UNIT 3: BIOLOGICAL BASIS OF BEHAVIOUR Flashcards
Are the central building blocks of the nervous system, 100 billion strong at birth.
Neurons or Nerve Cells
Is an electrically excitable cell that processes and transmits information by electrical and chemical signaling.
Neurons or Nerve Cells
TYPES OF NEURONS
Carry incoming information from the sensory receptors to the brain and spinal cord.
Sensory Neurons
TYPES OF NEURONS
Carry outgoing information from the brain and spinal cord to the muscles and glands.
Motor Neurons
TYPES OF NEURONS
The brain and spinal cord that communicate internally and intervene between the sensory inputs and motor outputs
Interneurons
STRUCTURE
- A neuron’s outer surface is made up of a ____.
- This structure allows smaller molecules and molecultes withouth electrical charge to pass through it, while stopping larger or highly charged molecules
Semipermeable membrane
PARTS OF A NEURON
Contains the nucleus of the neuron
Soma/Cell Body
PARTS OF A NEURON
Cluster of fibers that extends from the soma
Dendrites
PARTS OF A NEURON
Serves as an input sites where signals are received from other neurons
Dendrites
PARTS OF A NEURON
A thin fiber that connects neurons
Axon
PARTS OF A NEURON
This is where signal are transmitted electrically from soma to other neurons
Axon
PARTS OF A NEURON
It ends in multiple terminal buttons
Axon
PARTS OF A NEURON
Range in length from a fraction of an inch to several feet
Axon
PARTS OF A NEURON
A productive coat of fat and protein that wraps around the axon.
Myelin Sheath
PARTS OF A NEURON
Acts as an insulator, increasing the speed at which the signal travels.
Myelin Sheath
PARTS OF A NEURON
Crucial for the normal operation of the neurons.
Myelin Sheath
PARTS OF A NEURON
- Contains synaptic vesicles (houses neurotransmitters, the chemical messengers of the nervous system).
- Found at the end of the axon
Axon Terminal
Defined as a sudden, fast, transitory, and propagating change of the resting membrane potential. Only neurons and muscle cells are capable of generating this neural impulse; the property is called the excitability.
Action Potential
Information moves along a neuron in the form of neural impulse called an?
Action Potential
An electrochemical impulse that travels from the cell body down to the end of the axon.
Action Potential
- Happens when there are differences in the concentrations of the ions, inside and outside of the cell.
- -70 mV is present when neurons are at rest.
Resting Potential
These are in-charge of letting in and out of ions.
Ion Channels
Some channels only open at a certain voltage, there are referred to as?
Voltage-gated Ion Channels
What causes the Action Potential?
- Caused by a stimulus with certain value expressed in millivolts (mV).
- A stimulus must have a sufficient electrical value.
TYPES OF THRESHOLDS OF STIMULI
Cannot cause an action potential.
Subthreshold Stimuli
TYPES OF THRESHOLDS OF STIMULI
- Enough to produce an action potential. (Nerve Impulse)
- Usually around -50 mV to -55 mV.
Threshold Stimuli
TYPES OF THRESHOLDS OF STIMULI
Also produces an AP, but have higher strength than Threshold Stimuli.
Suprathreshold Stimuli
PHASES OF A ACTION POTENTIAL
Is the initial increase of the membrane potential to the value of the threshold potential
Hypolarization
PHASES OF ACTION POTENTIAL
The threshold potential opens voltage-gated sodium channels and causes a large influx of sodium ions.
Depolarization
PHASES OF ACTION POTENTIAL
During this phase, the inside of the cell becomes more electropositive, until the potential gets closer the electrochemical equilibrium for sodium of 61+ mV.
Overshoot
PHASES OF ACTION POTENTIAL
- The sodium permeability suddenly decreases due to the closing of its channels.
- The overshoot value of the cell potential opens voltage-gated potassium channels, which causes a large potassium efflux, thus decreasing the cell’s eletropositivity.
Repolarization
PHASES OF ACTION POTENTIAL
- A state in which the membrane potential is more negative than the default membrane potential.
- After that the membrane establishes again the values of membrane potential
Hyperpolarization
- Divided into Central Nervous System (CNS) and Peripheral Nervous System (PNS)
- Includes the brain (the part of the nervous system that resides in the skull) and the spinal cord.
