The human brain and nervous system Flashcards
The nervous system
CNS - brain and spinal cord
PNS - nerves and sensory organs of the body outside of the brain and spinal cord
Anatomical directions
Caudal <——————–> Rostral
Posterior <—————> Anterior
^ Dorsal v Ventral
Neurons
Sensory - respond to external stimuli, transmit sensory information to CNS (afferent = arriving)
Motor - carry messengers from CNS to muscles and glands. (efferent = exiting)
Interneurons - transmit messages to other neurons
Features of the PNS
- Somatic: in contact with the external environment:
conveys information from sensory detectors to the brain and controls movement - Autonomic: internal environment: regulates internal functioning e.g. digestion, respiration, circulation, secretion of sex hormones
Both systems use:
- AFFERENT nerves (sensory information TOWARDS CNS)
- EFFERENT nerves (motor signals AWAY from CNS to the organs).
Autonomic NS
Sympathetic - activated by conditions that promote arousal e.g. increase heart rate, energy expenditure
- Fight or Flight system
Parasympathetic - activated by conditions of recovery e.g. decrease heart rate, energy conservation
- Rest and Digest system
Divisions of the brain
- Hindbrain
- Midbrain
- Forebrain
The Hindbrain
Myelencephalon
- Medulla - controls basic functioning (breathing) and involved in reflex responses
Metencephalon
- Cerebellum - involved in the development and coordination of movement
- Pons - regions involved in motor control and sensory analysis
The Midbrain
Mesencephalon
- Tectum - relays visual and auditory information
- Superior colliculus (visual)
- Inferior colliculus (auditory)
Tegmentum
- Substantia nigra - movement and reward
- Red nucleus - basic body movements
- Reticular formation - controls consciousness and arousal
The forebrain
Diencephalon
- Epithalamus - contains pineal gland
- Thalamus - relay station for sensory info transmitted to cerebral cortex
- Hypothalamus - sensor for human’s basic needs
Telencephalon
- Limbic system (emotion)
Amygdala (fear and anger)
Cyngulate gyrus (+ and - emotions, pain and attentional processes)
Hippocampus (memory)
- Basal Ganglia - voluntary movement, muscle tone and posture
Caudate nucleus
Putamen
Globus pallidus
The four lobes of the brain
Frontal lobe
- Posterior region - primary motor cortex involved in the control of voluntary body movements
Anterior region - prefrontal cortex complex intellectual functioning
Occipital lobe
- Initial visual reception which is passed to temporal and parietal lobes
Parietal lobe
- Anterior region - somatosensory cortex (sensory info)
- Posterior region - complex visual processing (where an object is)
Temporal lobe
- Auditory information - language processing, comprehension of words
- Memory functions
- Complex visual processing (what an object is)