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