Chapter 3 Flashcards
What are the different parts of brain anatomy?
- Horizontal plane - splits the brain in half horizontally
- Sagittal plane - splits the brain in half to the left and right hemisphere
- Coronal plane - splits the brain in half vertically
- Dorsal part - above the horizontal plane (superior) and back of the brain (posterior)
- Ventral - below the horizontal plane (inferior) and front of the brain (anterior)
- Lateral - Toward the side, away from the midline
- Medial - Toward the midline, away from the side
What are the different components of the spinal cord?
It is segmented with a sensory (they can have clusters of neurons called dorsal root ganglia (inside the CNS it is a nucleus)) and motor nerve on each side, with the entering dorsal roots carrying sensory information and the exiting ventral roots carrying motor information.
Describe the structure and functions of the autonomic
nervous system.
Its two parts are the sympathetic and parasympathetic nervous systems. The SNS is a network of nerves that prepare the organs for fight or flight, consisting of chains of ganglia just to the left and right of the spinal cord’s central regions. The PNS facilitates vegetative, nonemergency responses. It consists of the cranial nerves and nerves from the sacral spinal cord which have long preganglionic axons extend from the spinal cord to parasympathetic ganglia close to each organ. Shorter postganglionic fibers then extend from the parasympathetic ganglia into the organs themselves.
What are the major components of the hindbrain?
- Medulla - The head and the organs connect to the medulla and adjacent areas by 12 pairs of cranial nerves, which control automatic reflexes such as heart beating.
- The Pons - It also contains nuclei for several cranial nerves. It has axons from each half of the brain cross to the opposite side of the spinal cord so that the left hemisphere controls the muscles of the right side and vice versa
- Cerebellum - A structure with deep folds that control movement and balance/coordination. It also controls timing, and also to other cognitions such as learning depending on area.
What are the major components of the midbrain?
- Superior colliculus (side of the tectum) - important for vision
- inferior colliculus (other side of the tectum) - important for hearing
- Tegmentum (under the tectum)
- Substantia nigra - gives rise to a dopamine-containing pathway that facilitates readiness for movement.
What are the major components of the forebrain?
- Left hemisphere - controls muscles on the right side of the body
- Right hemisphere - controls muscles on the left side of the body
- Cerebral Cortex - outer portion of the brain
- Thalamus: the main source of input to the cortex
- Hypothalamus: Essential for control of eating, drinking, temperature control, and reproductive behaviors
- Amygdala: Part of a circuit that is central for evaluating emotional information, especially with regard to fear.
What are the differences of the laminae and columns of the cortex?
Laminae are layers of cell bodies parallel to the surface of the cortex. They vary in prominence from one part of the cortex to another. Columns, however, are cells perpendicular to the laminae which have similar properties to one another such as reacting the same to the same stimuli.
What are the four lobes of the cerebral cortex and their functions?
- Occipital - the main target for visual information. It has a primary visual cortex which helps with visual perception and imagery.
- Parietal - monitors the information about eye, head, and body positions and passes it on to brain areas that control movement.
- Temporal - important for auditory information and complex vision such as movement perception and facial recognition. The left temporal lobe is responsible for speech.
- Frontal - containing the primary motor cortex and the prefrontal cortex. It has a precentral gyrus which is important for fine movements.
What is the binding problem?
The question of how various brain areas produce a perception of a single object. How do we bind a bunch of information into one, singular experience?
Why is the binding problem important theoretically?
It concerns what we perceive and how it can change as long as the right stimuli are there.
What are the four major methods for studying the relationship between brain activity and behavior?
- Examining the effects of brain damage
- Examining the effects of stimulating a brain area
- Recording brain activity during a behaviour
- Correlating brain anatomy with behaviour
What are the methods for correlating brain anatomy with behaviour?
- Phrenology - relating skull anatomy to behavior > foundation to the idea that damages to the brain lead to abnormal behaviour
- Computerized axial tomography (CAT scan) - a dye is injected into the blood to increase contrast in the image. The person’s head is then placed into a scanner with X-rays passing through to be recorded by detectors on opposite sides and construct images of the brain
- Magnetic resonance imaging (MRI) - Any atom with an odd-numbered atomic weight has an axis of rotation. An MRI device applies a magnetic field to align all the axes of rotation, and then tilts them with a brief radio frequency field. When the radio frequency field is turned off, the atomic nuclei release electromagnetic energy as they relax and return to their original axis. By measuring that energy, MRI devices form an image of the brain
What are the different nervous systems?
