Human Phyisology Lab

What is the definition of reflex?

Any response that occurs automatically without conscious effort.

What are the uses of reflexes in our body?

Simple reflexes are unlearned and predictable responses. Acquired reflexes are a result of practice and learning.

What are the common components of a reflex arc?

Receptor, sensory neuron, integration center, motor neuron and effector

Patellar reflex
a. What are the expected responses?
b. What muscles are activated to show the responses?
c. Are the responses ipsilateral, contralateral, or consensual?
d. What are the nerves responsible for these reflexes?

A. The leg kicks upwards

B. Quadriceps femoris muscle and the
hamstring muscle

C. Ipsilateral

D. spinal nerves L2, L3, and L4

Plantar reflex:
a. What are the expected responses?
b. What muscles are activated to show the responses?
c. Are the responses ipsilateral, contralateral, or consensual?
d. What are the nerves responsible for these reflexes?

A. The normal response is downward contraction of the toes. The abnormal response is the upgoing big toe and fanning outward of the other toes.

B. Flexor hallucis longus and flexor digitorum longus

C. Ipsilateral

D. spinal nerves L4, L5, and S1

Biceps reflex
a. What are the expected responses?
b. What muscles are activated to show the responses?
c. Are the responses ipsilateral, contralateral, or consensual?
d. What are the nerves responsible for these reflexes?

A. The biceps muscle contracts and the forearm jerks

B. Activates the stretch receptors inside the biceps muscle

C. Ipsilateral
D. C5 and C6

Achilles reflex
a. What are the expected responses?
b. What muscles are activated to show the responses?
c. Are the responses ipsilateral, contralateral, or consensual?
d. What are the nerves responsible for these reflexes?

A. Downward movement of the foot
B. Gastrocnemius and soleus muscles

C. Ipsilateral
D. S1 and S2 nerves

Palmaris brevis reflex
a. What are the expected responses?
b. What muscles are activated to show the responses?
c. Are the responses ipsilateral, contralateral, or consensual?
d. What are the nerves responsible for these reflexes?

A. Contraction of the palmaris brevis muscle
B. Palmaris brevis muscle

C. Ipsilateral

D. Ulnar nerve

Pupillary reflex
a. What are the expected responses?
b. What muscles are activated to show the responses?
c. Are the responses ipsilateral, contralateral, or consensual?
d. What are the nerves responsible for these reflexes?

A. Constriction of the pupils

B. Iris sphincter muscle and the iris dilator muscle

C. Ipsilateral and contralateral
D. CNII (afferent) and CNIII (efferent)

Accommodation reflex
a. What are the expected responses?
b. What muscles are activated to show the responses?
c. Are the responses ipsilateral, contralateral, or consensual?
d. What are the nerves responsible for these reflexes?

A. A near object causes the eyes to converge, lens shape: a near object causes the ciliary muscle to
contracts and makes the lens more convex, and pupil size: a near object causes pupil constriction

B. Medial rectus, sphincter pupillae, and ciliary muscles

C. Ipsilateral and contralateral

D. CNII (afferent) and CNIII (efferent

Ciliospinal reflex
a. What are the expected responses?
b. What muscles are activated to show the responses?
c. Are the responses ipsilateral, contralateral, or consensual?
d. What are the nerves responsible for these reflexes?

A. Dilation of the ipsilateral pupil in response to pain

B. Dilator pupillae muscle

C. Ipsilateral
D. The cervical sympathetic fibers.

What is a consensual reflex? Give one example

Any reflex observed on one side of the body when the other side has been stimulated. An example is shining a light in one eye, while concealing the other

The sympathetic nervous system activates the

"fight-or-flight" response, dilating pupils, increasing heart rate and respiration, and inhibiting digestion.

The parasympathetic nervous system activates the

"rest-and-digest" state, causing pupils to constrict, slowing heart rate and respiration, and stimulating digestion

Which part of the body controls the responses you see in the post-pointing and rotating chair experiments?

Semicircular canal

What is the vestibulo-ocular reflex? The five components of this reflex

stabilizes vision by automatically moving the eyes in the opposite direction of head movements, mediated by a three-neuron arc

What is the Jendrassik maneuver? How does it impact the patellar reflex?

