Vestibule - Static Equilibrium The horizontally positioned utricle
Utricle
The utricle and saccule are the two otolith organs in the vertebrate inner ear. They are part of the balancing system in the vestibule of the bony labyrinth. They use small stones and a viscous fluid to stimulate hair cells to detect motion and orientation. The utricle detects linear accelerations and head-tilts in the horizontal plane. The word utricle comes from Latin uter, meaning 'leather bag'.
Full Answer
What structures detect changes in static equilibrium in the body?
Equilibrium. Motion in the following two structures is detected as follows: The vestibule is the primary detector of changes in static equilibrium. A sensory receptor called a macula is located in the walls of the saccule and utricle, the two bulblike sacs of the vestibule. A macula contains numerous receptor cells called hair cells,...
What is the basic condition for static equilibrium?
The fundamental and basic condition for static equilibrium is that an object must not be experiencing any type of motion, irrespective of translational or rotational. Furthermore, an object which is in translational equilibrium does not travel from one place to another.
What is the second equilibrium condition for the meter stick?
The second equilibrium condition (equation for the torques) for the meter stick is τ1 + τ2 + τ + τS + τ3 = 0. When substituting torque values into this equation, we can omit the torques giving zero contributions. In this way the second equilibrium condition is + r1m1g + r2m2g + rmg − r3m3g = 0.
What is an example of static equilibrium biomechanics?
This particular example illustrates an application of static equilibrium to biomechanics. A weightlifter is holding a 50.0-lb weight (equivalent to 222.4 N) with his forearm, as shown in Figure. His forearm is positioned at β = 60∘ β = 60 ∘ with respect to his upper arm.
What structures contribute to an individual's static equilibrium?
Explanations. Static equilibrium it is detected and provided by mechanoreceptors in the vestibule of the inner ear, the utricle and saccule. They all have receptors for static equilibrium. Dynamic equilibrium is provided by the semicircular canals-three ring-like extensions from the vestibule.
What is the structure of static equilibrium?
What is static equilibrium? Technically, a body (or structure) is in static equilibrium if it is not accelerating. This means that it is moving at a constant velocity.
What is responsible for static equilibrium?
Static equilibrium is maintained by vestibular apparatus of inner ear. It contains saccule and utricle (or sacculus and utriculus). These are the otolith organs present in inner ear.
What are the requirements for a system to be in static equilibrium?
What are the conditions for a body to be in Static Equilibrium? Two conditions of equilibrium must be satisfied to ensure that an object remains in static equilibrium. Firstly, the net force acting upon the object must be zero. Secondly, the net torque acting upon the object must also be zero.
What is an example of static equilibrium?
For an object to be considered in static equilibrium, it should satisfy two conditions: (1) the net force acting on the object is zero; and (2) the net torque acting on the object is also zero. A book at rest on top of a table and a balanced seesaw are examples of systems under static equilibrium.
What are the 3 types of equilibrium?
There are three types of equilibrium: stable, unstable, and neutral. Figures throughout this module illustrate various examples.
Which structure is important to your sense of balance and equilibrium?
The ear is a sensory organ that picks up sound waves, allowing us to hear. It is also essential to our sense of balance: the organ of balance (the vestibular system) is found inside the inner ear. It is made up of three semicircular canals and two otolith organs, known as the utricle and the saccule.
What are the three conditions of static equilibrium?
Conditions for equilibrium require that the sum of all external forces acting on the body is zero (first condition of equilibrium), and the sum of all external torques from external forces is zero (second condition of equilibrium). These two conditions must be simultaneously satisfied in equilibrium.
What are the conditions necessary for static equilibrium and dynamic equilibrium?
The condition Fnet=0 must be true for both static equilibrium, where the object's velocity is zero, and dynamic equilibrium, where the object is moving at a constant velocity. Below, the motionless person is in static equilibrium. The forces acting on him add up to zero.
Which of the following is the condition for static equilibrium select all apply?
To achieve complete static equilibrium, a system must have both rotational equilibrium (have a net torque of zero) and translational equilibrium (have a net force of zero).
What is a static equilibrium in chemistry?
Static equilibrium refers to a condition where the reaction occurring in a system is completely halted and there exists no movement between the reactants and the products corresponding to the chemical reaction.
What is the structure that contains the receptors for dynamic equilibrium?
