This document summarizes the anatomy and physiology of the human sense of smell. It discusses:
- The olfactory epithelium containing olfactory receptor cells that detect odors and transmit signals to the brain.
- Supporting cells and basal stem cells that provide structure and regenerate receptors.
- Odor molecules binding to receptors and activating G proteins and cAMP to trigger nerve impulses.
- The olfactory bulb and pathways that carry signals to parts of the limbic system and brain involved in emotion and conscious perception.
olfactory system and functioning, pathway of olfaction, neural tract involved in olfaction , endocrine pathway of olfaction, cells and neurons involved in olfaction
olfactory system and functioning, pathway of olfaction, neural tract involved in olfaction , endocrine pathway of olfaction, cells and neurons involved in olfaction
This PPT covers Anatomy and Physiology of respiratory system. Anatomy of respiratory organs, Mechanism of respiration, Internal Respiration, external respiration, Transport of oxygen in blood, Transport of carbon dioxide in blood, Regulation of respiration, lung volume and lung capacities are explained.
Micturition (The Guyton and Hall physiology)Maryam Fida
The process by which the urinary bladder empties when it becomes filled.
It is a reflex process
ANATOMY OF URINARY BLADDER BODY = in which urine is collected
NECK = funnel shaped extension and connecting with the urethra.
URETHRAL SPHINCTER.
1. INTERNAL URETHRAL SPHINCTER.
made up of detrusor muscle
2. EXTERNAL URETHRAL SPHINCTER.
made up of skeletal muscle fiber.
EXTERNAL URETHRAL SPHINCTER is responsible for voluntary control of micturition
The walls of the ureter contain smooth musle and are innervated by both sympathetic and parasympathetic nerves.
Parasympathetic stimulation increases peristaltic contraction .
Sympathetic stimulation inhibited MICTURITION REFLEX Filling of urinary bladder 300 – 400 ml
|
stimulation of sensory stretch receptors
present on the wall of bladder
|
Afferent impulses pass via pelvic nerve
|
reaches the sacral segments of spinal cord
|
synapses with postganglionic neuron
|
Efferent impulses via pelvic nerve
causes contraction of detrusor muscle
and relaxation of internal sphincter
|
flow of urine in to urethra and
stimulation of stretch receptors present
in urethra
|
it send afferent impulses via pelvic nerve
|
Inhibition of pudendal nerve
|
Relaxation of external sphincter
|
voiding of urine
Once a micturition begins ,, it is a “self regenerative “.
THAT IS,
the initial contraction of bladder
further activates the receptors to
causes still further increase in sensory
impulses from the bladder and urethra.
These impulses in turn further increases in reflex contraction of bladder.
about nerve fibers
It is the structural and the functional unit of nervous system.
The human nervous system contains approximate 1012 neurons.
A nerve fiber is a thread like extension of a nerve cell and consists of an axon and myelin sheath (if present) in the nervous system.
In peripheral nervous system it is formed by
schwann’s cell. While in case of central nervous system it is formed by oligodendroglia.
The places ,where myelin sheath is absent are called node of ranvier(2-3µm) and these are present once about 1-3 mm distance along the myelin sheath.
IT PREVENTS LEAKAGE OF IONS BY 5000 FOLDS.
IT INCREASES VELOCITY OF CONDUCTION BY 5-50 FOLDS DUE TO
SALTATORY CONDUCTION i.e. ABOUT 100 m/s IN CASE OF
MYELINATED NERVE FIBERS WHILE IN NONMYELINATED
IT IS ABOUT 0.25 m/s.
SALTATORY CONDUCTION CONSERVES ENERGY BECAUSE ONLY NODES OF RANVIER GET DEPOLARISED.
These are α type motor nerve fibers.
The neurotransmitter released at the neuron endings is acetylcholine(Ach).
It always leads to muscles excitation . Inhibition takes place centrally due to participation of interneurons.
they innervate smooth muscles , cardiac muscles and glands.
