Semi-finals Review on Human Body Systems
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Transcript of Semi-finals Review on Human Body Systems
SEMI-FINALS REVIEW on HUMAN BODY SYSTEMSPrepared by: Earshad B. BanjalNatural Science DepartmentCollege of Arts & Sciences EducationUniversity of Mindanao, Matina, Davao City
THE EXCRETORY SYSTEM
excretes METABOLIC WASTES (urea, excess water & minerals) from the body
PRINCIPAL ORGANS:
1. KIDNEY – water, urea &
other metbolic wastes
2. LUNGS – water vapor &
carbon dioxide
3. LIVER – urea
4. SKIN – water, salt, urea
NEPHRON – functional unit of KIDNEYS
HOW IS URINE PROCESSED & EXCRETED?
1. Blood enters through Glomerulus, which is covered by the Bowman’s capsule, where FILTRATION happens.
2. Salt, urea, ions, and dissolved substances (all called filtrate) move through the tubules (proximal, Loop of Henle, & distal).
3. REABSORPTION, or the reabsorption of important substances like water & salt, happens mostly in the Loop of Henle.
HOW IS URINE PROCESSED & EXCRETED? (cont.)
4. The filtrate with substances that were not reabsorbed enters the collecting duct, in the process of URINE EXCRETION.
5. This filtrate is now called urine, and will now flow to the ureters.
TRACE THE PATH OF URINE FLOW.
1. From the COLLECTING DUCT, urine flows through the URETER.
2. URETER empties urine into the URINARY BLADDER.
3. URINARY BLADDER temporarily stores urine, until it is excreted through the URETHRA.
THE NERVOUS SYSTEM
collects information about the body’s
internal & external environment, processes
that information, & responds to it
DIVISIONS OF THE NERVOUS SYSTEM:
1. Central Nervous System – the brain & spinal cord
2. Peripheral Nervous System – the nerves
NEURON – the basic unit (cell) of the Nervous System
Neurons transmits IMPULSE,
or electrical signals.
DENDRITES receives, AXON
transmits the signals to other neurons.
THREE TYPES OF NEURONS:
1. SENSORY – collects stimulus
from the outside
2. INTERNEURON – transmits
impulse to other neurons, to
the spinal cord, or brain
NEURON transmits chemical signals, or NEUROTRANSMITTERSTHREE TYPES OF NEURONS:
3. MOTOR NEURONS – carries
signals to the effectors, or
target organs
HOW ARE SIGNALS GENERATED?
When stimulus is transformed
into impulse in dendrites, the signal
travels along the axon. As it reaches
the synapse, the axon releases
neurotransmitters.
THE CENTRAL NERVOUS SYSTEM
DIVISIONS OF THE BRAIN:
1. Cerebrum – largest; voluntary activities, intelligence, learning, judgment
a) HEMISPHERES: Left – logic, analytic, reasoning; Right – arts, passion, creativity
2. Cerebellum – “little brain”; involuntary, balance & coordination
THE CENTRAL NERVOUS SYSTEM (CNS)
DIVISIONS OF THE BRAIN:
3. Brain Stem – connects the brain & spinal cord; involuntary; life-sustaining activities, breathing, heart rate, BP, swallowing
a) Midbrain
b) Pons
c) Medulla Oblongata
THE PERIPHERAL NERVOUS SYSTEM (PNS)
Transmits signals to the brain through the spinal cord & receives signals from the brain that enervates the effectors.
DIVISIONS OF THE PNS:
1. Sensory Division – from sense organs to CNS
2. Motor Division – from the CNS to muscles or glands (all called effectors)
a) SOMATIC NERVOUS SYSTEM: voluntaryb) AUTONOMIC NERVOUS SYSTEM: involuntary
i. SYMPATHETIC - stimulatesii. PARASYMPATHETIC - relaxes
THE SKELETAL SYSTEM
supports the body; protects internal organs; stores minerals; site of blood formation
DIVISIONS OF THE SKELETAL SYSTEM:
1. Axial – central axis includes skull, vertebrae, & ribcage
2. Appendicular – arms & legs
OSCTEOCYTE – basic unit (cell) of the Skeletal System
HAVERSIAN CANAL provides pathway for nerves & vessels to the osteocytes.
