WEEK 1: Nervous System Anatomy Flashcards
Which parts of the body make up the Central Nervous System (CNS)?
The spinal cord and the brain ! :)
What is the function of the CNS?
The CNS organises and analyses information gained from the sensory organs.
Which parts of the body make up the Peripheral Nervous System (PNS)?
The PNS resides outside the brain and spinal cord to relay information to the rest of your body.
What is the main function of the PNS?
It passes sensory information to the CNS and transmits motor impulses to the effector organs. Connects the CNS with the rest of the body.
What is the two divisions the PNS is first split into?
The PNS is split into the sensory (afferent) division and the motor (efferent) division.
What is the structure of the afferent division? and what is its function in the PNS?
The afferent (sensory) division’s structure consists of the somatic and visceral sensory nerve fibres. These nerve fibres conduct impulses from receptors to the CNS.
What is the structure of the efferent division? and what is its function in the PNS?
The efferent (motor) division’s structure consists of motor nerve fibres. These motor nerve fibres conduct the impulses from the CNS to effectors (muscles and glands).
What systems are within the motor (efferent) division?
The Somatic Nervous System (SNS) and the Autonomic Nervous System (ANS)
What is the SNS?
Somatic motor (voluntary). It is an in-automatic process which controls the function of voluntary behaviours of the body and conveys sensory information to the CNS.
What is the ANS?
Visceral motor (involuntary). An automatic process that is conducted by impulses from the CNS to cardiac muscles, smooth muscles, and glands. Sends and receives messages to regulate the autonomic behaviours of the body.
What are the two divisions of the Autonomic Nervous System (ANS)?
Sympathetic division and Parasympathetic division
What is the Sympathetic NS?
The Sympathetic NS mobilises bodily resources by activating the network or nerves that prepares the body/organs for rigorous activity.
What is the Parasympathetic NS?
The Parasympathetic NS conserves bodily resources by facilitating a vegetative, nonemergency response.
What do you call the anatomical direction that is positioned away from the midline of the body?
Lateral e.g., your ears are lateral to your eyes.
What do you call the anatomical direction that is toward the middle.
Medial e.g., your chest is medial to your arms.
Where is the Anterior located?
Toward the front end
Where is the Posterior located?
Toward the rear end
Where is the Dorsal located?
Toward the back away from the ventral side
Where is the Ventral located?
Toward the stomach, away from the dorsal side
Where is the Lateral located?
Toward the side, away from the midline
Where is the Medial located?
Toward the midline, away from the side
What is the function of the spinal cord?
The spinal cord communicated with the sensory organs and muscles, except with those of the head.
What is the sensory nerves in the spinal cord responsible for?
The sensory nerves in the spinal cord are responsible for bringing sensory info from the body to the brain (entering the dorsal roots)
What is the motor nerves in the spinal cord responsible for?
The motor nerves are responsible for transmitting motor info from brain to body (exiting the ventral roots)
What matter does the spinal cord consist of?
Grey matter and white matter
Where is grey matter located?
In the centre of the spinal cord.
What does grey matter consist of?
Grey matter consists of densely packed cell bodies and dendrites.
What does white matter consist of?
White matter consists of myelinated axons and carries information from the grey matter to other areas of the spinal cord other brain.
What is a spinal reflex?
A spinal reflex occurs independently to the brain and is when interneurons in the spinal cord receive sensory input, and excite motor neurons controlling the muscles that withdraw the limb.
What does the brain stem consist of?
The Hindbrain structures, the midbrain, and other central structures of the brain.
What parts of the brain does the hindbrain consist of?
The medulla, pons, and cerebellum
Where is the medulla?
The Medulla is located just above the spinal cord.
What is the medulla responsible for?
The medulla is responsible for vital reflexes such as breathing, heart rate, salivation, vomiting etc.
What is the cranial nerves?
We have 12 pairs of cranial nerves which enter and exit the brain directly. It allows the medulla to control sensations from the head, muscle movements in the head, and many parasympathetic outputs.
Where is the pons located?
The pons lies on anterior and ventral to the medulla
What is the pons latin term?
“bridge”
What is the pons responsible for?
The pons is responsible for things like sleep and wake cycles, breathing (by working together w/ the medulla).
What is the Cerebellum function?
The Cerebellum (aka. little brain) helps regulate motor movements, coordination, balance. It is also important for shifting attention between auditory and visual stimuli. Greatly affected by alcohol
What does the Midbrain consist of?
The tectum and the tegmentum.
Where is the tectum?
The tectum is at the roof of the midbrain.
What is the tectum composed of?
The superior and inferior colliculi (involved in sensory function)
What does the Tegmentum contain?
