LECTURE 1 Flashcards
3 planes which the brain and body can be viewed
saggital ( side cross section)
coronal (through middle)
transverse ( top and bottom )
anatomical terminology
Above = superior
Below = inferior
Front = anterior or ventral
Back = posterior or dorsal
Medial = close to (midline)
Lateral = away from/next to (midline)
sensory integrative and motor functions of the nervous system
Sensory function
detect external & internal changes
Integrative function
analyses & makes decisions based on voluntary and involuntary responses
Motor function
initiates motor movement & glandular secretions
Cerebrum
largest part of the brain. It contains the cerebral cortex and subcortical regions
separated into 2 hemispheres that are connected by a large fibre bundle called the corpus callosum
Cerebellum
located in the posterior region of the brain, it is mainly responsible for balance and coordination
Brainstem
contains the midbrain, pons and medulla oblongata. It communicates with the PNS to control involuntary processes such as breathing and heart rate.
Cerebral cortex
The outer layer of the cerebrum is composed of the cerebral cortex
Four functionally and anatomically distinct lobes: frontal, parietal, temporal and occipital
Frontal lobe
higher cognitive functions, such decision-making and problem-solving. It is also responsible for some features of language and voluntary movement
Parietal lobe
integrates information from the visual pathway, coordinates motor movement and interpretation of sensory information
Temporal lobe
interpreting speech and hearing, object recognition and emotion
Occipital lobe
processing primary visual information
what are subcortical regions
Brain regions that lie underneath the cortex are referred to as subcortical regions
examples of subcortical structures and their functions
hypothalamus, amygdala, hippocampus, thalamus and basal ganglia
Responsible for many functions including memory, emotions, motor movement & processing sensory information
Midbrain
Serves as a connection between the brainstem and subcortical regions
What does the midbrain consist of
colliculi – directs eye movement towards objects of interest
tegmentum – coordination of movement, alertness/sleep
cerebral peduncle – control of ocular muscles
5 sections of the spinal cord
The spinal cord is divided into 5 main sections based on the corresponding body area that is innervated: cervical (neck), thoracic (chest), lumbar (lower back), sacral (hip) and coccygeal (tail)
role of the enteric part of the autonomic ns
Regulates movement of water & solutes between gut and tissues
role of sympathetic and parasympathetic ns
Sympathetic is responsible for the ‘fight or flight’ reaction that occurs in response to a stressful stimulus
Parasympathetic nervous system balances the sympathetic response by stimulating ‘rest and digest’ pathways
Afferent & efferent pathways
Afferent pathways carry sensory information from the periphery up to the brain via ascending nerve tracts
The brain sends signals down to peripheral nerves along efferent descending nerve tracts to control motor output
Reflex arc – leg jerk response
When the knee is hit, sensory afferents in the knee send information to the dorsal column of the spinal cord. These afferents synapse onto interneurons within the spinal cord
The interneurons send information to the muscles of the legs via efferents nerve that originate in the ventral horn
The efferent fibers communicate with the muscles, causing them to contract, resulting in a jerk of the leg
This reflex arc occurs without input from the brain
2 main cell groups in the CNS
neurons (‘nerve cells’) and glia (‘support cells’)
types of glial cells
Glial cells are further subdivided into microglia, astrocytes, oligodendrocytes & ependymal cells
Bipolar neurons
1 main dendrite and 1 axon
Retina of the eye, inner ear, olfactory area of brain
Unipolar neurons
Just 1 process from the cell body, part way down the axon
Always sensory neurons (pain, temperature, touch, pressure)
Multipolar neurons
Many dendrites and 1 axon
Most neurons in the CNS
Microglia
Immune cells that survey the CNS and respond to signs of infection or damage
Surveillant = smaller, with multiple processes
Activated = larger, with rounded cell body & shorter processes
Astrocytes
Small, star-shaped cells that provide support for the development and homeostatic maintenance of the nervous system and cerebral blood vessels
Form a ‘glial scar’ after severe injury
Oligodendrocytes
Cells that form the lipid-rich sheath of myelin that wraps around some neurons to increase the speed at which information is transmitted by the neuron
In the PNS, these cells are called Schwann cells
White & grey matter
Areas of brain that contain myelin (bundles of axons) are called white matter, while regions of unmyelinated cell bodies are referred to as the grey matter
what is the neurovascular unit
Blood vessels in the brain are made up of endothelial cells, astrocytes, pericytes (capillaries), smooth muscle cells (arteries) and neurons
blood-brain barrier (BBB)
Endothelial cells of the brain express form tight junction proteins. These junctions allow the brain to create a physical barrier between the blood and the brain, called the blood-brain barrier (BBB)
This gives the brain a high degree of selectively, thereby protecting it against entry by potentially harmful substances in the blood
Where is cerebrospinal fluid found
Cerebrospinal fluid (CSF) is contained within the ventricles and in the subarachnoid spaces of the brain and spinal cord
Role of CSF
CSF provides buoyancy for the brain and cushion it against injury, as well as waste removal
How is CSF made
CSF is produced from filtered blood by the choroid plexus in the ventricles
