The Biology Behind Behavior Flashcards
What are the fundamental building blocks of the nervous system?
Neurons and glial cells
Define neurons
Specialised cells that receive, conduct, and transmit electrochemical signals allowing for two way communication between the body and brain
What are dendrites?
Bushy fibers which receive information and conduct it towards the cell body
What is an axon?
Conducts information away from the dendrites to the muscles or glands or the dendrites of other neurons
What is a synapse?
The junction between adjacent neurons where chemical signals in the form of neurotransmitters, are transmitted across minuscule gaps
Do you dendrites receive or transmit information?
Signal receivers
Do you axons conduct or receive signals?
Conduct signals
What do Schwann cells do?
Produce myelin
What is myelin?
A lipid membrane surrounding the axon that helps increase signal transmission
In the central nervous system what are groups of cell body is called?
Nuclei
In the central nervous system why are groups of axons called?
Tracts
In the peripheral nervous system what are groups of cell body is called?
Ganglia
In the peripheral nervous system what are those of axons called?
Nerves
What are the three different types of neurons in the nervous system?
(1) Sensory neurons (afferent neurons)
(2) Motor neurons (efferent neurons)
(3) interneurons
What are sensory neurons?
Afferent nerve runs but send information from sensory receptors and body tissues towards the central nervous system for processing.
Why are motor neurons?
Efferent neurons that send information away from the central nervous system to glands and muscles
What are interneurons?
They send information between motor and sensory neurons, and are primarily located within the central nervous system
What are glial cells?
Provide protection and support for neurons, maintain homoeostasis, and form myelin
What is myelin? What cells form it?
A fatty insulation wrapping axons to increase the speed and efficiency of signal conduction. Formed by glial cells.
How does multiple sclerosis develop?
When the myelin sheet is damaged, nerve signals slow down and stop if this degeneration persists, caused by inflammation of an autoimmune response the disease develops
What are the symptoms of multiple sclerosis?
Loss of motor control, visual impairments, loss of coordination, slurred speech, and numbness and weakness in the limbs
What are the four main types of glia?
Oligodendrocytes, Schwann cells, microglia, and Astrocytes
What are Oligodendrocytes?
Wrap myelin extensions around the axons of neurons in the central nervous system
What is the purpose of Schwann cells?
Wrap myelin to one segment of a single neuron in the peripheral nervous system
Can Schwann cells and Oligodendrocytes direct axonal regeneration after damage?
Only Schwann cells can direct axonal re-generation after damage. (Located in the PNS)
What is the function of microglia?
They react to damage or disease as a macrophage would, they multiply, trigger inflammatorily responses and engulf cellular debris
What are astrocytes?
Astrocytes vary greatly in function, (1) Some astrocytes cover blood vessels throughout the brain and are in contact with the cell bodies of neurons. These astrocytes help regulate the passage or prevention of certain chemicals between the blood and central nervous system neurons
(2) other types of astrocytes have been shown to modulate neuronal activity, control the blood brain barrier, and to establish and sustain effective synopsis
What does neuronal function and communication depend on?
Membrane potential of each cell
What is membrane potential?
The difference in electrical charge between the exterior and interior of the cell that allows information to be passed from one area of the body to another
What does the internal fluid of an axon at rest mostly contain?
Negatively charged ions
What does the external fluid of an axon at rest usually contain
Mostly positively charged ions
What is the measurement of an axon at rest called? What is this value?
Resting potential, -70 mV
Is the resting potential of an axon considered to be polarised or non-polarised
Polarised
When a neuron fires, the selective permeability of the axon surface changes either to decrease or increase the resting membrane potential. When A net gain occurs what does the membrane potential become?
Depolarised
When a neuron fires, the selective permeability of the axon surface changes either to decrease or increase the resting membrane potential. When A net loss of positively charged ions occurs what does the membrane potential become?
Hyperpolized
When post synaptic depolarisations occur, does this increase or decrease the neurons chance of firing? What is this called?
It increases the neurons chances of firing, this is called excitatory post synaptic potentials (EPSPs)
When post synaptic hyperolarization occur, does this increase or decrease the neurons chance of firing? What is this called?
Decrease the neurons chances of firing, inhibitory post synaptic potentials
What type of responses are EPSPs and IPSP? What does this term mean?
Graded responses, their answer to this are proportional to the intensity of the original signals that create them (strong signals generate large postsynaptic potentials, and weak signals generate small post synaptic potentials)
What must the neuron do since it receives hundreds of thousands of signals? In what two ways does it do this?
It must integrate the incoming EPSP and IPSP signals into one signal. This occurs both spatially and temporally.
What is spatial summation
Adds incoming EPSP or IPSP signals that are received simultaneously on different parts of the receptive membrane to account for many areas of input.
What is temporal summation?
