EST-ACT-AP

BIOLOGY ACADEMY

Human Systems
Endocrine - Excretory

Dr. Mina Samuel

drminasamuel@hotmail.com
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EST-ACT-AP Bio-Academy... Human Systems I-(18) Dr. Mina Samuel

Human Systems I

I. Endocrine System
Gland Hormone Function
Anterior . Growth hormone (GH) Stimulates growth
pituitary . Thyroid-stimulating hormone Stimulates thyroid gland
(TSH)

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. Adrenocorticotropic hormone Stimulates adrenal cortex gland
(ACTH)
. Follicle-stimulating hormone Stimulates gonads to produce sperm and ova

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(FSH)
. Luteinizing hormone (LH) Stimulates ovaries and testes
. Prolactine Milk secretion from mammary gland
Posterior . Oxytocin Uterus contraction to give birth
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pituitary
. Antidiuretic hormone (ADH) Water retention (decrease water in urine)
Urine volume / urine concentrated
Thyroid . Thyroxin Controls metabolic rate
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. Calcitonin Lowers blood calcium levels

Parathyroid Parathormone (PTH) Raises blood calcium levels
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Thymus Development of immune system

Pancreas (islets of . lnsulin sugars in Blood (glucose glycogen)
Langerhans)
. Glucagon sugars in Blood (glycogen glucose)
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Adrenal gland . Cortisone Blood sugar

a) Adrenal cortex . Aldosterone Salt retention release during hypotension
Rise Blood pressure

B) Adrenal medulla . Epinephrine (adrenaline) Emergency - Danger

. Norepinephrine (noradrenaline)
Testes . Testosterone Support spermatogenesis
Male sex hormone (steroids) Male secondary sex characteristics
Ovaries . Estrogen Female secondary sex characteristics

. Progesterone Endometrial thickness to get uterus ready for

Female sex hormones (steroids) pregnancy

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EST-ACT-AP Bio-Academy... Human Systems I-(18) Dr. Mina Samuel

 Endocrine gland is a ductless gland release hormones

 Hormones are formed by endocrine glands and distributed in the body by blood plasma
 Hypothalamus forms the hormones of the posterior pituitary
 Coffee decrease ADH function which lead to increase urine volume and dilute it.
 Insulin stimulate cells to utilize glucose

Pancreas is only organ work both

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Endocrine Gland Exocrine Gland

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Hormone Digestive enzymes

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The Hypothalamus:
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Located in the brain; it is the bridge between the endocrine and nervous systems

Hypothalamus Hypothalamus
TSH releasing hormone
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Anterior pituitary anterior pituitary

TSH master mother gland
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Thyroid

Thyroxin (- ve feedback mechanism)

Thyroid Parathyroid Pancreas Adrenal gland Testes Ovaries
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 Homeostasis role:

Temperature

Blood pressure

Heart pulse

PH

Hormone level

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EST-ACT-AP Bio-Academy... Human Systems I-(18) Dr. Mina Samuel

II. Excretory System

 Excretion is the removal of metabolic wastes. This includes removing CO2 and water from cell respiration,
and nitrogenous wastes from protein metabolism.
 The organs of excretion in humans are the skin, lungs, liver, and the kidneys.
 Skin excretes sweat.
 For body temperature regulation in hot environment, blood circulation increased to the skin
and evaporation of perspiration cools the skin surface

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 The liver does not excrete any substances from the body, but it is the site of deamination of amino acids
and the production of urea.
 The kidneys excrete excess water and urea.

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 The Kidney
 The kidney adjusts both the volume and the concentration of urine depending on the animal's intake of
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water and salt and the production of urea.
 That's controlled by anti-diuretic hormone (ADH), that's released by the posterior pituitary and targets the
collecting tube of the nephron for water reabsorption.
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 The Nephron
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 It's the basic functional unit of the kidney.

 Each human kidney contains about 1 million nephrons.
 The nephron carries out its job in four steps: filtration, secretion, reabsorption, and excretion.
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1- Filtration
 Filtration occurs by diffusion.
 It is passive and nonselective.
 The filtrate contains everything small enough to diffuse out of the glomerulus and into Bowman's capsule,
including glucose, salts, vitamins, wastes such as urea, and other small molecules.

2- Secretion
 Secretion is the active.
 Selective uptake of molecules that did not get filtered into Bowman's capsule.
 This occurs in the tubules of the nephron.

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EST-ACT-AP Bio-Academy... Human Systems I-(18) Dr. Mina Samuel

3- Reabsorption
 Reabsorption is the process by which most of the water and solutes (glucose, amino acids, and
Vitamins) are transported back into the capillaries and thus back to the body.
 This process occurs in the tubule.

4- Excretion
 Excretion is the removal of metabolic wastes, for example, nitrogenous wastes. Everything that passes

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into the collecting tubule is excreted from the body.

