biology
1.Human interaction and coordination
Interaction
- Essential for survival
- Internal/external stimuli
Changes in the environment affecting the body
- Sensory receptors
Receive stimuli
Some of them found in sense organs
- The nervous system (neurons)
Information processor
Receives information from sensory receptors and initiates the appropriate response, coordinating and integrating all the cell functions
- Effector organs
Endocrine system
- Endocrine glands
- Hormones
Musculoskeletal system
- Muscles and bones
- Movement
2.Nerve cells
Two type of cell
- Neurons
Highly specialised
Star-shaped cells
Don´t regenerate
- Dendrites
- Soma
- Nerve fibre
- Neuroglia
Support, nourish and protect neurons
- Astrocytes
- Oligodendrocytes
- Schwann cells
3.Nerve impulses and synapses
Synapses: when the nerve impulse passes from one neuron to the next via connections
3 parts
- Presynaptic terminal
End of axon of first neuron
Contains numerous synaptic vesicles that store neurotransmitters
- Synaptic cleft
Small space between 2 neurons
- Postsynaptic terminal
Dendrites or soma of the second neuron
Process
- The nerve impulse reaches the end of the presynaptic neuron’s axon
- The neuron releases the neurotransmitters in the synaptic vesicles into the synaptic cleft
- The neurotransmitters cross the synaptic cleft
- They join to specific receptors in the membrane of the postsynaptic neuron
- This generates a new electric current or nerve impulse in the second neuron
- The new impulse passes from the soma to the end of the axon
4.The nervous system
Coordinates all the body´s functions
Responsible for intellectual function, emotions and feelings
Divided into two parts
- Central nervous system
Responsible for higher cognitive functions, general sensory integration and coordination
Consists of two parts
- Grey matter
Neuron somas and dendrites
- White matter
Neuron axons covered in the myelin sheath
Consists of brain and spinal cord , protected by
- Skull and spinal column
- Meninges
Nerve cells
- Sensory neurons
Carry information from the receptors to the central nervous systems
- Motor neurons
Carry information from the central nervous system to the effector organs
- Interneurons
Connect sensory and motor neurons
5.The endocrine system
Endocrine glands that produce hormones
- Nerve information
Transmitted by electrical impulses and chemical messengers
Quick response
- Endocrine information
Transmitted by chemical messengers (travel through the blood to their target cells)
Lower response
Hypothalamic-pituitary axis
- Regulates function of endocrine system
- Regulates the activity of the pituitary gland using hypothalamic releasing hormones
- The hypothalamus sends out releasing hormones which stimulate the pituitary gland to secrete/produce pituitary hormones
- The pituitary hormones act on their target organs. These organs are endocrine glands that respond by secreting other hormones
- When these final hormones are released, blood receptors send message to the hypothalamus and pituitary gland, preventing the secretion of their respective hormones
- This stops he cascade of hormone release
Pituitary hormones
- Vasopressin
- ACTH
- Oxytocin
- TSH
- FSH
- LH
- GH
- LTH
Endocrine glands
- Pineal gland
Regulates sleep cycle
- Pituitary gland
Pituitary hormones
- Parathyroid glands
Parathyroid hormone
- Thyroid gland
Thyroxine – stimulates cell metabolism, growth and development
Calcitonin – bone calcification by reducing blood calcium levels
- Pancreas
Insulin – reduces blood glucose levels and stimulates storage of glycogen
Glucagon – increases blood glucose levels
- Adrenal glands
Cortex – corticosteroids
Medulla – adrenaline
- Testicles
Androgens
Testosterone
- Ovaries
Oestrogens
Progesterone
6.Nervous and endocrine system health
Drugs
- Substances that affect the normal activity of the central nervous system
- Cause different feelings, from relaxation to euphoria
Withdrawal syndrome
- Physiological dependence on drugs or alcohol
Brain
- Cerebral cortex
Receives, interprets and process information from sense organs
Voluntary motor responses
Intellectual and mental functions
Regulates function of the rest of the nervous system
- Limbic system
Regulates endocrine system
Responsible for emotions, feelings and basic instincts
- Cerebrum
- Cerebellum
Motor coordination and balance
Movements precise and coordinated
Makes us aware of our spatial orientation
- Brain stem
Regulates the autonomic functions that keep us alive
(Heartbeat, respiratory movements, blood pressure…)
- Hypothalamus
Controls the pituitary gland (regulates the endocrine system and autonomic nervous system)
Regulates hunger, thirst, body temperature, biological rhythms
- Epithalamus
Contains the pineal gland
Regulates sleep cycle, menstrual cycle…
- Thalamus
Association of pleasure/displeasure
Like/dislike feelings to sensory stimuli
Spinal cord
- Connected to the brain stem
- White matter-outside
- Grey matter-inside
- Sensory root
Stimuli
- Spinal ganglion
Sensory branch of spinal nerve
- Motor root
Answer
- Conduit function
Information from the sense organs
Brain´s responses
- Reflex function
Involuntary motor responses
- Peripheral nervous system
Connects central nervous system to the peripheral organs, receptors and effectors
Nerve
- Axons isolated by their myelin sheath
- Covered in a layer of connective tissue
Nerve ganglion
- Cluster of nerve cell bodies
Two types
- Cranial nerves
Emerge from the brain
- Spinal nerves
Emerge from the spinal cord
Branch off all over the body
Cranial and spinal can be
- Sensory
Information from sensory organs
- Motor
Information to effector organs
- Mixed
Both types of information
Autonomic nervous system
- Parasympathetic nervous system
Constricts pupils
Stimulates saliva
Slows heartbeat
Constricts airways
- Sympathetic nervous system
Dilates pupils
Inhibits saliva
Increases heartbeat
Relaxes airways
Somatic nervous system
- Sensory nerves
- Motor nerves
- Controls voluntary acts and reflexes
- Voluntary actions and reflexes
Voluntary actions
- Generated consciously in an area of the cerebral cortex
Reflexes
- Generated consciously in the spinal cord
- Rapid response
- Involve reflex arc
+ Sensory neuron
In the nerve ganglia
Information from the sensory receptors
+ Interneuron
In the grey matter of the spinal cord
+ Motor neuron
In the grey matter
Reflex response to effector organ