WEEK 2 LECTURE + TUTORIAL Flashcards
MECHANICS OF THE NS (43 cards)
Lobes of the Brain
*Divided into four main lobes, which are apart of the cerebral cortex
- Frontal Lobe
2.Parietal Lobe
3.Temporal Lobe
4.Occipital Lobe
Frontal Lobe
Location, functions, damage
Location: Front of the brain, behind the forehead
Functions: Higher cognitive functions (problem-solving), motor control (voluntary movement), speech production (Broca’s area) , personality and emotions (regulates behaviour and impulses)
Damage: can lead to personality changes, poor judgement and motor deficits
Parietal Lobe
Location, Functions, Damage
Location: Behind the frontal lobe, at the top- middle of the brain
Functions: Sensory processing (contains the somatosensory cortex which interprets pain), spatial awareness (depth perception), mathematical reasoning (problem-solving skills)
Damage: problems with reading and writing, agnosia issue recognising objects by touch
Temporal Lobe
Location, function, damage
Location: Both sides of the brain, near the ears
Functions: Hearing and language comprehension (contains hippocampus and Wernicke’s area), emotional regulation (processing emotions and social interactions)
Damage: memory loss, difficulty understanding speech (Wernicke’s aphasia) and emotional instability
Occipital Lobe
Location, Function, Damage
Location: At the back of the brain, behind the eyes
Functions: Visual processing (contains the primary visual cortex), object and facial recognition (helps in identifying people and objects
Damage: Vision problems, hallucinations or difficulty recognising faces (prosopagnosia)
Summary
Frontal: Forehead, Thinking
Parietal: Top, Perception
Temporal: Ears, hearing, comprehension
Occipital: Eyes, visual interpretations
CNS: Spinal Cord
- Continuous with brainstem
-Long, conical structure
-Thickness of adults middle finger
-Mediates transmission of info from the brain and the body
-Protected by vertebrae
-Core of grey matter
-Grey Matter: Processing and Cognition
-White Matter: Communication between brain regions
-Discs between vertebra to buffer them from shock
-Dorsal: Towards the back
-Ventral: Towards the front
Main Functions
- Coordinating certain reflexes
-Conduit ( a channel for something to flow) for sensory and motor information
Afferent VS Efferent Neurons
- Afferent Neurons (Sensory): These carry signals from the body to the spinal cord (like touch, pain, or temperature). Their axons enter through the dorsal root and connect to the dorsal horn of the spinal cord. Think of “afferent” as “arriving” at the spinal cord.
- Efferent Neurons (Motor): These send signals from the spinal cord to muscles and organs to produce movement or responses. Their cell bodies are located in the ventral horn, and their axons exit through the ventral root. Think of “efferent” as “exiting” the spinal cord to cause an effect.
- Afferent = sensory, arrives at the spinal cord through the back (dorsal)
- Efferent = motor, exits from the front (ventral) to control movement
PNS: Main Functions
- Connects the CNS to limbs and organs via cranial and spinal nerves
-Carries info from the environment to CNS
-Carries messages from the CNS to muscles and glands (efferent neurons)
Cranial Nerves Facts
-12 pairs
-10 Brainstem, 1/11 in Forebrain
-Exception: Vagus Nerve
Vagus Nerve / Wandering Nerve
- Transmits information to your gut and enteric system
12 Cranial Nerves
- Olfactory (smell)
-Optic (vision)
-Oculomotor (eye movement)
-Trochlear (eye movement)
-Trigeminal (face sensation)
-Abducens (eye movement)
-Facial (facial movement)
-Vestibulocochlear (hearing)
-Glossopharyngeal (taste)
-Vagus (movement)
-Accessory (neck movement)
-Hypoglossal (tongue movement)
Spinal Nerves PNS
- 31 Pairs
-Each pair associated with a particular segment of the spinal cord
-Named dependent on vertebral level they attach
-Spinal nerves can contain sensory and motor fibres
Somatic NS
-Voluntary control of body movement
-Recieves sensory info and controls spinal nerves that innervate skin, joints and muscles
- Afferent neurons carry sensory info from the skin (sensory neuron)
-Efferent neurons control skeletal muscles (motor neuron)
-Neurons are excitatory
Autonomic NS
-Controls involuntary functions and internal environment
-Afferent neurons carry sensory info from internal organs to CNS
Has three further subdivisions
1. Sympathetic Nervous system
2. Parasympathetic Nervous System
3. Enteric Nervous System
ANS Functions
-Any response for activities which expend energy
-Coordinates fight or flight
- Activities involves with the increase in the body’s supply of stored energy
-Rest and relax response
ENS Functions
-The ‘second brain’
-Lines your gastrointestinal tract from oesophagus to rectum
-Main role in controlling digestion
-Activity dependent on local factors
Gut-Brain Axis:
-Complex interplay between gut microbiota, the immune system and the CNS
-Gut microbiota regulates brain function by preserving the CNS immune homeostasis
-Direct action Vagus Nerve
-Indirect immune
Sensory Neurons
-Part of the PNS
-Contain sensory receptors for detecting sensory changes
-Sends info about these changes to the CNS
-Cell body in PNS, axons enter CNS
-Axon terminals located in CNS
Motor Neurons
-Part of the PNS
-Synapses to skeletal muscle to command movement or onto glands to release hormones
-Relays signal from CNS to PNS
-Dendrites and cell body in CNS, axon enters PNS
Relay Neurons
-Part of the PNS
-Synapses to skeletal muscle to command movement or onto glands to release hormones
-Relays signal from CNS to PNS
-Dendrites and cell body in CNS, axon enters PNS
Neuronal Membrane
-Made up of two layers of lipid molecules
-Hydrophilic: water attracting
-Hydrophobic: water repelling
-Barrier: water soluble molecules cannot pass through
Cations +VE
-Sodium (extracellular)
-Potassium (intracellular)