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#	Question	Answer
1	Which two systems jointly coordinate and integrate body activities?	The neural system and the endocrine system jointly coordinate and integrate body activities.
2	What type of coordination does the neural system provide?	The neural system provides an organised network of point-to-point connections for quick coordination.
3	What does the endocrine system provide?	The endocrine system provides chemical integration through hormones.
4	What are neurons?	Neurons are highly specialised cells that can detect, receive and transmit different kinds of stimuli.
5	How is the neural system organised in Hydra?	In Hydra, the neural system is composed of a network of neurons.
6	Into which two parts is the human neural system divided?	The human neural system is divided into the central neural system (CNS) and peripheral neural system (PNS).
7	What does the CNS include?	The CNS includes the brain and spinal cord and is the site of information processing and control.
8	What does the PNS comprise?	The PNS comprises all the nerves of the body associated with the CNS.
9	What are the two types of nerve fibres in the PNS?	The two types are afferent fibres and efferent fibres.
10	What is the function of afferent nerve fibres?	Afferent nerve fibres transmit impulses from tissues/organs to the CNS.
11	What is the function of efferent nerve fibres?	Efferent nerve fibres transmit regulatory impulses from the CNS to the concerned peripheral tissues/organs.
12	Into which two divisions is the PNS divided?	The PNS is divided into the somatic neural system and autonomic neural system.
13	What is the role of the somatic neural system?	It relays impulses from the CNS to skeletal muscles.
14	What is the role of the autonomic neural system?	It transmits impulses from the CNS to involuntary organs and smooth muscles.
15	Into which systems is the autonomic neural system further classified?	It is classified into sympathetic and parasympathetic neural systems.
16	What is the visceral nervous system?	It is a part of the peripheral nervous system comprising nerves, fibres, ganglia and plexuses connecting the CNS and viscera.
17	What are the three major parts of a neuron?	Cell body, dendrites and axon.
18	What is the function of dendrites?	Dendrites transmit impulses towards the cell body.
19	What is an axon?	The axon is a long fibre whose distal end is branched.
20	What is a synaptic knob?	Each branch of the axon terminates in a bulb-like structure called a synaptic knob.
21	What do synaptic vesicles contain?	Synaptic vesicles contain chemicals called neurotransmitters.
22	In which direction do axons transmit nerve impulses?	Axons transmit nerve impulses away from the cell body to a synapse or neuromuscular junction.
23	What are the three types of neurons based on the number of axons and dendrites?	Multipolar, bipolar, and unipolar neurons.
24	What is a multipolar neuron?	A multipolar neuron has one axon and two or more dendrites and is found in the cerebral cortex.
25	What is a bipolar neuron?	A bipolar neuron has one axon and one dendrite and is found in the retina of the eye.
26	What is a unipolar neuron?	A unipolar neuron has a cell body with one axon only and is usually found in the embryonic stage.
27	What are the two types of axons?	Myelinated axons and non-myelinated axons.
28	What forms the myelin sheath around myelinated nerve fibres?	Schwann cells form the myelin sheath around the axon.
29	What are nodes of Ranvier?	The gaps between two adjacent myelin sheaths are called nodes of Ranvier.
30	Where are myelinated nerve fibres commonly found?	They are found in spinal and cranial nerves.
31	Where are unmyelinated nerve fibres commonly found?	They are commonly found in autonomous and somatic neural systems.
32	Why are neurons called excitable cells?	Neurons are excitable because their membranes are in a polarised state.
33	What is resting potential?	The electrical potential difference across the resting plasma membrane is called resting potential.
34	What is depolarisation?	Reversal of membrane polarity at the stimulated site is called depolarisation.
35	What is action potential?	The electrical potential difference across the plasma membrane at the stimulated site is called action potential or nerve impulse.
36	How is nerve impulse conducted along the axon?	Current flow reverses polarity at adjacent sites, generating action potentials sequentially along the axon.
37	Through what structures is a nerve impulse transmitted from one neuron to another?	A nerve impulse is transmitted through junctions called synapses.
38	What is a synapse?	A synapse is formed by the membranes of a pre-synaptic neuron and a post-synaptic neuron, which may or may not be separated by a synaptic cleft.
39	What are the two types of synapses?	Electrical synapses and chemical synapses.
40	What is the characteristic feature of electrical synapses?	In electrical synapses, pre- and post-synaptic membranes are in very close proximity and electrical current flows directly between neurons.
41	Why is transmission faster in electrical synapses?	Because electrical current flows directly from one neuron to another.