Their main work is to maintain homeostasis with the help of autonomic nervous system.
they can lead to either excitation or inhibition of effector organs
Erlanger and Grasser studied the action potential of mixed nerve trunk by means of cathode ray oscilloscope and they obtained the compounded spike. So they divided nerve fibers into 3 groups. They observed that the main cause of difference in nerve fibers is diameter
AS Diameter increases
Velocity of conduction increases.
Magnitude of electrical response increases.
Threshold of excitation decreases.
Duration of response decreases.
Refractory period decreases.
Salivary gland by Pandian M, Dept. of Physiology, DYPMCKOP,MH, INDPandian M
Functional anatomy of mouth
Salivary Glands location & structure of salivary glands
Additional gland
Nerve supply to the salivary glands
Composition of saliva
Regulation of Salivary secretion
Function of saliva
Applied aspects of Salivary secretion
This PPT covers Anatomy and Physiology of respiratory system. Anatomy of respiratory organs, Mechanism of respiration, Internal Respiration, external respiration, Transport of oxygen in blood, Transport of carbon dioxide in blood, Regulation of respiration, lung volume and lung capacities are explained.
Micturition (The Guyton and Hall physiology)Maryam Fida
The process by which the urinary bladder empties when it becomes filled.
It is a reflex process
ANATOMY OF URINARY BLADDER BODY = in which urine is collected
NECK = funnel shaped extension and connecting with the urethra.
URETHRAL SPHINCTER.
1. INTERNAL URETHRAL SPHINCTER.
made up of detrusor muscle
2. EXTERNAL URETHRAL SPHINCTER.
made up of skeletal muscle fiber.
EXTERNAL URETHRAL SPHINCTER is responsible for voluntary control of micturition
The walls of the ureter contain smooth musle and are innervated by both sympathetic and parasympathetic nerves.
Parasympathetic stimulation increases peristaltic contraction .
Sympathetic stimulation inhibited MICTURITION REFLEX Filling of urinary bladder 300 – 400 ml
|
stimulation of sensory stretch receptors
present on the wall of bladder
|
Afferent impulses pass via pelvic nerve
|
reaches the sacral segments of spinal cord
|
synapses with postganglionic neuron
|
Efferent impulses via pelvic nerve
causes contraction of detrusor muscle
and relaxation of internal sphincter
|
flow of urine in to urethra and
stimulation of stretch receptors present
in urethra
|
it send afferent impulses via pelvic nerve
|
Inhibition of pudendal nerve
|
Relaxation of external sphincter
|
voiding of urine
Once a micturition begins ,, it is a “self regenerative “.
THAT IS,
the initial contraction of bladder
further activates the receptors to
causes still further increase in sensory
impulses from the bladder and urethra.
These impulses in turn further increases in reflex contraction of bladder.
about nerve fibers
It is the structural and the functional unit of nervous system.
The human nervous system contains approximate 1012 neurons.
A nerve fiber is a thread like extension of a nerve cell and consists of an axon and myelin sheath (if present) in the nervous system.
In peripheral nervous system it is formed by
schwann’s cell. While in case of central nervous system it is formed by oligodendroglia.
The places ,where myelin sheath is absent are called node of ranvier(2-3µm) and these are present once about 1-3 mm distance along the myelin sheath.
IT PREVENTS LEAKAGE OF IONS BY 5000 FOLDS.
IT INCREASES VELOCITY OF CONDUCTION BY 5-50 FOLDS DUE TO
SALTATORY CONDUCTION i.e. ABOUT 100 m/s IN CASE OF
MYELINATED NERVE FIBERS WHILE IN NONMYELINATED
IT IS ABOUT 0.25 m/s.
SALTATORY CONDUCTION CONSERVES ENERGY BECAUSE ONLY NODES OF RANVIER GET DEPOLARISED.
These are α type motor nerve fibers.
The neurotransmitter released at the neuron endings is acetylcholine(Ach).
