RESPONDING TO THE ENVIRONMENT (HUMANS) Flashcards
WHAT ARE THE COMPONENTS THAT HELP HUMANS RESPOND TO THE ENVIRONMENT
- nervous system (involving nerves)
- endocrine system (involving hormones)
EXPLAIN WHY IS THERE A NEED FOR A NERVOUS SYSTEM IN HUMANS
- reaction to stimuli (stimuli can be external and internal)
- coordination of the various activities of the body
EXPLAIN THE FUNCTION OF A NERVE
nerves send and carry signals to and from all parts of the body and are made up of neurons
DESCRIBE THE FUNCTIONS OF SENSORY AND MOTOR NEURONS
SENSORY:
* conduct nerve impulses from the receptors to the CNS and are mostly unipolar
MOTOR:
* conduct nerve impulses from the CNS to the effectors and are multipolar
DESCRIBE THE FUNCTIONS OF PARTS OF THE SENSORY AND MOTOR NEURONS
THE CELL BODY, CYTOPLASM, MYELIN SHEATH AXON AND DENDRITES
CELL BODY:
* consists of cytoplasm and a prominent nucleus.
* cytoplasm contains dark granules which are rich in RNA and involved in protein synthesis
DENDRITES:
* conducts nerve impulses towards the cell body
AXONS:
* conducts nerve impusles away from cell body
MYELIN SHEATH:
* the myelin sheath insulates the nerve fibres and accelerates the transmission of nerve impulses
DESCRIBE THE FUNCTION OF THE CEREBRUM
STATE LOCATION OF CEREBRUM
- largest part of the brain, folds and grooves that enlarge the brain surface
- controls voluntary actions
- receives and interprets sensations from sense organs
- higher thought processes
DESCRIBE THE FUNCTION OF THE CORPUS CALLOSUM
STATE THE LOCATION OF THE CORPUS CALLOSUM
- c-shaped structure between the two hemispheres of the cerebrum
- connects the left and right hemispheres of the brain - allowing communication between both hemispheres
DESCRIBE THE FUNCTION OF THE CEREBELLUM
STATE THE LOCATION OF THE CEREBELLUM
- situated behind and below the cerebellum
- coordinates all voluntary movements
- controls muscle tension to maintain balance
DESCRIBE THE FUNCTION OF THE MEDULLA OBLONGATA
STATE THE LOCATION OF THE MEDULLA OBLONGATA
- an extension of the spinal cord and has the same structure
- transmits nerve impulses between the spinal cord and the brain
- controls involuntary actions
DESCRIBE THE FUNCTION OF THE SPINAL CORD
STATE THE LOCATION OF THE SPINAL CORD
- starts just below the foramen magnum and extends through the vertebral canal of the vertebral column of the lumbar region
- provides a pathway for nerve impulses to and from the brain. nerve impulses from receptors enter the spinal cord via spinal nerves. impulses are then transmitted along ascending tracts in the spinal cord to the brain. the impulses are transmitted from the brain, via motor neurons in descending tracts, back down the spinal cord
- the spinal cord contains reflex centres that initiate reflex
DESCRIBE THE FUNCTION OF THE SPINAL CORD
STATE THE LOCATION OF THE SPINAL CORD
- starts just below the foramen magnum and extends through the vertebral canal of the vertebral column of the lumbar region
- provides a pathway for nerve impulses to and from the brain. nerve impulses from receptors enter the spinal cord via spinal nerves. impulses are then transmitted along ascending tracts in the spinal cord to the brain. the impulses are transmitted from the brain, via motor neurons in descending tracts, back down the spinal cord
- the spinal cord contains reflex centres that initiate reflex actions.
STATE THE LOCATION AND FUNCTION OF THE PERIPHERAL NERVOUS SYSTEM
- 12 pairs of cranial nerves to/from the brain
- 31 pairs of spinal nerves to/from the spinal cord
- conducts nerve impulses from the receptors to the CNS via the sensory neurons
- conducts nerve impulses from the CNS to the effectors via the motor neurons
SUMMARISE THE AUTONOMIC NERVOUS SYSTEM LOCATIONS AND FUNCTIONS
SYMPATHETIC NERVOUS SYSTEM AND PARASYMPATHETIC NERVOUS SYSTEM
- heart - increases heart rate, decreases heart rate
- blood vessels in skin - blood vessels constrict, blood vessels dilate
- blood vessels of the heart, lungs and skeletal muscles - blood vessels dilate, blood vessels constrict
- digestive system - decreases peristalsis and digestion, increases peristalsis and digestion
- muscles of the bronchioles - muscles relax and bronchioles dilate, muscles contract and bronchioles constrict
- muscle of the eye - radial muscles contract, circular muscles relax, pupils dilate , radial muscles relax, circular muscles contract, pupils constrict
- sweat glands - stimulates sweat production
- liver - stimulates conversion of glycogen to glucose
- adrenal medulla - stimulates the release of adrenalin
DEFINE REFLEX ACTION AND REFLEX ARC
- a reflex action is a rapid, involuntary response of an effector to a stimulus received by a receptor
- a reflex arc is the pathway along which nerve impulses are transmitted from a receptor to an effector to bring about a response to a stimulus during a reflex action
DEFINE THE DIFFERENCES BETWEEN THE SYMPATHETIC NERVOUS SYSTEM AND THE PARASYMPATHETIC NERVOUS SYSTEM
- the SNS prepares the body for an emergency
- the PSNS allows the body to return to normal after stimulation by the SNS