Module 13 Nervous System Flashcards
What are the neuroglia?
Support of cells of the nervous system and work to enhance performance of the nervous system
Where are oligodendrocytes and what do they do form?
Found in the CNS and form the myelin sheath in the brain and spinal cord
Where are astrocytes found and what do they form?
They extend through the brain tissue; help form the blood brain barrier, attach neurons to blood vessel; and provide structural support
Where are Schwann cells found and what do they form
Form the Mylan sheath around nerves in the PNS; forms neurilemma
What are the functions of the blood brain barrier
Exist throughout the brain allows small molecules today if he’s across the brain and blocks larger molecules
Sensory (afferent) neurons
Detector stimuli - then transmit info about he stimuli to the CNS
Interneurons
Found only in the CNS, connect the incoming sensory pathways without going motor pathways
Motor (Efferent) neurons
Relay messages from the brain to the muscle or gland cells
Membrane potential
When ions with opposite electrical charges are separated by a membrane
Polarized
When I member and has an excess of positive ions on one side and an excess of negative ions on the other side
Cervical spine innervates
Chest, head, neck, shoulders, arms, hands and diaphragm
Thoracic spine innervates
Intercostal muscles of the rib cage, the abdominal muscles and back muscles
The lumbar spinal nerves innervates
Lower abdominal wall and parts of the thighs and legs
This sacral spine innervates
Thighs, but ox, skin of the legs and feet and anal and genital region’s
Cauda equina
Andel of nerve roots
Ascending tracts
Convey sensory signals up the spinal cord to the brain
Descending tracts
Docs motor impulses down the spinal cord to the skeletal muscles
Autonomic (visceral) reflexes
Involve secretion from glance or of the contraction of smooth muscle (such as pupil dilation).These reflexes are governed by autonomic neurons
Somatic reflexes
Involve contraction of a skeletal muscle after being stimulated by a somatic motor neuron. Somatic reflexes protect the body against harm and maintain posture
What does the thalamus do
It’s a gateway for nearly every sensory impulses travelling to the cerebral cortex. Processes and filters his impulses transmitting some but not all. Relays messages regarding certain complex movements; involved in memory and emotion
What does the hypothalamus do
Controls the autonomic nervous system, responsible for hunger, thirst, temperature regulation, controls pituitary gland, is involved in multiple emotional responses such as fear anger pleasure and aggression
What is the role of the hippocampus
Converting short term memory to long-term memory and is crucial for memory and learning
Amygdala
Stores and can recall emotions from past events
Olfactory (I) cranial nerve
Carry the impulses for the sense of smell
Optic (II) cranial nerve
Lead from the eyes to the brain they carry sensory impulses for site
Oculomotor (III) cranial nerve
Arise from the midbrain and travel into the eye Orbitz. These are mostly motor nerves and raise the eyelids, rotate the eye, just the amount of light that enters the eye and adjust focus
Trochlear (IV) cranial nerves
Are the fourth and smallest of the cranial nerves, they control eye-movement
Trigeminal (V) cranial nerves
Largest of the cranial nerves, they are a mixed nerves and are responsible for sensory input from the face and motor enervation to muscles of mastication (chewing)
Abducens (VI) cranial nerves
Originate from the Ponds and they abduct the eyes
Facial (VII) cranial nerves
Carry motor and pauses for facial expressions and carry motor impulse is to tear and salivary gland’s. Sensory fibres carry impulses from taste receptors on interior tongue
Vestibulocochlear (VIII) cranial nerves
Originate from that year and these nerves are sensory and have two branches. The cochlear branch which is responsible for hearing and the vestibular branch which is responsible for balance
Glossopharyngeal (IX) cranial nerves
Are associated with the tongue and the pharynx
Vagus (X) cranial nerve
Only cranial nerves that extend from the medulla oblongata and travel through the neck to the thorax and abdomen.These mixed nerves carry sensory impulses from the throat, esophagus, thorax and abdomen to the brain. The motor fibres supply the heart and many smooth muscles and glands
Hypoglossal (XII) nerves
Pass into the tongue and these are mostly motor and they move the tongue in speaking, chewing and swallowing
Accessory (XI) cranial nerves
Originate from the medulla oblongata and spinal cord. The cranial branches join a Vagus nerve to carry impulses to the muscles of the throat. The spinal branch supplies motor impulses to the muscles of the back and neck
Dura mater
Outer protective layer of the meninges
What does the brain stem consist of?
Midbrain, pons varolii, medulla oblangata
Midbrain
Contains tracts that relaysensory and motor impulses. It also contains centres for auditory and visual reflexes as well as clusters of neurons and integral to muscle control
Pons
Contains trucks that conveys signals to and from different parts of the brain. Several cranial nerves arise from this area; they include cranial nerves trigeminl V, abducens VI, facial VII, vestibulocochlear VIII
Medulla oblongata
I touch is the brain to the spinal cord, besides relaying Sensorimotor signals between the brain and the spinal cord, the medulla contains nuclei that perform functions vital to human life these include the cardiac centre which regulates the heart rate, the vasomotor centre which controls blood vessel diameter which in return affects blood pressure and two respiratory centres which regulate breathing