Occurs when high-frequency post synaptic potential overlap with one another and Sammy to create a more intense signal
In temporal summation, where does summation occur?
The axon hillcock–The base of the cell body that connects to the axon
What is a threshold level? What is its value?
If the sum of excited Tori signals and inhibitory signals exceeds and minima intensity sufficient to depolarise the membrane past it’s threshold level (usually about -55mV) this generates an action potential
Once an action potential is triggered what occurs?
Adjacent Axson all statements causing more and more action potential is to fire is triggering the next action potential
Are action potentials graded responses?
No, increasing depolarisation past it’s threshold will not increase the intensity of the neural impulse
What type of responses are action potentials?
All or none responses; they occur either fully or not at all
Increasing the intensity of the stimulus or number of stimuli will not change the intensity of the response
What are chemical messengers called? when do they release?
Neurotransmitters; they are released into the synaptic left between neurons when an action potential reaches the axon terminal
Where are neurotransmitters located before release into the synaptic cleft?
Each neuron prepackages the appropriate neurotransmitter into vesicles the cluster near the pre-synaptic membrane is rich in voltage activated calcium channels
When do you voltage activated calcium channels open? What does this allow?
Voltage activated calcium channels open when stimulated by action potentials. This causes an influx of calcium ions into the axons terminal button, causing synaptic vesicles to fuse with the presynaptic membrane is followed by the subsequent release of neurotransmitters into the cleft period neurotransmitter molecules bind to post synaptic receptors and excite (generate EPSPs) or inhibit (generate IPSPs) the post synaptic neurons ability to fire. Then excess neurotransmitters are reabsorbed.
What is reuptake?
When the presynaptic neuron reabsorbs excess neurotransmitters
What are the two types of neurotransmitters?
Small molecule neurotransmitters and large molecule neurotransmitters
What are the four types of small molecule neurotransmitters
Acetylcholine, amino acids, monoamines, and unconventional neurotransmitters
What is the name of the large molecule neurotransmitters
Neuropeptides
What is the function of Acetylcholine?
Muscle stimulation, learning and memory
What are the behavioural and physical mail functions associated with ACh?
Motor control loss and dementia and all is Eimers disease characterised by the deterioration aCh producing an hour on this
What is the function of glutamate
It has a major role in mediating excitatory signals; involved in cognition, memory, and learning
What is associated with behavioural and physical now functions of glutamate?
Imbalance associate with memory loss in all timers disease; oversupply associated with Maranda and D crease in motor control in ALS patients
What is the function of GABA?
It plays a major role in mediating inhibitory signals; involved in motor control and vision
What behavioural and physical malfunctions are associated with GABA?
Deficiency associated with seizures, tremors, and anxiety
What is the function of norepinephrine?
Major role in controlling alertness and arousal; increases heart rate
What behavioural and physical now functions are associated with norepinephrine
Imbalance associated with mood disorders, manic depression
What is the function of dopamine?
Major role in award motivated behaviour; influences attention, emotion, and movement
What is associated with behavioural and physical malfunctions of dopamine?
Undersupply associated with tremors in muscle rigidity in Parkinson’s disease; oversupply associated with schizophrenia and impulsive behaviour
What is the function of seratonin?
Major role in the regulation of mood, appetite, arousal, and sleep
What is associated with behavioural and physical now functions of serotonin?
Undersupply associated with depression, sleep problems, and compulsive behaviour
What is the function of nitrous oxide?
Involved in redox signalling; relaxes gastrointestinal smooth-muscle; vasodilator
What behavioural and physical malfunctions are associated with nitrous oxide?
Deficiency associated with depressed mood and impulsive behaviour
What is the function of endorphins?
Pain and stress inhibitors
What behavioural and physical malfunctions are associated with endorphins?
Undersupply associated with hyper sensitivity to pain and depression; oversupply associated with in sensitivity to pain and addictive behaviour
Where is acetylcholine present?
It is present at every junction between motor neurons and skeletal muscles
What does ACh uptake by muscle cells causes the muscles to do?
Contract
When ACh transmission is blocked what occurs?
Muscle contraction occurs resulting in paralysis
When ACh is released into the central nervous system what role does it play
Plays a role in learning and memory
What type of neurotransmitter is ACh?
Small molecule neurotransmitters
What type of neurotransmitter are amino acid’s?
Small molecule neurotransmitter
What type of neurotransmitter are Monoamines?
Small molecule neurotransmitters
What type of neurotransmitter is unconventional neurotransmitters?
Small molecule neurotransmitters
What type of neurotransmitter are neuropeptides?
Large molecule neurotransmitters
Which neurotransmitter comprises the majority of fast acting neurotransmitters found in the nervous system?
Amino acid neurotransmitters
What are the four primary amino acid neurotransmitters?
Aspartate, glutamate, glycine, and gamma aminobutyric acid (GABA)
What is the major excitatory neurotransmitter in the CNS?
