The Nervous System Flashcards
How is the nervous system organised?
*CENTRAL NERVOUS SYSTEM (CNS)
brain and spinal cord
*PERIPHERAL NERVOUS SYSTEM
(Afferent neurons are those that take sensory information and direct it towards the central nervous system. Efferent neurons take messages from the CNS and deliver them to muscles and glands.)
-afferent neurons (sensory neurons)
-sensory input
-efferent neurons
somatic motor neurons (Somatic nervous system SNS)=voluntary actions and some reflexes.
OR
autonomic neurons (involuntary responses)
-sympathetic
-parasympathetic
(enteric nervous system)
There are neurons and glial cells
What do glial cells do?
They can keep balance of chemicals, maintain blood brain barrier, they make myelin (to make myelin sheath around axons )cerebral spinal fluid which is protective. They also have important immune function.
Describe the CNS
Brain
-2 major functions: control behaviour and to regulate the body’s physiological processes
-thought, forming memories, movement, and awareness
Spinal Cord
-Conducts signals to and from the brain
-Contains circuits of neurons which can control some of our simple reflexes
Cranial Nerves (16 of them)
-e.g. Optic nerve relay messages from your eyes to your brain to create visual images
Describe briefly what the cerebrum contains and does?
Cerebrum
*Hippocampus= Memory processing and retention
*Basal Ganglia= regulation of motor performance
*Amygdala: coordinate autonomic and endocrine responses of emotional states
*Cerebral Cortex (outer grey matter layer)= 2 hemispheres two halves are connected by a tube (they communicate by white matter tract called the corpus callosum)
Responsible for higher-order thinking, such as problem-solving, reasoning, and processing sensory information. It is divided into two hemispheres, the left and right, each controlling the opposite side of the body. The cerebrum can be further divided into four lobes:
What are Sulci, Gyri and fissure in the brain?
Sulci= fold/groove
Gyri=raised ridge
fissure=a deeper grove
The cerebrum consists of two cerebral hemispheres the outer layer called the cortex (gray matter) and the inner layer (white matter).
Describe the frontal lobe of the cerebral cortex
*Frontal Lobe: Involved in motor function, problem-solving, spontaneity, memory, language, initiation, judgment, impulse control, and social and sexual behavior.
Frontal lobe is divided into;
1. Primary Motor Cortex= Consciously aware of voluntary muscle movement. Brainspinal cordmuscle (middle of brain=higher extremities. Higher part of brain=lower extremities)
2. Motor Association Cortex=planning, processing and recognition of movement
3. Frontal Eye Field=voluntary eye movement
4. Prefrontal Cortex=Executive Functions, Behaviour, Personality
5. Broca’s Area=Typically located in the dominant hemisphere and stimulates the muscles that help us produce speech and form words
Describe the parietal lobe of the cerebral cortex
*Parietal Lobe: Responsible for processing sensory information it receives from the outside world, mainly relating to spatial sense and navigation (proprioception), the main sensory receptive area for the sense of touch.
Parietal lobe is divided into;
1. Primary Somatosensory Cortex=awareness of somatosensory, touch, pain and temp
Peripheralspinal cordbrain
2. Somatosensory Association Cortex=processing somatosensory, memory of sensation and compares to old, recognition of sensations.
3. Posterior Association Complex=Important for proprioception and Development of spatial awareness, it also extends into occipital and temporal lobes, Somatosensory stimuli – parietal lobe
Visual stimuli – occipital lobe
Auditory stimuli – temporal lobe
Describe the occipital lobe of the cerebral cortex
*Occipital Lobe: Primarily responsible for processing visual information.
The occipital lobe is divided into;
- Primary Visual Cortex=Awareness of visual stimuli
Eyeoptic nerveprimary visual cortexvisual association cortex - Visual Association Cortex=Processing visual info, understand, recognise, and use memory of stimuli
Describe the temporal lobe of the cerebral cortex
*Temporal Lobe: Involved in processing auditory information and is also important for the processing of semantics in both speech, vision and smell.
Temporal lobe is divided into;
1. Primary Auditory Cortex=Awareness of auditory stimuli
Earvestibulocochlear nerveprimary auditory cortexauditory association cortex
2. Auditory Association Cortex=processing, understand, recognise, memory of auditory stimuli
3. Wernicke’s Area= Usually in the dominant hemisphere. Comprehension and understanding of written and spoken language
4. Primary Olfactory Cortex/Associate Cortex=
Primary, consciously aware of smells
Association: Process, analyse, recognise
Describe the cerebellum
Cerebellum
Located at the back of the brain, it is responsible for coordination, balance, and fine muscle control. It contains Purkinje cells (neurons).
Describe all parts of the brainstem and what they do
Brain Stem:
1. Medulla oblongata
2. Pons
3. Midbrain
*The medulla contains the cardiac, respiratory, vomiting and vasomotor centres, and therefore deals with the autonomic functions of breathing, heart rate and blood pressure as well as the sleep–wake cycle
*pons handles all of your unconscious movements and processes. These cycles include everything from your sleeping to your breathing.
*The midbrain functions as a relay system, transmitting information necessary for vision and hearing. It also plays an important role in motor movement, pain, and the sleep/wake cycle.
Describe the diencephalon and what it’s divided into
diencephalon
It is involved in coordinating with the endocrine system to release hormones, relaying sensory and motor signals to the cerebral cortex, and regulating circadian rhythms
is made up of four main components.
1. Thalamus=Function: Sensory relay centre that directs sensory information to the cerebral cortex.
2. Subthalamus: Function: Primarily involved in motor control and coordination.
3. Hypothalamus: Function: Regulates homeostasis, controls the endocrine system, influences emotions and behaviours, and regulates the autonomic nervous system.
4. Epithalamus: Function: Contains the pineal gland, which produces melatonin, regulating the sleep-wake cycle and circadian rhythms. It also contributes to emotional responses and the sense of smell.
What is in the forebrain, midbrain and hindbrain
forebrain= cerebrum and diencephalon
midbrain=midbrain
hindbrain=pons, medulla oblongata and cerebellum
What is Proprioception?
Proprioception= co-ord of visual, auditory and somatosensory stimuli, spacial and body awareness
What are the meninges and what do the do?
They help with;
*Protecting the brain and spinal cord from physical injury.
Containing and circulating cerebrospinal fluid (CSF), which acts as a cushion and helps maintain a stable environment for the brain.
*Providing a barrier that helps prevent the entry of harmful substances and pathogens into the central nervous system.
*Supporting the blood vessels that supply nutrients to the brain and spinal cord.
The meninges are three protective layers that surround the brain and spinal cord:
*Dura Mater: Outer and tough.
*Arachnoid Mater: Delicate and holds cerebrospinal fluid.
*Pia Mater: Innermost, in direct contact with the brain and spinal cord.
They protect, cushion, and support the central nervous system. (even spinal cord)
What is the blood-brain barrier (BBB)?
The blood-brain barrier (BBB) is a protective barrier in the brain that separates the bloodstream from brain tissue. It prevents harmful substances from entering the brain, regulates the exchange of nutrients and waste, and maintains a stable brain environment. It acts as a defense against infections and can limit the effectiveness of certain drugs in reaching the brain.
What are spinal ganglia
Dorsal Root Ganglia contain the cell bodies of afferent nerve fibres.
Sensory impulses going to the CNS
Ventral Root Ganglia contain the cell bodies of efferent nerve fibres.
Motor impulses away from the CNS
What are the region that are vertebrae are divided into?
cervical nerves
thoracic nerves
lumber nerves
sacral nerves
coccyx
