Anatomy & Physiology: Nervous System (The Brain) Flashcards
Nervous System
This system coordinates and controls several activities in the body, governs people’s consciousness, their personalities, how they learn, and their ability to memorize.
Central Nervous System (CNS)
This complex system of nerve tissue is comprised of the brain and spinal cord. It is where information processing and control occurs.
Peripheral Nervous System (PNS)
This system is comprised of the nerves associated with the CNS. It connects all nerves of the body to the CNS.
Afferent Nerve Fibers
Transmit impulses from organs and tissues of the body to the CNS.
Efferent Nerve Fibers
Transmit impulses from the CNS to the organs and tissues of the body.
Somatic Nervous System (SNS)
Primarily controls voluntary activities such as walking and riding a bicycle.
Autonomic Nervous System (ANS)
Responsible for activities that are non-voluntary and under unconscious control.
Sympathetic Nervous System
This system focuses on emergency situations by preparing the body for fight or flight.
Parasympathetic Nervous System
This system controls involuntarily processes unrelated to emergencies. This system deals with “rest or digest” activities.
The Ventricles of the Brain
A network of cavities filled with cerebrospinal fluid and consists of 4 cavities.
Cerebrospinal Fluid (CSF)
Ventricles of the brain are filled with this and surround the CNS. Covers the brain and spinal cord.
Cerebellum
This is found beneath the cerebrum and behind the brainstem. It helps coordinate body movements, posture, and balance.
Brainstem
This is found between the thalamus and the spinal cord. It is the lowest part of the brain that connects the brain with the spinal cord. Unconscious functions like breathing, heart rate, and blood pressure are controlled by the brainstem.
Cerebrum
This part of the brain is the largest and part of the forebrain. It controls higher-order functions such as interpreting touch, speech and language, reasoning, emotions, and fine motor control.
Cerebral Cortex
Surrounds the entire cerebrum. It is divided into a left and right hemisphere.
Gyri
Ridges of the cerebral cortex
Sulci
Grooves of the Cerebral Cortex
Fissures
Very large grooves of the vertebral cortex.
Neurons
Nerve cells that make up the nervous system.
Sensory Neurons
Afferent nerve cells that send information toward the CNS. This information is what is sensed, using the five senses, from the external environment.
Motor Neurons
Efferent nerve cells that carry impulses away from the CNS to the effectors, which are typically tissues and muscles of the body.
Interneurons
Nerve cells that act as a bridge between motor and sensory neurons in the CNS. These neurons help form neural circuits, which helps neurons communicate with each other.
White Matter
Found in the spinal cord and surrounds the grey matter. Made up of Myelinated and unmyelinated axons connecting neurons from different parts of the brain.
Grey Matter
The cerebral cortex, a type of neural tissue that contains three types of neurons.
Limbic System
Controls emotions and memory and part of the forebrain.
Hypothalamus
Found between the thalamus, this structure plays a role in regulating the autonomic nervous system. It is primarily concerned with homeostasis and regulates various activities such as hunger, anger, and the response to pain.
Amygdala
Recognized as the aggression center, areas of this region produces feelings such as anger, violence, fear, and anxiety.
Thalamus
Different sensory inputs come through the nerves and end here, which directs this information to various parts of the cerebral cortex. It is the major center for receiving input to the brain from the periphery and the brain stem. It is the center for acquisition of knowledge, awareness, emotion, and memory.
Hippocampus
Helps convert short-term memory to long-term memory.
Cell Body
This is the main part of the nucleus of the nerve cell.
Dendrites
These are appendages attached to the cell body that receives signals from other neurons.
Axon
This is the long structure attached to the cell body. It conducts and transmits information to other cells.
Mylein Sheath
Functions like a blanket that provides a layer of insulation around the axon of a neuron, increasing the speed of electrical signal transmission.
Neural Impulses
Electric signals transmitted by neurons.
Resting Potential
At the resting state, the inside of the neuron is more negatively charged, while the outside of the neuron is more positively charged.
Action Potential
The inside of the neuron becomes more positively charged, while the outside of the neuron becomes more negatively charged.
Neurotransmitters
Proteins on synaptic vesicles that carry chemical messages.
