Unit 4 lecture Flashcards
How many neurons does our nervous system contain?
85 billion neurons
How many synapses (contacts with other neurons) does each neuron have?
10 thousand contacts (synapses)
What are the three major functions of the nervous system?
- Sensory function (afferent neurons)
- Integrative functions (interneurons)
- Motor functions (efferent neurons)
Describe sensory functions
- Information goe to the brain and spinal cord via cranial and spinal nerves
- Contains afferent neurons
- Anything going to the brain is afferent
- This regards any senses
Describe integrative function
- Integrates sensory information by analyzing and storing it
- Interneurons are the integrating neurons
- They recognize the sense (feel of car keys) and then connect it with what it is (recognizing that they are actually car keys)
Describe motor functions
- Contains efferent neurons
- Go from the brain to the rest of the body sending out signals
- Know that they are car keys from the integrative function and the motor functions tells your hands to put the keys in the ignition
What is the Nervous system broken up into?
- Somatic Nervous system deals with the body and movement
- Autonomic Nervous system deals with automatic movements and actions like blood pressure and standing up
- Sympathetic: Fight or flight
- Parasympathetic: Rest and digest
What are two cell neuronal tissue types:
- Nerve cells (neurons)
- Involved in the generation and interpretation of ‘electrical signals’
- Exciting cells
- Glial cells (Neuroglia)
- Support neuronal cell activity
- 10 times more plentiful than neurons
- Making sure you have the right amount of sodium and potassium
- No excitation just support exciting cells (neurons)
What are the functions of glial cells?
- Insulate
- Support
- Nourish neurons
What are the glial cells that wrap themselves around neurons?
Schwann cells that insulate neurons
What are some functions of neurons?
- Process information
- Sense environmental and internal changes
- Ex. Its hot in here, this exercise is painful (aka. lactic acid build up)
- Communicate changes to other neurons
- Command body responses
What are the four major anatomical features of a neuron?
- Dendrites
- Cell Body
- Axon
- In the picture, it is mylonated
- Can be long (meter long) or short (in the brain)
- Synapses
- Signals presynaptic terminal to release neurotransmitters
Define resting potential
The resting potential is relatively steady voltage across the membrane
What do graded voltage do?
They have changes occur in response to sensory stimuli or synaptic inputs that they will send action potentials
What does it mean all or nothing?
Action potentials are transient, “all or none” changes in the voltage which allow transmission of information
What is the brain and what does it do?
- Control center of the human body
- Center of intelligence, behavior, memory, and emotion
- Coordinates activity of skeletal muscles
- Influences activity of visceral organs and glands
What is the brain composed of?
- 85-100 billion neurons and even more neuroglia
How does the brain act as a processing center?
- Interpretation of sensory information is based on path traveled and destination in the brain
- It sends actions and recieves sensations on the correct paths
What happens to the brain when we learn and develop new skills?
- Plasticity: anatomical changes in the brain; new synapses form and new pattern of activity develops; also neurogenesis (new neurons)
What are the four major parts of the brain?
- Cerebrum
- Cerebellum (small, hind brain)
- Diencephalon
- Thalamus (gate keeper)
- Hypothalamus
- Epithalamus
- Brain Stem
- Pons
- Medulla oblongata
- Midbrain
What are the 2 cerebral hemisohere’s specialties?
Right: Music, face recognition, visual imagery, spatial abilities
Left: Language, logic, reason
What are the five lobes in the brain?
- Frontal
- Parietal
- Temporal
- Occipital
- Insula
What are the functions of the frontal lobe?
- Reasoning
- Planning
- Part of speech and movement
- Emotions
- Problem solving
What are the functions of the parietal lobe?
- Preception of stimuli related to touch
- Pressure
- Temperature
- Pain
What are the functions of the Temporal lobe?
- Preception and recognition of auditory stimuli and memory
What are the functions of the occipital lobe?
- Many aspects of vision
What are the functions of the insula lobe?
- Integrates autonomic information
- Associated to visceral function
Define and differentiate beteen fissure and sulcus
Fissure and sulcus are invaginations in the brain however..
- Fissure is larger like inbetween the two hemispheres
- Sulcus is smaller like between lobes
How is the cerebrum organized? What does it contain?
Contains
- Foldings
- Gyri (gyrus)
- Sulci (sulcus)
- Fissures (deep envaginations including both gyri and sulci)
- Gray matter (cerebral cortex)
- Cell bodies/neurons that are the processing centers
- White matter (Cerebral white matter)
- Axons and pathways
- Important gyri, sulci, and fissures
- Longitudinal fissure
- Central sulcus
- Lateral cerebral sulcus
- Transverse fissure
How is the cerebellum organized?
- 2 Cerebrall hemisphere
- Cerebellar cortex
- Gray matter
- Contains the neurons
- Arbor Vitae
- White matter
- Contains the tracts
- Recieves the plan for movements
- Comparator of movements
- Partly in charge of posture and center of gravity
- Alcohol impairs the cerebrellum
What are the meninges?
Connective tissue coverings that surround the brain and spinal cord
What are the meninges functions?
- Protects underlying neural tissues
- Anchors the brain in cranial cavity and spinal cord in vertebral cavity
What are the three layers of the meninges?
