Chapter 13 and 14 Flashcards
Where is the arachnoid mater
Under the Dura Mater
What is the Dura Mater
The most superficial brain layer, thick/tough layer firmly attached to the inner layer of the skull.
It is divided into the PERIOSTEAL LAYER and the MENINGEAL LAYER
Subarachnoid space
Inferior to the arachnoid mater
Contains many blood vessels and the cerebrospinal fluid that feeds the brain
Pia Mater
Thin, highly vascular layer that closely adheres with the brain.
Provides most of the blood supply to the brain and selects which blood constituents can enter the brain.
Forms the Blood Brain Barrier, because the capillary walls block certain substances from entering the brain
Cerebrospinal fluid
Clear liquid that fills ventricles and canals
Brain produces and absorbs @ 500ml/day
150ml circulate at any one time and takes @ 6 hours to cycle through
What are the functions of the CSF?
1) buoyancy- floats brain so it is neutrally buoyant
2) protection- cushions brain from hitting inside of skull
3) chemical stability- rinses away wastes, provides optimal chemical environment for neuronal signaling
Brain damage due to interrupted blood flow
@ 10 seconds- loss of consciousness
@ 1-2 min- impairs brain function
@ 4 min- irreversible brain damage
Blood Brain Barrier (BBB)
Highly permeable to H2O, glucose, and lipid soluble substances (alcohol, nicotine, caffeine, anesthetics)
In places with no BBB, the brain monitors fluctuations in pH, osmolarity
Limbic System
Center of emotion and learning
Controls emotion and memory
Controls gratification and aversion
How many cranial nerves?
12
Provides sense of smell
Olfactory Nerve
Provides Vision
Optic Nerve
Provides some eye movement, opening of eyelid, construction of pupil, focusing
Oculomotor Nerve
Provides eye movement
Trochlear Nerve
Main sensory nerve to face
Trigeminal Nerve
Provides eye movement
Abducens Nerve
Innervates facial muscles and provides facial expressions
Facial Nerve
Provides hearing and sense of balance
Auditory (Vestiblulocochlear) Nerve
Provides control over swallowing, salivation, gagging, sensations from posterior 1/3 of tongue, control of BP and respiration
Glossopharyngeal Nerve
Provides swallowing, speech, regulation of viscera
Vagus Nerve
Provides swallowing, head, neck, and shoulder movement
Accessory Nerve
Provides tongue movements of speech, food manipulation and swallowing
Hypoglossal Nerve
What are sensory tracts?
Ascending (to the brain) pathways carry conscious and unconscious sensations
Spinothalamic tract
Anterolateral system
Carries pain, temperature, light touch, pressure, tickle, and itch sensations
Spinomesencephalic tract
Carry action potentials from cutaneous pain receptors
Contributes to eye reflexes
Dorsal column/medial- lemniscal system
Carries sensations of 2 point discrimination, proprioception, pressure, and vibration
Primary neurons
First-order neurons
Enter the spinal cord and ascend to the medulla where they synapse with secondary neurons
Secondary neurons
Second-order neurons
Cross over and project to the thalamus
Tertiary neurons
Third-order neurons
Extend from the thalamus to the somatic sensory cortex
Trigeminothalamic tract
Carries sensory information from the face, nose, and mouth
Spinocerebellar tracts
Carry unconscious proprioception to the cerebellum from the same side of the body
Long-term memory
Declarative memory: retention of events and facts
Procedural memory: retention of motor skills
Short-term memory
Few seconds to a few hours
Easily forgotten if we stop mentally reciting it or if we get distracted
Hold something in mind long enough to carry out an action
Immediate memory
Hold something in mind for a few seconds to get a feeling for the flow of events
Telencephalon
Cerebrum
Diencephalon
Thalamus, hypothalamus
Mesencephalon
Midbrain
Mesencephalon
Pons, cerebellum
Rhombencephalon
Contains the medulla oblongata
Myelencephalon
Medulla oblongata
Regulates heart rate and blood vessels
Regulates breathing
Vomiting, swallowing, sneezing, coughing, hiccuping
Part of the sensory pathway for taste, hearing and equilibrium
Cerebellum
Equilibrium and balance
Metencephalon
Pons
Part of the voluntary motor control pathway
Helps with equilibrium and respiratory control
(Metencephalon)
What connects the spinal cord to the cerebrum?
Brainstem
Consists of the medulla oblongata, pons, and midbrain
What is the pathway for ascending and descending nerve tracts called?
Medulla oblongata
What structure relays information between the cerebrum and the cerebellum, and is the site of reflex centers?
Pons
What structure is part of the auditory pathway, and lies in the middle of the brain?
Midbrain
What is the function of the Reticular Formation?
It controls cyclic activities, like the sleep-wake cycle
What are the functions of the cerebellum?
Control muscle movement and tone
Governs balance
Motor skills
What are the functions of the Thalamus?
Major sensory relay center
Influences mood and movement
Hypothalamus
Controls homeostasis
Regulates endocrine function (hormones)
What are the functions of the cerebrum?
Controls conscious perception, thought, and conscious motor activity
Basal nuclei
Part of cerebrum
Controls muscle activity and posture, largely inhibits unintentional movement when at rest
Limbic system
part of the cerebrum
Autonomic response to smell, emotion, mood, memory, and other such functions
What is decussation?
Crossing to the opposite side of the body
i.e. Each half of the brain controls the opposite half of the body
Superior colliculi
Reflex movements of theHead eyes and body toward visual, auditory, or tactile stimuli such as loud noises, flashing lights, or startling pain; they receive touch and auditory input
Inferior colliculi
Involved in hearing, and are an integral part of the auditory pathways in the CNS
What is the folia?
The ridges on the cerebellum
