MIR ASRAR

 Ncert shortnotes on human respiratory system Human respiratory system consists of a pair of nostrils, pharynx, larynx, bronchi and bronchioles that finally terminates into alveoli. Nasal chamber  open into pharynx that leads to  larynx . Larynx contains voice box (sound box) that help in sound production. The trachea, primary, secondary and tertiary bronchi and initial bronchioles are supported by  incomplete cartilaginous rings  to prevent collapsing in absence of air. Each bronchiole terminates into an irregular walled, vascularized bag like structure called  alveoli . The branching network of bronchi, bronchioles and alveoli collectively form the lungs. Two lungs are covered with double layered  pleura  having pleural fluid between them to reduce the friction on lung surface. Conducting parts  include nostrils, pharynx, larynx and trachea. Main functions include- Transport of atmospheric air to alveoli. Removing foreign particles from air, humidifying it and bringing it to body tem

 __This is what i make for u is  ncert shortnotes. CENTRAL NERVOUS SYSTEM The brain is the central information processing organ of our body, and acts as the ‘command and control system’. It controls the voluntary movements, balance of the body, thermoregulation, and the brain also processes vision, hearing, speech etc. The human brain is well protected by the skull. Inside the skull, the brain is covered by  cranial meninges  consisting of an outer layer called  dura mater a very thin middle layer called  arachnoid and an inner layer called  pia mater . The brain can be divided into three major parts: forebrain midbrain hindbrain Fig. Brain  Forebrain The forebrain consists of cerebrum thalamus hypothalamus A deep cleft divides the cerebrum longitudinally into two halves, which are termed as the left and right  cerebral hemispheres . The hemispheres are connected by a tract of nerve fibres called  corpus callosum . The layer of cells which covers the cerebral hemisphere is called  cere