Nervous System W5 Flashcards
Two Parts of CNS
Central Nervous System
- The spinal cord: Send motor commands from brain to body, send sensory info from the body to the brain, coordinate reflexes.
- The brain: Controls thought, memory, touch, motor skills, breathing, temperature and every other bodily process.
Two parts of PNS
Caries sensory information from body to CNS vis sensory nerves
Carries motor information from CNS to body via motor nerves
Two parts of Motor (efferent) Division
(1) Somatic nervous system
- Controls voluntary activities via signals from CNS to skeletal muscles
(2) Autonomic nervous system
- Controls involuntary activities
Two Parts of Autonomic Nervous System
(1) Parasympathetic nervous system - - prepares the body for rest and repair by returning body to homeostasis after threat has been subsided
(2) Sympathetic nervous system
- prepares for flight or fight response when body is under stress.
Both act via Reflexes
The Brain Stem
- Relay Centre (connecting the cerebrum and cerebellum to the spinal cord)
- Controls Autonomic Functions eg breathing, heart rate, body temp etc
- Where 10/12 cranial nerves originate
Thalamus
Relays sensory information from the body to other areas of the brain
Hypothalamus
- Master control of autonomic System - Controls behaviours such as hunger, thirst,sleep and sexual response
- Regulates body temperature, blood pressure, emotions, and secretion of hormones.
Limbic System
- Controls Emotional Behaivours
Structures of the Limbic System
- Thalamus,
- Hypothalamus
- Amygdala
- Hippocampus
Thalamus in Limbic System
Sensory Gateway
Hypothalamus in Limbic System
Regulates Emotions
(fear, sexual drive and aggression we feel)
Amygdala in Limbic System
Rage or aggression
Hippocampus in Limbic System
Memories
Limbic system help connect those memories to the emotion experiences when the memories form
Cerebrum
Cerebral Cortex
- Grey Matter (Nerve cell bodies)
- White Matter (Nerve fibres)
- Conscious Mind
Conscious Mind in Cerebral Cortex
- Aware of ourselves and our sensation
- Communicate
- Remember
- Understand
- Initiate Voluntary movements
Cerebellum
- coordinate muscle movements and balance
Gyrus
Elevated Ridges
Sulcus and Fissures
Shallow deep grooves that determine boundary of lobes
Central Sulcus
Divides frontal/parietal lobes
Lateral Sulcus
Divides frontal/temporal/parietal lobes
Longitudinal Fissure
Separates hemispheres into left and right
Cerebral Lobes
- Parietal lobe
- Frontal lobe
- Temporal lobe
- Occipital lobe
Parietal lobe
- Processing somatosensory input (touch, pain, temperature, proprioception (sense position and movement of our body and limbs in space))
- Integrates visual and auditory inputs - spatial awareness
(informing us about objects in our external environment)
Frontal Lobe
- Movement Control
- Problem solving, reasoning, planning
- Personality, behaviour, emotions
- Language production and articulation
(Defining us as who we - decision making, planning, problem solving and reasoning)
Temporal Lobe
- Hearing
- Language Comprehension
- Memory (formation and retention)
- Contains Wernickes area so responsible for language comprehension and understanding
(Receives and processes auditory information from the ears)
Occipital Lobe
- Visual Processing
- Visual Memories
- Visual Perception (special information)
(Processing and interpreting vision allowing us to detect and recognise colour, light, objects and movement)
(Enables us to form visual memories)
Cerebral Cortex functional Areas
- Motor areas
- Sensory areas
- Association areas.