Glutamate
What is the major inhibitory neurotransmitter in the CNS?
GABA (modified derivative of glutamate)
What are the four monoamine neurotransmitters?
Dopamine, epinephrine, norepinephrine and serotonin
What are the four monoamine neurotransmitters synthesised from?
Single amino acids and is slightly larger than an amino acid neurotransmitter
What are the two types of monoamine neurotransmitters?
Catchecholamines and indolamines
What amino acid synthesises dopamine?
Tyrosine
What amino acid synthesises epinephrine ?
Tyrosine
What amino acid synthesises norepinephrine ?
Tyrosine
What group of monoamine neurotransmitters are synthesised by tyrosine? What neurotransmitters do these include?
Catchecholamines; dopamine, epinephrine, and norepinephrine
What are neurons called that release epinephrine?
Adrenergic
What are neurotransmitters called that release norepinephrine?
Noradrenergic
What neurotransmitters make up the monoamine neurotransmitter group indolamine? Which amino acid is this synthesised from?
Serotonin; tryptophan
What are the unconventional neurotransmitters? What are two examples of subclasses of these organisms?
The unconventional neurotransmitters act along different pathways and are a group of misfits; soluble gas neurotransmitters and endocannabinoids
What neurotransmitters does the subclass soluble gas neurotransmitters include?
Carbon monoxide and nitric oxide
What is the unique value of soluble gas neurotransmitters?
Due to their high lipid solubility, these neurotransmitters readily pass through cellular membranes and quickly stimulate a second messenger before being deactivated
Where are most neurotransmitters released in a cell?
Axon terminal
Where are endocannabinoids generally released from in a cell?
Dendrites of a cell; not the axon
What is the function of endocannabinoids?
Affect presynaptic neurons and inhibit or reduce synaptic transmission
What behavioural effects do endocannabinoids produce?
Role in long term memory interference, stress and anxiety suppression, regulation of motivation and pleasure associated with feeding behaviour
What are the five categories of large molecule neurotransmitters?
Pituitary peptides, hypothalamic peptides, brain gut peptides, opioid peptides, and miscellaneous peptides
How are neuropeptides used?
They are used for neuronal Communication just as they are used for hormonal communication
What is the difference between the release of neuropeptides and peptide hormones?
Neuropeptides are released from neuronal cells in signal to other neighbouring neurons; peptide hormones are released from neuroendocrine cells and travel through the blood various receptors in the body
Do neuropeptides have local or distant communication?
Local
Do peptide hormones have local or distant communication?
Distant
What are endorphins?
(Endogenous morphine) Neuropeptide transmitters released in response to pain and intense exercise, helps explain why eating spicy food and working out make someone feel good afterwards
What do endorphins mimic?
Morphine
What are agonists?
Molecules that are structurally similar enough to certain neurotransmitters to allow them to bind to the same receptors and elicit a similar response
What are antagonists?
Molecules that also bind to the same receptors but instead block the neurotransmitters function
What are the two divisions of the nervous system?
Peripheral nervous system and central nervous system
What is the central nervous system?
Consists of the brain and spinal cord and is responsible for making decisions
What is the peripheral nervous system?
Consists of sensory and motor near on that connect the central nervous system to the rest of the body and is responsible for reflexes, gathering information, transmitting this information to the CNS, and then transmitting CNS Decisions throughout the body
What are the two divisions of the peripheral nervous system?
Somatic nervous system
Autonomic nervous system
What is the somatic nervous system?
It interacts with the external environment and enables us to control our skeletal muscles voluntarily
What is the autonomic nervous system?
It regulates our internal environment, such as our glands and smooth muscles, autonomously (on its own) and therefore is considered to be involuntary
What are the two divisions of the autonomic nervous system?
Sympathetic and parasympathetic nervous systems
What is the sympathetic nervous system?
It arouses the body under stressful conditions and uses energy resources to do so; releases epinephrine and norepinephrine to create a flight or fight response
Which division of the nervous system creates a fight or flight response?
Sympathetic nervous system
What is the parasympathetic nervous system?
It re-gains control when the stress or condition passes and acts to conserve energy and bring the body back to homoeostasis
Why are the two divisions of the central nervous system?
The brain and spinal cord
What covers the brain and spinal cord?
Three layers of connective-tissue called the meninges and Cerebrospinal fluid (CSF)
Why are the three layers of the meninges?
(Exterior) dura mater, arachnoid membrane, and pia mater (internal)
What is cerebrospinal fluid?
It is found in between the arachnoid membrane and the pia mater, it supports and cushions the brain and spinal cord to provide added protection against trauma and aid in the circulation of nutrients to the brain
What is the spinal cord?
It is a bundle of nerve fivers connected to the brain
What two types of matter are in the spinal cord? Which is the inner layer and which is the outer layer?
