Biological 6-10 Flashcards
Hormones
Enable communication between cells through the blood (endocrine system)
Similarities between neural and endocrine systems
- production of chemicals stored for later release
- some chemicals are hormones and neurotransmitters
- stimulated to release chemicals
- each react with specific receptors
Differences between neural and endocrine systems
- Neural communication is fixed between channels to precise locations; hormonal signalling is more generalised
- Neural messages are very rapid; hormonal communication is slower and more prolonged
- Neural messages either fire or dont; hormones require more for greater effect
- Some neural communication is under voluntary control; hormone release is not
Hormonal Classification and action
- PROTEIN hormones made up of amino acids- BIG so bind with receptors on membrane
- STEROID hormones made up of cholesterol-SMALLER so pass through membrane and bind with receptors on the cytoplasm
Location of Major Endocrine Glands (7)
- Hypothalamus
- Pituitary Gland
- Pineal gland
- Thyroid Gland
- Thymus
- Adrenal Gland
- Pancreas
- Ovary (women)
- Testis (men)
What does the Pineal gland produce?
Melatonin
affects sleep and light
Job of the hypothalamus in relation to pituitary gland
Makes Hypothalamic Releasing Hormones that stimulate or inhibit release from the pituitary gland
Job of the pituitary gland
releases tropic hormones which influences release of hormones from other glands
What controls the Anterior Pituitary Gland?
Hypothalamic Releasing Hormones
What controls the Posterior Pituitary Gland?
Nerve stimulation from hypothalamus
What does the Posterior Pituitary Gland produce?
Anti-diuretic hormone (ADH/Vaporessin)
Oxytocin
What is the job of Anti-diuretic hormone? (secreted by the pituitary gland)
- stimulates the re-absorption of water by kidneys
- stimulates vasoconstriction
What is the job of oxytocin? (secreted by the posterior pituitary gland)
- causes muscle contraction in uterus (childbirth)
- stimulates ejection of breast milk
Why is oxytocin known as the tend and befriend
- levels respond to social stimulation (inhibits stress)
- elevated levels during sexual arousal and orgasm
What does the Anterior Pituitary Gland produce?
- growth hormones
- thyroid stimulating hormones
- gonadotrophins (sex hormone release)
- Adrenocorticotropic Hormone (ACTH)
- Prolactin
What is the job of the growth hormones? (Anterior pituitary glands)
-regulates GROWTH rates (not enough growth hormones causes pituitary dwarfism; too much causes gigantism)
What is the job of thyroid stimulating hormones? (Anterior pituitary glands)
-stimulates THYROXINE by the thyroid gland. if thyroid can’t produce enough thyroxine, it swells up
What is the job of Gonadotrophins? (Anterior Pituitary Glands)
- Luteinizing Hormone- production of PROGESTERONE and TESTOSTERONE (ovaries and testes and adrenal cortex
- Follicle Stimulating Hormone- production of ESTROGEN ad SPERM (ovaries and testes)
What is the job of PROLACTIN?
- tissue development in breasts during pregnancy
- stimulates milk production after birth
- sexual desire: more prolactin after orgasms reducing sexual desire)
Structure of the Adrenal Gland
- Sits on top of the kidneys
- Made up of Medulla (inside),NERVE IMPLUSES and Cortex (outside), ACTH from anterior pituitary
Job of the Adrenal Medulla (Fight, Flight, F**k Hormones
-Secretes Adrenaline and Noradrenaline which regulates heart rate, glucose release and peripheral blood vessels
Job of the Adrenal Cortex
- SEX HORMONES (Adrogens and Estrogens(testes/ovaries)
- MINERALOCORTICOIDS (Aldosterone-kidneys retain sodium and excrete potassium, maintains blood pressure, maintains salt and water in the body
- CORTICOSTEROIDS (stress hormones-Cortisol)
Job of the Pancreas
-secretes insulin (takes up excess glucose) and glucagon (releases glucose)
Job of the testes
-secretes androgens–> Testosterone (begins in prenatal development to determining sex, then bursts in puberty)
Job of testosterone in puberty? (male hormone)
- growth and development of the male reproductive structures
- increased skeletal muscle growth
- enlargement f the larynx (voice changes)
- increased body hair
- sexual drive
Job of the Ovaries
-secretes female sex hormones (estrogen)
What is the job of Estradiol (female hormone)
-breast development
distribution of fat
-maturation of uterus and vagina
What is the job of Progestrone (female hormone)
-thickens the lining of uterus in pregnancy
What is the job of Estradiol and Progestrone?
- stimulates changes in uterus during the menstrual cycle
- influences sexual behaviour
Describe the link between the colour red and testosterone
Those who prefer the colour red had higher levels of testosterone and were viewed as more aggressive.
What is the job of Adrenocorticotropic Hormone?
Stress Hormone Release-stimulates release of stress hormones from adrenal cortex
Name the two pathways in which stress enters the body
Sympathetic Adrenal Medullary (SAM) Axis Hypothalamic Pituitary (HPA) Axis
What are the roles of Adrenaline and Noradrenaline in the SAM Axis?
increased
- heart rate
- blood pressure
- redirection of blood muscle/organs
What is the role of cortsol in the short term?
