Biology And Behaviour Flashcards
What do sensory/afferent neurons do?
Transmit sensory information from receptors to spinal cord and brain
What do motor/efferent neurons do?
Transmit motor information from the brain and spinal cord to muscle and glands
What are interneurons?
Found between other neurons.
Which neurons are the most numerous?
Interneurons
What is the CNS composed of?
Brain and spinal cord
What is the PNS composed of?
Nerve tissue and fibre outside of the brain and spinal cord; helps connect the CNS to the rest of the body
PNS can be split into somatic and autonomic nervous system. They are?
Somatic consists of sensory and motor neurons; sensory through efferent, motor through afferent
Autonomic regulates heartbeat, respiration, digestion, and gland secretion; involuntary muscles -> autonomic, independent of conscious control
Autonomic nervous system split into:
Sympathetic and parasympathetic.
Parasympathetic nervous system:
Conserve energy; resting and sleeping states
- reduce heart rate
- constrict bronchi
- managing digestion by increasing peristalsis and exocrine secretions
- contracts bladder
Which neurotransmitter is responsible for the autonomic nervous system?
Acetylcholine
Sympathetic nervous system:
Activated by stress; fight or flight reactions
- increased HR
- distribute blood to muscles
- increase blood glucose
- decrease digestion and peristalsis
- release epinephrine into blood
- relaxes bronchi
- inhibits bladder contraction
The brain is covered with a thick sheath of connective tissue called the meninges, made up of:
Dura mater -> arachnoid mater -> pia mater
Human brain can be split into 3:
Hindbrain, midbrain, forebrain
Hindbrain and midbrain form the brain stem; developed first
Forebrain:
prosencephalon divides to form telencephalon and diencephalon
Cerebral cortex - perceptual, cognitive, behavioural processes
Basal ganglia - movement
Limbic system - emotion and memory
Thalamus - sensory relay station
Hypothalamus - hunger, thirst, and emotion
Midbrain:
mesencephalon - receives sensory and motor information from rest of body; involuntary reflexes
Inferior and superior colliculi; sensorimotor reflexes
Hindbrain:
rhombencephalon - controls balance, motor coordination, breathing, digestion, arousal
Rhombencephalon - splits into myelencephalon and metencephalon
Cerebellum - refined motor movements
Medulla oblongata - vital functioning like breathing and digestion
reticular formation - arousal and alertness
Cerebral cortex:
Complex perceptual, cognitive, and behavioural processes
Basal ganglia:
Movement
Limbic system:
Emotion and memory
Thalamus:
Sensory relay station
Hypothalamus:
Hunger, thirst, and emotions
Cerebellum:
Refined motor movements
Medulla oblongata:
Vital functioning such as breathing and digestion
Reticular formation:
Arousal and alertness
In prenatal life, the brain develops from?
The neural tube
Myelencephalon becomes the?
Medulla oblongata, which regulates vital functions such as breathing, HR and BP
Metencephalon becomes the?
Pons and cerebellum
Pons contain sensory and motor pathways between cortex and medulla
Cerebellum helps maintains posture and balance; coordinates body movements
Midbrain/Mesencephalon becomes the superior and inferior colliculi, which are?
Superior colliculi receives visual sensory input
Inferior colliculi receives auditory sensory input; eg. Reflexive reactions to sudden noises
Telencephalon becomes the?
Cerebral cortex, basal ganglia, and limbic system
Diencephalon becomes the?
Thalamus, hypothalamus, posterior pituitary and pineal gland
Thalamus:
Relay station for incoming sensory information; sorts and transmits info to appropriate areas of cerebral cortex
Hypothalamus:
Divided into lateral (LH), ventromedial (VMH), anterior (AH)
Controls homeostatic function, behaviour, endocrine functions, autonomic nervous system
Four Fs of the hypothalamus:
Feeding
Fighting
Flighting
Sexual functioning
Lateral hypothalamus (LH):
Hunger center; detects when the body needs food -> triggers eating and drinking
If destroyed, one Lacks Hunger
Ventromedial hypothalamus (VMH):
Satiety center; provides signal to stop eating
If destroyed, one is Very Much Hungry
Anterior hypothalamus:
Controls sexual behaviour
Also sleep and body temperature
Basal ganglia:
Coordinate muscle movement
Receive info from cortex and relay info to brain and spinal cord
Parkinson’s relates to destruction of basal ganglia
Limbic system: septal nuclei, amygdala, hippocampus
Associated with emotion and memory
Septal nuclei associated with?