Grey matter (inner) and white matter (outer)
What is grey matter?
That in a portion of the spinal-cord composed of cell bodies and unmyelinated interneurons
What is white-matter?
The outer portion of the spinal-cord composed of myelinated axons
What is the function of the spinal cord?
The spinal-cord transmit sensory information from the body to the brain and transmits motor information from the brain to the body
Where are afferent nerve tracts found? What did they do?
There found on the backside of the spinal cord. They carry sensory information to the brain
What are efferent nerve tracts? Where are they found?
Efferents nerve tracts are found on the ventral side of the spinal-cord. They carry motor function information to the skeletal muscles via the somatic nervous system or smooth muscles by the autonomic nervous system
Which organs are involved with the somatic nervous system?
Skin and skeletal muscles
Which organs are involved with the autonomic nervous system?
Smooth muscles
Where do you afferent nerve tracts enter the spinal cord?
Dorsal horn
Where do you efferent nerve tracts enter the spinal cord?
Ventral horn
The vertebrate embryo contains a fluid filled neural tube with three distinct swelling is that eventually develop into?
Forebrain, midbrain, and hindbrain
What does the forebrain differentiate into?
Telencephalon and diencephalon
What does the midbrain become?
Mesencephalon
What does the hindbrain differentiate into?
Metencephalon and mylencephalon
What is the oldest portion of the brain? What are its divisions?
Brainstem; diencephalon, mesencephalon, metencephalon, and myelencephalon
Which portion of the brain experiences the greatest growth during development? What are is left and right portions called?
Telencephalon; cerebral hemispheres
What is the order from top to bottom the distinct swellings the neural tube early in gestation?
Forebrain, midbrain, hindbrain, and spinal cord
What is the order of the brain sections from top to bottom later in gestation?
Telencephalon, diencephalon, mesencephalon, metencephalon, and myelencephalon
What is another name for the mylencephalon? Where is this structure located?
Medulla ; it lies at the posterior (bottom) part of the brain and connects the brain to the spinal cord
What is the reticular formation structure a part of?
The mylencephalon (medulla)
What is the reticular formation? What does it do?
It is a complex neural networkof nuclei extending from the myelencephalon the mesencephalon. The reticular formation please and important role in regulating sleep, movement, attention, alertness, and various autonomic functions including: heart rate, blood pressure, vomiting, coughing, and sneezing
What three portions of the brainstem house the reticular formation?
Myelencephalon, metencephalon, and mesencephalon
What are the two major structures of the metencephalon?
Pons and cerebellum
What is the pons?
A bulged section of the reticular formation that connects the medulla with the cerebral cortex
What is the function of the pons?
It serves as a communication and coronation centre between the body and the hemispheres of the brain
What is the function of the cerebellum?
It is a large convoluted structure that controls balance, or nation, equilibrium, and fine motor skills
What sections are the mesencephalon divided into?
Tectum and tegmentum
What structure is the tectum a part of ? What are its subdivisions?
Mesencephalon; inferior colliculi and superior colliculi
What is the function of the inferior colliculi? Where is it located?
It regulates auditory function; tectum/ mesencephalon
What is the function of the superior colliculi? Where is it located?
Regulates visual motor function; tectum/mesencephalon
What are the three major components of the tegmentum?
Periaqueductal gray, substantia nigra and red nucleus
Where is the periaqueductal gray located? What is its function?
Tegmentum/ mesencephalon; analgesic mediator of opiate drugs
What is the function of the substantia nigra and red nucleus? Where are these located?
Help to regulate visual motor function; tegmentum/mesencephalon
Loss of substantia nigra results in what disease?
Parkinson’s disease
What is Parkinson disease? Loss of function of what causes it?
slow and progressive deterioration of muscle, movement, and balance control. Loss of the substantia nigra causes this
What are the divisions of the diencephalon?
Thalamus and hypothalamus
What is the function of the thalamus?
It receives sensory information pertaining to each of the senses except for smell. (Important to relay station to the cortex)
Where does the thalamus send information it receives from the cortex?
Cerebellum and medulla
Where is the hypothalamus located? What is its function?
Located below the thalamus in the diencephalon; functions to regulate various motivated behaviours including hunger, thirst, sleep, body temperature, and sexual behaviour
How does the hypothalamus regulate behaviour?
It influences specific warm on release from the pituitary gland
What is the largest division of the human brain?
Telencephalon
What is the function of the telencephalon?
It interprets sensory information, enables complex volunteer emotion, and allows one to think, learn, and speak
What covers the cerebral hemispheres of the telencephalon?
Cerebral cortex–it is highly convoluted increase its functional surface area and without increasing its volume
What are the four specialised regions of the cerebral cortex?
The motor cortex, the somatosensory cortex, auditory cortex, and the visual cortex
What are the deep grooves of the cerebral cortex called?