Motor Areas
- Located in the frontal lobe
- Control/Regulate voluntary movements
Sensory Areas
- Found in the parietal, temporal, and occipital lobes
- Process Sensory inputs for Perception
(Receive and process sensory information from the external environment or the body itself)
Association Areas
- Integrates inputs from various sources for understanding and meaning
(Responsible for integrating and interpreting information received from sensory inputs, combining it with memories, emotions, and thoughts)
3 Parts of Motor Areas
- Primary Motor Cortex
- Premotor Cortex
- Brocas Area
Primary Motor Cortex
Relays motor command via chain of motor neurons to skeletal muscles for voluntary movement
- Motor homunculus (Map) - somatotopic organisation
Map (Specific regions of the cortex are responsible for motor control of specific areas of the body)
Premotor Cortex
- Stores Repetitious movements
- Movements activated or guided by sensory input
(eg brake pedal when see red light)
Brocas Area
- Language Processing and speech production
Sensory Areas: Somatic Sensations
- Primary somatosensory cortex
- Somatosensory association cortex
Primary somatosensory cortex
- Processes touch, temperature, pain, proprioception sensory information
- Sensory Homunculus
Somatosensory association cortex
- Integrates and analyses different somatosensory inputs into understanding area
Sensory Areas: Hearing
Temporal Lobe
- Primary Auditory Cortex (Processes auditory information)
- Auditory Association Area (Interprets sounds and associated auditory input with other sensory information
- Wernickes Area (Comprehension of written and spoken language)
Sensory Areas: Vision
Occipital Lobe
- Primary Visual Cortex (Receives visual information that originates from the retina in the eyes- Right side of retina sees left and vis versa)
- Visual Association Area (interpretation of light stimuli based on past experiences - how we recognise people)
divisions of the NS
What is A and what is its function?
Frontal lobe
movement control, problem solving, personality, language production and articulation
What is B and what is its function?
parietal lobe
process somatosensory input (touch, pain, temperature, proprioception)
integrates visual and auditory inputs— spatial awareness
What is C and what is its function?
occipital lobe
visual processing, memories, perception ( special information)
What is D and what is its function?
cerebellum
balance + coordination
What is E and what is its function?
spinal cord
receives sensory information from body to brain
receives motor information from brain to body
What is F and what is its function?
brain stem
vital function eg. HR/RR
What is G and what is its function?
temporal lobe
hearing
Ventral roots
- Contain motor neurons that originate in the anterior horn of the spinal cord’s gray matter and carry motor signals away from the CNS to muscles and glands throughout the body.
Dorsal Roots
- Dorsal roots contain sensory neurons with their cell bodies located in the dorsal root ganglion (a swelling of the dorsal root). These neurons transmit sensory signals from receptors in the body (such as skin, muscles, and organs; related to touch, temperature, pain and proprioception) and send them to the CNS.
White Matter in Spinal Cord
- Consists of bundles of neuronal axons that extend up and down its length.
- Allows messages (action potentials) to pass between different areas of grey matter within
the central nervous system. - Can be divided into pairs of dorsal columns (towards the back), ventral columns (towards the front) and lateral columns (towards the side).
Gray Matter in Spinal Cord
- Made up of cell bodies, axon terminals (endings) and dendrites of neurons.
- Functions to receive information and regulate outgoing information.
- Divided into a dorsal horn (situated dorsal/posterior), ventral horn (situated ventral/anterior) and lateral horn (situated lateral).
Function of dorsal horn
- Contains cell bodies of interneurons that relay sensory input related to touch, pain, temperature, and proprioception from the body
Function of ventral horn
- Contains cell bodies of motor neurons that supply skeletal muscle to control voluntary skeletal muscle movements and regulate certain involuntary muscle activities.
Function of lateral horn
- Contains cell bodies of preganglionic neurons that contribute to the sympathetic division of the autonomic nervous system that regulate functions like heart rate, blood pressure, and visceral organ
Neuronal pathways - Descending pathways
Carries motor information from BRAIN TO BODY.
Neuronal pathways - Ascending pathways
sensory information from the peripheral nerves is transmitted to the cerebral cortex
Sensory receptors
- Specialized to respond to changes in their environment, which are called stimuli
Sensation
- Awareness of the stimulus
- Occur in Brain
Perception
- Interpretation of the meaning of the stimulus
- Occur in Brain
Mechanoreceptors
- Respond to mechanical force such as touch, pressure (including blood pressure), vibration, and stretch
Thermoreceptors
- Respond to temperature changes.
Chemoreceptors
- Respond to chemicals in solution (molecules smelled or tasted, or changes in blood or interstitial fluid chemistry)
Nociceptors
- Pain receptors
- Respond to potentially damaging stimuli that result in pain.
Photoreceptors
- Such as retina in the eye
- Respond to light
Receptive Field
- Peripheral Area which if stimulated leads to activity in the neuron
- Smaller receptive fields greater the ability for our brains to accurately localise a stimulus site
Neurotransmitters produced in Sympathetic
- norepinephrine captured by adrenergic receptors