinal cord autonomously regulates organs, glands, and visceral muscles like the heart, lungs, and digestive system, constantly providing feedback to the brain through the sympathetic and parasympathetic nervous systems.

sympathetic nervous system

The sympathetic nervous system dominates during stress or threats, increasing arousal to prepare the body for action.

parasympathetic nervous system

The parasympathetic nervous system dominates during daily activities, restores calm after stress, and maintains homeostasis.

memory

encoding - converting raw sensory information into a memory.​

storage - retention of encoded information in the brain.​

retrieval - recovering information from storage into our conscious awareness.​

sensory memory

iconic, haptic, echoic, olfactory, gustatory

iconic memory

• This is the visual sensory memory register that stores visual images after its stimulus has ceased. ​

echoic memory

This is a type of sensory memory of auditory information (sounds)

short term memory (stm)

Occurs in:​	Brain (Frontal cortex)​
Function​	Active manipulation and temporary storage of information from sensory and long-term memory.​
Capacity​	5-9 pieces of information​
Duration​	12-30 seconds unless rehearsed​

long term memory

• FUNCTION:​

• Storehouse for information encoded from Short-Term Memory​

• CAPACITY:​

• Potentially Unlimited​

• DURATION:​

• Potentially permanent​

explicit memory

semantic memory - facts and general knowledge

episodic memory - personal experiences

implicit memory

procedural memory - simple motor responses

fear and anxiety - simple classically conditioned responses

improving memory

mnemonic devices, narrative chaining, acronym

dementia

Dementia is a broad term for conditions that impair thinking, behavior, and daily functioning.

alzheimer’s disease

Alzheimer’s disease is a neurodegenerative condition that gradually destroys neurons, leading to memory loss, confusion, impaired thinking, personality changes, and overall cognitive decline.

symptoms of alzheimer’s disease

memory loss, lack of cognitive skills, decline in social skills, personality changes

diagnosis of alzheimer’s disease

There is no simple diagnostic test for Alzheimer's disease, but CT and MRI scans can rule out other conditions and show brain mass loss in later stages, while PET scans reveal declines in neural activity as the disease progresses.

four changes in the brains of people with AD

Alzheimer's disease is characterized by the presence of amyloid plaques that disrupt neuron communication, neurofibrillary tangles causing neuron death, and a severe lack of acetylcholine, which is crucial for memory. As neurons die, brain atrophy occurs, leading to shrinkage of the brain.