Fissures
What are the shallow grooves of the cerebral cortex called?
Sulci
What are the raised bridges between fissures and sulci?
Gyri
What is the longitudinal fissure?
The largest fissure that almost completely separates the cerebral hemispheres
What is the corpus callosum?
The largest cerebral commissure
What is a cerebral commissure?
A nerve tracts that joins two hemispheres
What connects the various lobes of the brain?
Cerebral commissure
Where is the frontal lobe located? What is its function?
It is located just behind the forehead; it is involved with the decision making, planning, emotions, behavioural control, and motor control
Where is the motor cortex located? What is its other name?
Located within the posterior portion of the frontal lobe; precentral gyrus
What is the function of the motor cortex?
It controls the planning and execution of voluntary movements.
Where is the parietal lobe located? What is its function?
Is located at the top and rear of the head; it in the great sensory information, processes tactile sensory information ( pressure, pain, touch) and helps as perceive the spatial location of objects and our own bodies
The integration of sensory information, processing of tactile and sensory information and perceive spatial location Is facilitated by what? What is another name for this?
Somatosensory cortex; postcentral gyrus
Where is the somatosensory cortex located?
The parietal lobe portion adjacent to the motor cortex
What separates the motor cortex from the somatosensory cortex?
The central sulcus
Where is the occipital lobe located? What is it main function?
It is located at the back of the head; it primarily deals with visual processing involving the visual cortex
Where is the visual cortex located within the occipital lobe? What divides this region?
It is located in the most posterior portion of the occipital lobe; divided by the calcarine fissure
Where is the temporal lobe located? What is its function?
Located below the frontal and parietal lobes; it is involved with auditory processing, language comprehension, speech, and memory
What is the sylvian fissure?
The fish are separating the temp oral lobe from the frontal and parietal lobes above
Where is the auditory cortex found?
It is located in the sylvian fissure
Where is the hippocampus located? What is its function?
Temporal lobe; plays a major role in the development and processing of memories
Where is the amygdala located? What is its function?
Temporal lobe; processes memories and has been linked to the emotional responses of fear and aggression
What is lateralisation of function?
The functional differences between the left and right hemispheres
What is the theory of cerebral dominance?
It states that one hemisphere plays a dominant role in controlling behavioural and cognitive functions, well the other plays a minor role
Are both hemispheres involved when one side is dominant?
Yes, both play a role but one has a slight fever towards the dominant hemisphere regarding the specific function
What is a aphasia?
A lack of ability to comprehend or produced language caused by brain damage
Where is Broca’s area? What does damage to this area cause?
The inferior prefrontal cortex of the left cerebral hemisphere; damage to this area results in expressive aphasia were normal language comprehension still takes place yet the production of language becomes disruptive and impaired
What are other names for expressive aphasia? What is expressive aphasia?
Ataxic/motor aphasia; normal language comprehension still takes place, yet the production of language becomes disrupted and impaired
Where is Wernicke’s area? What does damage to this area cause?
Located in the posterior temp oral lobe of the left cerebral hemisphere; produces deficits in language comprehension
What type of aphasia does damage to Wernicke’s area cause? What other names does this have?
Receptive aphasia/sensory aphasia
What lies between Wernicke’s and Broca’s areas?
Sylvian fissure
What is the result of damage to the areas an example of?
Localisation and lateralisation of cortical functions
What does the lesion method of brain study allow?
Allows one to compare the subjects behaviour prelesion and postlesion to try to discover the functions of the targeted structure
What is the purpose of an electroencephalogram?
Measures the electrical activity emitted from the brains billions of no runs and produces an amplified read out
What are the neural oscillations of an EEG called?
Brain waves
What is a positron emission tomography PET scan?
And imaging tool that can track each brain areas energy consumption
How does PET scan work?
2-deoxyglucose is injected into the carotid archery for direct delivery to the cerebral hemispheres; it cannot be metabolised so it accumulates in active neuronal cells that the PET scan identifies
Why is computed tomography scan?
Scans that use computer processing to integrate a series of x-rays taken from different angles to create cross sectional images of the brain and other body structures
What is magnetic resonance imaging?
Brain scans measure the signals that relaxing hydrogen atoms in bed after being temporarily realigned by radio waves within a magnetic field. They create cross-sectional images of a higher resolution than CT scans
What is a functional MRI?
It produces images of active brain areas by tracking the flow oxygenated blood to these areas
What are hormones?
Chemical messengers of the endocrine system
Where do hormones travel through to reach their target tissues?
The bloodstream
How did the responses of hormones compare to neurotransmitters?
The effects of hormones are comparatively slow to initiate yet prolonged in response
What is the function of the hypothalamus?
Links the nervous system to the Endocrine system by way of regulating and controlling the pituitary gland
What is the function of the pineal gland?