The receptors for dynamic equilibrium are found in the crista ampullaris of the semicircular canals. These receptors respond to changes in angular motion.
What is equilibrium equation in structural analysis?
Equilibrium equations, which set the externally applied loads equal to the sum of the internal element forces at all joints, or node points, of a structural system, are the most fundamental equations in structural analysis and design.
Why is static equilibrium important?
An object which is in static equilibrium is unable to move. This is because all the forces which act on it compensate for one another. This concept is quite important in the design of rigid structures.
What is the basic condition of static equilibrium?
The fundamental and basic condition for static equilibrium is that an object must not be experiencing any type of motion, irrespective of translational or rotational. Furthermore, an object which is in translational equilibrium does not travel from one place to another.
What is the requirement of translational equilibrium?
The requirement with translational equilibrium is that the vector sum of all external forces is zero. Moreover, the directions and magnitude of external forces cancel each other out. The requirement with rotational equilibrium is that all the external torques cancel each other out.
What is the sum of all the external forces acting on an object or body?
Here, the sum of all the external forces acting on the object or body, “m” is its mass and a⃗ CM refers to the linear acceleration of its centre of mass. Furthermore, in equilibrium, the acceleration certainly happens to be zero.
Which equilibrium condition expresses rotational equilibrium?
The second equilibrium condition for the static equilibrium of a particular rigid body expresses rotational equilibrium:
Which equation shows the first equilibrium condition?
Equation (2) shows the first equilibrium condition. Moreover, this is the equilibrium condition for forces which one encounters when studying the applications of Newton’s laws.
Which is the correct option for static equilibrium?
A1 The correct option is A., which is “it is the equilibrium of a system whose parts are in motion.” This is because static equilibrium is the equilibrium of a system whose parts are at rest.
How to solve static equilibrium?
By the end of this section, you will be able to: 1 Identify and analyze static equilibrium situations 2 Set up a free-body diagram for an extended object in static equilibrium 3 Set up and solve static equilibrium conditions for objects in equilibrium in various physical situations
How many forces are acting on a stick?
With (Figure) and (Figure) for reference, we begin by finding the lever arms of the five forces acting on the stick:
How to determine the force of a ladder?
We can identify four forces acting on the ladder. The first force is the normal reaction force N from the floor in the upward vertical direction. The second force is the static friction force f = μsN f = μ s N directed horizontally along the floor toward the wall—this force prevents the ladder from slipping. These two forces act on the ladder at its contact point with the floor. The third force is the weight w of the ladder, attached at its CM located midway between its ends. The fourth force is the normal reaction force F from the wall in the horizontal direction away from the wall, attached at the contact point with the wall. There are no other forces because the wall is slippery, which means there is no friction between the wall and the ladder. Based on this analysis, we adopt the frame of reference with the y -axis in the vertical direction (parallel to the wall) and the x -axis in the horizontal direction (parallel to the floor). In this frame, each force has either a horizontal component or a vertical component but not both, which simplifies the solution. We select the pivot at the contact point with the floor. In the free-body diagram for the ladder, we indicate the pivot, all four forces and their lever arms, and the angles between lever arms and the forces, as shown in (Figure). With our choice of the pivot location, there is no torque either from the normal reaction force N or from the static friction f because they both act at the pivot.
How many masses are attached to a uniform meter stick?
Three masses are attached to a uniform meter stick, as shown in (Figure). The mass of the meter stick is 150.0 g and the masses to the left of the fulcrum are m1 = 50.0g m 1 = 50.0 g and m2 = 75.0g. m 2 = 75.0 g. Find the mass m3 m 3 that balances the system when it is attached at the right end of the stick, and the normal reaction force at the fulcrum when the system is balanced.
Which component of the net force satisfies the equation?
We see from the free-body diagram that the x -component of the net force satisfies the equation
What are the two issues in a SI unit?
The second important issue concerns the hinge joints such as the elbow. In the initial analysis of a problem, hinge joints should always be assumed to exert a force in an arbitrary direction, and then you must solve for all components of a hinge force independently . In this example, the elbow force happens to be vertical because the problem assumes the tension by the biceps to be vertical as well. Such a simplification, however, is not a general rule.
How to analyze a system in equilibrium?
Identify the object to be analyzed. For some systems in equilibrium, it may be necessary to consider more than one object. Identify all forces acting on the object. Identify the questions you need to answer. Identify the information given in the problem. In realistic problems, some key information may be implicit in the situation rather than provided explicitly.