Fill in the blank:
The Brain weighs about __lbs. It contains just __% of the body’s weight but contains __% of the body’s blood supply.
Weighs 3lbs.
2% body’s weight.
20% body’s blood.
What are the coverings collectively of the brain called?
Meninges
Fibrous tissue attaching muscle to the scalp.
Galea Aponeurotica
Dura Mater
“Hard Mother”
Is the outer and toughest covering of the brain & also separates most of the two halves of the brain.
Arachnoid
“Spiderlike”
Is the middle layer covering of the brain. It Circulates cerebrospinal fluid and blood.
Pia Mater
“Delicate Mother”
Is the innermost covering of the brain. It adheres to the brain. if you tear it, you will tear the brain.
Arachnoid Villae
Secrete Cerebrospinal Fluid (CSF) in the brain’s sinus.
How is CFS produced?
It is produced by the Choroid Plexuses, located in the walls of the ventricles. Reabsorbed by the arachnoid villae in the dural venous sinuses.
What are the functions of CFS?
- Provides mechanical protection for the brain and spinal cord, and it provides buoyancy.
- Provides chemical protection: It is the optimal environment for neuron function.
- Circulates nutrients to parts of the brain, and it is an exchange area for wastes.
Blood-Brain Barrier
The brain requires a different operating environment than the body. This barrier separates the two systems.
What are three (3) typical clinical situations for a skull fracture?
- Subdural Hematoma
- Epidural Hematoma
- Subarachnoid Hematoma
Subdural Hematoma
A pool of blood under the dura that puts pressure on the brain.
Epidural Hematoma
A pool of blood between the dura and skull.
Subarachnoid Hematoma
is functionally an intracerebral hemorrhage and is usually untreatable once it occurs, because draining it would cause more brain trauma.
CFS
Cerebrospinal Fluid
Hydrocephalus
Blockage of CFS circulation can cause water in the Brain.
Where does CFS circulate through the Ventricles of the Brain?
Ventricles of the brain are reservoirs of CFS.
- Two Lateral Ventricles are located in the Cerebral Hemisphere.
- The Third Ventricle is in the midline between the halves of the Thalamus.
- The Fourth Ventricle is between the Cerebellum and Brain Stem.
What two main arteries supply blood to the brain?
The Internal Carotid Artery and the Basilar Artery.
formed by the junction of the right and left vertebral arteries
What is The Circle of Willis formed by?
The joining of The Internal Carotid Artery and The Basilar Artery in the Center of the brain.
What arteries branch out from the Circle of Willis?
The Anterior Cerebral Artery, The Middle Cerebral Artery, and The Posterior Cerebral Artery.
What is the function of the Circle of Willis?
The Circle of Willis provides anastomoses for the two sides of the brain and backup for failure of one of our arteries.
Diving Reflex
This reflex shuts off circulation to unneeded parts of the body on immersion in very cold water.
Medulla Oblongata
The continuation of the spinal cord within the skull, forming the lowest part of the brainstem and containing control centers for the heart and lungs.
Foramen Magnum
The hole in the base of the skull through which the spinal cord passes.
Define Ipsilateral and Contralateral .
Ipsilateral - Same Side
Contralateral - Opposite Side
This part of the brain controls the nuclei for cranial nerves V, VI, VII, and VIII.
The Pons (“bridge”)
Diencephalon
Found between the midbrain and cerebrum. It contains the Epithalamus, Thalamus, Hypothalamus, and Ventral Thalamus and the Third Ventricle.
Pineal Gland
Secretes Melatonin, a sleep inducer, and sets the internal biologic clock.
Hypothalamus
Located under the Thalamus. It relays reflexes related to smell.
- It secretes hormones for regulating the hormones of the anterior pituitary gland.
- It is the major regulator of homeostasis. It receives input that is interpreted to correct for changes in osmotic pressure, hormone concentrations, and blood temperature.
- It controls the autonomic nervous system (heart rate, respiration, gastrointestinal tract, urinary bladder) and body temperature.
- It also regulates thirst and hunger responses and controls and regulates rhythms of sleep and wakefulness.