Influences the bodies daily circadian rhythm
What is the function of the pituitary gland?
It secretes numerous peptide hormones and is often referred to as the master gland because of its significant influence over other organs and endocrine glands in the body
What is the function of the thyroid gland?
It influences the rate of cellular metabolism
What is the parathyroid gland?
The parathyroid or four small land is located on the backside of the thyroid. They play a major regulatory role in the release and uptake of calcium
What is the role of the adrenal glands?
They mediate the body stress response; help maintain blood volume and pressure; and influence metabolism
What is the function and location of the pancreas?
The pancreas is a large plant located behind the stomach that maintains healthy blood sugar levels
What is the endocrine function of the ovary?
To release sex for months to develop and maintain the health of the reproductive system
What is the endocrine function of the testis?
To produce testosterone to develop one physically, pretty sperm, and maintain healthy bone and muscle mass
What are the five main hormones of the hypothalamus?
(1) Thyrotropin-releasing hormone
(2) Gonadotropin releasing hormone
(3) growth hormone releasing hormone
(4) corticotropin releasing hormone
(5) somatostatin
What gland is thyrotropin releasing hormone (TRH) released from? What is its function?
Hypothalamus; stimulates release of thyroid stimulating hormone (TSH) and prolactin from anterior pituitary
What gland is gonadotropin releasing hormone released from? What is its function?
Hypothalamus; Stimulates the release of follicle-stimulating hormone (FSH) and luteinizing hormone (LH) from anterior pituitary
What gland growth hormone releasing hormone released from? What is its function?
Hypothalamus; Stimulates the release of growth hormone (GH) from anterior pituitary
What gland is corticotropin releasing hormone (CRH) released from? What is its function?
Hypothalamus; stimulates release of adrenocorticotropic hormone (ACTH) from anterior pituitary
What gland is somatostatin released from? What is its function?
Hypothalamus; inhibits pituitary release of growth hormone (GH) and thyroid stimulating hormone (TSH)
Why are the six hormones released from the anterior pituitary gland?
1) Growth hormone (GH)
2) Prolactin
3) Adrenocorticotropic hormone (ACTH)
4) thyroid stimulating hormone (TSH)
5) luteinizing hormone (lh)
6) follicle stimulating hormone
What gland releases growth hormone? What is the function of this hormone?
Anterior pituitary gland; in childhood promotes growth; in adulthood maintains healthy bone and muscle mass
What gland releases prolactin?What is the function of this hormone?
Stimulates milk production in women
What gland releases adrenocorticotropic hormone ? What is the function of this hormone?
Anterior pituitary gland; stimulates release of corticosteroids from adrenal glands
What gland releases thyroid stimulating hormone? What is the function of this hormone?
Anterior pituitary gland; stimulates release of triiodothyronine h(T3) and thyroxine (T4) from the thyroid gland
What gland releases luteinizing hormone? What is the function of this hormone?
Anterior pituitary gland; acts on ovaries are females to regulate estrogen; acts on testes of males to regulate testosterone
What gland releases follicle stimulating hormone (FSH)? What is the function of this hormone?
Anterior pituitary gland; in females stimulates release of eggs; in males regulates normal sperm production
What are the two hormones released by the posterior pituitary gland?
1) oxytocin
2) anti diuretic hormones (ADH) (vasopressin)
What gland releases oxytocin? What is the function of this hormone?
Posterior pituitary gland; regulates female reproductive functions of childbirth and breastfeeding
What gland releases antidiuretic hormone (ADH)/vasopressin? What is the function of this hormone?
Posterior pituitary gland; regulates bodys water balance
What two hormones are released by the thyroid gland?
1) triiodothyronine (t3)
2) thyroxine (t4)
What gland releases triiodothyronine? What is the function of this hormone?
Thyroid gland; important regulator of metabolism
What gland releases thyroxine? What is the function of this hormone?
Thyroid gland; important regulator of metabolism
What hormone is released by the parathyroids?
Parathyroid hormone (pth)
What gland releases parathyroid hormone ? What is the function of this hormone?
Parathyroid; regulates the body’s calcium and phosphate levels to a very narrow range
What is the stress hormone of the body?
Cortisol
What two hormones are released by the adrenal cortex?
1) cortisol
2) aldosterone
What gland releases cortisol? What is the function of this hormone?
Adrenal cortex; increases blood glucose levels; suppresses immune system
What gland releases aldosterone? What is the function of this hormone?
Adrenal cortex; regulates the bodies balance of salt and water; helps regulate blood pressure
What two hormones are released by the adrenal medulla?
1) epinephrine
2) norepinephrine
What gland releases epinephrine ? What is the function of this hormone?
Increases heart rate and blood flow to muscles and brain; increases blood glucose levels
What gland releases norepinephrine ? What is the function of this hormone?
