Midterm and Post-Midterm Flashcards
Name three communication systems of the body
Nervous, Immune and Endocrine
What is CNS comprised of?
Brain and Spinal Cord
Name the parts of the autonomic NS
Parasympathetic and Sympathetic
Parasympathetic system roles
Rest and digest
Name of the neurons that play a crucial role in information transmission in parasympathetic NS
Cholinergic Neurons
Role of the Sympathetic NS
Fight or Flight
What is the major neurotransmitter associated with sympathetic NS
Norepinephrine
Is there any interaction between the sympathetic and parasympathetic systems?
Yes, sympathetic and parasympathetic systems interact to influence each other’s functions. E.g., parasympathetic is responsible for arousal, sympathetic for orgasm.
Somatic Nervous System
Subdivision of the PSN that allows for movement and muscle control.
Afferent pathway
Pathway used to carry information from the sensory sites to the brain
Efferent pathway
Pathway used to carry information from the brain to the motor sites of the body
Three components of the NS
Input, Integration and Output
Frontal Lobe Role
Language, Emotional regulation, Executive Functioning
Parietal Lobe
Sensory information of the body
Temporal lobe
Auditory information processing, involved in some aspects of learning, memory and language
Occipital lobe
Interpretation of visual information. Damage to that part of the brain may affect vision and cause concussions that affect balance and vision
What are subcortical structures responsible for?
Motivation, emotion, learning, memory, homeostasis, containing a sensory relay station
Amygdala
Fear/Anxiety/Reward value association
Hippocampus
Learning and Memory
Hypothalamus
Homeostasis, hormonal relay of the body
Thalamus
Relay station of the brain
What is midbrain made of and what do these structures do
Substantia Nigra, Ventral tegmental area, both involved in mood, reward and addiction
What does hindbrain contain
Medulla, pons, cerebellum
Cerebellum role
Balance, contains procedural memories
Microglia
Responsible for immune response, homeostasis, supporting neural function
Oligodendrocyte
Produces myelin sheath around axons, nurtures and sustains the environment around neurons
What is the oligodendrocyte of the PNS
Schwann cell
Astrocyte
Neural support, damage reparation, regulation of neuronal communicaton
PNS alternative to Astrocytes
Satellite cells
What were Berthold’s Observations? (3)
- Testes are transplantable
- Transplanted testes can function and produce sperm
- There are no specific nerves directing testicular function
What evidence would be sufficient for establishing the effects of hormones? (3)
- Hormonally dependent behavior should disappear when the source of the hormone is removed or the actions of the hormone are blocked
- After the behavior stops, restoration of the missing hormonal source or its hormone should reinstate the absent behavior
- Hormone concentrations and behavior in question should be covariant (behavior should only be observed when hormone concentration is relatively high)
Quasi-Experimental Design
Falls between experimental and non-experimental designs. Aims to investigate cause and effect relationships but lacks on key elements such as random assignment
Antigen
Can be a hormone: a molecule that can bind to a specific antibody
Antibody
A protein made by plasma cells in response to an antigen - has a specific site for the antigen to bind
How are antibodies produced?
An antigen of interest is injected into an animal to increase the antibody count
Immunoassays
Analytical techniques used for qualification of an analyte (hormone) based on the antigen-body reaction
Bioassays
Testing the effects of hormone and measure its biological activity on a living animal
Chorionic hormone
Hormone associated with pregnancy
Radioimmunoassays
Based on a principle of competitive binding of antibody to an antigen that results in change in radioactivity. Has two types of hormones: 1. Hot (labeled with radiation) and cold (unlabeled); levels of radiation show the concentration
EIA and ELIZA
Works on the principle of competitive binding of an antibody to an antigen. Instead of using radiolabeled hormone, it uses an enzymatic tag that changed the color of a substrate molecule.
Immunocytochemistry
A technique applied to cells to determine locations of a hormone in specific cells
Immunohistochemistry
A technique applied to tissues to determine locations of a hormone in specific tissues
Autoradiography
Radiolabeled hormones are injected into tissue to determine hormonal uptake and indicate receptor location. If a radiolabeled hormone is bound to a ligand, it will emit radiation that will be seen as dark spots on a film
Blot Test
Used to identify several proteins at the same time.
In Situ Hybridization
Determining whether a particular substance is produced in a specific tissue. Similar to autoradiography, but n this case a radiolabeled cDNA s introduced and if a mRNA of interest is present the cDNA will hybridize with it and appear as dark spots on the film
Intracrine mediation
Intracrine substances regulate intracellular events
Autocrine mediation
Autocrine substances influence the same cells that secreted them
Paracrine mediation
Paracrine cells secrete chemicals that affect adjacent cells
Endocrine mediation
Endocrine cells secrete chemicals into bloodstream where they can influence distant cells
Ectocrine mediation
Ectocrine substances are released into the environment to communicate with others
What neurohormones are produced by Hypothalamus or Pituitary?
Oxytocin, norepinephrine, Gonadotropin-releasing hormone, Corticotropin releasing hormone
What makes pancreas special?