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 Urinary bladder serves to store urine

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EST-ACT-AP Bio-Academy... Human Systems I-(18) Dr. Mina Samuel

III. The Eye and The Ear

The Eye

 Cones: photoreceptors in the retina that distinguish different colors

 Cornea: tough, clear covering that protects the eye and allows light to pass through
 Iris: colored part of the eye that controls how much light enters the eye

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 Lens: focuses light onto the retina

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 Pupil: small opening in the middle of the iris
 Retina: converts light into nerve impulses that are carried to the brain

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EST-ACT-AP Bio-Academy... Human Systems I-(18) Dr. Mina Samuel

The Ear

 Ear canal: where sound enters

 Different tones (pitches) cause different section of the basilar membrane to vibrate and so
human can distinguish the sound tone.

 Eustachian tube: equalizes pressure between environment and inner ear

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 Semicircular canals: fluid filled, helps you maintain your balance

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 Tympanum: ear drum, vibrates as sound waves hit it

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EST-ACT-AP Bio-Academy... Human Systems I-(18) Dr. Mina Samuel

IV. Muscles

There are three types of muscle: smooth, cardiac, and skeletal.

1- Smooth or involuntary muscle:

It makes up the walls of blood vessels and the digestive tract. It is under the control of the autonomic nervous
system.

2- Skeletal or voluntary (striated) muscle:

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They are very large and multinucleate. They work in pairs, one muscle contracts while the other relaxes.

3- Cardiac muscle:

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It's involuntary and striated muscle. It generates its own action potential. Individual heart cells will beat on
their own, even when removed from the body. aS
Myofibrils

 Skeletal muscle cell cytoplasm has thousands of fibers called myofibrils that run parallel to the length of
the cell.
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 Myofibrils consist of thin (actin protein) and thick (myosin proteins) filaments.

 Contraction of muscles filaments requires:

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a) Actin and Myosin interact within sarcomeres and slide over each other
b) Binding of Ca2+ ions to troponin
c) Energy (ATP)
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 ball and socket joints: as pelvic joint and shoulder joint (move in all directions)
 Scapula is flat triangle bone
 Ligaments: connect bones to each other at joints.
 Tendons: connect bones to muscles.
 The percussion of Achilles’ tendon by a reflex hammer Induces the extension of the leg
 Cartilage: Connective tissue with a protein matrix that reduce friction between bones.

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EST-ACT-AP Bio-Academy... Human Systems I-(18) Dr. Mina Samuel

Assignment 18

Questions 1-4:

(A) Adrenal cortex

(B) Adrenal medulla
(C) Pancreas
(D) Thymus
(E) Anterior pituitary

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1. Important to the development of the immune system
2. Secretes hormones that stimulate the ovaries and testes
3. Both increases and decreases blood sugar levels

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4. Secretes the fight-or-flight hormone

5. Which of the following occurs in muscle cells during skeletal muscle contraction?
(A) Sarcomerase digests sections of muscle fibers, resulting in shortened muscle segments.
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(B) O2 concentration increases.
(C) Actin and myosin proteins interact within sarcomeres.
(D) Myosin is depleted.
(E) ATP accumulates.
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6. Hormones released by the posterior pituitary are synthesized by the

(A) Hypothalamus.
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(B) Thalamus.
(C) Anterior pituitary.
(D) Thymus.
(E) Thyroid.
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7. The hypothalamus secretes a hormone called TRH that stimulates the anterior pituitary to secrete TSH. TSH
binds to receptors in the thyroid gland and causes it to release T3and T4. When blood levels of T3 and T4 are
sufficiently high, TRH synthesis is blocked. This series of events is an example of
(A) Anti-homeostasis
(B) A negative feedback loop
(C) Hyperthyroidism
(D) Hypothyroidism
(E) Amplification

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EST-ACT-AP Bio-Academy... Human Systems I-(18) Dr. Mina Samuel

Questions 8-11
(A) Pituitary gland.
(B) Testis.
(C) Thyroid gland.
(D) Pancreas.
(E) Adrenal gland.

8. Produces insulin.
9. Produces FSH (follicle-stimulating hormone).

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10. Produces an iodine-containing hormone that affects metabolic rate.

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11. Produces epinephrine for fight-or-flight response.

Questions 12-14

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(A) Insulin.
(B) Growth hormone.
(C) Progesterone.
(D) Thyroxin.
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(E) Secretin.

12. It is secreted by the pituitary gland.

13. It directly controls metabolic rate.
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14. Its concentration in the blood rises when the corpus luteum develops.
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15. In the diagram the human skeleton, which of the following is a ball-and-socket joint?
(A) 1
(B) 2
(C) 3
(D) 4
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(E) 5

16. Which of the following organs secretes the hormone responsible for the "fight-or-flight"
reaction in mammals?
(A) Liver.
(B) Kidney.
(C) Pancreas.
(D) Cowper's gland.
(E) Adrenal gland.