It always leads to muscles excitation . Inhibition takes place centrally due to participation of interneurons.
they innervate smooth muscles , cardiac muscles and glands.
Their main work is to maintain homeostasis with the help of autonomic nervous system.
they can lead to either excitation or inhibition of effector organs
Erlanger and Grasser studied the action potential of mixed nerve trunk by means of cathode ray oscilloscope and they obtained the compounded spike. So they divided nerve fibers into 3 groups. They observed that the main cause of difference in nerve fibers is diameter
AS Diameter increases
Velocity of conduction increases.
Magnitude of electrical response increases.
Threshold of excitation decreases.
Duration of response decreases.
Refractory period decreases.
Salivary gland by Pandian M, Dept. of Physiology, DYPMCKOP,MH, INDPandian M
Functional anatomy of mouth
Salivary Glands location & structure of salivary glands
Additional gland
Nerve supply to the salivary glands
Composition of saliva
Regulation of Salivary secretion
Function of saliva
Applied aspects of Salivary secretion
Olfaction is one the major sense. In the following presentation, a brief description of the olfactory system is given. In this following topics are discussed: olfactory membrane, olfactory bulb, odor pathway, anosmia, directional smelling and plasticity. By the end of it, you will be able to describe the olfactory pathway of the nervous system.
Smell & Taste theory updated on 2021 BY PANDIAN M. Pandian M
10.13 & 10.14 Describe and discuss perception of smell and taste sensation
At the end of the session, the first phase MBBS student should be able to
1] Describe the location, structure, and afferent pathways of taste receptors.
2]Describe the location, structure, and afferent pathways of smell receptors.
3]Name the basic taste sensations, identify the five distinct gustatory modalities.
4] describe the cells of a taste bud.
5] explain how taste receptors are activated and explain the mechanism of taste transduction for each taste quality.
6] explain how olfactory receptors are activated and explain the mechanism of olfactory transduction.
7] identify the three cranial nerves that transmit taste information to the cerebral cortex.
The French Revolution, which began in 1789, was a period of radical social and political upheaval in France. It marked the decline of absolute monarchies, the rise of secular and democratic republics, and the eventual rise of Napoleon Bonaparte. This revolutionary period is crucial in understanding the transition from feudalism to modernity in Europe.
For more information, visit-www.vavaclasses.com
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Biological screening of herbal drugs: Introduction and Need for
Phyto-Pharmacological Screening, New Strategies for evaluating
Natural Products, In vitro evaluation techniques for Antioxidants, Antimicrobial and Anticancer drugs. In vivo evaluation techniques
for Anti-inflammatory, Antiulcer, Anticancer, Wound healing, Antidiabetic, Hepatoprotective, Cardio protective, Diuretics and
Antifertility, Toxicity studies as per OECD guidelines
Read| The latest issue of The Challenger is here! We are thrilled to announce that our school paper has qualified for the NATIONAL SCHOOLS PRESS CONFERENCE (NSPC) 2024. Thank you for your unwavering support and trust. Dive into the stories that made us stand out!
Acetabularia Information For Class 9 .docxvaibhavrinwa19
Acetabularia acetabulum is a single-celled green alga that in its vegetative state is morphologically differentiated into a basal rhizoid and an axially elongated stalk, which bears whorls of branching hairs. The single diploid nucleus resides in the rhizoid.
A Strategic Approach: GenAI in EducationPeter Windle
Artificial Intelligence (AI) technologies such as Generative AI, Image Generators and Large Language Models have had a dramatic impact on teaching, learning and assessment over the past 18 months. The most immediate threat AI posed was to Academic Integrity with Higher Education Institutes (HEIs) focusing their efforts on combating the use of GenAI in assessment. Guidelines were developed for staff and students, policies put in place too. Innovative educators have forged paths in the use of Generative AI for teaching, learning and assessments leading to pockets of transformation springing up across HEIs, often with little or no top-down guidance, support or direction.