What is the equation for the first equilibrium condition?
Equation 12.21 and Equation 12.22 are two equations of the first equilibrium condition (for forces). Next, we read from the free-body diagram that the net torque along the axis of rotation is
Why does a ladder slip in Equation 12.31?
But the ladder will slip if the net torque becomes negative in Equation 12.31. This happens for some angles when the coefficient of static friction is not great enough to prevent the ladder from slipping.
How to identify the forces acting on a ladder?
We can identify four forces acting on the ladder. The first force is the normal reaction force N from the floor in the upward vertical direction. The second force is the static friction force f = μsN directed horizontally along the floor toward the wall—this force prevents the ladder from slipping. These two forces act on the ladder at its contact point with the floor . The third force is the weight w of the ladder, attached at its CM located midway between its ends. The fourth force is the normal reaction force F from the wall in the horizontal direction away from the wall, attached at the contact point with the wall. There are no other forces because the wall is slippery, which means there is no friction between the wall and the ladder. Based on this analysis, we adopt the frame of reference with the y -axis in the vertical direction (parallel to the wall) and the x -axis in the horizontal direction (parallel to the floor). In this frame, each force has either a horizontal component or a vertical component but not both, which simplifies the solution. We select the pivot at the contact point with the floor. In the free-body diagram for the ladder, we indicate the pivot, all four forces and their lever arms, and the angles between lever arms and the forces, as shown in Figure 12.15. With our choice of the pivot location, there is no torque either from the normal reaction force N or from the static friction f because they both act at the pivot.
What are the two issues in a SI unit?
The second important issue concerns the hinge joints such as the elbow. In the initial analysis of a problem, hinge joints should always be assumed to exert a force in an arbitrary direction, and then you must solve for all components of a hinge force independently . In this example, the elbow force happens to be vertical because the problem assumes the tension by the biceps to be vertical as well. Such a simplification, however, is not a general rule.
What is net force on a ladder?
The net force on the ladder at the contact point with the floor is the vector sum of the normal reaction from the floor and the static friction forces:
How many masses are attached to a meter stick?
Three masses are attached to a uniform meter stick, as shown in Figure 12.9. The mass of the meter stick is 150.0 g and the masses to the left of the fulcrum are
What is static equilibrium?
Static equilibrium maintains the position of the head in response to linear movements of the body, such as starting to walk or stopping. Dynamic equilibrium maintains the position of the head in response to rotational motion of the body, such as rocking (as in a boat) or turning.
Where does the perception of equilibrium occur?
The perception of equilibrium occurs in the vestibular apparatus. Motion in the following two structures is detected as follows: The vestibule is the primary detector of changes in static equilibrium. A sensory receptor called a macula is located in the walls of the saccule and utricle, the two bulblike sacs of the vestibule.
What is the vestibule?
The vestibule lies between the semicircular canals and the cochlea. It contains two bulblike sacs, the saccule and utricle, whose membranes are continuous with those of the cochlea and semicircular canals, respectively. The saccule and utricle contain receptors that help maintain equilibrium.
What are graded potentials in the hair cells of the maculae and cristae?
Graded potentials in the hair cells of the maculae and cristae result in changes in the amounts of neurotransmitter secreted. In response to these changes, action potentials are generated in the fibers of the vestibular nerve, which subsequently joins the vestibulocochlear nerve.
What is the hair cell in the Crista Ampullaris?
Like the maculae of the vestibule, each crista ampullaris contains numerous hair cells whose stereocilia and kinocilium protrude into a gelatinous matrix, the cupula (which is analogous to the otolithic membranes of the maculae).
How many vestibular structures are there?
e) equilibrium: within the vestibular apparatus: there are five vestibular structures, each containing a specialized mechanoreceptor (site of transduction), a maculae, within the utricle and saccule, and a cristae within the ampullae of the superior, horizontal, and posterior semicircular canals. Upgrade to remove ads.
What is the vestibule?
Tap card to see definition 👆. The central cavity of the bony labyrinth of the ear containing the functional components of the membranous labyrinth involved in the sensations of static equilibri um which are two vestibular structures, each containing a specialized mechanoreceptor, a maculae, ...
What is the structure of the semicircular canal?