Pleasure ; addictive behaviours
Amygdala associated with?
Defensive and aggressive behaviours including fear and rage
Hippocampus associated with?
Learning and memory processes; consolidate information to form long-term memories
Cerebral cortex composed of?
Frontal, parietal, temporal, occipital
Frontal lobe composed of:
Prefrontal cortex, motor cortex, and Broca’s area (vitally important for speech production)
Prefrontal cortex manages executive function by supervising and directing operations of other regions, such as perception, memory, emotion, impulse control, and long-term planning. Damage to prefrontal cortex impairs overall supervisory functions.
Primary motor cortex initiates voluntary motor movements by sending neural impulses down the spinal cord toward the muscles.
Parietal lobe composed of:
Somatosensory cortex, which is involved in somatosensory information processing (touch pressure, temperature, pain)
Central region of parietal lobe associated with spatial processing and manipulations; spatial orientation
Occipital lobe contains?
Visual cortex
Temporal lobe is composed of:
Auditory cortex and Wernicke’s area
Auditory cortex is primary site for sound processing.
Wernicke’s area associated with language reception and comprehension.
Dominant hemisphere (usually the left) is:
Primarily analytic in function, managing details; language, logic, math
Whereas non dominant hemisphere is associated with intuition, creativity, music cognition, and spatial processing.
Functions of acetylcholine:
Transmit nerve impulses to the muscles
Linked to attention and arousal
Loss of cholinergic neurons to the hippocampus is associated with Alzheimer’s
Functions of Epinephrine/norephinephrine
Known as catecholamines together with dopamine: all play important roles in emotions
Epinephrine/norepinephrine controls alertness and wakefulness; primary neurotransmitter of sympathetic nervous system
Epinephrine secreted by the adrenal medulla
Functions of dopamine:
Plays important role in movement and posture
High concentrations found in basal ganglia to help smooth movements and maintain posture.
Too much dopamine, oversensitivity to dopamine: schizophrenia
Too little dopamine: Parkinson’s
Functions of serotonin:
Regulating mood, eating, sleeping, and dreaming
Oversupply causes manic states, under supply causes depression
Functions of GABA:
Produces inhibitory postsynaptic potentials; stabilises neural activity in the brain
Causes hyperpolarisation of postsynaptic membrane
Functions of glycine:
Inhibitory; increases chloride influx into neuron, hyperpolarizes
Function of glutamate:
Excitatory neurotransmitter
The endocrine system utilises which chemical messenger?
Hormones; travel to destination through bloodstream
Hypothalamus links endocrine to nervous system; regulates hormonal function of pituitary gland; maintained by the hypophyseal portal
Pituitary “master” gland into anterior and posterior: anterior releases hormones that regulate endocrine glands, itself controlled by hypothalamus
Adrenal gland: adrenal cortex and medulla; medulla releases epinephrine and norepinephrine; cortex produces corticosteroids and testosterone and estrogen
Gonads produce sex hormones in higher concentrations
Neural crest: cells at leading edge of neural folds
Migrate to form disparate tissues, dorsal root ganglia, melanocytes, and calcitonin producing cells
Neural tube will form CNS
Alar plate differentiates into sensory neurons
Basal plate differentiates into motor neurons
Overtime, the neural tubes invaginates and folds over itself multiple times
Rooting reflex
Turning of the head in the direction of a stimulus; towards the nipple
Moro reflex:
React to abrupt movements of their heads by reaching arms out and crying
Babinski reflex:
Causes toes to spread apart when sole is stimulated
Grasping reflex:
When infant closes fingers around object placed in hand
Gross motor skills progresses from:
Head to toe in development
Social skills move from:
Parent oriented to self oriented to other oriented in development