This Gasta posits a strategic approach to integrating AI into HEIs to prepare staff, students and the curriculum for an evolving world and workplace. We will highlight the advantages of working with these technologies beyond the realm of teaching, learning and assessment by considering prompt engineering skills, industry impact, curriculum changes, and the need for staff upskilling. In contrast, not engaging strategically with Generative AI poses risks, including falling behind peers, missed opportunities and failing to ensure our graduates remain employable. The rapid evolution of AI technologies necessitates a proactive and strategic approach if we are to remain relevant.
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2024.06.01 Introducing a competency framework for languag learning materials ...Sandy Millin
http://sandymillin.wordpress.com/iateflwebinar2024
Published classroom materials form the basis of syllabuses, drive teacher professional development, and have a potentially huge influence on learners, teachers and education systems. All teachers also create their own materials, whether a few sentences on a blackboard, a highly-structured fully-realised online course, or anything in between. Despite this, the knowledge and skills needed to create effective language learning materials are rarely part of teacher training, and are mostly learnt by trial and error.
Knowledge and skills frameworks, generally called competency frameworks, for ELT teachers, trainers and managers have existed for a few years now. However, until I created one for my MA dissertation, there wasn’t one drawing together what we need to know and do to be able to effectively produce language learning materials.
This webinar will introduce you to my framework, highlighting the key competencies I identified from my research. It will also show how anybody involved in language teaching (any language, not just English!), teacher training, managing schools or developing language learning materials can benefit from using the framework.
2. Important for enjoyment &
selection of food .
Flavours are combinations of
taste and smell (smell contribution
is about 80 %)
Gives warning of harmful
substances or places
3. Primary Sensations of Smell
Based on psychological studies, one attempt to classify
these sensations is the following:
•
•
•
•
•
•
•
1. Camphoraceous
2. Musky
3. Floral
4. Pepperminty
5. Ethereal
6. Pungent
7. Putrid
In recent years, specific studies of the genes that encode
for the receptor proteins, suggest the existence of at least
100 primary sensations of smell
5. • The nose contains 10–100 million olfactory receptors
contained within an area called the olfactory epithelium.
• olfactory epithelium lies in the superior part of each
nostril.
• In each nostril, the olfactory membrane has a surface
area of about 2.4 square centimeters.
• The olfactory epithelium consists of three kinds of cells:
olfactory receptors,
supporting cells / sustentacular cells
basal cells
6. Olfactory receptors
• The receptor cells for the smell sensation are the olfactory cells .
• They are actually bipolar nerve cells derived from the CNS .
• There are about 100 million of these cells in the olfactory epithelium.
• The mucosal end of the olfactory cell forms a knob .
• From knob 4 to 25 olfactory hairs (olfactory cilia), project into the
mucus that coats the inner surface of the nasal cavity.
• These projecting olfactory cilia form a dense mat in the mucus.
• These cilia react to odours in the air and stimulate the olfactory
cells
7.
8. Supporting cells/sustentacular cells
The receptor cells in the olfactory epithelium are interspersed among
sustentacular cells or supporting cells.
Supporting cells are columnar epithelial cells.
They provide physical support, nourishment and electrical insulation for
the olfactory receptors,
They help detoxify chemicals that come in contact with the olfactory
epithelium.
9. Basal cells
• Basal cells are stem cells located between
the bases of the supporting cells.
• They continually undergo cell division to
produce new olfactory receptors, which live for
only a month or so before being replaced.
• This process is remarkable - olfactory
receptors are neurons, and mature neurons
are generally not replaced.
• The olfactory renewal process is carefully
regulated - a bone morphogenic protein
(BMP) exerts an inhibitory effect.
• [ BMPs are a large family of growth factors
originally described as promoters of bone
growth]
10. Spaced among the olfactory cells in the olfactory membrane are many small
Bowman’s glands that secrete mucus onto the surface of the olfactory membrane
mucus is carried to the surface of the epithelium by ducts.
