Comparison of nervous systems Flashcards
conscious/subconscious control
The somatic nervous system:
The autonomic nervous system:
conscious
Subconscious
The somatic nervous system: What are the effectors?
skeletal muscle
The autonomic nervous system: What are the effectors?
Smooth/cardiac muscle
myelinated/unmyelinated
The somatic nervous system:
The autonomic nervous system:
myelinated
unmyelinated
Autonomic nervous system:neurotransmiter
- noradrenaline
- acetylcholine
which out of the somatic and autonomic nervous system has 2 antagonist sub-systems
The autonomic nervous system
autonomic/somatic nervous system:
Which is involved in the eye-blink reflex
The somatic nervous system
autonomic/somatic nervous system: involved in iris reflex (pupil dilation)
The autonomic nervous system
autonomic/somatic nervous system:
involved in heart rate control
The autonomic nervous system
autonomic/somatic nervous system:
Involved in ventilation movements
The autonomic nervous system
autonomic/somatic nervous system:
Involved in swallowing reflex
The somatic nervous system
autonomic/somatic nervous system:
Involved in temperature control
The autonomic nervous system
Explain the function of the Autonomic Nervous System
The autonomic nervous system includes all the motor neurones that take information to the internal organs. It controls the activity of the smooth muscle in the body (arteries/arterioles and the wall of the gut). It also control the rate of beating of the cardiac muscles.
Most of the activities that are controlled by the autonomic nervous system are not usually under voluntary control.
The autonomic nervous system is divided into two components:
- The Sympathetic Nervous System
2. The Parasympathetic Nervous System
The sympathetic nervous system
The motor neurones of the sympathetic nervous system go to all the organs within the body. The neurotransmitter that they release is called Noradrenaline.
Noradrenaline has similar effects on target tissues as the hormone adrenaline.
Noradrenaline causes an increase in
heart rate
Breathing rate;
Blood pressure
Dilation of pupil of the eye
Define antagonism
A mammal is rarely fully relaxed or active. The two divisions work ANTAGONISTICALLY
Opposing signals from the two types of neurones adjust an organ’s activity to an appropriate level –such as HEART RATE.
Control of heart rate:
What part of the brain influence heart rate?
The cardiovascular system in the medulla oblongata. Nerves from here affect the frequency of contractions; action potentials sent along the accelerator nerve increase heart rate, those sent along the vagus nerve decrease heart rate.
Control of heart rate:
Controlled by a region of the brain called the medulla oblongata.
The medulla oblongata has two centres:
Centre which increases heart rate- linked to the sinoatrial node by sympathetic nervous system.
Centre which decreases heart rate –linked to sinoatrial node by the parasympathetic nervous system.
CO2 and pressure changes in the blood stimulate parts of the brain via receptors
Describe how the sympathetic and parasympathetic nervous systems are involved in the control of ventilation rate (4marks).
- During exercise there is an increased rate of respiration
- This cause the pCO2 to increase/blood pH CO2 to fall
- This is detected by the chemorecptors in the aortic bodies
The key areas of the brain that are associated with speech and language are found in the:
Left hemisphere. Motor portions of language are attributed to Broca’s area within the frontal lobe.
Speech comprehension is attributed to what area?
Wernicke’s area at the temporal-parietal lobe junction.
These two regions are interconnected by a large white matter tract, the arcuate fisculus
Explain the location an function of Broca’s area
Located in the frontal lobe of the left hemisphere only;
Involved in production of articulate speech, clear and fluent.
Motor neurones from Broca’s area stimulate the muscles of the mouth, larynx, intercostal muscles and diaphragm to produce vocal sounds
Describe the possible effects of injury to the Brocas area
Injury to Broca’s area can cause difficulty in speaking. The individual may know what words he or she wishes to speak, but will be unable to do so. The condition is called Broca’s aphasia (or expressive aphasia).
Describe the possible effects of injury to the Wernicke’s area
located in the temporal lobe of the left hemisphere only, next to the primary auditory cortex.
Involved in the interpretation of both written and spoken language, referred to as the language comprehension centre.
Vital for locating appropriate words from memory to identify meaning.
Describe the possible effects of injury to the Wernicke’s area
People who have damage in this area of the brain can not understand someone speaking to them, even though they can hear perfectly. A condition called Wernicke’s aphasia (or Receptive Aphasia)
Briefly describe the concept of the sensory/ motor homunculus
Some parts of the body contain more receptors than others, and consequently a larger area of brain is devoted to them.
What is the motor homunculus?
This model shows what a personsbody would look like if each part grew in proportion to the area of the cortex of the brain concerned with its movement
What is the sensory homunculus?
This model shows what a man’s body would look like if each part grew in proportion to the area of the cortex of the brain concerned with its sensory perception
