6) Nervous System Flashcards
(49 cards)
Somatic vs autonomic nervous system
voluntary VS involuntary
Somatic: we are in control of reaction
Autonomic: regulation of functions of internal organs like heart
What does the cerebrum do
The right hemisphere controls muscles on the left side of the body. Left hemisphere controls the right. It controls speech, emotions, reading, thinking and learning
What does the cerebellum do
It is the back of the brain and controls balance and walking and talking
What does the brain stem do
It controls hunger, thrust and basic body functions like breathing
What is the somatic nervous system
Contains sensory neurons + motor neurons from the CNS to the skeletal muscles.
Eg. Knee jerk, withdrawal reflex
What is the autonomic nervous system
Contains sensory neurons + motor neurons from CNS to smooth muscle, cardiac muscles and glands
Eg. Pupil reflex, “fight and flight”, “rest and digest”
What are neurones
They are specialized cells that function to conduct nerve impulses
Description of cell body
Contains a nucleus, endoplasmic reticulum, ribosomes, Golgi apparatus, mitochondrion, and other organelles
Description of dendron
Cytoplasmic extensions from the cell body. The end branches of dendrons are called dendrites. Transmit nerve impulses toward cell body
Description of axon
Cytoplasmic extensions from cell body
Ends are called axon terminals
Transmits nerve impulses away from cell body
Description of myelin sheath
Insulates axon
Speeds up conduction of nerve impulses along axon
Description of node of ranvier
Regions where myelin sheath is absent
Description of axon terminals
Transmit nerve impulses to next neuron
Structure of spinal chord
Made up of bundles of nerve fibers
Carries messages between brain and rest of body
General functions of nervous systems
Sensory receptors -> processing of information -> effector
All parts of eye?
Sclera Iris Cornea Pupil Aqueous humor Suspensory ligament Vitreous humour Choroid Retina Macula Optic nerve Optic disc
Define a synapse
A junction between two neurons or a junction between a neurone and an effector such as a muscle or a gland
Voluntary action be involuntary action
Does not involve sensory neurons, controlled consciously, involves brain
VS
involves sensory neurones, controlled unconsciously and may or may not involve brain
Describe reflex action knee-jerk reflex
(Brain not involved/ no relay neuron involved)
1) tap applied at patella tendinitis which stretches the upper thigh muscle
2) stretch receptor detects stretching of thigh muscle
3) sensory neurons transmits nerve impulses to CNS
4) motor neuron transmits impulses from CNS to effector
5) effector: upper thigh muscles contracts and causes the leg to kick upwards
Describe reflex action withdrawal reflex
1) finger placed near the heat
2) heat receptor on skin detect heat
3) sensory neurons transmit nerve impulses to spinal chord
4) spinal chord: nerve impulses are transmitted across a synapse to the relay neurone
5) then across another synapse to the motor neuron that transmits the nerve impulse to effector
6) effector: bicep muscle contracts and causes hand to withdraw
Features of sclera
White fibrous coat that extends from cornea to posterior of eye ball and it is avascular
Features of aqueous humour
Watery fluid
Features of vitreous humour
Jelly-like substance
Features of cornea
Transparent
Denser than air
Avascular