The secretion moistens the surface of the olfactory epithelium and dissolves
odourants so that transduction can occur.
12. MECHANISM OF EXCITATION OF OLFACTORY CELLS.
Cilium is the portion which respond to the olfactory chemical stimuli.
The odourant substance on coming in contact with olfactory surface
first diffuse in to the mucus which covers the cilia.
Then binds with a receptor protein that protrudes through the ciliary
membrane.
This receptor is a long molecule, it threads its way through the
membrane 7 times, folding inward and outward.
Odourant binds with portion of receptor and coupled to G-PROTEIN.
G-PROTEIN –a combination of 3 subunits.
15. On excitation of receptor,an alpha subunit breaks away
from G-PROTEIN and activates adenylcyclase.
Activated cyclase converts many molecules of intracellular
adenosine-tri-phosphate into cyclic-adenosine
monophosphate(cAMP).
This cAMP activates another near by membrane protein,a
gated sodium ion channel.
Allows large number of sodium ions to pour into receptor
cell cytoplasm.
Sodium ions helps in exciting the olfactory neuron and
transmitting action potential in to the CNS through an
olfactory nerve.
16.
17. Odourant + receptor protein
Activation of G protein
Activation of adenylate
cyclase
ATP cAMP
Opening of Na+ channels
Na+ influx
Mechanism of olfactory cell stimulation
18. Physical factors affect the degree of
stimulation.
Only volatile substances that can be sniffed into
the nostrils can be smelled.
The stimulating substance must be at least
slightly water soluble so that it can pass through
the mucus to reach the olfactory cilia.
The substance should be at least slightly lipid
soluble, because lipid constituents of the cilium
itself are a weak barrier to non-lipid-soluble
odourants.
19.
20. Cribiform plate separates nasal cavity and cranial cavity.
Olfactory bulb lies above cribiform plate.
Small nerves from olfactory membrane in nasalcavity pass through the small
perforations in the cribiform plate to enter olfactory bulb in the cranial cavity.
Olfactory nerve fibers leading from olf.bulb are called Cranial nerve I or olf.
Tract.
21. Short axons from the olfactory cells terminate in multiple globular structures
within the olfactory bulb called glomeruli.
Each bulb has several thousand such glomeruli,each of which is the terminus for
about 25,000 axons from olfactory cells.
Each glomerulus also is the terminus for dendrites from about 25 large mitral
cells and about 60 smaller tufted cells, the cell bodies of which lie in the olfactory
bulb superior to the glomeruli.
These dendrites receive synapses from the olfactory cell neurons,
the mitral and tufted cells send axons through the olfactory tract to transmit
olfactory signals to higher levels in the central nervous system.
Some research has suggested that different glomeruli respond to different
odours.
24. The olfactory tract enters the brain at the anterior junction between the
mesencephalon and cerebrum;
there, the tract divides into two pathways, one passing medially into the medial
olfactory area of the brain stem, and the other passing laterally into the lateral
olfactory area.
The medial olfactory area represents a very old olfactory system, whereas the
lateral olfactory area is the input to
(1) A less old olfactory system and (2) a newer system
25. Olfactory pathway
Olfactory Tract
Medial Olfactory area Lateral Olfactory area
Prepyriform cortex
Septal Nuclei
Hypothalamus
Limbic system
(primitive parts)
(Very Old
Olfactory System)
Pyriform Cortex
Amygdala
Thalamus
Orbitofrontal
Cortex
(Newer System)
Limbic system
(hippocampus)
(Less Old Olfactory
System)
Olfactory receptor cell Olfactory nerve
Olfactory bulb
27. Very Old Olfactory System
More primitive responses to olfaction
salivation, liking lips and primitive emotional drives
to smell
Less Old Olfactory System
Learned control of food intake
Aversion to food that have caused nausea and
vomiting.
Newer System
Conscious perception & analysis of odour
Odour discrimination