42	Are electrical synapses common in humans?	No, electrical synapses are rare in our system.
43	What separates neurons at a chemical synapse?	A fluid-filled space called the synaptic cleft.
44	Which chemicals are involved in transmission at chemical synapses?	Neurotransmitters.
45	Where are neurotransmitters stored?	Neurotransmitters are stored in synaptic vesicles present in axon terminals.
46	What happens when an impulse reaches the axon terminal?	Synaptic vesicles move towards the membrane and fuse with the plasma membrane.
47	What happens after synaptic vesicles fuse with the plasma membrane?	Neurotransmitters are released into the synaptic cleft.
48	What do released neurotransmitters bind to?	They bind to specific receptors on the post-synaptic membrane.
49	What is the effect of neurotransmitter binding on the post-synaptic membrane?	It opens ion channels allowing entry of ions and generation of a new potential.
50	What type of potentials may develop in the post-synaptic neuron?	Excitatory or inhibitory potentials.
51	What is the role of the brain in the body?	The brain is the central information processing organ and acts as the command and control system.
52	Name some functions controlled by the brain.	Voluntary movements, balance, involuntary organ functions, thermoregulation, hunger, thirst, circadian rhythms, endocrine activities, and behaviour.
53	What higher mental functions are processed by the brain?	Vision, hearing, speech, memory, intelligence, emotions, and thoughts.
54	What protects the human brain?	The skull and cranial meninges protect the brain.
55	Name the three layers of cranial meninges.	Dura mater, arachnoid, and pia mater.
56	Which meningeal layer is in direct contact with brain tissue?	Pia mater.
57	Into which three major parts is the brain divided?	Forebrain, midbrain, and hindbrain.
58	What are the components of the forebrain?	The forebrain consists of cerebrum, thalamus, and hypothalamus.
59	Which is the major part of the human brain?	Cerebrum forms the major part of the human brain.
60	Into what is the cerebrum divided?	The cerebrum is divided longitudinally into left and right cerebral hemispheres.
61	What connects the two cerebral hemispheres?	The cerebral hemispheres are connected by corpus callosum.
62	What is the cerebral cortex?	The cerebral cortex is the layer of cells covering the cerebral hemispheres.
63	Why is the cerebral cortex called grey matter?	It is called grey matter because neuron cell bodies are concentrated there, giving it a greyish appearance.
64	What are association areas of the cerebral cortex responsible for?	They are responsible for intersensory associations, memory, and communication.
65	What is white matter in the cerebrum?	Fibres of tracts covered with myelin sheath forming the inner part of the cerebral hemisphere are called white matter.
66	What is the function of the thalamus?	Thalamus is a major coordinating centre for sensory and motor signalling.
67	Where is the hypothalamus located?	The hypothalamus lies at the base of the thalamus.
68	What functions are controlled by the hypothalamus?	It controls body temperature, urge for eating, and drinking.
69	What are hypothalamic hormones secreted by?	They are secreted by neurosecretory cells in the hypothalamus.
70	What structures form the limbic system?	Inner parts of cerebral hemispheres and associated deep structures like amygdala and hippocampus form the limbic lobe or limbic system.
71	What are the functions of the limbic system?	It is concerned with olfaction, autonomic responses, regulation of sexual behaviour, expression of emotional reactions, and motivation.
72	Where is the midbrain located?	The midbrain is located between the thalamus/hypothalamus of the forebrain and pons of the hindbrain.
73	Which canal passes through the midbrain?	The cerebral aqueduct passes through the midbrain.
74	What are corpora quadrigemina?	Four round swellings present in the dorsal portion of the midbrain are called corpora quadrigemina.
75	What are the components of the hindbrain?	Pons, cerebellum, and medulla oblongata.
76	What is the function of pons?	Pons consists of fibre tracts that interconnect different regions of the brain.
77	Why does the cerebellum have a highly convoluted surface?	To provide additional space for many more neurons.
78	What functions are controlled by the medulla oblongata?	Respiration, cardiovascular reflexes, and gastric secretions.
79	Which structures form the brain stem?	Midbrain, pons, and medulla oblongata form the brain stem.
80	What is the function of the brain stem?	It forms connections between the brain and spinal cord.
81	What is resting potential?	The electrical potential difference across the resting neural membrane is called resting potential.
82	In what form is nerve impulse conducted along the axon membrane?	As a wave of depolarisation and repolarisation.
83	Which neuron structures are asked to be differentiated?	Dendrites and axons.