exam 1 Flashcards
What are the main components of the Central Nervous System (CNS)?
Brain and spinal cord
The brain is located within the cranial cavity, while the spinal cord is located within the spinal vertebral column.
What does the Peripheral Nervous System (PNS) consist of?
Nerves located outside cranial and vertebrae column
It includes sensory and motor nerves that connect the CNS with the rest of the body.
What is the role of afferent nerves in the Somatic Nervous System (SNS)?
Bring in stimuli from external to CNS
Examples include stimuli from skin, skeletal muscles, joints, and eyes.
What is the role of efferent nerves in the Somatic Nervous System (SNS)?
Motor signals to move skeletal muscles from CNS
Efferent nerves are responsible for voluntary movements.
What is the function of the Autonomic Nervous System (ANS)?
Interacts with internal environment
It regulates involuntary bodily functions.
What are the two divisions of the ANS?
Sympathetic and parasympathetic nerves
Each division has distinct roles in responding to stress and relaxation.
What are the characteristics of sympathetic efferent nerves?
First stage neurons are short, second stage neurons are longer
They stimulate and mobilize energy resources in response to threats.
What is the role of parasympathetic efferent nerves?
Conserve energy and promote psychological relaxation
Their first stage neurons exit from the brain and sacral spinal cord.
How many cranial nerves are there?
24 cranial nerves
12 exit from the right hemisphere and 12 from the left hemisphere.
What is the function of the meninges?
Three layers of tissue that protect the CNS
The layers are dura mater, arachnoid, and pia mater.
What is the purpose of cerebrospinal fluid?
Provides support and cushioning to the brain
It is housed within the ventricles and subarachnoid space.
What is the blood-brain barrier?
Barrier between blood vessels and neural tissue
It prevents toxins from entering the brain and regulates the flow of essential substances.
What are the main components of a neuron?
Dendrites, axon, cell body (soma), synaptic buttons
Neurons transmit signals and communicate through synapses.
What distinguishes unipolar, bipolar, and multipolar neurons?
Based on the number of extensions from the cell body
Unipolar has 1 extension, bipolar has 2, and multipolar has more than 2.
What is a nucleus in the context of the CNS?
Group of cell bodies within the CNS
It is analogous to ganglia in the PNS.
What are the types of glial cells?
Oligodendrocytes, Schwann cells, microglia, astrocytes
Each type has distinct roles in supporting and protecting neurons.
What is the function of oligodendrocytes?
Myelinate axons in the CNS
They have many extensions that cover multiple axons.
What is the role of astrocytes?
Support neurons and regulate blood supply
They are involved in the blood-brain barrier and chemical movement.
What are the three axes of the nervous system?
Longitudinal, dorsoventral, mediolateral
These axes help describe the orientation and structure of the nervous system.
What are the five groups of spinal levels?
Cervical, thoracic, lumbar, sacral, coccygeal
There are a total of 31 spinal levels.
What characterizes the dorsal and ventral horns of the spinal cord?
Dorsal horn contains grey matter; ventral horn contains motor neurons
The dorsal root brings sensory information, while the ventral root carries motor commands.
What is the primary function of the medulla?
Regulates basic physiological reflexes
- consists of recticular formation: formation of relay neurons which maintain appropriate level of arousal to environment
- regulates circadium rythym
It is part of the myelencephalon.
What structures are found in the midbrain?
Tectum and tegmentum
(compose the Mesencephalon)
They are involved in sensory processing and motor control.
What does the thalamus do?
Processes and relays sensory information to the cerebral cortex
It consists of two lobes connected by the massa intermedia.
What is the function of the hypothalamus?
Regulates motivated behaviors and controls the pituitary gland
It plays a key role in homeostasis.
What is the corpus callosum?
The largest cerebral commissure connecting the two hemispheres
It facilitates communication between the left and right sides of the brain.
What are the major gyri of the cerebral cortex?
Precentral gyrus, postcentral gyrus, superior temporal gyrus
These gyri are involved in motor and sensory processing.
What is the neocortex?
Represents 90% of the cerebral cortex and has 6 layers
It is involved in higher-order brain functions.
What is the role of the limbic system?
Regulates motivated behaviors such as fleeing, fighting, feeding, and sexual behaviors
It includes structures like the amygdala and hippocampus.
What is the basal ganglia involved in?
Regulating motor movement and decision-making
It includes structures like the striatum and globus pallidus.
What is the myelencephalon commonly known as?
The medulla oblongata.
True or False: The metencephalon includes the pons and cerebellum.