Within the ampulla of each semicircular canal is a complex mechanoreceptor structure , the crista ampullaris; the ampulla has a ridge covered by neuroepithelium consisting of sensory hair cells and supporting cells; the hair cells attached to a gelatinous mass, the cupula, which rests on top of the crista ampularis; when the perilymph in one of the semicircular canals moves, the hair cells in the crista ampullaris are stimulated to send nerve impulses to the brain; this advises the brain of whether or not a person has their balance during body movements or if their body is in motion, e.g, riding in a car.
What are the components of the membranous labyrinth?
The functional components of the membranous labyrinth, a series of three interconnected perilymph-filled tubes with enlarged ends, involved in the sensations of dynamic equilibrium; the contain the cristae ampullaris which detect acceleration in the three perpendicular planes (superior, horizontal, and posterior); these accelerometers make use of hair cells similar to those on the organ of Corti, but these hair cells detect movements of the fluid in the canals caused by angular acceleration about an axis perpendicular to the plane of the canal; tiny floating particles aid the process of stimulating the hair cells as they move with the fluid; the nerve impulses thus generated are transmitted along the vestibular branch of cranial nerve eight to the CNS.
Which sense interprets balance when one is moving, or at least the head is moving?
The special sense which interprets balance when one is moving, or at least the head is moving; the semicircular canals contain the receptors for dynamic equilibrium; within each semicircular canal is a complex mechanoreceptor called a crista ampullaris which contains the mechanoreceptors (Hair cells) for dynamic equilibrium; when the perilymph in one of the semicircular canals moves, the hair cells in the crista ampullaris are stimulated to send nerve impulses to the brain; this advises the brain of whether or not a person has their balance during body movements or if their body is in motion, e.g, riding in a car or turning one's head from side to side.
Which structure detects acceleration in the planes of the canal?
The dilation or expanded end of each of the semicircular canals of the vestibular apparatus which contains the specialized mechanoreceptor structure, the crista, which detect acceleration in the planes of the canal ; these accelerometers make use of hair cells to detect movements of the fluid in the canals caused by angular acceleration about an axis perpendicular to the plane of the canal; the nerve impulses thus generated are transmitted along the vestibular branch of cranial nerve eight to the CNS.
How to solve static equilibrium?
By the end of this section, you will be able to: 1 Identify and analyze static equilibrium situations 2 Set up a free-body diagram for an extended object in static equilibrium 3 Set up and solve static equilibrium conditions for objects in equilibrium in various physical situations
What does the negative sign in the equation tell us?
The negative sign in the equation tells us that the actual force at the elbow is antiparallel to the working direction adopted for drawing the free-body diagram. In the final answer, we convert the forces into SI units of force. The answer is
How much does a horizontal strut weigh?
A uniform horizontal strut weighs 400.0 N. One end of the strut is attached to a hinged support at the wall, and the other end of the strut is attached to a sign that weighs 200.0 N. The strut is also supported by a cable attached between the end of the strut and the wall. Assuming that the entire weight of the sign is attached at the very end of the strut, find the tension in the cable and the force at the hinge of the strut.
Where is the pivot located on a free body diagram?
Free-body diagram for the forearm: The pivot is located at point E (elbow).
Where is the pivot on a meter stick?
Check Your Understanding Repeat (Figure) using the left end of the meter stick to calculate the torques; that is, by placing the pivot at the left end of the meter stick.
Definition and Meaning of Static Equilibrium
A Balance of Forces
- The fundamental and basic condition for static equilibrium is that an object must not be experiencing any type of motion, irrespective of translational or rotational. Furthermore, an object which is in translational equilibrium does not travel from one place to another. In contrast, an object in rotational equilibrium is certainly not rotating around an axis. The requirement with tran…
Conditions and Equations For Static Equilibrium
- According to Newton’s second law of motion, the linear acceleration of a rigid body takes place due to net force acting on it. Its representation is as follows: ∑kF⃗ k=ma⃗ CM. (1) Here, the sum of all the external forces acting on the object or body, “m” is its mass and a⃗ CM refers to the linear acceleration of its centre of mass. Furthermore, in equilibrium, the acceleration certainly happen…
Solved Question For You
- Q1Which of the following is not true with regards to static equilibrium? A. It is the equilibrium of a system whose parts are in motion B. It refers to any system in which the sum of the forces, and torque, on each particle of the system happens to be zero C. It takes place when all the forces acting on an object are balanced and the object is not in motion in relation to the relative plane D…