BASIC STRUCTURE:
1. Epiphysis – end part; covered w/ cartilage
2. Diaphysis – long body part
3. Periosteum – covers the bone
4. Marrow – storage for fats; site of blood cell formation
OSSIFICATION – bone formation
Joints – hold bones together
1. Diarthroces – allows movement
2. Synarthroces – do not allow movement, example: suture joint in the skull
LIGAMENTS connects skeletal muscles to the bones.
TYPES OF SKELETAL SYSTEM
3. Exoskeleton – external; insects and other animals
4. Endoskeleton – inside: humans and animals
OSTEOPOROSIS – bone degradation
THE MUSCULAR SYSTEM
THREE TYPES OF MUSCLE TISSUE:
1. Skeletal Muscle – connected to the bones; voluntary; striated (banded): biceps, calf muscles, abs
2. Smooth Muscle – forms the structure of some internal organs; involuntary; unstriated: urinary bladder, stomach, intestine
3. Cardiac Muscle – involuntary; striated: heart only
MYOFIBER – a bundle of muscle, composed of myofibrils
HOW DO MUSCLES CONTRACT?
Each MYOFIBRIL is composed of ACTIN & MYOSIN filaments. Muscle will contract if actin & myosin are attached to each other (called CROSS-BRIDGE). If not, muscles are relaxed.
Muscles work in pairs. Muscle pairs are ANTAGONISTIC, meaning they work oppositely. Example: when biceps contract, triceps relax; vice-versa.
SARCOMERE – single length of actin & myosin, bounded by Z-disc
THE INTEGUMENTARY SYSTEM
barrier against infection & injury; regulates body temperature; removes wastes from the body; gathers information; produces vitamin D
PRIMARY STRUCTURES:
1. Skin – major organ of the integumentary system
2. Hair – composed of keratin; protects us from UV; prevent dirt from entering the body; insulation from cold
3. Nail – composed of keratin
MELANOCYTES – skin cells, producing melanin (brown pigment)
LAYERS OF SKIN:
1. EPIDERMIS – outermost layer; contain MELANOCYTES; produces keratin
2. DERMIS – contains collagen, nerves, vessels, glands, smooth muscles, hair follicles; SEBACEOUS GLANDS – produce oil
3. HYPODERMIS (SUBCUTANEOUS LAYER) – fats (adipose tissue)
THE RESPIRATORY SYSTEM
picks up oxygen from INSPIRATION (inhalation) & releases carbon dioxide in EXPIRATION (exhalation)
PRIMARY STRUCTURES:
1. Nose – warms & moistens the air; traps dirt
2. Pharynx (throat) – passageway for both air & food
3. Epiglottis – prevents the entrance of food to trachea
4. Larynx – voice box
BREATHING relies on simple DIFFUSION of gases
5. Trachea – cartilaginous; traps and sweeps out dirt through CILIA
6. Bronchi & bronchioles – branch off to each lung
7. Alveoli – grape-like structures where gas exchange occurs
8. Lungs – two structures that house the bronchi & alveoli, and other related structures
9. Diaphragm – dome-shaped muscle beneath the lungs
TRACE THE PATHWAY OF AIR IN & OUT OF THE RESPIRATORY SYSTEM
BREATHING MECHANISM
During inspiration:
Rib cage rises; Diaphragm contracts (lowers); Air pressure decreases; Volume increases
During expiration:
Rib cage lowers; Diaphragm relaxes (rises); Air pressure increases; Volume decreases
THE ENDOCRINE SYSTEM
delivers chemical messages (hormones) throughout the body
hormones are released by the endocrine glands to target organs or substances
GLANDS:
1. Exocrine glands – with ducts (vessel) pouring into external environment or the digestive system
2. Endocrine glands – ductless, pour its contents directly into the blood
PITUITARY GLAND – the master gland of the Endocrine System
(Please refer to your book for the complete list of hormones, Introduction to Biology by Aldea, et al., pages 116-117)
NEGATIVE FEEDBACK SYSTEM – regulates the secretion of the endocrine glands by inhibiting the glands themselves if there is an excess of the substance to be controlled; or activating the glands if there is a deficiency of the substance to be controlled
EXAMPLES OF ENDOCRINE-RELATED DISORDER
1. Diabetes Mellitus – inactive pancreas, deficiency in insulin production
2. Cretenism (hypothyrodism) – small stature; low metabolism, lack energy
3. Pituitary dwarfism – small stature, short appendages, underdeveloped body parts
4. Gigantism - “giant” physical stature from overproduction of Growth Hormone
5. Goiter – enlarged thyroid gland, less production of thyroxine because of decreased consumption of Iodine-rich food
THE REPRODUCTIVE SYSTEM
Sexual development in both male and female starts at the onset of PUBERTY, when the hypothalamus signals the pituitary glands to produce Follicle-stimulating Hormone (FSH) and Luteinizing Hormone (LH).