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EST-ACT-AP Bio-Academy... Human Systems I-(18) Dr. Mina Samuel

17. Myofibrils (myofilaments) are elements of muscle cells composed chiefly of

(A) Actin and myosin
(B) Tendons and ligaments
(C) Tropomyosin
(D) Cartilage
(E) carotene

Questions 18-20
(A) Glucagon hormone

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(B) Antidiuretic hormone
(C) Parathyroid hormone
(D) Thyroid hormone
(E) Insulin hormone

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18. Raises blood calcium
19. Promotes water retention
20. Lowers blood glucose
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21. Sarah saw a big snake while hiking. She started to run and her heartbeat increased to 100 bpm. Which of the
following organs is implicated in this response?
(A) adrenal cortex
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(B) adrenal medulla

(C) pancreas
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(D) thymus
(E) anterior pituitary

22. In the following graph, the time of the greatest increase in the
blood sugar levels occurs:
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(A) during the first 2 hours

(B) between the 2nd and the 4th hour
(C) between the 4th and the 6th hour
(D) between the 6th and the 7th hour
(E) between the 7th and the 8th hour

23. All of the following are examples of homeostasis in the human body EXCEPT:
(A) insulin is released after eating a sugary snack to maintain a constant blood glucose level
(B) carbon dioxide is exhaled from lungs to ensure a stable pH of blood
(C) on hot days, sweating makes sure body temperature remains at 37°C
(D) being able to run and throw objects with high precision ensures we can protect ourselves from predators
(E) urinating will remove unnecessary excess water from the body

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EST-ACT-AP Bio-Academy... Human Systems I-(18) Dr. Mina Samuel

24. Measurements that are normal for an average healthy human at rest include which of the following?
I. Body temperature of 37°C (98.6°F).
II. Systolic blood pressure of 180 mm of mercury.
III. Heart rate of 60-80 beats per minute.
(A) I only.
(B) II only.
(C) I and II only.
(D) I and III only.
(E) I, II, and III.

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25. Each of the following situations demonstrates homeostasis in the human body EXCEPT
(A) Pituitary-thyroid feedback loop.
(B) Selective reabsorption by renal tubules.

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(C) Development of secondary sex characteristics.
(D) Increased breathing rate following strenuous exercise.
(E) Breakdown of liver glycogen during physical stress.
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26. Which of the following is a flat triangular bone in humans?
(A) Humorous
(B) Femur
(C) Scapula
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(D) Radius
(E) Tibia
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Questions 27-30 (Advanced Experiment)

The table below summarizes an analysis of samples taken from a healthy person's blood, kidney (glomerular
filtrate), and urine. These data are given in grams per 100 milliliters of sample.
Blood Plasma Glomerular Filtrate Urine
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(A) Urea 0.03 0.03 2.0

(B) Glucose 0.10 0.10 0.0
(C) Amino acids 0.05 0.05 0.0
(D) Total inorganic salts 0.72 0.72 1.5
(E) Proteins 8.00 0.00 0.0

27. Data that suggest the kidneys may have a role in mineral homeostasis.
28. Data that suggest these organic molecules are LEAST likely to be reabsorbed back into the blood after have
passed into the glomerular filtrate.
29. Data that suggest these molecules do NOT pass from the blood to the glomerular filtrate.
30. Data that suggest the person tested did NOT exhibit symptoms of untreated diabetes mellitus.

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EST-ACT-AP Bio-Academy... Human Systems I-(18) Dr. Mina Samuel

31. A person exposed to the heat of the desert under-goes certain changes in bodily function that result in cooling of
the body. Which of the following would be the most likely change?
(A) Increased blood circulation to the skin.
(B) Increased erection of hairs (goose bumps).
(C) Increased muscular activity.
(D) Decreased sweating.
(E) Decreased beat loss from the capillary beds of the skin.

32. Which of the following is NOT a major function of the mammalian kidney?

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(A) Elimination of urea and other nitrogenous wastes.
(B) Maintenance of water balance.
(C) Manufacture of antibodies.
(D) Regulation of salt excretion.

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(E) Formation of urine from glomerular filtrate.

33. Which of the following statements about temperature regulation in humans living in hot environments is
correct?
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(A) Perspiration insulates the body and prevents heat loss.
(B) Evaporation of perspiration cools the surface area of the skin.
(C) Blood is shunted from the head region to the body cavity.
(D) Blood is more likely to travel near the long bones than near the skin.
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(E) Goose bumps cool by decreasing the surface area of the skin.
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EST-ACT-AP Bio-Academy... Human Systems I-(18) Dr. Mina Samuel

Assignment 18 Answers

Human Physiology I
1 D 11 E 21 B 31 A

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2 E 12 B 22 C 32 C

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3 C 13 D 23 D 33 B

4 B 14 C
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5 C 15 D 25 C
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6 A 16 E 26 C
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7 B 17 A 27 D

8 D 18 C 28 A
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9 A 19 B 29 E

10 C 20 E 30 B

With My best wishes dears

Dr. Mina Samuel

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EST-ACT-AP Bio-Academy... Human Systems I-(18) Dr. Mina Samuel

Assignment 18 Student Answers

Student Name: .

Human Physiology I
1 11 21 31

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2 12 22 32

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3 13 23 33
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4 14 24

5 15 25
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6 16 26

7 17 27
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8 18 28

9 19 29

10 20 30

With My best wishes dears

Dr. Mina Samuel

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