5.1.5 Plant And Animal Responses Flashcards
What are the two sections of the mammalian nervous system?
Central and Peripheral Nervous system
What is the difference between the somatic and autonomic nervous system?
- Somatic = Conscious control from sense organs
- Autonomic= Subconscious control
What is a ganglion?
Collection of nerves outside of central nervous system
What is the function of the brain?
Processes information from receptor cells and hormonal system
What is the cerebrum used for?
Voluntary actions
How is the cerebrum adapted for its role?
Highly folded: Large surface area so more neurones
Cerebral cortex contains three layers for sensory,association and motor
what is the role of the cerebellum?
Unconscious actions
What is the role of medulla oblongata?
Autonomic functions e.g. heart rate
What is the role of the hypothalamus?
Regulates temperature water and patterns of behaviour
What is the role of the anterior pituitary gland?
FSH and growth hormone
What is the role of the posterior pituitary gland?
Stores and releases hormone made by hypothalamus
What are the features of the sympathetic nervous system?
Fight or flight
Increases activity
What is the structural organisation of the sympathetic neurones?
Pre ganglionic- Short,lightly myelinated and secrete acetyl choline
Posy ganglionic- long, unmyelinated and secrete noradrenaline
What are the features of the parasympathetic nervous system?
Rest and digest
So decrease activity
What are the features of the parasympathetic structural organisation?
Pre ganglionic neurone- Lightly myelinated and long
Post ganglionic neurone- Unmyelinated and short
Both secret acetylcholine
Why are reflexes important for survival?
- Avoids harm/ damage to the body
- Prevents overloading of brain when response is always the same
What is the difference between the knee jerk and blinking reflex?
Knee Jerk goes through only spinal cord
Blinking reflex only goes through brain not through spinal cord s
What is the nervous system process during the fight of flight response?
- Involves sympathetic nervous system
- Impulses activate smooth muscles and glands including adrenal medulla
What is the hormonal system process during fight or flight?
Adrenal cortisol system is activated ny releasing CRF
Release of ACTH by pituitary gland
ACTH binds too cells of adrenal cortex and stimulates release of hormones
What is the process of glycogenolysis triggered by adrenaline?
- Adrenaline binds to receptor activating adenyl cyclase enzyme
- Converts ATP to cAMP on inner surface of membrane
- Increased cAMP activates protein kinases which phosphorylase and activate other enzymes
- Enzymes added convert glycogen to glucose
How is the need for a change in heart rate detected?
Baroreceptors- detect changes of blood pressure in aorta,vena cava and carotid arteries
Chemoreceptors- Detect chemical changes in blood
How is heart rate increased via the sympathetic nervous system?
Via accelerator nerve which increases generation of SAN in heart
How is heart rate decreased by the parasympathetic nervous system?
Via the vagus nerve
What is a neuromuscular junction?
The connector between motor neurones and muscle cells
How does an action potential travel across a neuromuscular junction to stimulate a response?
- Action potential arrives at end of neurone and neurotransmitter is released
- Neurotransmitter binds to receptors on sarcolemma depolarising membrane
- Depolarisation travels along t tubules
- Ca2+ released from sarcoplasmic reticulum
- Ca2+ bind to muscle leading to contraction
What are three key features of muscle cells?
- Elongated cells which form fibres
- Conduct action potentials
- Contractile properties