Chapter 14 Flashcards
What does rostral mean?
Toward the forehead
What does caudal mean?
Toward the spinal cord
What sex has a larger brain?
Men
Regions of the brain?
Cerebrum, cerebellum, and brainstem
How much volume is the cerebrum?
83% of brain’s total volume
What separates the cerebral hemispheres from one another?
Longitudinal fissure
What are gyri?
Thick folds
What are sulci?
Shallow grooves
What are fissures?
Deep grooves
What connects the cerebral hemispheres?
Corpus callosum
What separates the cerebrum and cerebellum?
Transverse cerebral fissure
What regions of the brain have gyri and sulci?
Cerebrum and cerebellum
How much volume is the cerebellum?
10%
What are the regions of the brainstem?
Midbrain (or mesencephalon), pons, and medulla oblongata
Where is gray matter in the brain?
Outside, forming a cortex
Where is gray matter in the spinal cord?
Inside the white matter
What is gray matter made up of?
Neurosomas, dendrites, and synapses
What is white matter made up of?
Tracts of myelinated axons that connect parts of brain to one another and to spinal cord
What are meninges?
Connective tissue membranes enveloping the brain and spinal cord
How is the dura mater of the cranium different from that of the spinal cord?
It adheres to the cranial bones, unlike in the spinal cord
What do meninges do for the brain?
Protect it, and provide structural framework for its arteries and veins
What are the layers of the cranial dura mater?
Outer periosteal and inner meningeal dural sheath
What separates the layers of cranial dura mater?
Dural sinuses, which collect blood circulating through the brain
Does the pia mater in the cranium adhere/sink into sulci?
Yes, sometimes
What is meningitis?
Inflammation of the meninges, particularly pia and arachnoid
What are the ventricles of the brain?
4 internal chambers - 2 lateral, and 3rd and 4th
What is the interventricular foramen?
A tiny pore which connects to the third ventricle from the lateral ventricle
What is the third ventricle?
A narrow medial space beneath corpus callosum
What is the cerebral aqueduct?
From the third ventricle, running through midbrain, connecting to the fourth ventricle
What is the choroid plexus?
A spongy mass of blood capillaries on the floor of each brain ventricle
What are ependymal cells?
The type of neuroglia that produces cerebrospinal fluid
What does CSF do?
Bathe the external surface of the CNS, fill the canals and ventricles of the CNS
Functions of the CSF?
Buoyancy, protection, regulation of chemical environment of nervous tissue
How much blood does the brain need?
15% of the body’s total
What happens if blood supply to brain is interrupted for 10 seconds?
Loss of consciousness
What happens if blood supply to brain is interrupted for 1-2 minutes?
Impairment of neural function
What happens if blood supply to brain is interrupted for 4 minutes?
Irreversible brain damage
What does the brain barrier system do?
Regulate what substances can get into the brain tissue fluid
What are the points of entry to the brain?
Blood capillaries in the brain tissue, and capillaries of the choroid plexus
What is the choroid plexus?
A network of capillaries lined by specialized cells (like ependymal cells)
What is the blood-CSF barrier?
Tight junctions between ependymal cells of choroid plexus
What is the brain barrier system highly permeable to?
Oxygen, carbon dioxide, alcohol, caffeine, nicotine, and anesthetics
What may allow pathogens to enter the brain tissue?
Trauma and inflammation of brain barrier system
What are circumventricular organs?
Places in the 3rd and 4th ventricles where the barrier is absent, and blood has direct access to the brain
Where is the medulla oblongata?
Most inferior part of brainstem
What does the medulla oblongata do?
Connect brain and spinal cord, relay info to the cerebrum, regulate autonomic visceral functions such as heart rate, blood pressure, digestion, etc
What are pyramids?
Ridges on anterior surface of medulla oblongata that contain corticospinal tracts for motor signals
What cranial nerves are in the medulla oblongata?
VIII (partially), IX, X, and XII
What are olives?
Prominent bulges on medulla oblongata
Where is the pons located?
Rostral to medulla oblongata
What cranial nerves are in the pons?
V, VI, VII, and VIII
What does reticular formation in pons do?
Sleep, respiration, posture
Where is the midbrain?
Connecting hindbrain to forebrain, rostral to pons
Cranial nerves of midbrain?
CN III and CN IV, aka oculomotor and trochlear
What do the superior colliculi do?
Help w/ visual reflexes
What do the inferior colliculi do?
Receive signals from inner ear
What do the cerebral peduncles do?
Anchor cerebrum to brainstem
What connects the 2 hemispheres of the cerebellum to each other?
Vermis
What is the reticular formation?
Web of gray matter running vertically through all levels of the brainstem
What does the reticular formation do?
Somatic motor control, cardiovascular control, pain modulation, sleep and consciousness, and habituation
What does the cerebellum do?
Contains more than half of all brain neurons, and helps w/ motor coordination, posture, and equilibrium. Fine-tunes movements both conscious and subconscious
Cognitive functions of the cerebellum?
Comparing textures of objects, perceiving space, recognizing objects from different views, keeping judge of elapsed time, judging pitch of tones, planning, scheduling, emotion control
What are folia?
Folds in the superficial cortex of gray matter covering the cerebellum
What is the amygdala responsible for?
Expressing emotional feelings
What region does the pineal gland belong to?
Epithalamus
What does bacteria and white blood cells in the CSF mean?