It is both endocrine and exocrine. It secretes digestive juices into the intestine via ducts and hormones directly into the bloodstream with its endocrine compartment
Define resistance
Regular levels of a certain hormone are not enough to cause an effect due to insufficient levels of hormone receptors
Major chemical classes of hormones (3)
Polypeptides, Steroids, Amines
Hydrophillic hormones
Need a receptor to get into a cell
Hydrophobic (lipid soluble) hormones
Need a carrier protein to circulate in blood
Chorionic Hormones
Hormones produced by placenta
Corticotropin-releasing hormone
Synthesized within the anterior portion of Pvam stimulates secretion of adrenocorticotropic hormone
Gonadotropin-releasing hormone (GnRH)
Synthesized within the preoptic area of the anterior hypothalamus and it controls the release of luteinizing hormone (LH) and follicle stimulating hormone (FSH) -> Nourishes sexual glands
Growth hormone-releasing hormone
Secreted within the ventromedial nucleus and arcuate nucleus of the hypothalamus and it stimulates growth hormone -> Tells the glands that produce growth hormone to release it
Thyrotropin releasing hormone
Synthesized mainly in the paraventricular and anterior paraventricular nuclei of the hypothalamus. Stimulates cells in the anterior pituitary gland to produce and release thyroid-stimulating hormone
Melanotropic releasing hormone
Nourishes glands that produce melatonin
Kisspeptin
Has an important role in initiating secretion of gonadotropin releasing hormone at puberty; involved in sexual maturation
Dopamine
Primary prolactin-inhibitory hormone
Somatostatin
Mainly acts to inhibit secretion of growth hormone and thyroid secretion hormone through the inhibitory effects on insulin, glucagon and secretin production
Present in both hypothalamus and delta cells in the pancreas
Turner Syndrome
Congenital Condition; Lack of X or damage to the second X or Y; Female external appearance, limited ovarian development; unable to attain puberty without intervention
Turner - Cannot turn
What are androgens responsible for?
Differentiation of external genitalia
What is DHT crucial for?
It is crucial for the process of genital fusing
Klineifelter Syndrome (XXY)
The presence of Y chromosome is sufficient for SRY gene activation and masculinization -> Sexed as male at birth
XYY Individuals
Taller and more prone to learning disabilities
Androgen insensitivity syndrome
Functional androgen receptors are absent. Vagina is reduced in length and lacking utero and fallopian tube
Congenital Adrenal Hyperplasia
lack 21 hydroxylase; little to no impact on male individuals; causes male genitalia development in females
5-a reductase deficiency
Genetic males with this deficiency are born with ambiguous genitalia and small testes; considered females at birth.
At puberty, testosterone masculinizes the body, causing hair growth and the genitalia to develop, resembling a male-typical penis and scrotum
Swyer Syndrome
Rare disorder; sex glands fail to develop in XY individual that lacks SRY gene
have functionless gonads and genitalia that resembles female’s
People will not experience puberty and will have high cancer chances if there is no surgical intervention
Oval testes
Incomplete gonadal differentiation
Specificity of anterior pituitary - hypothalamus communication
The two communicate via closed portal.
Hypothalamus stimulates anterior pituitary to release hormones into the blood.
Posterior pituitary - hypothalamus communication
The two have a direct connection, unlike anterior pituitary, posterior pituitary doesn’t need a closed portal or a mediator for communication
Hormones released by the posterior pituitary
Oxytocin and vasopressin
Vasopressin and its roles
Antidiuretic hormone
Helps retain water and slow bleeding
vasoPRESSin - think of pressing down on the wound to slow down bleeding
Oxytocin and its roles
Administered during birth to trigger uterine contractions. Also triggers sucking reflex in babies
Pineal gland role and location
Located at the top of midbrain
Responsible for melatonin production and circadian rhythm control
Melatonin
Synthesized from serotonin
Melatonin levels rise in the absence of light and fall in the presence of light
Responsible for drowsiness
Inhibitory Hypothalamic Hormones
Dopamine and Somatostatin
What triggers thyroid to produce hormones
Thyroid produces hormones in response to thyrotropin - releasing hormone produced by anterior pituitary
Excitatory Hypothalamic hormones
Corticotropin-releasing hormone
Gonadotropin releasing hormone
Growth Hormone Releasing Hormone (GHRH)
Thyrotropin Releasing Hormone
Kisspeptin
Thyroid produces _____ substances dependent on the dietary level of _____
Iodinated substances, iodate
Role of triiodothyronine and thyroxine
Regulation of body metabolism, brain and NS development control, sexual maturation, temperature regulation
Low levels of ____ result in reduced levels of ______ function
iodine, thyroid function
Main hormones produced by thyroid
Triiodothyronine (T3) and Thyroxine (T4), both are fat soluble
Parathyroid Hormones
Parathyroid hormone (PH) and calcitonin
Parathyroid hormone function
Increases blood calcium levels
Calcitonin
Decreases blood calcium levels
Glucagon
- Released from alpha cells
- Travels to the liver and breaks
down stored glycogen - Opposes insulin and increases
blood levels of glucose
What does pancreas contain
Alpha, beta and delta cells
