Anatomy and physiology- Nervous system Flashcards
what are the components of the CNS (Central nervous system)
Brain
Cerebellum
Spinal cord
What are the components of the PNS (Peripheral Nervous System)
Cranial nerves
Peripheral nerves
Nerve plexi
Autonomic nervous system: sympathetic and parasympathetic
what is the CNS?
The Central Nervous System (CNS): This is made up of the brain and spinal cord. Nerve fibres branching out into the rest of the body from the CNS form the peripheral nervous system.
what is the PNS?
The Peripheral Nervous System (PNS): The peripheral nerves constantly send information to and from the CNS. Some nerves in the PNS form into groups to keep important areas under fine control
what are the three main divisions of the PNS (Peripheral Nervous System)?
autonomic, sensory and motor.
Define autonomic in terms of the PNS
involuntary actions. Two divisions: sympathetic and parasympathetic.
Define Sensory in terms of the PNS
Sensory - transmit information from around the body to the CNS.
Define Motor in terms of the PNS
Motor - carry signals from the brain to voluntary skeletal muscles.
What is a neuron/nerve cell?
The basic unit of the nervous system is a special cell called a neuron or nerve cell. It has a cell body with a nucleus and projections called axons and dendrites.
What is the function of Axons?
Axons carry nerve impulses
What is the function of dendrites?
Dendrites receive impulses
what is The myelin sheath?
The myelin sheath (think of insulation on an electrical wire) has a number of functions including protecting the nerves from other electrical impulses, and speeding the time it takes for a signal to travel down the axon.
what are Effectors?
The peripheral tissue at the end of the neural pathway.
what are the 3 different types of neurons?
Motor neurons
Sensory neurons
Interneurons
what is the function of motor neurons?
Motor neurons transmit messages from the brain to the muscles to generate movement
What is the function of sensory neurons
Sensory neurons detect light, sound, odour, taste, pressure, and heat and send messages about those things to the brain.
What is the function of interneurons?
Interneurons - carry information between two neurons (sensory and motor neurons)
neurons communicate with one another at junctions what are these called
synapses
What is the brain stem?
The brain stem = is the lowest section of the brain which connects it to the spinal cord
What is the brain stem?
The brain stem = is the lowest section of the brain which connects it to the spinal cord
what are the three main parts of the brain?
- The brain stem = is the lowest section of the brain which connects it to the spinal cord.
- The cerebellum = is at the back of the brain stem and is linked to it by nerve tracts.
- The cerebrum = it is the largest part of the brain.
where is the cerebellum
The cerebellum = is at the back of the brain stem and is linked to it by nerve tracts.
what is the cerebrum?
The cerebrum = it is the largest part of the brain.
What are the two parts of the cerebrum?
the cerebral cortex and the cerebral hemispheres
The cerebrum is divided into 4 sections or lobes, what are these?
- Frontal, 2. Temporal, 3. Parietal, 4. occipital
What is the cerebral cortex?
The cerebral cortex is the outer layer of the brain and contains grooves and ridges, which increase the surface area. The cerebral cortex is formed of neurons that lack the myelin sheath covering, and appears pinkish-grey. There is white matter that lies beneath the grey matter:
What is white matter composed of?
White matter is composed of bundles of myelinated axons which connect the various grey matter regions together.
what is the function of Myelin?
Myelin acts as an insulator and hence nerve signals are transmitted at greater speed through white matter.
what is grey matter composed of?
Grey matter is composed of the neuronal cell bodies and dendrites, as well as unmyelinated nerve fibres.
What is the function of grey matter?
Grey matter functions as the regions of the brain where information is processed.
what is the hypothalamus?
Hypothalamus: is located in the floor of the third ventricle and is the master control of the autonomic system
What is the function of the hypothalamus?
plays a role in controlling behaviours such as hunger, thirst, sleep, and sexual response. It also regulates body temperature, blood pressure, emotions, and secretion of hormones.
what is the pituitary gland?
Lies in a small pocket of bone at the skull base and is connected to the hypothalamus of the brain by the pituitary stalk. Known as the “master gland,” it controls other endocrine glands in the body
what is the function of the pituitary gland?
It secretes hormones that control sexual development, promote bone and muscle growth, and respond to stress.
What is the pineal gland?
Pineal gland (body): once called the ‘third eye,’ the pineal gland is a small gland located deep in the centre of the brain and is located behind the third ventricle
What is the function of the pineal gland?
It helps regulate the body’s internal clock and circadian rhythms by secreting melatonin. It has some role in sexual development.
What is the Thalamus?
serves as a relay station for almost all sensory information that comes and goes to the cerebral cortex
What is the function of the thalamus?
It plays a role in pain sensation, attention, alertness and memory.
What is the Corpus callosum?
The corpus callosum is a large bundle of more than 200 million myelinated nerve fibers that connect the two brain hemispheres, permitting communication between the right and left sides of the brain
what is the function of the corpus callosum?
The primary function of the corpus callosum is to integrate motor, sensory, and cognitive performances between the cerebral cortex on one side of the brain to the same region on the other side.
What is the Pons?
Pons: (which means “bridge” in Latin is middle part of the brain stem)
what is the function of the Pons?
Relays messages from the cerebral cortex and the cerebellum. Any messages descending from the brain or ascending to it must cross this critical “bridge-like” structure
what is the function of the Pons?
