25 Questions Flashcards
preparing for MESA day
Which lobe of the brain is important for vision?
Where is it located?
Occipital lobe
-located at the back portion of the brain, behind the parietal lobe and temporal lobe
Which part of the brain is important for reasoning?
Where is it located?
- Frontal lobe
- Located in front of the central sulcus (center sulcus/division of the brain)
Describe three functions of the nervous system.
- Sensory Input-monitors changes in the environment both outside/within the body
- Integration-the CNS processes the sensory inputs, interprets/collects info
- Motor Output – the nervous system triggers a response by stimulating the effector organs; muscles and glands.
What is the approximate weight of an adult normal brain? What % of the total human body weight does the brain represent?
3 pounds
2%
Describe the three membranes known as meninges.
Pia mater- “soft layer” innermost lining of brain
arachnoid-middle layer between dura and pia web of collogen
Dura mater- “tough layer” restrict the movement of the brain within the skull
Describe the two types of cells the brain is made of.
1) Neuron
-basic functional unit of nervous system
→ consist of motor, sensory, and interneurons
2) Glial Cell
-support/protect CNS and neuron activity
Describe the four primary structures of a neuron.
1) Cell body: nucleus and source of information for protein synthesis
2) dendrites: receive stimulus and carries it impulses toward the cell body
3) axon: fiber which carries impulses away from cell body
4) myelin sheath: Insulating layer of cells around axon; helps conduct electrical impulses
Describe the amygdala and its function.
Part of limbic system, the amygdala is located in the temporal lobe and is involved in memory, emotion, and fear
Describe the hypothalamus and its function.
Hypothalamus: involved in regulating activities of internal organs, monitoring info from Auto NS, controlling the pituitary gland and hormones, and regulate sleep and appetite (basic functions of life)
Describe an action potential.
Quite simply, It is the form in which stimuli travel across motor neurons to the central nervous system.
It is a series of brief membrane potential changes along the axon of a neuron conducted through saltatory conduction. At the atomic level, it is produced when a stimuli causes the membrane of the cell to depolarize, and the entrance of potassium ions causing the inside of the cell to turn positive, allowing the membrane to become more permeable to sodium ions, eventually the threshold level of membrane potential is reached and the action potential is allowed to travel.
What is the limbic system and what is its function?
- Limbic system: a group of brain structures (hypothalamus, amygdala, hippocampus, septum, basal ganglia, etc.)
- help regulate expression of emotions and emotional memory; subconscious, instinctive behavior
Describe the thalamus and its function.
symmetrical, double-lobed dense gray matter structure in center of brain
- located in forebrain, part of limbic system
- switchboard; filters and relays info to various brain regions; sensory process+movement
Describe the midbrain and its function.
it connects brain stem and higher centers of the brain
midbrain (mesencephalon)-relay station for messages to-and-from brain
-controls visual, auditory, and eye movement
-it is a small region that is the top part of the brain stem beneath the cerebral cortex
Describe the cerebellum and its function.
area of the hindbrain
Influences balance, coordination, and posture.
Describe how neurons transmit electrochemical impulses.
through a series of brief membrane potential changes known as action potentials
-in a myelinated neuron, they travel along gaps, also known as nodes of Ranvier, on the myelin sheath covering the axon of a neuron. This process is known as saltatory conduction.
At the atomic level, the membrane of the neuron cell depolarizes from a stimuli
-K ions enter, causing the inside of the cell to become positive, allowing the membrane to become more permeable to sodium ions
Describe the medulla oblongata and its function.
located beneath the pons, it is the lower half of brainstem
Controls involuntary activities such as heart rate and breathing.
Describe the four ventricles of the ventricular system.
aid in production/circulation of CSF
Lateral ventricles (left and right)- two largest ventricles; located in each hemisphere of cerebrum
third ventricle-located below lateral ventricles, which it sends/receives messages from
fourth ventricle- located behind medulla oblongata and pons; diamond shaped cavity that protects brain from trauma and forms central cavity of spinal cord
Describe four functions of cerebrospinal fluid.
- PROTECTION: Absorbs physical shocks to the brain
- ENVIRONMENT: it maintains sufficient intercranial pressure for normal development of the CNS by enhancing brain perfusion and preventing ischemia
- TRANSPORT: carries nutritive materials and neuroendocrine hormones to and removes wastes from nervous tissue
- SUSPENSION: It suspends the brain and spinal cord in their proper positions to prevent them from being impaired by their own weight
What characterizes white and gray matter in the brain?
Gray matter-composed of nerve cell bodies; majority of the cerebral cortex
-function: senses and muscle control
white mater-axonal and nerve fibers
-function: automatic activity: temperature, blood pressure, heart rate
Describe a cerebral aneurysm.
When the wall of a blood vessel is weakened causing it to bulge or balloon out
Describe epilepsy.
short, recurrent, periodic attacks on motor, sensory, or psychological malfunction.
brain disorder in which a person has repeated seizures (convulsions) over time. Seizures are episodes of disturbed brain activity that cause changes in attention or behavior.
Describe a negative feedback loop and give two examples.
In a negative feedback system some factor, such as blood pressure, changes. The change is detected by a sensor. The sensor sends a message to an integrating center which in turn stimulates an effector. The effector will do something to alter the factor that changed.
Examples: parasympathetic-forces us to calm down, sympathetic-causes us to stress “flight or fight”
What is agoraphobia?
anxiety disorder involving attacks of intense fear and anxiety
Describe Multiple Sclerosis.
progressive destruction of myelin sheath of neurons in the CNS, disappearance of digodendrocytes, proliferation of astrocytes, myelin sheath deteriorate to scleroses (hardened scars or plaque) in multiple regions, interfere with transmission of impulses (short-circuiting)
symptoms: movement impaired, infections, double vision, concentrated on areas w/ heavy scleroses.
