This is a rapid, monosynaptic (single synapse), ipsilateral reflex that helps to maintain the length of muscles and contributes to joint stabilization. A common example of this reflex is the knee jerk reflex that is elicited by a rubber hammer striking against the patellar tendon, such as during a physical exam.

Which reflex is contralateral?

The crossed extensor reflex is contralateral, meaning the reflex occurs on the opposite side of the body from the stimulus. To produce this reflex, branches of the afferent nerve fibers cross from the stimulated side of the body to the contralateral side of the spinal cord.

Is the salivary reflex ipsilateral or contralateral?

The secretion was greatest when the subject chewed on the same side of the mouth (ipsilateral) as the salivary flow was recorded. Less salivary flow resulted when the subjects chewed on the opposite side of the mouth (contralateral).

Is patellar reflex an autonomic reflex?

Autonomic Reflexes

Activity 1- Patellar reflex The patellar tendon reflex or knee-jerk reflex is a monosynaptic stretch reflex that assesses the nervous tissue between (and including) the L2 and L4 segments. It can be done by tapping the patellar ligament (just below the knee) with a reflex hammer.

Is the patellar reflex Monosynaptic or Polysynaptic?

Examples of monosynaptic reflex arcs in humans include the patellar reflex and the Achilles reflex. Most reflex arcs are polysynaptic, meaning multiple interneurons (also called relay neurons) interface between the sensory and motor neurons in the reflex pathway.

2-Minute Neuroscience: Knee-jerk Reflex

What kind of reflex is the patellar reflex?

The patellar reflex is a clinical and classic example of the monosynaptic reflex arc. There is no interneuron in the pathway leading to contraction of the quadriceps muscle. Instead, the sensory neuron synapses directly on a motor neuron in the spinal cord.

Where is the knee reflex?

knee-jerk reflex, also called patellar reflex, sudden kicking movement of the lower leg in response to a sharp tap on the patellar tendon, which lies just below the kneecap.

Is patellar knee jerk reflex somatic or autonomic?

reflexes that involve stimulation of skeletal muscles via the somatic nervous system and are under conscious control. Ex: Patellar (knee jerk) reflex. a neural pathway between the point of stimulation (receptor), to the brain or spinal cord, and to the responding organ(effector).

Is the knee jerk reflex innate?

Pulling your hand away from a hot object, blinking because it's very bright or kicking when someone taps the tendon below your kneecap - these are all innate reflex actions. ... The knee-jerk reflex involves a sudden kicking movement of your lower leg after the tendon just below your kneecap has been tapped.

Is patellar reflex somatic or autonomic quizlet?

Some examples of the somatic nervous system include: the blinking reflex, knee jerk reflex, gag reflex, and the startle reflex and rooting reflex in infants. An example of a monosynapticreflex is the patellar (knee jerk) reflex.

What is the salivary reflex?

a change in the secretion of the salivary glands caused by unconditioned or conditioned stimulation of their effector nerves.

Which of the following is a normal response to the patellar reflex test?

The patellar reflex occurs when an abrupt change arises in muscle length; in this case, it is produced by the tendon stretching, which is caused when the hammer stroke is applied [3, 4]. The normal response must be a sudden leg extension.

What function is the receptor in knee jerk reflex?

Tapping the patellar tendon stretches the quadriceps muscle and causes the sensory receptor of the muscle, called a spindle fiber, to send a signal along the afferent neuron to the spinal cord.

Is patellar reflex innate or acquired?

Reflex actions, such as the knee-jerk reflex tested by doctors and the sucking reflex of human infants, are very simple innate behaviors. Some organisms perform innate kinesis, undirected change in movement, and taxis, directed change in movement, behaviors in response to stimuli.

Do we have patellar reflex at birth?

The pectoralis major was the most readily elicitable reflex in all infants (100%), regardless of maturity. Achilles, patellar, biceps, thigh adductors, and brachioradialis reflexes also were obtained in at least 98% of babies of greater than 33 weeks gestation.

Which of the following is innate reflex?

placental mammals appear to be innate. They are hereditary and are a common feature of the species and often of the genus. Reflexes include not only such simple acts as chewing, swallowing, blinking, the knee jerk, and the scratch reflex, but also stepping, standing, and mating.

Is knee jerk reflex somatic?

Reflexes can be categorized as either autonomic or somatic. Autonomic reflexes are not subject to conscious control, are mediated by the autonomic division of the nervous system, and usually involve the activation of smooth muscle, cardiac muscle, and glands. ... The knee jerk reflex is called a monosynaptic reflex.

What is the name of the nerve that carries the sensory information for the patellar reflex?

Striking the patellar tendon with a tendon hammer just below the patella stretches the quadriceps tendon. This stimulates stretch sensory receptors (most importantly, muscle spindles) that triggers an afferent impulse in a sensory nerve fiber of the femoral nerve leading to the lumbar region of the spinal cord.

What are examples of somatic reflexes?

This occurs when a nerve pathway connects directly to the spinal cord. Examples of reflex actions include: Jerking your hand back after accidentally touching a hot pan. Involuntary jerking when your doctor taps on your knee.

Where is the patellar tendon?

The patellar tendon connects the bottom of the kneecap (patella) to the top of the shinbone (tibia). Despite its name, the patellar tendon is actually a ligament. Tendons connect a muscle to a bone. Ligaments connect two muscles.

What does no patellar reflex mean?

Patellar tendon reflex.

You sit on the exam table with your knee bent and your foot hanging down, not touching the floor. Your doctor will use a rubber hammer to tap firmly on the tendon just below your kneecap. ... A decreased or absent reflex may mean that there is compression in the L2, L3, or L4 region.

What is the knee jerk reflex an example of?

Doctors will test reflexes by tapping the tendon just below the knee, and this causes the leg to kick out. This knee-jerk reflex is an example of a simple monosynaptic reflex.