#2 villalobos brain, heart, reproductive syste and embryo development
TRANSCRIPT
BRAIN STRUCTURE AND PHYSIOLOGY
THE NERVOUS SYSTEM
TWO MAJOR DIVISIONS
• The Central Nervous System (CNS)• Peripheral Nervous System (PNS)
THE CENTRAL NERVOUS SYSTEM
Controls the center of the body;• relays messages•processes information•analyzes information
PARTS THAT MAKE UP THE CNS
• Cerebrum: largest most prominent region of the human brain (front of the brain). Responsible for the voluntary or conscious, activity of the body. Site of intelligence, learning and judgment.• Cerebellum: second largest region of the brain.
Coordinates and balances the actions of the muscles. (back of the brain)• Thalamus: receives messages from all the
sensory receptors throughout the body and then relays information to the proper region of the cerebrum for further processing.
THE PERIPHERAL NERVOUS SYSTEM
• Nerves stimulate regions of the head and neck, spinal nerves, and ganglia.• It can be divided into the sensory division and the
motor division• Sensory division: transmits impulses from sense
organs to central nervous system.• Motor division: transmits impulses from the
central nervous system to the muscles or glands.
THE NERVOUS SYSTEM : COMMUNICATION
•A. Neurons = masses of nerve cells that transmit information
1. Cell Body - contains the nucleus and two extensions
2. Dendrites – shorter, more numerous, receive information
3. Axons – single, long “fiber” which conducts impulse away from the cell body, sends information
BASIC DIVISIONS OF THE NERVOUS SYSTEM
CARDIOVASCULAR SYSTEM
HUMAN CIRCULATORY SYSTEM
• Systemic Circulation – delivers blood to all body cells and carries away waste
• Pulmonary Circulation – eliminates carbon dioxide and oxygenates blood (lung pathway)
STRUCTURE OF THE HEART
• Heart Size: (size of a fist) approximately 14 cm x 9 cm • Located in the
mediastinum (space between lungs, backbone, sternum), between the 2nd rib and the 5th intercostal space. • The distal end of the
heart is called the apex
WALLS OF THE HEART
• Epicardium – outer layer, reduces friction• Myocardium –
middle layer, mostly cardiac muscle• Endocardium – thin
inner lining, within chambers of the heart
HEART CHAMBERS & VALVES
• Heart has 4 chambers: • 2 Atria – thin upper
chambers that receive blood returning to the heart through veins.. Right and Left Atrium
• 2 Ventricles – thick, muscular lower chambers. Receive blood from the atria above them. Force (pump) blood out of the heart through arteries. Right and left ventricle.
• Septum – separates the right and left sides of the heart
Valves of the Heart – allow one-way flow of blood
• 4 total (2 Atrioventricular Valves (AV) & 2 Semilunar valves)
• Left Atrioventricular valve – also called the bicuspid valve or mitral valve. Between left atrium and ventricle
• Right Atrioventricular valve – also called the tricuspid valve. Between right atrium and ventricle
• Aortic Semilunar – or just aortic valve. Between the left ventricle and the aorta
• Pulmonary Semilunar, or just pulmonary valve. Between the left ventricle and the aorta
BLOOD VESSELS
•Blood Vessels: arteries, veins, capillaries
•ARTERIES : strong elastic vessels which carry blood moving away from the heart. Smallest ones are arterioles which connect to capillaries.•VEINS - Thinner, less muscular vessels carrying blood toward the heart. •Smallest ones are called venules which connect to capillaries. Contain valves.
CAPILLARIES
Penetrate nearly all tissues. Walls are composed of a single layer of squamous cells – very thin. Critical function: allows exchange of materials (oxygen, nutrients) between blood and tissues.
MAJOR BLOOD VESSELS
• Aorta - Ascending Aorta, Aortic Arch, Descending Aorta, Abdominal Aorta. The aorta is the largest artery. (leaves left ventricle)
• Pulmonary Trunk – splits into left and right, both lead to the lungs (leaves left ventricle)
• Pulmonary Veins – return blood from the lungs to the heart (connects to left atrium)
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• Superior and Inferior Vena Cava – return blood from the head and body to the heart (connects to right atrium)
MALE REPRODUCTIVE SYSTEM
Major Structures: testes, vas deferens, prostate, penis
MALE REPRODUCTIVE SYSTEM
• Function: Produces and delivers sperm• Parts: scrotum, seminiferous tubules, epididymis,
vas deferens, testes, urethra, penis
PARTS
• Scrotum: where testes remain outside the body cavity. Temperature 37°C.
• Seminiferous tubules: located in the testis are clusters of hundreds of tiny tubules.
• Epididymis: where fully matured sperm are stored.
• Testes: makes sperms, produces testosterone.
• Vas deferens: the tube that carries sperm from the epididymis to the urethra.• Urethra: tube that
carries urine from the bladder and releases it from the body.• Penis: contain a
tube(urethra) that leads to the outside of the body.
FEMALE REPRODUCTION
Main Structures•Ovary•Uterus•Fallopian Tubes•Vagina•Cervix
FEMALE REPRODUCTION
• OVARY - this is where the eggs are produced through cell division (MEIOSIS)
• - each ovary takes turns releasing eggs every month, twins occur if two eggs are released
• Ovaries secrete both estrogen and progesterone.
• Estrogen is responsible for the appearance of secondary sex characteristics of females
• Progesterone regulates
menstruation
EMBRYO DEVELOPMENT
• An egg is usually a few days old before it implants in the uterus. At this point, it has already divided several times and is called a blastula.
Uterus
• The uterus consists of a body and a cervix. The cervix protrudes into the vagina.
• The uterus maintains an
environment for accepting a fertilized egg.
• The fertilized ovum becomes an embryo, attaches to a wall of the uterus, creates a placenta, and develops into a fetus (gestates) until childbirth.
• If no fertilized egg reaches the uterus, the lining is shed monthly in a process known as menstruation
FEMALE REPRODUCTIVE SYSTEM
• Cervix• Fallopian Tubes• Vagina• Ovary• Uterus
REVIEW QUESTIONS
Questions:1.Name the stage of development the embryo is a hollow ball of
identical cells:2. Name the part of the female reproductive system the egg cells
are released:3. Name the structure specialized for taking blood away from the
heart:4. Which part of the brain is responsible for the voluntary or
conscious, activity of the body? 5. List the four different lobes of the brain: 6. which structure transports deoxygenated blood back to the heart?
REVIEW ANSWERS
Questions:1. Name the stage of development the embryo is a hollow ball of identical
cells:(blastula)2. Name the part of the female reproductive system the egg cells are
released:(ovaries)3. Name the structure specialized for taking blood away from the heart:(arteries)4. Which part of the brain is responsible for the voluntary or conscious, activity
of the body? (cerebrum) 5. List the four different lobes of the brain: (parietal lobe, occipital lobe, frontal
lobe, temporal lobe) 6. which structure transports deoxygenated blood back to the heart?
(pulmonary artery)
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