Lecture 9 - Nervous System #2 Flashcards
What makes up the brain stem
- > pons
- > medulla oblongata
- > midbrain
What is the cerebrum
- > location of conscious thought
- > makes you, you -
> formed from the telencephalon
What are the functional areas of the cerebrum
Motor (efferent) areas
- > control voluntary motor functions
Sensory (afferent) areas
- > provide conscious awareness of sensation
Association areas
- > intergrade and store information
gyri
- > the surfaces of the cerebrum folds into elevated called gyri
- > adjacent gyri are separated by grooves called fissures
telencephalon
- > makes up the cerebrum, the telencephalon refers to the region of the brain that includes the cerebral cortex and several subcortical structures including the hippocampus and basal ganglia.
What separates the right and left cerebral hemispheres
- > the longitudinal fissure
- > though they are separate, they are still connected by a band of white matter axons (corpus callosum) which allow communication between the two hemispheres
List all of the lobes of the brain and what do they control
Frontal - > voluntary motor control; contains prefrontal cortex which controls intelligence, personality, etc.
Occipital - > vision and visual memory
Parietal - > general sensory functions
Temporal - > hearing and smell
Insula - > (hidden under other lobes) memory and taste
What are the sections of the brain which are associated with speech association
Broca’s area - > left frontal lobe; language production
Wernicke’s area - > left temporal lobe; processing of words heard
- > both areas are connected by a group of nerve fibres called arcurate fasciculus
Humonculus
a neurological map of the outer layer of the brain which is divided into sections, each one responsible for a specific function i.e. moving your mouth
Diencephalon
- > “inner brain”
- > encloses third ventricle made up of 3 paired structures
- > thalamus
- > hypothalamus
- > Epithalamus
Thalamus main function/ purpose
- > sensory relay station (except scent)
- > sorts and relays information to be sent to cerebral cortex
Hypothalamus function/ purpose
- > controls overall body homeostasis i.e. body temp, food and water intake, sleep-wake schedule
Epithalamus function/ purpose
- > houses the pineal gland which secretes melatonin, a hormone which helps regulate day-night cycle
- > forms the roof of the third ventricle
functions of the midbrain, pons and medulla oblongata
Midbrain - > visual and auditory reflex centre
Pons - > relays info from cerebrum to cerebellum, helps with respiration
Medula Oblongata - > sensory and visceral control centres (pain, heart rate, vomiting)
Explain the limbic system
- > region of the brain where cerebral cortex meets the subcortical structures
- > associated with the brains pleasure centre
- > functions in learning, motivation, memory and emotion
- > made of of many structures (hippocampus, hypothalamus, and amygdala)
explain the Hippocampus
- > R/L hippocampus
- > responsible for learning, special orientations, navigation, spacial memory
- > makes short term memory into longterm memory (link to Alzheimers)
- > emotional responses to stimuli
Explain the amygdala
- > memory; stores and interprets emotion and mood
- > links to psychopaths (amygdala is smaller with less function)
- > in charge of memory
Explain the science of addiction
- Addictive behaviour floods the the pleasure centre of the brain with dopamine (10X)
- Hippocampus responses to dopamine by recording memories and the amygdala creates a conditional response to the stimulus associated w/ addiction
- Repeated exposure to dopamine causes the pleasure centre to communicate with the planning area of the prefrontal cortex to see out addiction (cravings)
- Prolonged addiction causes the brain to reduce the dopamine receptors so patient must feed addiction to increase/ maintain that dopamine rush
Cerebellum
- > input from cortex, brainstem, and sensory receptors allows smooth and coordinated movement
- > cerebellar hemispheres are connected by vermis
- > encases the fourth ventricle
- > each hemisphere contains 3 lobes
folia
- > transversely orientated gyri
arbor vitae
- > tree- like pattern of cerebellar white matter
- > very important for life
spinal cord functions
- a pathway for sensory input and motor impulses
- responsible for reflexes, which are the quickest response to stimuli
spinal cord anatomy
- > grey matter in the centre, white matter around the edge
- > has dorsal and ventral horns
- > R/L horns are connected by a thick band of grey matter called grey commissure
- > central canal is hollow and filled with cerebrospinal fluid
Name the spinal enlargements and why do they exist?