Nervous System
Lies outside the brain and spinal cord
Peripheral Nervous System (PNS)
Peripheral Nervous System is Composed of ____ nerve pairs: nerves ____ emerging from the brain, and ____ nerves emerging from the spinal cord.
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31
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Peripheral Nervous System has two types of neuron, namely ____ and ____
Sensory neurons (afferents)
Motor neurons (efferent).
Body’s processing centre.
Central Nervous System (CNS)
Made up of the brain and spinal cord.
Central Nervous System (CNS)
Controls most of the functions of the body, including: awareness, movement, thinking, speech, and the 5 senses — seeing, hearing, feeling, tasting and smelling
Central Nervous System (CNS)
TYPES OF NEURONS FOUND IN THE PNS
Detect sensations (e.g. heat, pain)
Sensory/Afferent Neurons
TYPES OF NEURONS FOUND IN THE PNS
Transmits messages towards the central nervous system
Sensory/Afferent Neurons
TYPES OF NEURONS FOUND IN THE PNS
Transmits messages away the central nervous system to the effector
Motor/Efferent Neurons
TYPES OF NEURONS FOUND IN THE PNS
Examples of effectors are muscles, skin, sense organs, etc.
Motor/Efferent Neurons
TYPES OF NEURONS FOUND IN THE PNS
Divided into Somatic and Autonomic
Motor/Efferent Neurons
TYPES OF MOTOR/EFFERENT NEURONS
Handles the voluntary movements of the body
Somatic
TYPES OF MOTOR/EFFERENT NEURONS
Innervates the outer sections of the body (e.g. skin and skeletal muscles).
Somatic
TYPES OF MOTOR/EFFERENT NEURONS
Handles the involuntary movements of the body
Autonomic
TYPES OF MOTOR/EFFERENT NEURONS
Innervates the internal organs (responsible for the heart beating, breathing, and etc.)
Autonomic
Complements the nervous system by regulating the body’s internal environment through hormones, which are chemical messengers secreted into the bloodstream. Each hormone affects specific target cell equipped with receptors for that hormone.
Endocrine System
PARTS OF THE ENDOCRINE SYSTEM
Serves as the control center, regulating the pituitary gland and, through it other endocrines.
Hypothalamus
PARTS OF THE ENDOCRINE SYSTEM
Located in the lower middle part of the brain
Hypothalamus
PARTS OF THE ENDOCRINE SYSTEM
Lies below the hypothalamus
Pituatary Gland
PARTS OF THE ENDOCRINE SYSTEM
Known as the “Master Gland” because it produces the most different hormones and controls the secretion activity of other endocrine glands.
Pituatary Gland
PARTS OF THE ENDOCRINE SYSTEM
Secretes hormones that control growth, metabolism, and other glands.
Pituatary Gland
PARTS OF THE ENDOCRINE SYSTEM
Produces melatonin, a hormone that helps regulate the body’s sleeo-wake cycle
Pineal Gland
PARTS OF THE ENDOCRINE SYSTEM
Regulates the level of sugar in the bloodstream by secreting insulin
Pancreas
PARTS OF THE ENDOCRINE SYSTEM
Located in the neck
Thyroid
PARTS OF THE ENDOCRINE SYSTEM
Regulates metabolism through the secretion of hormones
Thyroid
PARTS OF THE ENDOCRINE SYSTEM
Secrete hormones like adrenaline and cortisol to help the body manage stress and emergencies.
Adrenal Glands
PARTS OF THE ENDOCRINE SYSTEM
The outside part; Adrenal Cortex secretes hormones that regulate sugar and salt that keeps the body balanced and help resist stress. Also responsible for growth of pubic hair.
Adrenal Glands
PARTS OF THE ADRENAL GLAND
The inside part; ____, secretes two hormones that arouse the body to deal with stress and emergencies: ____
Adrenal Medulla
Epinephrine (Adrenaline) and Norepinephrine (Noradrenaline).
PARTS OF THE ENDOCRINE SYSTEM
In Females, the ovaries produce hormones that regulate sexual development, ovulation, and growth of sex organs
Gonads
PARTS OF THE ENDOCRINE SYSTEM
In Males, the testes produce hormones that regulate sexual development, production of sperm, and growth of sex organs.
Gonads