Exaggerates the patellar reflex by countering some of the normal descending inhibitory brainstem inputs to reflex arc interneurons

What is the vestibulo-ocular reflex? The five components of this reflex?

An automatic reflex that keeps your vision stable by generating eye movements that oppose head movements. Receptor, efferent Pathway, central Nervous System, efferent Pathway and effector

How to calculate average heart rate?

Count the number of pulses in 10 seconds, then multiply by 6

How to calculate real time heart rate?

Measure the duration of a pulse, then HR = 60 / the duration of a pulse

How to calculate pulse amplitude?

subtract the minimum value from the maximum value and then divide the result by two

What are the components in the reflex arc of the diving reflex?

Bradycardia and peripheral vasoconstriction

What are the benefits of diving reflex, in aquatic and terrestrial animals respectively?

aquatic animals: to conserve O2 and terrestrial animals: to conserve body heat

What is the pacemaker of the human heart? During the diving reflex, which neurotransmitter is released to affect the pacemaker?

Sinoatrial node and acetylchloine

Which organs receive significantly less blood, as demonstrated by your lab activity?

Reduced to the limbs and peripheral organs to preserve oxygen for the brain and heart

What are the trigger and the two prominent effects of the human diving reflex?

The trigger is cold water and the effects are peripheral vasoconstriction and bradycardia

In the first trimester of pregnancy, which organ produces estradiol and progesterone

corpus luteum

Gonadotropin-releasing hormone (GnRH)

stimulates the release FSH and LH the anterior pituitary

The hypothalamus releases

Gonadotropin-releasing hormone (GnRH)

The gonads releases

Activin and inhibin

What are the phases of a uterine cycle

menses, proliferative phase, secretory phase

The ovarian cycle is the

monthly process where an egg is developed and released from the ovary to potentially be fertilized, and it consists of two main phases: the follicular phase and the luteal phase.

In the follicular phase (before ovulation)

follicles mature in the ovary, and an egg develops within the dominant follicle. The second phase, ovulation, is the event where the mature egg is released from the ovary.

In the luteal phase (after ovulation)

the ruptured follicle transforms into the corpus luteum, which produces hormones like progesterone to prepare the body for a potential pregnancy. 

What happens at fertilization? Where does fertilization occur?

a sperm cell and egg cell combine, with the sperm's genetic material joining the egg's to form a single cell called a zygote. Occurs in the fallopian tube.

How many sets of chromosomes are in the egg at the time of fertilization?

The egg contains one set of 23 chromosomes,

What are the molecular triggers of sexual differentiation

SRY

What are the haploid and diploid states of cells?

Diploid cells contain two complete sets of chromosomes (2n), one inherited from each parent, while haploid cells contain only one complete set (n). Diploid cells are the somatic cells (body cells), while haploid cells are the gametes

What is a Graafian follicle?

the dominant follicle to ovulate

What is atresia?

Cell death of ovary follicles

What are the developmental stages of follicles?

primordial, primary, secondary, late preantral/tertiary, antral/Graafian, and preovulatory follicles

Structure and function of the three parts of sperm

The head holds the male DNA, and the acrosome. The midpiece is filled with mitochondria, the energy needed for the tail's movement. The tail, a long flagellum, propels the sperm through the female reproductive tract to reach and fertilize the egg.

What is the zona pellucida?

A protective layer surrounding the egg cell (oocyte), acting as a barrier and a binding site for sperm

What is the acrosome?

contains digestive enzymes to break down the outer membrane of the ovum, called the zona pellucida

What is the SRY gene (location, function)? What is testis determining factor?

the protein product of SRY gene is called testis determining factor

Spermatogenesis occurs in

the seminiferous tubules

How many gametes does each process generate from one germ cell?

One primary spermatocyte yields four sperm cells, while one primary oocyte produces one functional egg (ovum) and three polar bodies. Both processes begin with a diploid (2n) germ cell (spermatogonium or oogonium) and involve meiosis to produce haploid (n) gamete

Sertoli cell

Stimulates spermatogenesis and form barrier to prevent antibodies or toxic substances to reach germ cells

Granulosa cells

In female, convert testosterone to estradiol

Theca cell

In female, produce testosterone

Inhibin cells

Secreted by Sertoli cells and inhibits FSH production

Leydig cells

In males secretes testosterone and gives feedback on LH

Activin

Stimulates FSH secretion