True.
Fill in the blank: The __________ is responsible for regulating vital functions such as heart rate and breathing.
myelencephalon.
What structures are included in the mesencephalon?
The midbrain, including the tectum and tegmentum.
Which part of the brain is referred to as the ‘forebrain’?
The telencephalon and diencephalon
What is the primary function of the diencephalon?
To relay sensory information and regulate autonomic functions.
thalamus and hypothalamus (optic chiasm and pit)
Multiple choice: Which of the following is NOT part of the metencephalon? A) Pons B) Cerebellum C) Thalamus
C) Thalamus.
Short answer: Name one key function of the cerebellum.
Coordination of voluntary movements.
True or False: The thalamus is located in the telencephalon.
False.
What is the role of the hypothalamus?
To regulate homeostasis and endocrine functions.
Fill in the blank: The __________ connects the cerebellum to the brainstem.
pons.
Multiple choice: Which part of the brain is involved in visual and auditory processing? A) Myelencephalon B) Mesencephalon C) Diencephalon
B) Mesencephalon.
tectum - superior and inferior colliculi
Short answer: What is the primary function of the medulla oblongata?
To control autonomic functions such as breathing and heart rate.
True or False: The telencephalon contains structures such as the cerebral cortex and basal ganglia.
True.
What is the role of the reticular formation located in the myelencephalon?
To regulate wakefulness and alertness.
Fill in the blank: The __________ plays a crucial role in balance and motor control.
cerebellum.
Multiple choice: Which structure is primarily involved in the processing of sensory information? A) Mesencephalon B) Myelencephalon C) Metencephalon
A) Mesencephalon.
Short answer: Name the two main components of the diencephalon.
Thalamus and hypothalamus.
True or False: The pons is part of the myelencephalon.
False.
What is the primary function of the thalamus?
To act as a relay station for sensory information.
Fill in the blank: The __________ is responsible for the coordination of complex movements.
cerebellum.
Multiple choice: Which part of the brain is involved in regulating emotions? A) Diencephalon B) Metencephalon C) Mesencephalon
A) Diencephalon.
Short answer: What is the role of the cerebral cortex within the telencephalon?
To process complex sensory information and facilitate higher cognitive functions.
True or False: The mesencephalon is primarily responsible for motor control.
True.
What is a major function of the pons?
To serve as a communication pathway between different parts of the brain.
Lissencephalic
= cortecies with no folds
Gyrencephalic
= corticies with folds
Gyri
Bump
Sulci
valley
3 major fissures
- Central Fissure
- Lateral Fissure
- Longitudinal Fissure
Pyramidal cells
Multipolar neurons with body shape of pyramid, long apical dendrites head towards cerebral cortex
- in neocortex
Stellate cells
star shaped interneurons with short axons
- in neocortex
Neocortex organization
- Layers are organized by size, density, proportion of cells in columnar fashion
- Culumnar Organization: Due to vertical connections across layers because of pyramidal apical dendrites. Therefore, neurons within a given column of the neocortex form a minicircuit with a single function
Longitudinal axis
rostral/anterior = toward front
cauddal/inferior = toward tail
PNS axis
distal and proximal
Brain axis
- Sagittal Plane: vertical plane that divides left and right portions
- Horizontal Plane: divides into two top and bottom halves
- Frontal Plane: divides brain into front and back halves
- Cross section: horizontal plane cuts through spinal cord/long narrow structures
Basal ganglia
- Regulates motor movement and involved in decision making
- Striatum = caudate and putamen are connected to make striatum, which receives in put from neocortex and outputs to globus pallidus
- Globus pallidus = located between thalamus and striatum
- Nucleus accumbens = part of reward pathway
Epigenetic methods
- DNA methylation: attachment of methyl group to a nucleotide base
- Can increase or decrease expression
- Histone remodeling: histones can change shape, therefore change shape of adjescent DNA
- Can increase or decrease expression
Tectum
- Composed of 4 swelling situated on dorsal side of midbrain
- 1 pair at top - visual function
- Superior colliculi
- 1 pair at bottom
- Inferior colliculi - auditory function
- 1 pair at top - visual function
Tagmentum
- Tegmentum:
- Composed of 3 structures
- Periaqueductal grey
- Surrounds cerebral aqueduct
- Sensory structure that manages pain, contains opiod receptors = Analgesic
- Activates reward system
- Red nucleus
- Motor structure involved in control
- Red due to increased blood supply
- Substantia nigra
- Motor Structure involved in motor control and dopamine system