Cerebral and lumbosacral enlargements are enlarged portions of the spinal cord which is the intersection point where the the axons controlling upper limbs meet (theres alot)
Describe the length of the vertebral column in reference to the spinal cord
- > spinal cord is shorter than the vertebral column (only runs 2/3 of its length) because it moves when you bend over
- > it ends at around L1-L2
conus medularis
the “end” of the spinal cord, which is tapered
cauda equina
group of axons which project from the conus medularis
filum terminal
found within the cauda equina, this thin strand of pia mater helps anchor the conus medularis to the cocyx
what is a lumbar puncture
also known as a spinal tap, this procedure is performed by getting a patient to bend over, expanding the space between L3-L4, and extracting cerebrospinal fluid for sampling (meningitis test)
what are Dermatomes
areas of the skin supplied by one single spinal nerve; maps out skin sensation
cranial nerves
- > 12 pairs of nerves associated with the brain
- > two attached to forebrain, rest to brain stem
*Oh Once One Takes The Anatomy Final Very Good Vacations Are Heavenly*
Label the cranial nerves
Cranial Nerve I
- > Olfactory Nerve
- > sensory nerve
- > fibres pass through cribiform plate in skull embeded in nasal cavity
- > sense of smell
Cranial Nerve II
- > Optic nerve
- > sensory nerve
- > criss-cross before entering the brain at the optic chiasm
- >sight
Cranial Nerve III
- > Ocularmotor nerve
- > motor nerve
- > moves eyebals
- > controls superior, inferior and medial rectus, inferior oblique, and levator palpebrae superioris
Cranial Nerve IV
- > Trochlear Nerve
- > motor nerve
- > controls the superior oblique muscle with a pulley called the trochlea
Cranial Nerve V
- > Trigeminal Nerve
- > mixed nerve
- > three branches innervate sensory fibres to the face and motor fibres for chewing
- > Ophthalmic branch
- > Maxillary branch
- > Mandibular branch
Cranial Nerve VI
- > Abducens Nerve
- > mixed nerve
- > intervates the lateral rectus of the eye
Cranial Nerve VII
- > Facial Nerve
- > mixed nerve
- > sense of taste for anterior 2/3 of tongue
- > five branches control muscles of facial expression
*Temporal
*Zygomaticus
*Buccal
*Mandibular
*Cervical
Cranial Nerve VIII
- > vestibulocochlear nerve
- > mixed but very little motor function
- > mostly sensory for hearing and equilibrium
Cranial Nerve IX
- > glossopharyngeal nerve
- > mixed nerve
- > intervates posterior 1/3 of the tongue for the perception of taste
- > tongue and pharyx muscles for swallowing
Cranial Nerve X
- > Vagus nerve
- > mixed nerve
- > connects and intervates all internal organs (heart,lungs ect), with few exceptions
- > last thing you want damaged
Cranial Nerve XI
- > Accessory nerve
- > motor nerve
- > intervates trapezius and sternocleiomastoid muscles
Cranial Nerve XII
- > hypoglossal nerve
- > motor nerve
- > intervates intrinsic and extrinsic tongue muscles
What is a plexus
- > groups of spinal nerves which are named after their vertebral location
- > Plexuses are responsible for coordinated movemnet of a body region
Cervical plexus
- > located on the lateral sides of the neck (cervical vertebrae)
- > function is to innervate the head, neck and shoulders
- > contains the phrenic nerve
Phrenic nerve
this nerve travels down the neck and through the thorasic cavity to innervated the diaphragm and allows you to breath
brachial plexus
- > innervates the upper limbs
- > extends laterally below the cervical plexus and down the arm
- > includes a lateral radial nerve, a medial ulnar nerve and a central median nerve
lumbar plexus
- > innervates the lower limbs
- > extends laterally from the lumbar vertebrae and down the anterior surface of the leg
- > the important branch of the lumbar plexus is the femorial nerve, whihc controls the anterior thigh muscles (hip flexors)
Sacral Plexus
- > innervates the buttocks, genitals, posterior thigh, leg and foot
- > emerges from the sacral foramen and runs down the length of the leg
- > contains the sciatic nerve (largest and longest nerve) which controls part of the thigh, the leg and the foot
corpus callosum
band of white matter axons which connects both hemispheres of the cerebrum and allows for communication between the two