Each hemisphere of the brain is divided into what four lobes?
Frontal, Parietal, Occipital, and Temporal.
Falx Cerebri
Separates the two hemispheres of the brain.
Fill in the Blank:
The nervous system sends ____ signals to individual cells.
The endocrine system secretes ____.
Electrical signals.
Hormones.
What are some of the functions of the Nervous system?
- Efferent Nerves send Efferent Impulses away from the brain to produce action in different organs.
- Sensory Impulses, or Afferent Impulses, deliver information from peripheral nerves to the brain. These impulse stimulate action in response to sensory input.
Integrative Function
Occurs within the Hypothalamus and Midbrain. It analyzes information input from afferent impulses, files these data, and stimulates action in response to sensory input.
Glioma
A malignant tumor of the glial tissue of the nervous system.
Astrocytoma
A type of cancer that can form in the brain or spinal cord that arise from astrocytes.
PNS
Peripheral Nervous System
The Peripheral Nervous System is further divided into 2 other systems. What are they and describe their function.
- Somatic Nervous System (SNS) - Is Voluntary and conducts impulses to the skeletal muscles.
- Autonomic Nervous System (ANS) - Is involuntary and conducts impulses to the internal organs.
The Autonomic Nervous System (ANS) is further divided into 2 other systems. What are they and their functions?
- Sympathetic Nervous System - which controls increases survival activity through “fright-fight-flight” reactions.
- Parasympathetic Nervous System - which controls rest, recovery, and relaxation.
What is the difference between Afferent Impulses and Efferent Impulses?
- Afferent (‘ferre’ means “to carry”), which carry impulses towards the Central Nervous System (sensory).
- Efferent (meaning “away from”), which carry impulses away from the brain toward the periphery (motor).
List the Seven (7) categories of the Spinal and Cranial Nerves.
BONUS: Are they Afferent or Efferent?
- General Somatic Sensory Neurons (afferent)
- Special Somatic Sensory Neurons (afferent)
- General Visceral Sensory Neurons (afferent)
- Special Visceral Sensory Neurons (afferent)
- General Somatic Motor Neurons (efferent)
- General Visceral Motor Neurons (efferent)
- Special Visceral Motor Neurons (efferent)
What are the functions of the General Somatic Sensory Neurons and how are they transmitted?
(Afferent)
Transmit impulses of pain, temperature, touch, proprioception, and vibration. These impulses are transmitted to the brain from the skin, joints, muscles, and cranial nerves.
What are the functions of the Special Somatic Sensory Neurons and how are they transmitted?
(Afferent)
Transmit impulses for vision, hearing, and balance. These impulses are transmitted from the organs of special sense toward the brain via the cranial nerves.
What are the functions of the General Visceral Sensory Neurons and how are they transmitted?
(Afferent)
Transmit information impulses from the autonomic nervous system (ANS) about the condition of the Viscera. The impulses are transmitted to the brain along the cranial nerves and the spinal nerves.
What are the functions of the Special Visceral Sensory Neurons and how are they transmitted?
(Afferent)
Transmit impulses of taste and smell from the organs of special sense to the brain along the cranial nerve.
What are the functions of the General Somatic Motor Neurons and how are they transmitted?
(Efferent)
Transmit outgoing impulses to the skeletal muscles from the brain along the cranial nerves and spinal cord.
What are the functions of the General Visceral Motor Neurons and how are they transmitted?
(Efferent)
Transmit outgoing impulses from the Central Nervous System (CNS) to the Viscera in the Autonomic Nervous System (ANS) (smooth muscle, cardiac muscle, and glands) along the cranial and spinal nerves.
What are the functions of the Special Visceral Motor Neurons and how are they transmitted?
(Efferent)
Transmit outgoing impulses from the Central Nervous System (CNS) along the cranial nerves to the skeletal muscles of facial muscles, larynx, and pharynx.
The brain’s surface is convoluted with Gyri (Plural: Gyrus) and Sulci (Plural: Sulcus). Define them.
- Gyri / Gyrus - a ridge or fold between two clefts on the cerebral surface of the brain.
- Sulci / Sulcus - a groove or furrow, especially one on the surface of the brain.