Adrenal medulla; increases heart rate and alertness; acts as a vasoconstrictor
What to hormones are secreated by the pancreas?
1) insulin
2) glucagon
What gland releases insulin? What is the function of this hormone?
Pancreas; decreases blood glucose levels
What gland releases glucagon ? What is the function of this hormone?
Pancreas; increases blood glucose levels
What two hormones are secreted by the ovaries?
1) estrogen
2) progesterone
What gland releases estrogen ? What is the function of this hormone?
Ovaries; develops secondary sexual characteristics; regulates reproductive function
What gland releases progesterone? What is the function of this hormone?
Ovaries; thickens endometrium for implantation
What gland releases testosterone? What is the function of this hormone?
Testes; develops male reproductive tissues; regulates secondary sexual characteristics
What hormone is secreted by the testes?
Testosterone
How doesn’t animal adjust to its environment?
Behaviour
How can behaviour be biologically modified?
Coordinated internal and external responses of the Endocrine system to a given situation
What are genes?
Small segment of DNA molecule is that code for proteins and are passed from parents to offspring through inheritable factors
Where are genes located?
Chromosomes
How many sets of chromosomes do you diploid organisms have?
Two sets of chromosomes; one pair from the mother and one from the father
What are the two forms of an allele?
Dominant and recessive
What is a dominant allele?
An allele that expresses (codes for a functional protein) regardless of the other allele
What is a recessive allele?
An allele that only expresses its tree when paired with another identical allele
What determines if genes are active or inactive?
Environmental circumstances
What is heredity?
The passing of treats from parents to offspring in the form of genes
What does heredity allow for?
Individuals to accumulate variations of traits over time and evolve
What is fitness?
And organisms ability to survive and propagate its genes
What is natural selection?
When an individual’s genes are selected for in the population in a pass to the next generation
When natural selection is repeated generations, what occurs?
Evolution
What is adaptive value?
A positive influence on an animals evolutionary fitness
What is nature versus nurture?
The debate whether behaviours were acquired genetically or through learning
What three factors influence and animals behaviour?
Its genetics, its experiences, and its current environment
What is the neurological disorder phenylketonuria (PKU)?
People with PKU lack the ability to phenylalanine hydroxylase into tyrosine to make dopamine. The high levels of PAH and low levels of dopamine lead to abnormal brain development. This can be avoided by following a PAH restricted diet to environmentally alter a hereditary condition
What is epigenetics?
The study of mechanisms of inheritance aside from the genetic code and changes to DNA sequences (epigenetic seeks to reveal way organisms with essentially identical DNA sequences possess such a large variation in trait expression)
What are two epigenetic mechanisms?
Chromatin remodelling and DNA methylation
What are histones?
Proteins are around which DNA winds
What is chromatin remodelling?
Occurs when histones change confirmations either to expose or hide DNA segments. Chromatin interferes with the ability of transcriptional protein machinery to access regulatory proteins and effectively regulate gene expression
What is chromatin?
Condensed DNA
What is DNA methylation?
Occurs when a methyl group is covalently added to the 5-carbon of cytosine bases in vertebrates. DNA methylation effectively blocks transcriptional protein machinery from binding to the methylated site thus reducing gene expression
What to groups do scientists compare to assess the influences of heredity?
Monozygotic and dizygotic twins
What are monozygotic twins?
Identical twins are developed from a single fertilised egg that splits into two resulting in two offspring the share exactly the same genes
What must differences in behaviour be attributed to in monozygotic twins?
Environmental factors
What are dizygotic twins?
Fraternal twins that develop from two separately fertilised eggs and are generally no more similar than any other pair of non-twin siblings
What percentage of their genes do you dizygotic twins and non-twin siblings share?
50%
What percent of their genes do monozygotic twins share?
100%
What factor do twin studies control for?
The environment, although the environment each twin faces is not identical, the difference with in a house is negligible compare to between houses
What are concordance rate? What type of study compares them?
The probability that both twins will possess the same tree given that one twin already possesses it; twin studies between monozygotic and dizygotic twins
How are concordance rates used?
If the concordance rate for a particular trait is found to be higher for monozygotic twins genetics are indicated playing important role in the expression of that trait
What are adoption studies? What do they control for?
Adoption studies control for hereditary factors and examine the variable of environment by studying monozygotic twins separated at birth via adoption
What can be used to quantify the heritability of a trait?
Twin and adoption studies
What is heritability ?
A measure of observed variations among populations not individuals
What are the successive stages of human development?
Prenatal, infancy, adolescence, and adulthood
What are the three stages of prenatal development?
The germinal stage, the embryonic stage and the fetal stage
What is the first part of the germinal stage?
Conception
What is the germinal stage?
It is characterised as the time period between fertilisation and implantation and last for approximately two weeks.
When does fertilisation occur?
It is when the sperm and ovum unite in one of the Fallopian tubes to create a fertilised egg or zygote.