- Central Nervous System - the brain and spinal cord
- Peripheral Nervous System - connects the brain and spinal cord to the rest of the body
- Somatic Nervous System - a part of the PNS which consists of the axons conveying messages from the sense organs to the CNS and from the CNS to the muscles
- Autonomic Nervous System - a part of the PNS which controls the body’s organs.
- Enteric Nervous System - a part of the ANS which controls the digestive system
Where is grey matter and white matter in the spinal cord?
There is grey matter in the center of the cord, that is densely packed with cell bodies and dendrites, with many neurons from the gray matter of the spinal cord sending axons to the brain or to other parts of the spinal cord through the white matter, containing myelinated axons.
What is the difference between PNS and SNS?
PNS can be related to and are generally the opposite of SNS in terms of their effect on bodily functions. The parasympathetic nervous system’s axons release the neurotransmitter acetylcholine onto the organs. Most sympathetic nervous system axons release norepinephrine, although a few, such as those onto the sweat glands, use acetylcholine.
What is the thalamus?
A pair of structures (left and right) in the center of the forebrain. Many nuclei of the thalamus receive their input from a sensory system, such as vision, process it in various ways, and transmit information to an area of the cerebral cortex - except for olfactory input.
What is the hypothalamus?
A small area just ventral to the thalamus which has widespread connections with the rest of the brain. It affects motivated behaviours - partly through nerves and partly by releasing hormones, the hypothalamus conveys messages to the pituitary gland
What is the Basal Ganglia?
A group of subcortical structures lateral to the thalamus, include the caudate nucleus, the putamen and the globus pallidus. It affects movement and are critical for gradual learning of skills and habits.
What is the basal forebrain?
The nucleus basalis receives input from the hypothalamus and basal ganglia and sends axons that release acetylcho- line to widespread areas in the cerebral cortex, which is key for arousal, wakefulness and attention.
What is the hippocampus?
A large structure between the thalamus and the cerebral cortex which is critical for memories and monitoring where you are and where you are going.
What are the ventricles?
Four fluid-filled cavities within the brain. Cells called the choroid plexus along the walls of the four ventricles produce cerebrospinal fluid (CSF), a clear fluid similar to blood plasma. CSF cushions the brain against mechanical shock and provides buoyancy.
What does the parietal lobe have?
It has a postcentral gyrus which has 4 bands that detect light, deep and a combination of pressure for touch
What does the prefrontal cortex do?
It has 3 regions with different functions. The posterior portion is associated mostly with movement. The middle zone pertains to cognitive control, emotional reactions, and certain aspects of memory. The anterior zone of the prefrontal cortex is important for making decisions, evaluating which of several courses of action is likely to achieve the best outcome.
What are some methods for examining the effects of brain damage?
- Studying victims of stroke etc. - looking at their changes in behaviour in relation to the damage in a part of the brain
- Ablation - the removal of a brain area, generally with a surgical knife.
- Lesion - creating damage in small, tiny structures under the surface of the brain. Done via a stereotaxic instrument, a device for the precise placement of electrodes in the brain that cause damage
- Gene knockout - directs a mutation to a gene that regulates one type of cell, transmitter, or receptor.
- Transcranial magnetic stimulation - the application of magnetic stimulation to a portion of the scalp with stronger stimulation inactivating the neurons, producing a “virtual lesion.” This can be made active again.
What are the methods used to examine the effects of stimulating a brain area?
- Stimulating electrodes - inserting an electrode into an animal’s brain and delivering brief, mild currents to an area.
- Optogenetic simulation
What are the methods used to record brain activity during behaviour?
- Record from electrodes in brain which activate from brain activity
- Electroencephalograph (EEG) - Records electrical activity of the brain through electrodes, ranging from just a few to more than a hundred, attached to the scalp
- Evoked potentials - the same device used for an EEG that records brain activity in response to a stimulus
- Magnetoencephalograph (MEG) - similar to an EEG but measures the faint magnetic responses generated by brain activity
- Positron emission tomography (PET) - provides a high-resolution image of activity in a living brain. glucose in the person is tagged with radioactive atoms. When it decays in certain brain areas that are activated, it releases a positron that collides with a nearby electron, emitting two gamma rays in opposite directions. Detectors around the head of the person catch the gamma rays and a system measures the distance and time to find the midpoint between them.
- Functional magnetic resonance imaging (fMRI) - they record the energy released by water molecules after removal of a magnetic field based on hemoglobin. When the brain uses more oxygen, the percentage of hemoglobin decreases and fMRI detects that change.
