Nervous System + conscious and unconscious response +spinal reflex Flashcards
Main parts of the nervous system
Central Nervous system: brain and spinal cord
Peripheral nervous system: autonomic Nervous System- sympathetic and parasympathetic Nervous System. And Somatic Nervous System
Central Nervous System:
Consist of brain and spinal cord; PROCESSES INFORMATION received from the INTERNAL AND EXTERNAL ENVIRONMENTS and ACTIVATES RESPONSES. Carries messages to and from the PNS
Brain
PROCESSES INFO RECEIVED through NEURAL PATHWAYS FROM THE BODY AND DIRECTS ACTIONS within it
Spinal cord:
2 major functions:
RECEIVE SENSORY INFO FROM THE BODY (via pns) and send these MESSAGES to the BRAIN FOR PROCESSING
RECEIVE MOTOR INFO FROM THE BRAIN and send it to relevant parts of the body (via pns) to control muscles, glands and organs so that actions can be taken.
Peripheral nervous system
Network of NERVES LOCATED OUTSIDE THE CNS.
Carries sensory information TO THE CNS from the body’s MUSCLES, ORGANS AND GLANDS (about the internal environment) and FROM THE SENSORY ORGANS (about the external environment)
Carries motor information FROM THE CNS to the body’s muscles, organs and glands.
Somatic Nervous System
Network of nerves that carries SENSORY INFORMATION to the CNS and MOTOR INFORMATION FROM THE CNS to body’s voluntary muscles
Autonomic Nervous System
connects the CNS TO THE BODY’S INTERNAL ORGANS (heart, stomach, liver) and GLANDS (sweat, salivary,adrenal), providing FEEDBACK TO THE BRAIN about THEIR ACTIVITIES
SELF REGULATION SYSTEMS
divides into SYMPATHETIC and PARASYMPATHETIC NS
Sympathetic Nervous System
Sub division of autonomic ns
Responsible for INCREASING the activity of most VISCERAL muscles, organs and glands in times of VIGOROUS ACTIVITY, STRESS OR THREAT.
When activated in times of threat, it works immediately
Parasympathetic Nervous System
Sub division of the autonomic Nervous System
Responsible for maintaining INTERNAL BODY ENVIRONMENT in a steady BALANCED state of NORMAL FUNCTIONING; CALMS OR RESTORES the body to its NORMAL STATE OF FUNCTIONING after and EXTREME EMOTION SUBSIDES or a THREAT HAS PASSED.
dominates most of the time.
Takes longer to return the body to its normal state due to lingering hormones released during sympathetic activation
Reasons for Activation
HEART RATE INCREASES to pump blood (& nutrients/ oxygen) around the body faster, carrying more oxygen & glucose to the muscles.
BLOOD PRESSURE INCREASES to push blood through capillaries at a faster rate to reach muscles for use.
BREATHING RATE GOES UP to take in more oxygen
BRONCHIOLES DILATE to allow more oxygen into lungs
PUPILS DILATE to let in more light and enhance vision
DIGESTION is slowed to divert oxygen to muscles to allow a faster response to threat
RELEASE OF SUGAR Provides instant energy to skeletal muscles and increase alertness
RELEASE OF ADRENALIN to activate muscles and organs to deal with the threatening situation and increase alertness
What is a conscious response to a sensory stimuli
is a reaction that INVOLVES AWARENESS.
Response will be: usually voluntary, purposeful and with some control
What is an unconscious response to a sensory stimulus?
A reaction that does NOT INVOLVE AWARENESS
Involuntary, unintentional, automatic and we cannot ordinarily control its occurrence.
Usually to avoid danger or minimise burn
Spinal reflex
An UNCONSCIOUS, INVOLUNTARY and AUTOMATICALLY occurring response to CERTAIN STIMULI sources WITHIN SPINAL CORD and WITHOUT any involvement of the brain.
IMMEDIATE RESPONSE- faster reaction time
ADAPTIVE RESPONSE- saves time, may minimise harm or save the life of the organism
PROVIDES INFO about the functioning of NS absconded of reflex could indicate damage.
Spinal Reflex process
- SENSORY RECEPTORS detect a STIMULUs
- SENSORY NEURONS carry the message along a SENSORY PATHWAY to the SPINAL CORD.
- INTERNEURONS in the SPINAL CORD relay the message to motor neurons
- MOTOR NEURONS carry the message along a MOTOR PATHWAY to hand muscles? causing a withdrawal reflex? the object (stimulis) is released before the brain perceives pain.
- WWhile the SPINAL REFLEX occurs, INTERNEURONS are also carrying the (?) message further up the spinal cord to the BRAIN
- A muscle contraction occurs in The hand? UNCONSCIOUSLY moves away from the SENSORY STIMULI in order to protect itself
- The message is received in the thalamus? And INTERPRETS it as PAIN
