Nervous system Flashcards
1
Q
What are the structural components of the brain?
A
- Cerebrum - divided into left and right cerebral hemisphere.
- Cerebellum - mass of cells under cerebrum.
- Corpus callosum - connects left cerebral hemisphere to right.
- Thalamus - directly under the corpus callosum.
- Hypothalamus - under the thalamus.
- Pituitary gland - next to the hypothalamus and is divided into a posterior and anterior region.
- Pons - connects medulla oblongata to hypothalamus.
- Medulla oblongata - under the hypothalamus, connected to it by the pons.
2
Q
What is the structure of the cerebrum?
A
- Divided into 2 identical hemispheres; the left and right cerebral hemispheres.
- The 2 hemispheres are connected by a mass of fibres called the corpus callosum, allowing information to be transmitted from one half to the other.
- Folded into gyri (ridges) and sulci (furrows) to increase surface area of cerebral cortex (containing grey matter - cell bodies of neurones in the cerebrum) to maximise the number of cell bodies that fit, hence the neurones in the cerebrum.
- Each hemisphere subdivided into 4 lobes: Frontal, parietal, occipital and temporal.
- Each hemisphere also divided into areas that fit into 3 groups depending on function:
1. Sensory areas - Receives impulses (indirectly) from receptors in the body.
2. Association areas - Compares input with past experience to interpret input and formulate response.
3. Motor areas - sends impulses to effectors to carry out appropriate responses. - Motor areas on left hemisphere control movement on right of body and vice versa.
3
Q
What are the functions of the cerebrum?
A
- Conscious thought.
- Emotional responses.
- Intelligence.
- Reasoning and judgment.
- Logic.
- Ability to override certain reflexes.
4
Q
What are the functions of the cerebellum?
A
- Coordination of muscle movement and posture.
- Involved in activities such as:
1. Muscular activities associated with balance and posture.
2. Judging position of objects and limbs.
3. Fine muscular tensions related to playing instruments and using tools. - All impulses that go to and from motor area in cerebrum go through cerebellum where they are modified and adjusted to meet requirements, to ensure muscular activities are smooth and coordinated.
- Involved with activities requiring little thought; including playing instruments and catching balls.
5
Q
Which sensors supply the cerebellum with information?
A
- Light sensors in the retina - involved in judging position.
- Balance organs in inner ear - involved with judging position and balance.
- Spindle fibres in muscles - gives information about muscular tension. Involved with judging posture and position.
- Joints - involved with judging position and posture of limbs.
6
Q
What are the functions of the medulla oblongata?
A
- Controls non-skeletal muscles (cardiac and involuntary).
- Controls autonomic nervous system.
- Cardiac centre controls heart rate and stroke volume.
- Respiratory centre controls breathing rate and tidal volume.
7
Q
What are the functions of the hypothalamus?
A
- Effectively connects nervous system with endocrine system.
- Major control centre in endocrine system.
- Major regulator in homeostasis.
- Good blood supply and many receptors in order to closely monitor internal environment; including, blood water potential and temperature.
- Controls pituitary gland, which secretes hormones.
8
Q
Why do animals need to respond to their environment?
A
- To detect danger and coordinate muscular movement involved in either fight or flight.
- To detect changes in the internal and external environment in order to maintain a constant internal environment so that their cells are not damaged/ metabolise efficiently.
9
Q
How is the the nervous system organised?
A
- The vertebrate nervous system is made up of the Central Nervous System (CNS) and the Peripheral Nervous System (PNS).
- The CNS consists of the brain and spinal chord.
- The PNS is divided into the autonomic nervous system (involuntary) and somatic nervous system (voluntary).
- The autonomic nervous system is further divided into the sympathetic and parasympathetic nervous system.
10
Q
What is the structure and function of the CNS?
A
- Consists of the brain and spinal chord.
- Made up of grey matter (cell bodies) and white matter (axons and dendrons of CNS neurones).
- Involved with coordination and all higher cognitive functions in an organism.
11
Q
What is the structure and function of the PNS?
A
- Consists of the autonomic and somatic nervous system.
- Consists of sensory and motor neurones.
- Involved with carrying information from receptors to CNS and from CNS to effectors.
12
Q
What is the structure and function of the somatic nervous system?
A
- Consists of sensory neurones carrying information relating to sensations.
- Consists of motor neurones carrying impulses from motor areas in cerebrum to voluntary skeletal muscles.
- Involved with controlling all muscles under conscious control; skeletal muscles.
13
Q
What is the structure and function of the autonomic nervous system?
A
- Divided into the sympathetic and parasympathetic nervous system.
- Consists of sensory neurones that carry information about homeostatic factors in the body, such as blood pH and pressure, to the medulla oblongata and and other factors such as temperature to the hypothalamus.
- Consists of motor neurones efferent from medulla oblongata that connect to cardiac and pulmonary muscles.
- Involved with controlling all non-voluntary nervous activity in the body including homeostasis, cardiac and other involuntary muscles.
14
Q
What are the differences between the somatic and autonomic nervous system?
A
- Most somatic neurones are myelinated while most autonomic neurones are non-myelinated.
- Autonomic connections to effectors always consist of 2 or more neurones connected via swelling called ganglion while all somatic connections to effectors only consist of one.
- There are 2 types of autonomic nerves, sympathetic and parasympathetic while there is only one type of somatic nerve.
15
Q
Why are sympathetic and parasympathetic nerves usually regarded as antagonistic?
A
Because in many cases, the effect of one on a certain activity is usually opposed by the effect of the other.
