The central nervous system Flashcards
brain
- the control center of the body
- 2% of the body weight and uses 20% of body’s oxygen in humans
3 segments:
Forebrain: telencephalon
Midbrain: mesencephalon
Hindbrain: metencephalon
spinal cord
most caudal, receives the sensory information from the body, sends efferent to muscles and glands
brain stem
consisting of the midbrain, pons, and medulla. Connects the brain to the spinal cord
midbrain
pons
transmits impulses between the brain and spinal cord, and contains centers that regulate the rate and depth of breathing
medulla oblaganta
controls heart rate, breathing rate, and flow of blood through the blood vessels
cerebrum
- largest part of the brain, contains learning and senses
- 2 hemispheres right and left
- Connected by the corpus callosum
- 4 sections: lobes
Frontal lobe
Parietal lobe
Occipital lobe
Temporal lobe
cerebellum
- second largest part of the brain
- Located below the cerebrum at the back of the skull
- Responsible for balance and muscle coordination
gray matter
absence of myelin in masses of neurons accounts for the gray matter of the brain - cerebral cortex
white matter
myelinated neurons gives neurons a white appearance - inner layer of cerebrum
thalamus
- Receives messages from sensory receptors
- Relays information to proper regions of cerebrum
hypothalamus
- Controls ANS
- Regulates body temperature (sweating/shivering)
- Regulates hunger, thirst, fatigue, anger, etc…
- Control of pituitary for endocrine function
spinal cord & meniges
- Consists of 5 segments:
Cervical
Thoracic
Lumbar
Sacral
Coccygeal - Responsible for receiving electrical signals from the peripheral nervous system and sending it into the brain for integration and processing. As well as, accepting signals from the brain and sending them to other parts of the body
- consists of white & gray matter
meniges
3 layers:
1. Dura mater (outer layer): consists of connective tissues, blood vessels, and nerves
Limit excessive movement of brain
- Arachnoid layer (middle-layer): elastic and web-like
Arachnoid villi protrude into superior sagittal sinus
and permit CSF reabsorption - Pia mater (inner-layer): contains nerves and blood
vessels
- Innermost meninx
- Delicate vascularized connection
- Clings tightly to the brain
Biological clock regulation
- Biological clocks are typically synchronized to light and dark cycles
- SCN acts as a pacemaker, synchronizing the biological clock
- Mammalian circadian rhythms rely on biological clock, molecular mechanism that directs periodic gene expression
- Coordinated by a group of neurons in the hypothalamus called the suprachiasmatic nucleus (SCN)
Circadian rhythms
cycles of sleep and wakefulness. Daily cycles of biological activity
Cerebrospinal fluid
Composition:
- Watery solution formed from blood plasma
- Less protein and different ion concentrations
than plasma
- Constant volume
Functions:
- Gives buoyancy to CNS structures
- Reduces weight by 97%
- Protects CNS from blows and other trauma
- Nourishes brain and carries chemical signals
Neural plasticity
- The ability of the nervous system to be modified after birth
- Changes can strengthen or weaken signaling at a synapse
memory & learning
- The formation of memories is an example of neural plasticity
- Short-term memory is accessed via in the hippocampus
- Hippocampus also plays a role in forming long-term memory, which is stored in the cerebral cortex
- Some consolidation of memory is thought to occur during sleep
Stem cells in the brain
- The adult brain contains neural stem cells
- Stem cells in the brain can give rise to neurons that mature and become incorporated into the adult nervous system
nervous system disorders
- Schizophrenia
- Depression
- Drug addiction
- Alzheimer’s disease
- Parkinson’s disease
- Genetic and environmental factors also play a role
alzheimer’s disease
- Mental deterioration by confusion and memory loss
- Caused by the formation of neurofibrillary tangles and amyloid plaques in the brain
- No cure for this disease, some drugs are effective at relieving symptoms
Parkinson’s disease
- Motor disorder cause by death of dopamine secreting neurons in the midbrain
- Muscle tremors, flexed posture, and shuffling gait
- No cure, although drugs and other approaches are used to manage symptoms
encephalization quotient (EQ)
measures relative brain size amongst different species
where does CNS only show?
brain and spinal cord
The part of the brain in charge of thinking and memory_______.
Cerebrum
Cerebellum
Medulla oblongata
cerebrum
The main function of the cerebellum is ________.
Consciousness
Muscle coordination
Homeostasis
Sense reception
muscle coordination
The spinal cord passes through ________.
Forearm ovale
Foramen magnum
Foramen rotundum
forearm magnum
Which of the following is the central nervous system of the meninges?
Dural sinuses
Dura mater
Arachnoid mater
Pia mater
arachnoid mater
The thalamus and hypothalamus are components of which major of the brain division?
Medulla
Pons
Midbrain
Diencephalon
Telencephalon
diencephalon
Which area of the brain has the highest density of neurons?
Frontal lobe
Cerebellum
Temporal lobe
pons
cerebellum