Insulin
Produced by beta cells
Mediates efficient energy movement from blood to cells
The only hormone that can lower blood sugar
What is the only hormone that can lower blood sugar
Insulin
Type 1 diabetes
Congenital, autoimmune, pancreatic cells are destroyed by the immune system
Type 2 diabetes
Developed due to poor diet
Body is unable to produce enough insulin
Insulin may also work improperly
Adrenal gland composition
Adrenal cortex (70%)
Adrenal medulla (30%)
Adrenal Cortex Composition
- Zona Glomerulosa
- Zona Fasciculata
- Zona Reticularis
Zona glomerulosa
Releases aldosterone in response to low sodium
GLOMERULES - REFERENCE
Zona Fasciculata
Releases glucocorticoids
FASCICULUS - REFERENCE
Zone Reticularis
Releases sex steroid hormones
RECTICULARIS - Sex/Rectum uk
Adrenal Medulla and hormone production
Releases three MONOAMINE hormones
1. Epinephrine
2. Norepinephrine
3. Dopamine
Gonads and primary hormones
Primarily produce steroid hormones that are required for gamete development
Gonadal hormones mediate behaviors necessary to bring the sperm and egg together
What mediates gonadal function
Gonadotropin produced in the pituitary is the primary mediator of gonadal function
Testes
Contain semiferous tubules where sperm cells undergo spermatogenesis
Sertoli cells
Located along the semiferous tubules and play a role in spermatogenesis
Leydig cells
Located between the tubes and testes
Produce androgen/testosterone in response to luteinizing hormone (from anterior pituitary)
Corpora Lutea (in ovaries)
Secrete progestins that support the uterine lining
Theca cells participate in _____ _____
Estrogen synthesis
Placental hormones role
Act to stimulate gonadal, mammary, adrenal and thyroid functions
Placental hormones list
Chorionic gonadotropin
Chorionic somatomammotropin
Chorionic corticotropin
Chorionic tyrotropin
Chorionic gonadotropin
Maintains corpora lutea functions and progesterone secretion, prevents ovulation
Relaxin
Produced by corpora lutea, softens pelvic ligaments for birth
What is a specificity of gastrointestinal hormones
They have intracrine and autocrine mediation which is a more primitive version of mediation
Main gastrointestinal hormones
Secretin
Cholecystokinin (CCK)
Gastrin
Ghrelin
Secretin
Sends signals to pancreas and triggers juice secretion for facilitating digestion
Inhibits gastrointestinal tract movement and gastric acid secretion
Cholecystokinin (CCK)
MAY BE involved in satiation
Causes exocrine pancreas to secrete digestive enzymes
Causes gallbladder to contract and release bile
Was found in the brain where it functions as a neurotransmitter or a neuromodulator
Gastrin functions
Induces secretion of water and electrolytes by stomach, liver and pancreas
Ghrelin
Stimulates GHRH release form anterior pituitary
Ghrelin levels reach its maximum before a meal and drop after
Physiological by-product hormonal regulation
Once the hormone causes a physiological change, restoring the balance, secretion stops
Negative feedback
Aimed to stimulate the system by reducing the hormone release rate or output
Positive feedback
Rarer than negative feedback, aimed to increase the production of hormone
Up-regulation
Hormone causes an increase in the production of receptors for that hormone
Down-regulation
Hormone overproduction causes an occupation or reduction of receptors
Steroid hormone receptors and steroid interaction
Located in either the nucleus or cytosol
Steroids are fat soluble -> can penetrate the membrane and bind to a receptor
Once bound they migrate to the nucleus if not already there
Protein and peptide hormone receptors are embedded in the ____
Membrane
Three domains of protein and peptide hormone receptors
Extracellular - binds to a hormone, forming a hormone-receptor complex
Transmemrane
Intracellular or cytoplasmic
Protein and peptide hormones with intrinsic enzymatic activity are found in the ______ domain
Intracellular/cytoplasmic
Protein and peptide hormone that require a second messenger are coupled with _____
A G-protein
Chromosomal Sex
Defined during fertilization
Determined by X or Y chromosome given by the sperm
Germinal Ridge and what makes it bipotential
Its ability to develop into either testes or ovaries
What is requires for the germinal ridge to develop into testes
SRY hormone and SOX9 hormone
What happens if either SRY or SOX9 is not present?
Germinal ridge develops into ovaries?
What do testes secrete and what does it cause
They secrete androgens which leads to a development of a male
What happens in the presence of ovaries or lack of gonads?
Female system is developed
What systems are present early in the embryonic development?
Mullerian and wulfian systems are both present
What hormones should be present for the wolfian system to develop
Mullerian inhibitory hormone and testosterone
What are androgens important for and what happens in their absence
They are important for the formation of a penis and a vagina forms in their absence
Organizational/Activational hypothesis of hormonal sexual differentiation
Sex hormones act during prenatal state to permanently ORGANIZE the nervous system and during adult life they have an ACTIVATIONAL effect
Female sexual desire
Is cyclical due to a cyclical GnRH hormone secretion which leads to a luteinizing hormone secretion which causes ovulation and leads to sexual desire
Male sexual desire
Seems to be constant due to a constant release of testosterone