Cell differentiation of the zygote is made possible because cells are totipotent. What does totipotent mean?
Cells have the ability to develop into any cell type
Once the zygote has divided and becomes 200-300 cells, what is it called?
Blastocyst
What are the two layers of the blastocyst?
Trophoblast and inner cell mass
What is the trophoblast?
The outer layer of the blastocyst that becomes the placenta
What is the inner cell mass?
The portion of the blastocyst that eventually forms the embryo and is further composed of three distinct germ layers they guide organisation and differentiation
What three layers are formed by the inner cell mass?
Ectoderm, mesoderm, and endoderm
Which embryonic layer is the ectoderm? What does this layer form?
Outermost layer; forms the epidermis, nervous system, and sensory organs
Which embryonic layer is the mesoderm? What does this layer form?
Middle layer;
Bones, cartilage, circulatory system, dermis, excretory system, muscles, and reproductive system
Which embryonic layer is the endoderm? What does this layer form?
Inner layer;
Endothelium, lining up day just abstract, line of respiratory system
What is implantation? What process occurs?
When the blastocyst attaches itself to the endometrial epithelium. The outer trophoblast will penetrate the decidualised uterine wall to establish a firm connection of the placenta to the mother well also modifying vasculature to maintain adequate blood supply
What role does the placenta serve?
The placenta serves an intermediary role between the developing fetus and mother by either supplying it with blood and nutrients or removing waste
When does the embryonic stage of development begin? what constitutes this stage?
During the third week following conception; blastocyst has attached to the year in lining and has begun to differentiate and is now an embryo and divides into the endoderm, mesoderm, and ectoderm
During what stage do the endoderm, mesoderm, and ectoderm form?
The embryonic stage
At 22 days, what is the first sign of the nervous system? What does this become?
Neural plate, folds into the neural groove, edges fuse to form the neural tube
What is the neural tube?
A structure formed during embryonic development that eventually becomes the brain and spinal cord
When specialised ectodermal sells break off from the neural tube as it is being formed, what do these cells create? What does this structure become?
Neural crest; do you cells differentiate into the majority of neuronal cells in the peripheral nervous system
What type of cells are neural crest cells and neural plate cells?
Embryonic stem cells
What are embryonic stem cells?
Pluripotent cells with a relatively unlimited capacity for self renewal under proper conditions
What is the final portion of the embryonic stage? Describe this portion of development
Organogenesis–when all of the major organs develop and the embryo now resembles a distinct 1 inch long human
When does the fetal stage begin and how long does it last?
The fetal stage begins when cell differentiation is almost complete, usually during the ninth week after conception, and lasts until birth
Because little differentiation is needed during the fetal stage what is the embryo now considered?
A fetus
What development characterises the fetal stage?
Tremendous growth, primarily due to bone and muscle formation
What is fetal viability?
The increased chance of babies survival as it approaches the 40th week following conception
What is habituation?
Decreased responsiveness with repeated stimulation
What are teratogens? What structure screens them out?
Any agent that can disrupt or hall the development of an embryo or fetus; The placenta screens them out from the mothers blood supply
What do teratogens lead to? What is an example?
Birth defects; fetal alcohol syndrome
What are four main reflexes babies are able to complete when born?
Moro reflex, sucking reflex, grasping reflex, babinski reflex
What is the Moro reflex?
And outstretching of limbs in response to a sudden loss of support
What is the sucking reflex?
Sucking that begins with an object touches the lips
What is the grasping reflex?
Firm grasping triggered when in object touches the palm
What is the Babinski reflex?
Flexing and fanning of toes in response to stroking the sole of the foot
In what direction do human infants develop?
Cephalocaudal direction–The head and upper body develop before the lower body and limbs
What are two types of motor skills?
Gross motor skills and fine motor skills
What are gross motor skills?
Skills that involve larger muscles such as arms and legs and are necessary for balance, coordination, and walking
What are fine motor skills?
They involve the coordination of smaller muscles such as those eyes and fingers and are necessary for intricate movements and hand eye coordination
What years are adolescent development characterised by?
The transitional years from childhood to adulthood
When does adolescent physical development begin?
Puberty
What is puberty?
The period when sexual organs mature; caused by a surge of hormones that alter moods, behaviour, and trigger the rapid development of primary and secondary sex characteristics
What are primary sex characteristics?
They include reproductive organs (ovaries, testes) and external genitalia necessary for reproduction
What are secondary sex characteristics?
Include nonreproductive features such as pubic hair and underarm hair in both sexes, breasts and hips and females, and facial hair and a deeper voice in males
What is the term for a girls first period?
Menarche
What is the term for a boys first sperm ejaculation?
Spermarche
What is social development?
When adolescents become aware of other peoples thoughts and judgements while simultaneously developing questions of who they are and who they want to become