Increased
- sensitivity of cells to adrenaline and noradrenaline
- blood sugar levels
- mental alertness
What is the role of cortisol on the long term processes?
switches off
- immune system
- growth and repair
- digestion
- reproduction
- regulation of sleep patterns
Describe stress going through the SAM Axis
Stressor is detected in the HYPOTHALAMUS and is communicated to the SYMPATHETIC NERVOUS SYSTEM which communicates to the ADRENAL MEDULLA (inside) and secretes ADRENALINE or NORADRENALINE
Describe stress going through the HPA Axis
Stressor is detected in the HYPOTHALAMUS and is communicated to the PITUITARY GLAND which releases ADRENOCORTICOTROPIC HORMONE (ACTH) through the blood which communicates to the ADRENAL CORTEX which secretes CORTISOL
How do we measure adrenaline and noradrenaline in the body?
blood samples, heart rates/blood pressure
How do we measure cortisol in the body?
cotton swab collects saliva
What are the effects of long term stress i.e continuous cortisol in the body
SYSTEMS SWITCH OFF
- immune system=increased risk of ILL-HEALTH
- growth and repair=INABILITY to health wounds
- digestion=increased risk of PEPTIC ULCERS
- reproduction=FERTILITY PROBLEMS
- regulation of sleep patterns=INSOMNIA
How could measure stress in the real world?
- exam periods
- caregiving
- stressful living conditions
- excessive lifestyles
- high stress jobs
- major life events
How could we measure stress in the lab?
- public speaking tasks
- mental arithmetic
- mirror-tracing
- injections
- cold pressor
- noise
- mutli-tasking
- strooptask
What is the link between ecstasy users and cortisol?
- impaired memory
- sleep problems
- depression and anxiety
- impaired immunity
- ill-health
Name the 2 systems under the NERVOUS SYSTEM
CENTRAL nervous system
PERIPHERAL nervous system
Name the 2 systems under the CENTRAL NERVOUS SYSTEM
BRAIN
SPINAL CORD
Name the 3 parts of the BRAIN in the CNS
- FOREBRAIN
- MIDBRAIN
- HINDBRAIN
Name the 2 parts of the FOREBRAIN in the CNS
- TELENCEPHALON
- DIENCEPHALON
Name the 2 parts of the TELENCEPHALON (FOREBRAIN)
- LIMBIC SYSTEM
- CEREBRAL CORTEX
Name the 2 parts of the DIENCEPHALON (FOREBRAIN)
- THALAMUS
- HYPOTHALAMUS
Name the 2 parts of the MESENCEPHALON (MIDBRAIN)
- TECTUM
- TEGMENTUM
Name the one part of the MIDBRAIN
MESENCEPHALON
Name the 2 parts of the HINDBRAIN
METENCEPHALON
MYELENCEPHALON
Name the 2 parts of the METENCEPHALON
- CEREBELLUM
- PONS
Name the one part of the MYELENCEPHALON
MEDULLA
Name the 2 parts of the PERIPHERAL NERVOUS SYSTEM
- AUTONOMIC NS
- SOMATIC NS
Name the 2 parts of the AUTONOMIC NS
- SYMPATHETIC NS
- PARASMPATHETIC NS
VENTRAL Direction
toward the FRONT (belly) or toward the BOTTOM of the head
DORSAL Direction (dolphin fins)
toward the BACK of the body or towards the TOP of the head
ROSTRAL/ANTERIAL Direction
toward the NOSE
CAUDAL/POSTERIOR Direction
toward the FEET (in humans) or TAIL
LATERAL Direction
towards the SIDES
MEDIAL Direction
towards the MIDDLE
BILATERAL Direction
on BOTH SIDE of the body or head
IPSILATERAL Direction
on the SAME side of the body or head
CONTRALATERAL Direction
on the opposite side of the body or head
HORIZONTAL section - autonomical plane (burger bun)
HORIZONTAL section in the brain
SAGITTAL section - autonomical plane (baguette)
DOWN THE MIDDLE FROM THE TOP of the brain
CORONAL section - autonomical plane (loaf of bread)
SLICE FROM THE FROM
3 facts about the brain
- brain cannot store glucose
- needs a constant supply of blood from glucose and oxygen
- interruption of glucose and oxygen to the brain causes unconsciousness
What structure protects the brain
skull and meninges
what structure protects the spinal cord
spinal column and meninges
WHAT is the meninges filled with and HOW does it add protection to the brain and spinal cord
cerebrospinal fluid which EXPANDS/COMPRESSES to stop brain bashing into bone
what is meningitis?
infection/inflammation of the meninges
how does the Blood-Brain Barrier protect the brain and spinal cord?
keeps out harmful substances i.e too big to pass
how does the ventricular system protect the brain and spinal cord?
