Chapter 3 - Anatomy & Research Methods & Module 4.3 - Plasticity after Brain Damage Flashcards
What is the central nervous system? (CNS)
The brain and spinal cord
What is the peripheral nervous system (PNS)?
Connects the brain and spinal cord to the rest of the body.
What is the somatic nervous system?
Part of the PNS, consists of the axons conveying messages from the sense organs to the CNS and from the CNS to the muscles.
What is the autonomic nervous system?
Part of the PNS - controls the heart, intestines and other organs.
Define dorsal
Toward the back and away from the stomach side. The top of the brain is dorsal.
Define ventral
Toward the stomach
Define anterior
Toward the front end
Define posterior
Toward the rear end
Define superior
Above another part
Define inferior
Below another part
Define lateral
Toward the side - away from the midline
Define medial
Toward the midline
Define proximal
Located close (approximate) to the point of origin or attachment
Define distal
Located more distant from the point of origin
Define ipsilateral
On the same side of the body
Define contralateral
On opposite sides of the body
Define coronal plane
Frontal place - brain structure as seen from the front
Define sagittal plane
As seen from the side
Define horizontal plane
As seen from above
What is the spinal cord
The spinal cord is part of the CNS and is located in the spinal column. It communicates with all the sense organs and muscles except of the head. Entering dorsal roots carry sensory information and exiting ventral roots carry motor information.
Cell bodies of sensory neurons are in clusters of neurons outside the spinal cord, called the dorsal root ganglia. Cell bodies of motor neurons are inside the spinal cord.
What does gray matter contain?
Cell bodies and dendrites. Many neurons from the gray matter send axons to the brain or other parts of the spinal cord through the white matter, containing myelinated axons.
What does the autonomic nervous system consist of?
Neurons that receive information from and send information to the heart, intestines and other organs. It consists of the parasympathetic and sympathetic nervous system.
What is the sympathetic nervous system?
A network of nerves that prepare the organs for vigorous activity, consists of chains of ganglia just to the left and right of the spinal cords central regions (thoracic and lumbar areas).
What does the sympathetic nervous system do?
It prepares organs for flight or fight responses. It increases breathing, increases heart rate, and decreases digestive activity. The sweat glands, adrenal glands, muscles that constrict blood vessels and erect hairs on the skin all have sympathetic inputs.
What does the parasympathetic nervous system do?
Facilitates vegetative non-emergency responses. It decreases heart rate, increases digestive activity and sexual arousal. It consists of the cranial nerves and nerves from the sacral spinal cord. Long preganglionic axons extend from the spinal cord to parasympathetic ganglia close to each internal organ. Shorter postganglionic fibres extend from the ganglia into the organs.
How do parasympathetic and sympathetic axons work?
Parasympathetic axons release acetylcholine onto the organs. The sympathetic axons release norepinephrine.
What is the hindbrain?
It consists of the medulla, pons, midbrain and certain central structures of the forebrain.
What is the medulla?
The medulla oblongata is just above the spinal cord and is an extension of the spinal cord into the skull. It controls vital reflexes, such as breathing, heart rate, vomiting, salivation, coughing and sneezing - through the cranial nerves, which control sensations from the head, muscle movements in the head and parasympathetic output to the organs. Damage to the medulla is often fatal and large doses of opiates suppress activity in the medulla often causing death. Nuclei for cranial nerves V to XII are in the medulla.
What is the pons?
The pons is anterior and ventral to the medulla. In the pons, axons from each half of the brain cross to the opposite side.
What is the cerebellum?
The cerebellum has many deep folds. It controls movement and is important for balance and coordination. It impacts on attention, auditory and visual systems and timing.
What is the midbrain?
The tectum is the roof of the midbrain. The swellings on each side of tectum are superior colliculus (important for vision) and inferior colliculus (important for hearing) and are important for sensory processing.
The tegmentum is under the tectum.