Meningitis
Degeneration of what neurons leads to muscle tremors?
Substantia nigra
What are the motor cranial nerves?
Trochlear, abducens, hypoglossal, and accessory
Vision association is what lobe?
Occipital
If you lack sensitivity in your right hand, what part of your brain is affected?
Postcentral gyrus in left parietal lobe
Portions of brainstem in order from rostral to caudal?
Diencephalon, mesencephalon, pons, medulla oblongata
What region of the brain does the diencephalon belong to?
The forebrain
What makes up the diencephalon?
The thalamus (left and right) and the hypothalamus
What does the thalamus do?
Bring in sensory information and help process it
What does the hypothalamus do?
Control emotions, hormone function, and autonomic functions. Feelings of hunger, thirst, body temp, and circadian rhythm
What is attached to the hypothalamus?
The pituitary gland
What does the mesencephalon do?
Process what you see and hear and control reflexes triggered by those stimuli
What does the pons do?
Connect cerebellum to brain stem to process and relay info and help w/ somatic and visceral motor control. Specifically respiratory rhythm
What is the gap between the 2 layers of dura mater called?
Dural sinus
How is the pia mater attached to the brain?
Held down by astrocytes
What are dural folds?
Areas where the dura mater stretches into the cranial cavity, providing support
What is the choroid plexus?
An area in each ventricle of the brain that produces CSF
What do ependymal cells w/ microvilli do in the brain?
Secrete CSF into the ventricles and remove waste from the CSF
What supplies blood to the brain?
Carotid arteries and vertebral arteries
How does blood leave the brain?
Via jugular vein
What separates the CNS neural tissue from general circulation?
Blood brain barrier
What makes up the blood brain barrier?
Endothelial capillary cells connected by tight junctions
Purpose of tight junctions in BBB?
They don’t allow material to diffuse between endothelial cells, besides lipid soluble ones
How can lipid soluble things reach the brain?
By diffusing into the interstitial fluid of the brain and spinal cord
How would larger molecules cross capillary walls of the brain?
Active or passive transport
What do neurons need to function?
Glucose, so endothelial cells always allow it to pass
What are the centers of the medulla oblongata?
Cardiovascular center and respiratory rhythmicity center
What is the cerebellum?
An automatic processing center
Functions of the midbrain?
Integrate visual info w/ other sensory output. Allow you to respond to visual and auditory stimuli w/ reflex responses. As well as maintain consciousness
Components of diencephalon?
Epithalamus, thalamus, and hypothalamus
Components of epithalamus?
Pineal gland
What does the pineal gland do?
Secrete melatonin
Where is outer layer of dura mater?
Fused to the periosteum
What is oxytocin?
Secreted by hypothalamus, stimulates smooth muscle contractions in uterus and stimulates mammary glands to release milk
What does the limbic system do?
Link conscious intellectual functions w/ unconscious and autonomic functions. Establish emotional states and control memory storage and retrieval. Motivation and aversion
General function of cerebrum?
Conscious thoughts, intellectual function, processes somatic, sensory, and motor information. Also subconscious control of skeletal muscle tone
What are association fibers?
Axons of white matter; interconnect cerebral cortex w/ inside of cerebral hemisphere
What are commissural fibers?
Axons of white matter; interconnect and allow communication between cerebral hemispheres. EX: corpus callosum and anterior fissure
What are projection fibers?
Axons of white matter; connect cerebral cortex to brainstem, cerebellum, diencephalon, and spinal cord
What are basal nuclei?
Masses of gray matter lateral to lateral ventricles that process sensory info and motor commands outside of our awareness
What make up the basal nuclei?
Caudate nucleus, lentiform nucleus, claustrum, and amygdaloid body
What does the caudate nucleus do?
Subconscious adjustment of voluntary motor commands
What does the lentiform nucleus do?
Subconscious adjustment of voluntary motor commands
What does the claustrum do?
Subconscious processing of visual info
What does the amygdaloid body do?
It’s a part of the limbic system so it helps w/ emotions and memories
What is an EEG?
Recording of electrical activity of brain or brainwaves
What are alpha waves?
Electrical waves in brains of resting adults
What are beta waves?
Electrical waves in brains of people concentrating intensely
What are theta waves?
Electrical waves in brains of children and agitated adults
What are delta waves?
Electrical waves in brains of people in deep sleep
What does the brainstem as a whole do?
Process info between the spinal cord and the cerebrum or cerebellum
What role do astrocytes play in the BBB?
They release chemicals that control the permeability of the endothelial cells that form the tight junctions
What does the frontal lobe of the cerebrum do?
Motor control, problem solving, speaking
What does the parietal lobe of the cerebrum do?
Touch perception, body orientation, sensory discrimination
What does the temporal lobe do?
Auditory processing, understanding speech, memory retrieval
What does the occipital lobe do?
Sight, visual reception and interpretation
What are the special sensory cortexes of the cerebrum?
Visual, auditory, olfactory (smell), and gustatory (taste)
What is the speech center?
Area of cerebrum responsible for coordinating vocalization functions
What does the prefrontal cortex do?
In frontal lobe; it integrates info from sensory areas and performs associated intellectual abilities
What does the left hemisphere of the cerebrum do?
Reading, writing, decision making, speech, language
What does the right hemisphere of the cerebrum do?
Control the senses, and recognition of faces and vocal inflections
What is an EEG?
A way to monitor electrical activity of brain