CSF in 4 ventricles around the brain and exits and wanders around subarachnoid space and acts as extra cushioning
What is the job of the MEDULLA OBLONGATA in the MYELENCEPHALON (hindbrain)
- controls cardiovascular system
-respiration
-muscle tone
(by receiving information on heart rate, bp, o2, co2)
What is the job of the PONS in the METENCEPHALON (hindbrain)
(links hindbrain and midbrain)
- respiration
- eye movement
- facial expressions
- chewing
What is the job of the CEREBELLUM in the METENCEPHLAON (hindbrain)
- communicates to motor cortex and sense organs
- voluntary muscle movements
- maintenance of balance and equilibrium
- muscle tone and posture
What is the job of the TECTUM (roof) in the MESENCEPHALON (midbrain)
- auditory and visual communication
What is the job of the TEGMENTUM (covering) in the MESENCEPHALON (midbrain)
- sensory process, movement, motor control
What is the job of TELENCEPHALON-the hemispheres (forebrain)
-Corpus Callosum is responsible for communication between the hemispheres
What is the job of the THALAMUS in the DIENCEPHALON (forebrain)
-receives sensory information and relays to the cortex
What is the job of the HYPOTHALAMUS in the DIENCEPHALON (forebrain)
- connected to pituitary gland and regulates ANS and Endocrine System
What is the job of the LIMBIC SYSTEM of the TELENCEPHALON (the hemispheres)
structures involved in stress and emotion, memory storage and retrieval
What are the structures in the LIMBIC SYSTEM of the TELENCEPHALON (the hemispheres)
- Cingulate Gyrus->controls emotional behaviour
- Fornix ->links hippocampus to hypothalamus
- Amygdala->emotional processing and motivation
- Hippocampus->involved in learning and memory
What is the white matter made up of in the forebrain
axons covered in myelin sheath
what is thegrey matter made up of in the forebrain
cortex made up or cells
name the 3 grooves in the brain
- longitudinal fissure
- central sculus (separates frontal lobe from parietal lobe)
- lateral fissure (separates temporal from frontal and parietal lobes)
name the 4 grooves in the brain
- frontal lobe
- parietal lobe
- temporal lobe
- occipital lobe
job of the occipital lobes
- main visual cortex
- damage-cortical blindness
- contralateral so damage to one side is shown on the other side
job of the parietal lobe
- sensation and perception
- integrates sensory information and spatial information
- contralateral
- damage-right/left confusion, sensory neglect, problems with spatial ability, disorders in perceiving ourselves
describe the structure of the somatosensory cortex (parietal lobe)
-big parts of this structure is dedicated to parts of the body that are most sensitive i.e. thumb part is bigger than wrist
job of the temporal lobe
- memory (HIPPOCAMPUS)
- emotion and mood (AMYGDALA)
- auditory and visual perception (WERNICKE’S AREA)
job of the frontal lobe
- receives information from other lobes (control lobe)
Wernicke’s Aphasia (located in the temporal lobe)
inability to understand words or arrange words into coherent speech
Broca’s Aphasia (located in the frontal lobe)
slow, non-fluent speech but is coherent
job of the motor cortex (frontal lobe)
movement is contralateral
roles of the pre-frontal cortex
planning and evaluation event monitoring monitoring emotions working memory (Phineas Gage had damage to this after railway accident)
parts of the frontal lobe
primary motor cortex premotor cortex frontal cortex prefrontal cortex Broca's area
Neuroanatomical Techniques of studying the brain
- Cell body stains
- Myelin Stains
- Membrane Stains
Histochemical Techniques to studying the brain
-locate specific neurons and neurotransmitters by adding artificial antibodies which bind to specific antigens
What are the disadvantages of measuring the brain using neuroanatomical and histochemical techniques?
-require brain slices so post-mortem
CAT Scans
- X Rays of patients brain to produce 2D image
- whiter image, denser brain tissue
- used for diagnosis of tumours, strokes, blood clots, neural degeneration
MRI Scans
- Magnetic Radiation from hydrogen atoms
- produces images in the 3 anatomical planes
fMRI Scans
- Heamodynamic Responses (metabolic activity)
- where brain consumes oxygen which equals activity
- warm colours (more activity) and cold colours (less activity)
PET Scans
- radioactive glucose is injected into patient which is taken up by active/metabolising cells
- difference between healthy and diseased brains
Advantages of Brain Imaging
- non-invasive for patient
- good spatial resolution (structures and functions)
- can be used to compare healthy brains and diseased brains and activity during tasks (PET,fMRI)
Disadvantages of brain imaging
- risks from XRAYS and Radiation
poor temporal resolution, not good at lining events to changes in images - noisy and scary/claustrophobic
- may be expensive/not portable
Recording electrical activity
- Micro-electrodes implanted into the brain to record neural activity of individual neurons (NOT SUITABLE FOR HUMANS)
- Macro-electrodes attached to scalp (EEG) to measure activity between active and neutral electrodes
4 types of EEG waves
- BETA - awake
- ALPHA - calm
- THETA - deep relaxation
- DELTA - deep sleep
Advantages of Macroelectrodes
- non-invasive
- ca differentiate between neurological conditions
Disadvantages of Macroelectrodes
time consuming, lots of equipment
- interpretation requires experience
- doesn’t establish activity in a single region
Disadvantages of brain damage studies
we don’t know what people were like before they had the brain damage
