Reflexes

Explanation : Superficial cutaneous reflexes are Scapular reflex, Upper abdominal reflex, Lower abdominal reflex, Cremasteric reflex, Gluteal reflex, Plantar reflex, Bulbocavernous reflex, Anal reflex.
Ref : Sembulingam 6th edition (Table- 142.2)

Explanation :

Ref : Sembulingam 6th edition (Table-144.3)

In penile erection initial penile vascular engorgement ias controlled by PNS part of ANS( S2,S3,S4 segments of spinal cord)

Erection and ejaculation
Erection and ejaculation are regulated by the autonomic innervation of the penis. The parasympathetic stimulation is excitatory for the penis, as it causes the erection. The parasympathetic stimuli relax the smooth musculature of the corpora cavernosa and produce vasodilation in the helicine arteries. The helicine arteries then fill the corpora cavernosa, compressing the venous outflow from the penis. This process is called the veno-occlusive mechanism and it results with penile erection.

On the other hand, the inhibitory sympathetic stimuli cause the ejaculation when the critical level of sexual excitement has been reached. The ejaculation process can be divided into two phases. In the first phase, the sympathetic stimuli cause the vasoconstriction of helicine arteries, contraction of the smooth muscle cells within the septa of corpus spongiosum and contraction seminal vesicles and prostate. This results in accumulation of seminal fluid into the proximal part of the urethra. During the second phase, the bulbospongiosus muscle contracts  and expels the seminal fluid through the urethra (ejaculation). When the ejaculation is finished the penis returns into the flaccid state. An individual normally produces 3-5 ml of semen per one ejaculation which contains about 300 million sperm cells.

Snell 8th - 402

During sleep:
1. Pulse & RR decreases
2. BP falls
3. Tendon relex lost

Explanation : Root value for Jaw jerk is Pons – V cranial nerve, Biceps jerk is C5, C6,Triceps jerk is C6 to C8 , Supinator jerk or radial periosteal reflex is C7, C8 ,Wrist tendon or finger flexion reflex is C8, T1, Knee jerk or patellar tendon reflex is L2 to L4, Ankle jerk or Achilles tendon reflex is L5 to S2.
Ref : Sembulingam 6th edition (Table-142.3)

Explanation : Trigeminal nerve acts as afferent nerve in case of corneal,conjunctival & nasal superficial mucous membrane reflexes. Glossopharyngeal nerve acts as afferent nerve in case of uvular & pharyngeal reflex.
Ref : Sembulingam 6th edition (Table- 142.1)

Function of brainstem
1. Control of respiration
2. Control of the cardiovascular system
3. Partial control of gastrointestinal function
4. Control of many stereotyped movements of the body
5. Control of equilibrium
6. Control of eye movements

Explanation : Stretch reflex is a monosynaptic reflex,Golgi tendon reflex/Clasp-knife reflex is disynaptic reflex,flexor withdrawl reflex is a polysynaptic reflex.
Ref : BRS Physiology 7th edition (Table- 2.8)

Loss of ankle jerk with extensor planter response
•       Subacute combined degeneration of spinal cord
•        Friedreich’s ataxia
•       Taboparesis
•       Multiple sclerosis
•       DM with cervical myelopathy.

Brain Areas for Control of the Gamma Motor System
The gamma efferent system is excited specifically by signals from the bulboreticular facilitatory region of the brain stem
and, secondarily, by impulses transmitted into the bulboreticular area from the following: (1) the cerebellum; (2) the basal ganglia; and (3) the cerebral cortex.
Because the bulboreticular facilitatory area is particularly concerned with antigravity contractions, and because the antigravity muscles have an especially high density of muscle spindles, the gamma efferent mechanism is believed to be important for damping the movements of the different body parts during walking and running.

Explanation : Functions of the cerebellum-
a. Vestibulocerebellum—control of balance and eye movement.
b. Pontocerebellum—planning and initiation of movement.
c. Spinocerebellum—synergy, which is control of rate, force, range, and direction of movement.

Ref : BRS Physiology 7th edition