FSH & LH affect the gonads (testis & ovaries).
In males, LH stimulates production of TESTOSTERONE; FSH stimulates the development of sperm cells.
In females, FSH stimulate the ovaries to produce ESTROGEN, to start producing egg. LH functions in menstrual cycle.
THE MALE REPRODUCTIVE SYSTEM
PRIMARY STRUCTURES:
1. Testes (testis pl.) – produces the sperm cells in the SEMINIFEROUS TUBULES
2. Epididymis – where sperm matures
3. Vas Deferens – tube that connects the epididymis to urethra; pathway of SEMEN (sperm + seminal fluid = semen) during EJACULATION
4. ACCESSORY GLANDS: Seminal Vesicle, Prostate Gland, & Bulbourethral Gland (Cowper’s Gland) – produce SEMINAL FLUID
5. Urethra – pathway for both semen & urine
One drop of semen = 2.5 million
SPERM STRUCTURE:
1. Head – houses the nucleus & acrosome (organelle that punctures the covering of the egg)
2. Midpiece – mitochondria-laden
3. Tail or Flagellum – for movement
LET’S TAKE A CLOSER LOOK!
THE FEMALE REPRODUCTIVE SYSTEM
PRIMARY STRUCTURES:
1. Ovary – produces the ovum (egg)
2. Fallopian Tube (Oviduct) – where the egg is released into & fertilization occurs
3. Uterus (womb)– houses the embryo
4. Cervix – opening of the uterus
5. Vagina – receives the penis during sexual intercourse
THE MENSTRUAL CYCLE
Happens every 28 days in the average
PHASES OF THE MENSTRUAL CYCLE
1. Follicular Phase – FSH & LH rise, cause the follicle (egg cell plus the surrounding cells) to mature; estrogen rises causing the walls of the uterus to thicken
2. Ovulation – release of egg into the oviduct, leaving the follicle in the ovary
3. Luteal – the follicle turns yellow (CORPUS LUTEUM) ; LH & FSH lower, progesterone is released to further thicken the uterine wall
4. Menstruation – last about 3-7 days; because of low estrogen, blood is shed with the ovum in it
FERTILIZATION & DEVELOPMENT
During sexual intercourse, millions
of sperm are released in the female
reproductive tract.
Only one sperm (usually) fertilizes an egg.
A ZYGOTE is formed in fertilization.
In case of multiple embryos, twins can develop either when: a zygote divides further into two embryo, or 2 sperm cells & 2 egg cells are simultaneously fertilized.
FERTILIZATION happens in the fallopian tube.
MARAMING SALAMAT PO SA PAKIKINIG.
DISCLAIMER
Dear Class (BE 305, 306, 327),
This will serve as a SUPPLEMENT for your review for the semi-final exam. The best thing for you to do is study your book, lecture notes, prior quizzes & the reports of your classmates. Please be guided accordingly to further instructions that I will post on Facebook on or before Monday, July 28.
Yours truly,
Your Handsome Teacher =)