- Dura mater
- Subdural space
- Arachnoid mater
- Subarachnoid space
- Pia mater
**Villi pick up cereberal fluid
Discuss the dura mater
- Most superficial layer
- Outer layer fuses with periosteum of skull (not fused around the spinal cord)
- Inner later folds into parts of cranial cavity forming sinuses
- Major dural folds
- Falx cerebri
- Falx cerebelli
- Tentorium cerebelli
Look at the flow chart of the CSF
What do ependymal cells do regarding CSF?
CFS diffuses through the ependymal cells on a ventricle
What are functions of the Cerebrospinal fluid (CSF)?
- Cushioning and shock absorption
- Chemical protection
- Exchange nutrients and wastes
Discuss the blood brain barrier
- Protective mechanism that maintains stable environment for the brain
- Capillaries of the brain are the least permeable of any capillaties in the body
- Neuroglial cells pack them together tightly
- Capillaties are selective partly due to presence of astrocytes (a type of neuroglia)
What are the four major parts of the brain?
- Cerebrum
- Cerebellum
- Diencephalon
- Thalamus
- Hypothalamus
- Epithalamus
- Brain stem
- Pons
- Medulla oblongata
- Midbrain
What are the functional areas of the cerebral cortex (gray matter)?
- Sensory areas
- Motor areas
- Association areas
What is the location and function of the primary motor area on the cerebrum?
Location: precentral gyrus in frontal lobe
Function: voluntary activation of skeletal muscles. Very simple movements
What is the location and function of the premotor area (motor association area)?
Location: anterior to primary motor area is the frontal lobe
Function: communicates with primary motor area and thalamus to coordinate complex learned movements
What is the location and function of the primary somatosensory area?
Location: post central gyrus in parietal lobe
Function: receives sensory impules from sensory receptors responding to touch, temperature and proprioception. The actual perception of the touch which is sent to be processed in the associative areas.
Discuss the motor and sensory outputs for body parts on the weird cortex image
What is the location and function of the primary visual area?
Location: medial portion of occipital lobe
Function: nervous signals traveling along the optic nerve provide information about color, shape, and movement of visual stimuli
-Recieves info directly from the optic nerve
What is the location and function of the visual association area?
Location: occipital lobe, anterior to the primary visual area
Function: receives sensory impulses from the primary visual area for recognition of visual stimuli (visual memory)
What is the location and function of the primary auditory area?
location: superior portion of temporal lobe
Function: receives impuleses arising from the vestibulocochlear nerve which provide info on the basic characteristics of sound (pitch, rhythm, loudness)
What is the location and function of the auditory association area?
Location: temporal lobe, inferior and posterior to the primary auditory area; typically found on left temporal lobe only
Function: interpretation and recognition of sound; determines if sound is speech, music, or a noise
What is the location and function of the wernike’s area?
- Part of the auditory association area
- Location: temporal lobe, posterior to primary auditory area on left lobe (usually)
Function: interprets the meaning of speech (translates words into thoughts)
What is the location and function of the broca’s area?
- A part of the motor speech area
- Location: frontal lobe - usually left side
- Function: controls the activity of muscles of the vocal cords to facilitate speech
What is aphasia, what is the common cause, and what are two types of it?
- Acquired communication disorder that impairs a person’s ability to process language but does not affect intelligence
- Most common cause is stroke
- Two common types:
- Broca’s aphasia (‘non-fluent aphasia’)
- Mainly noises and moans
- Wernicke’s aphasia (‘fluent aphasia’)
- Disconnected speech and thoughts
- Broca’s aphasia (‘non-fluent aphasia’)
What are basal (ganglia) nuclei and what are their functions?
The basal nuclei are center of cell bodies deep in the cortex (gray matter).
- Help initiate and terminate movements
- Suppress unwanted movements
- Regulate muscle tone
- Control subconscious contractions of skeletal muscles
What is cerebral white matter and what is it responsible for?
Myelinated axons that are bond into large tracts
-White matter is responsible for communication between cerebral areas and between cerebral areas and other parts of the brain
What do Association tracts in cerebral white matter do?
Association tracts contain axons that conduct nerve impulses between gyri in the same hemisphere
What do commissural tracts of cerebral white matter do?
Commissural tracts conduct nerve impulses between corresponding gyri from one hemisphere to another
-Largest one: corpus callosum
What do the projection tracts of the cerebral white matter do?
Projection tracts convey impulses to lower parts of the CNS (thalamus, brain stem. or spinal cord) or visa versa
What is the corpus callosum and what is it in charge of?
The corpus callosum is one of the three important groups of commissural tracts (the other two being the anterior and posterior commissures) - it is a thick band of axons that connects corresponding areas of the two hempispheres
Hemisphereic lateralization
- Brain is almost symmetrical on right and left sides and share performance of many functions
- Each hemisphere specializes in performing certain unique functions
- Lateralization seems less pronounced in female
- When cut the right brain controls the left side of the body and visa versa
What are the unique parts about the left and right hemisphere?
- In most people, the left hemisphere is more important for reasoning, numerical and scientific skills, spoken and written language, and the ability to use and understand sign language
- Conversely, the right hemisphere is more specialized for musical and artistic awareness; spatial and pattern perception; recognition of faces and emotional content of language; discrimination of different smells; and generating mental images of sight, sound, touch, and taste
Define nucleus
a cluster of neuronal cell bodies in the CNS
Define ganglion (ganglia)
A cluster of neuronal cell bodies in the PNS