Test 3 - In Class Review
Clear fluid circulating brain/spinal cord that is produced by a network of capillaries in brain's ventricles, reabsorbed into extensions of granulatioarachnoid mater
CSF
CSF is produced by:
Choroid Plexus
- Mechanical protection (shock absorption)
- Chemical protection (neuron signalling)
- Circulation of nutrients and waste
- Themoregulation
CSF Functions
Networks of axons allowing communication between nerves
Plexuses
The plexuses:
- Cervical (head/neck)
- Brachial (arms/hands)
- Lumbar (back/legs)
- Sacral (pelvis/lower limbs)
- Coccygeal
The root that carries sensory info
Dorsal root
The root that carries motor info
Ventral root
Components of a reflex arc:
1. Sensory receptor
2. Sensory neuron
3. Integrating center
4. Motor neuron
5. Effector
This reflex makes a muscle contract, helps maintain posture/balance, monosynaptic
Stretch reflex
Reflex that causes quick withdrawl of a limb, several muscles contract, polysynaptic, ensures stability and coordination, triggers crossed extensor reflex
Flexor reflex
This reflex causes an autonomic response (move hand away from a hot surface)
Inborn reflex
Reflex that develops through experience (slamming the breaks while driving)
Learned reflex
This reflex occurs when spinal cord processes information (knee-jerk)
Spinal reflex
This reflex occurs in the brainstem (tracking eyes while reading)
Cranial reflex
Somatic reflex controls:
Skeletal muscles
Autonomic visceral reflex controls:
Smooth/cardiac muscles and glands
Proprioceptors in skeletal muscles that monitor changes in muscle length, have sensory nerves around muscle fibers, adjust tension during stretching/reduce over-stretching
Muscle spindles
Located at the tendon muscle junction, slow adapting, respond to muscle tension/reduce tension, triggers tendon reflex
Tendon Organs
Meninges:
Dura mater, arachnoid mater, pia mater
Delicate inner layer that suspends spinal cord via extensions
Dentate ligaments
H shaped, contains dendrites, cell bodies, unmyelinated axons and neuroglia
Gray matter
These horns contain cell bodies and axons of interneurons/sensory neurons
Posterior horns
These horns have clusters of motor neurons that send signals for movement
Anterior horns
These horns are only in thoracic/upper lumbar/mid sacral, have autonomic neurons controlling the heart
Lateral horns
Lower portion of the spinal cord, nerve roots angle downward, looks like horse hair
Cauda Equina
Sensory nerve for smell
Olfactory
Sensory neuron for vision
Optic
Motor nerve, moves eyeballs, adjust lens, constricts pupil
Oculomotor
Motor nerve, moves eyeballs (IV)
Trochlear
Mixed nerve, touch/pain/thermal sensations, controls chewing and middle ear muscle
Trigemal
Motor nerve that moves eyeballs (VI)
Abducens
Mixed nerve, taste/touch/pain/thermal, facial muscles and expressions, tears/saliva
Facial
Sensory nerve, hearing and equilibrium
Vestibulocochlear
Mixed nerve, taste/pain/thermal, swallowing and saliva
Glossopharyngeal
Mixed nerve, taste/touch/pain/thermal, throat/larynx, swallowing, vocals, coughing, respiration
Vagus
Motor nerve, moves head and pectoral girdle
Accessory
Motor nerve, controls speech and swallowing
Hypoglossal
Brainstem components
Medulla, pons, midbrain
Lobes:
Frontal, parietal, temporal, occipital
Located between the diencephalon and spinal cord
Brainstem
Regulates breathing, heart rate, blood pressure, located between pons and spinal cord
Medulla
Controls motor coordination, is a relay station between cerebral cortex and cerebellum
Pons
Maintains conciousness, heart rate/breathing, sleep cycle, pain perception
Reticular formation
Allows us to read/speak/write/think, largest part of brain, contains outer cerebral cortex, gray matter and cerebral fissures
Cerebrum
Cortex that processes sensory, motor, integrative info
Cerebral cortex
Are in each hemisphere of the brain, produce CSF
Lateral ventricles
Narrow cavity connecting the lateral ventricles
Third ventricle
Between brainstem and cerebellum, circulates CSF to brain/spinal cord
Fourth ventricle
Narrow channel connecting 3rd and 4th ventricles
Cerebral Aqueduct