The substantial nigra - gives rise to a dopamine containing pathway that facilitates readiness for movement.
What is the limbic system?
It forms a border around the brainstem. Structures are important for motivation and emotions, such as eating, drinking, sexual activity, anxiety and aggression. The limbic system contains the olfactory bulb, hypothalamus, hippocampus, amygdala and cingulate gyrus of the cerebral cortex.
What is the diencephalon?
The thalamus and hypothalamus. It is a section distinct from the telencephalon (rest of the forebrain).
What is the thalamus?
The thalamus is a pair of structures (left and right) in the centre of the forebrain. Most sensory information goes to the thalamus which processes it and sends output to the cerebral cortex. The cerebral cortex sends information back to the thalamus, focusing its attention on particular stimuli.
What is the hypothalamus?
Ventral to the thalamus. The hypothalamus conveys messages to the pituitary gland, altering its release of hormones.
What is the pituitary gland?
An endocrine (hormone-producing) gland attached to the base of the hypothalamus by a stalk that contains neurons, blood vessels and connective tissue. It synthesises hormones that the blood carries to organs throughout the body.
What is the basal ganglia?
A group of subcortical structures lateral to the thalamus. Includes the caudate nucleus, putamen and the globes pallidus. It integrates motivational and emotional behaviour to increase visor of selected actions. It is important for movement, learning and remembering skills and habits as well as other types of learning that grows gradually.
What is the basal forebrain?
The nucleus basalis - on the ventral surface of the forebrain and receives input from the hypothalamus and basal ganglia and sends axons that release acetylcholine in the cerebral cortex. Key part of the brains system for arousal, wakefulness, attention and sleep.
What is the hippocampus?
Located between the thalamus and cerebral cortex, towards the posterior of the forebrain. Involved in memory.
What is the central canal?
The nervous system begins development as a tube surrounding a fluid canal. It is called the central canal in adulthood. The central canal is a fluid-filled channel in the centre of the spinal cord.
What are the ventricles?
Four fluid-filled cavities within the brain. Each hemisphere contains a large lateral ventricle. Toward their posterior they connect to the third ventricle at the midline, separating the left thalamus from the right thalamus. The their ventricle connects to the fourth ventricle in the centre of the medulla.
What is cerebrospinal fluid (CSF)?
CSF is produced by cells called choroid plexus. CSF fills the ventricles, flowing from the lateral ventricles to the third to the fourth. Some then flows into the central canal of the spinal cord. In the subarachnoid space, the blood reabsorbs the CSF. CSF cushions the brain against mechanical shock and provides buoyancy. CSF provides a reservoir of hormones and nutrition for the brain and spinal cord. If flow of the CSF is obstructed, it accumulates within the ventricles or subarachnoid space, increasing pressure on the brain. When in infants, the skull bones spread, causing an overgrown head. Called hydrocephalus and can lead to mental retardation.
What is gray and white matter?
Cells on the outer part of the cerebral cortex are gray matter. Axons extending inwards are white matter. Neurons in each hemisphere communicate with neurons in the corresponding part of the other hemisphere through the corpus callous and the anterior commissure.
What are laminae?
Laminae are layers of cell bodies that are parallel to the surface of the cortex and separated from each other by layers of fibres. The cerebral cortex contains up to 6 distinct laminae.
What are columns?
Cells are organised into columns of cells perpendicular to the laminae. Cells within a given column have similar properties to each other.
What is the occipital lobe?
Posterior end of the cortex - visual cortex or striate cortex. Damage to the occipital lobe results in normal eye and pupillary reflexes but no conscious visual perception or imagery.
What is the parietal lobe?
Located between the occipital lobe and the central sulcus (deep grove in the surface of the cortex). Area just posterior to the central sulcus is the post central gyrus (primary somatosensory cortex) - receives sensation from touch receptors, muscle-stretch receptors and joint receptors. Parietal lobe monitors body position and spatial and numerical information.