Relays messages from the cerebral cortex and the cerebellum. Any messages descending from the brain or ascending to it must cross this critical “bridge-like” structure
what is the Medulla?
the lower half of the brain stem
what is the function of the medulla?
it’s functions are involuntary, or done without thought. It helps regulate breathing, heart and blood vessel function, digestion, sneezing, and swallowing. This part of the brain is a centre for respiration and circulation.
what is the midbrain?
Midbrain: the upper part of the brain stem and connects the forebrain (cerebrum) and the hindbrain (cerebellum)
what is the function of the midbrain?
serves important functions in motor movement, particularly movements of the eye, and in auditory and visual processing
what are the brain ventricles?
four cavities located within the brain that contain cerebral spinal fluid (CSF).
what is The choroid plexus?
The choroid plexus is a plexus (a network of vessels and specialised cells) that produces the cerebrospinal fluid in the cerebral ventricles of the brain
The choroid plexus serves two important functions in the body, what are these?
It produces cerebrospinal fluid that helps to cushion and support the brain and protect it from damage.
Provides a barrier between the blood that protects the brain and central nervous system tissue from toxins and pathogens.
The meninges refer to the membranous coverings of the brain and spinal cord. There are three layers of meninges, known as?
the dura mater, arachnoid mater and pia mater.
what is dura mater?
Dura mater is the outer layer that also lines the skull bone.
what is the Arachnoid mater?
Arachnoid mater contains the blood vessels (the subarachnoid space below this is filled with CSF)
what is the pia mater?
Pia mater is the lower layer that covers the brain
what is the Function of spinal cord?
Sensory messages from the sensory organs pass upward through the spinal cord to the brain.
Motor signals from the brain pass downward through the spinal cord to the neurons (in the peripheral nervous system) that lead to the glands or muscles.
The somatic nervous system also mediates involuntary reflex arcs. The somatic nervous system consists of three parts, what are these?
Spinal nerves
Cranial nerves
Association
what are spinal nerves?
Spinal nerves: they are the peripheral nerves that carry sensory information into and motor commands out of the spinal cord.
What are cranial nerves?
Cranial nerves: they are the nerve fibers that carry information into and out of the brain stem. They include smell, vision, eye, eye muscles, mouth, taste, ear, neck, shoulders, and tongue.
what are association nerves?
Association nerves integrate and connect sensory input and motor output; these nerves number in the thousands
How many segments of nerves are there in the human body?
There are 43 segments of nerves in the human body. With each segment, there are sensory and motor nerves
how many segments of paired nerves are in the spinal cord?
31
How many nerves are paired in the brain?
12 nerves paired in the brain
what are the spinal nerves (name)
8 pairs of cervical spinal nerves
12 pairs of thoracic spinal nerves
5 pairs of lumbar spinal nerves
5 pairs of sacral spinal nerves
1 pair of coccyx spinal nerves
What nerve in the brain is used for smell
Olfactory
What nerve in the brain is used for vision?
Optic
What nerves in the brain are used for eye movement?
Oculomotor and Trochlear
what nerve in the brain is used for mastication/face sensation?
Trigeminal
what nerve in the brain abducts the eye
abducent
what nerve in the brain is responsible for facial expression?
Facial
what nerves in the brain are responsible for taste?
Facial and Glossopharyngeal
what nerve in the brain is responsible for hearing and balance?
vestibulocochlear
what two nerves in the brain are responsible for gag reflex
Glossopharyngeal and Vagus
what nerve in the brain is responsible for gag reflex and peristalsis?
Vagus
what nerve in the brain is responsible for a shoulder shrug
Accessory
what nerve in the brain is responsible for swallowing and speech
Hypoglossal
Name 2 parts of the brain located in the diencephalon
It is divided into four main parts including the epithalamus, thalamus, subthalamus, and hypothalamus
The opening in the skull through which the spinal cord travels from is called
Foramen magnum
Name 2 functions of the CSF, what does CSF stand for
Cerebrospinal fluid (CSF), provides nourishment, waste removal, and protection to the brain
Briefly describe the sympathetic nervous system
The sympathetic nervous system connects the internal organs to the brain by spinal nerves
Briefly describe the parasympathetic nervous system
Your parasympathetic nervous system is a network of nerves that relaxes your body after periods of stress or danger. It also helps run life-sustaining processes, like digestion, during times when you feel safe and relaxed
Name 4 functions of the parietal lobe
sensory perception and integration, including the management of taste, hearing, sight, touch, and smell.
Name 4 functions of the frontal lobe
memory, emotions, impulse control, problem solving, social interaction, and motor function.
Briefly describe the importance of myelin
This myelin sheath allows electrical impulses to transmit quickly and efficiently along the nerve cells
Briefly describe what bodily functions are controlled by the cerebellum
motor skills such as balance, coordination, and posture.
Describe the somatic nervous system.
Your somatic nervous system is a subdivision of your peripheral nervous system that stretches throughout nearly every part of your body. The nerves in this system deliver information from your senses to your brain. They also carry commands from your brain to your muscles so you can move around.
Describe the autonomic nervous system
The autonomic nervous system is a component of the peripheral nervous system that regulates involuntary physiologic processes including heart rate, blood pressure, respiration, digestion, and sexual arousal.
how many layers are their in a human eye?
three
what are the three layers of the eye?
The outer layer called the fibrous coat
The middle layer, called the vascular coat
The inner layer of photoreceptors and neurons called the nervous coat