It contains nuclei for cranial nerves and part of the reticular formation; red nucleus and stubstantia nigra (both involved in sensorimotor function); and the periaqueductal gray.
Where is the forebrain located?
At the most anterior and prominent part of the brain.
What hemispheres does a forebrain have?
Two cerebral hemispheres
What do these two cerebral hemispheres consist of?
- the outer cortex and subcortical regions
- outer portion is known as the “Cerebral cortex”
- each side receives sensory information and controls motor movement from the opposite (contralateral) side of the body.
Whats the structures underneath the cortex?
The hypothalamus and thalamus.
Where is the hypothalamus located?
It is the small area near the base; just below the thalamus (hypo=below)
What is the function of the hypothalamus?
The hypothalamus conveys messages to the pituitary gland to alter the release of hormones.
It is also associated with motivated behaviours e.g., drinking, eating, sexual behaviours.
What does the Limbic System consist of?
- A number of other interlinked structures that form a border around the brainstem
What does the Limbic System include?
- Olfactory bulb
- Hypothalamus
- Hippocampus
- Amygdala
- Cingulate gyrus of the cerebral cortex `
What is the Limbic System associated with?
- Motivated and emotional behaviour
Where is the Thalamus?
The Thalamus is a large two-lobed structure at top of the brain stem
What is the Thalamus?
It is a relay station from the sensory organs (except smell)
It is a main source of input to the cortex
Integrates information across senses
Where does information route from to the thalamus?
the cerebral cortex
What is the lateral geniculate nuclei responsible for?
vision
What is the medial geniculate nuclei responsible for?
hearing
What is the ventral posterior nuclei responsible for?
touch
What is the ventricles?
It is a four-filled cavities within the brain’s central canal containing cerebrospinal fluid.
The ventricles is what provides “cushioning” for the brain
It is also a reservoir of hormones and nutrition for the CNS
What is the meninges
The meninges is the membranes that surround the brain and spinal cord:
- dura mater (2 layers)
- arachnoid mater
- pia mater
What does the meninges contain?
- Pain receptors
What fluid flows through the spaces between the brain and meninges?
cerebrospinal fluid
What is another name of the cerebral cortex
the cerebrum
What does the cerebral cortex consist of?
The cerebral cortex consists of the cellular layers on the outer surface of the cerebral hemispheres
What are the names for its highly convoluted outer layer?
grooves and bumps
What is sulci
Grooves
What is gyri
Bumps
What does it mediate
Most complex functions of the brain seeing as it is the most recently evolved.
What does the longitudinal fissure do?
Separates the two cerebral hemispheres
What are the two cerebral hemispheres joined by?
they are joined by two bundles of axons called the corpus callosum and the anterior commissure.
How many lobes is the cerebral cortex divided into?
Four
Where is the Occipital Lobe located?
at the posterior end of the cortex
What is the occipital lobe also known as?
The striate cortex or the primary visual cortex
What is the occipital lobe responsible for?
It is highly responsible for visual input. Any damage to this area can result in cortical blindness.
Where is the Partietal Lobe located?
the parietal lobes are superior to the occipital lobes and posterior to the central sulcus and frontal lobes.
What does the Parietal Lobe contain?
It contains the postcentral gyrus, aka “the primary somatosensory cortex
What is the Parietal lobes function?
The parietal lobe is a primary target for touch sensations and info from muscle-stretch receptors and joint receptors
It is also responsible for processing and integrating infor about eye, head, and body positioning from info sent from muscles and joints. This makes it essential for spatial information and numerical information
What can damage to the parietal lobes result in?
unilateral neglect
Where is the temporal lobe located?
located on the lateral portion of each hemisphere near the temples
What is the temporal lobe a target for?
auditory information and essential for processing spoken language
it is also responsible for some complex aspects of vision, including movement and some emotional and motivational behaviours
What can damage to the temporal lobe result in?
Difficulty hearing, comprehending speech, memory impairments, and emotional changes
What does the Frontal Lobe contain?
the precentral gyrus, aka the “primary motor cortex”.
Prefrontal cortex: the most anterior portion of the frontal lobe
What is the primary motor cortex responsible for?
the control of fine motor movement
What is the prefrontal cortex responsible for?
It acts an integration centre for all sensory information and other areas of the cortex
What is the frontal lobe’s responsbility?
- Higher functions (e.g., abstract thinking and planning)
- our ability to remember recent events and information (“working memory”)
What can damage of the frontal lobe result in?
An inability to inhibit behaviour and or control emotion,
decreased planning and organisation , delayed responding to stimulus events (visual or auditory)
