Lecture 6 - Central Nervous System Flashcards
The CNS is made up of?
Brain and spinal cord
Brain
Control center of the body.
2% of body weight and uses 20% of body’s oxygen in humans.
Spinal cord
Most caudal, receives sensory information from the body, sends efferent to muscles and glands.
Forebrain is made of?
telencephalon and the diencephalon
Midbrain is made of?
mesencephalon
Hindbrain is made of?
metencephalon and the myelencephalon
Telencephalon is composed of?
cerebrum, hippocampus and basal ganglia
Diencephalon is composed of?
thalamus and hypothalamus
Metencephalon is composed of?
cerebellum and pons
Myelencephalon is composed of?
medulla oblongata
Brain stem
Consists of the midbrain, pons, and medulla oblongata; lies at the base of the cerebrum, and connects the brain to the spinal cord.
Midbrain
Contains centers for auditory and visual reflexes.
Pons
Lays between the midbrain and medulla oblongata; transmits impulses between brain and spinal cord.
Contains centers that regulate the rate and depth of breathing.
Medulla oblongata
Located in the brainstem, anterior and partially inferior to the cerebellum.
Controls heart rate, breathing rate, and flow of blood thru the blood vessels.
Encephalization quotient (EQ)
A measure of relative brain size and is often used to convey how small or large a species’ brain is compared to that of other species of similar body size.
Cerebrum
Largest part of the brain responsible for learning and senses.
What are the two hemispheres of the brain connected by?
corpus callosum
Each hemisphere receives sensory input from the ____ side.
opposite
What are the four lobes of the brain?
- Frontal lobe
- Parietal lobe
- Occipital lobe
- Temporal lobe
Cerebellum
2nd largest part of the brain.
Located below the cerebrum at the back of the skull.
Responsible for balance and muscle coordination.
Gray Matter (brain)
Absence of myelin in masses of neurons accounts for the gray matter of the brain - cerebral cortex.
White Matter (brain)
Myelinated neurons gives neurons a white appearance - inner layer of cerebrum.
What are the five segments of the spinal cord?
Cervical
Thoracic
Lumbar
Sacral
Coccygeal
Gray matter (spinal cord)
Consists of neuron cell bodies, dendrites, and unmyelinated axons.
White matter (spinal cord)
Consists of bundles of myelinated axons.
What are the three layers of Meninges?
- Dura mater (outer layer)
- Arachnoid layer (middle layer)
- Pia mater (inner layer)
Dura Mater
Outermost layer.
Consists of connective tissues, blood vessels, and nerves.
Limit excessive movement of brain.
Arachnoid Layer
Middle layer.
Elastic and web-like.
Arachnoid will protrude into superior sagittal sinus and permit CSF reabsorption.
Pia Mater
Innermost layer.
Contains nerves and blood vessels.
Delicate vascularized connections that clings tightly to the brain.
Thalamus
Receives messages from sensory receptors. Relays information to proper regions of cerebrum.
Hypothalamus
Control center of the brain.
Controls the autonomic nervous system, regulates body temperature, hunger, thirst, fatigue, anger, etc.
Control of pituitary for endocrine function.
Mammalian circadian rhythms rely on a ___________, a molecular mechanism that directs periodic gene expression.
biological clock
Cerebrospinal fluid (CSF)
Composition - watery solution formed from blood plasma, less protein and different ion concentrations than plasma, constant volume
Functions - gives buoyancy to and protects CNS structures, reduces weight by 97%. Nourishes brain and carries chemical signals.
Neural plasticity
Describes the ability of the nervous system to be modified after birth. Changes can strengthen or weaken signaling at the synapse.
Ex. formation of memories.
Hippocampus
Where short-term memory is accessed.
Also plays a role in forming long-term memory, which is stored in the cerebral cortex.
