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THE CARDIOVASCULAR SYSTEM BLOOD
Comprised of Collection of specialized cells suspended in plasma
the heart,
Delivers oxygen and nutrients to body cells, collects
blood vessels,
and blood waste, distributes hormones, spreads heat around
the body to control temperature, and plays a part in
fighting infection and healing injuries
These are the key functions of the cardiovascular system!
BLOOD GROUPS
Every individual falls into one of four blood groups, determined by
markers on the erythrocytes known as antigens.
Both antigens present = AB
Both absent = O
Only one present = A or B
Antigens are “foreigners” that are attacked by immune system
antibodies. If your cells have antibodies that attack B antigens,
then you are blood type A, and vice-versa.
Rh factor indicates the presence/absence of the D antigen:
(+) = present
(-) = absent
ARTERIES VEINS
Carry blood away from the Carry blood toward the heart
heart toward organs and Transport deoxygenated blood, except the
tissues pulmonary veins
Transport oxygenated blood, Blood inside is under relatively low pressure
except the pulmonary arteries
Some contain valves and smooth muscle to
Blood inside is under relatively prevent blood from flowing back down legs
high pressure
Two main veins returning blood to the heart:
Largest is the aorta – conveys superior and inferior vena cavae
blood from the heart
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CAPILLARIES THE HEART
Smallest and most numerous of Powerful organ composed of cardiac muscle
blood vessels tissue; about the size of a clinched fist
Convey blood between arteries
Operates as two coordinated pumps that send the
and veins
blood around the body
Many enter tissue to form a
capillary bed – the area where Contains four chambers and four valves to control
oxygen and other nutrients are blood flow
released, and where waste
matter passes into blood Has its own blood supply via the coronary arteries
EXTERNAL ANATOMY OF THE HEART INTERNAL ANATOMY OF THE HEART
PULMONARY AND SYSTEMIC CIRCULATION PULMONARY AND SYSTEMIC CIRCULATION
Pulmonary circulatory system Systemic circulatory system
– The right ventricle pumps – The left ventricle pumps
deoxygenated blood to the oxygenated blood to the rest Pulmonary vein
lungs to obtain oxygen. Blood of the body to deliver oxygen, Pulmonary artery
then flows back to the heart. nutrients, etc. Then carbon
dioxide and other wastes are
removed from the tissues
and carried back toward the
heart. Systemic veins Systemic arteries
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PULSE RATE THE CARDIAC CYCLE
Pulse rate – Number of heart beats per minute; indicator of Systole – contraction of
cardiac health chambers
Normal resting adult’s pulse rate is 65-80 Diastole – relaxation of
Higher than normal pulse rate indicates that the heart is chambers
working hard “Lub – dub” sound of the
Increases during exercise or stress heartbeat:
“Lub” occurs when the AV
valves close
“Dub” occurs when the SL
valves close
Heartbeat animation
BLOOD PRESSURE
Normal adult blood pressure = 120
Systolic pressure 80
Top number The Nervous System and Sensory Perception
Measures the pressure in the arteries during
ventricle contraction or systole
Functions of the nervous system: Perceives and responds to signals
Diastolic pressure from the environment called stimuli
Bottom number
Measures the pressure in the arteries during Facilitates cell-to-cell communication
ventricle relaxation or diastole This enables billions of cells comprising an organism to function as an
single, highly-integrated unit
Hypertension – chronic high b.p.
Major Divisions of the Nervous System HUMAN NERVOUS SYSTEM
Central nervous system
1. Brain
2. Spinal cord CENTRAL NERVOUS PERIPHERAL NERVOUS
SYSTEM (CNS) SYSTEM (PNS)
Peripheral nervous system
1. Afferent division
Contains sensory neurons that receive stimuli and
carry them to the CNS where they are processed SPINAL AFFERENT EFFERENT
BRAIN
CORD DIVISION
2. Efferent division DIVISION
(SENSORY (MOTOR
Contains motor neurons that carry the response generated
NERVES) NERVES)
in the CNS to effector organs, such as glands or muscles,
which carry out the response
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Nerves and Neurons
Neuron – nerve cell
Between 80 and 100 billion neurons in the human brain; millions more
throughout the rest of the human body
The neuron has a cell body and a nucleus, but it also has additional structures:
o Dendrites – receive sensory inputs and conduct them toward the cell body
o Axons – receive messages from the cell body and transmit them to other
neurons, muscles, or gland cells
How a signal is transmitted “The brain is the only known entity in the universe
The Brain capable of contemplating itself.”
-T.M. Graham, 1998
The organ of consciousness and creativity; the body’s command center
Through the spinal cord and nerve branches, the brain controls all body
movements and its motor output
Receives sensory information from both outside and inside the body
Works with the endocrine glands to maintain other body systems
Brain Facts The Cerebrum
The brain only accounts for 2% of the total body weight, but requires Also called the cerebral cortex
20% of the body’s blood Largest part of the brain
Contains the centers for memory and intelligence
Largest in size relative to other apes
Divided by the longitudinal cerebral
Protection fissure, line dividing right and left halves
o Three protective membranes (meninges) Left hemisphere – associated with right-hand coordination, spoken
o Cerebrospinal fluid (CSF) – absorbs and disperses excessive
language, number skills, scientific skills, and reasoning
mechanical forces Right hemisphere – associated with left-hand coordination,
musical and artistic abilities, spatial abilities, insight, and imagination
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Brain Structure Major Sections of the Brain
Cerebellum – involved with timing and accuracy of skilled movements;
controls balance and posture
Medulla oblongata – elongated stem that leads to the spinal cord; contains
reflex centers and controls vital functions such as heartbeat, breathing, and
digestion
Pons – anterior to the medulla; center of information transfer between the
cerebrum and cerebellum; some control of breathing
Corpus callosum – dense region under the cerebrum containing many axons
that carry impulses between the left and right hemispheres
Optic nerves – carry visual stimuli from the eyes to the cerebrum where they
are interpreted
Spinal Cord
The Spinal Cord
Complex bundle of nerve fibers
~16 to 18 inches long
Extends from base of brain down
to lower part of spinal column
31 pairs of nerves carry sensory
information and convey motor
information
Reflex Responses Eyes and Vision
A reflex is a rapid automatic response to a stimulus that is made Eyesight provides the brain with more input than all other senses combined
without thinking; an involuntary “knee-jerk” reaction
It is estimated that more than 50% of the information in the conscious mind
Response is processed through the spinal cord for quick reaction (not enters through the eyes
through the brain)
Involves only one
sensory neuron and
one motor neuron
Ex: patellar reflex
(see Fig. 23.3)
In contrast, voluntary
responses exhibit a delay
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Parts of the Eye Parts of the Eye, continued
Cornea – domed transparent “window” at front of eye Choroid – blood-rich layer that supplies the eye
Sclera – tough white protective outer sheath of eyeball Retina – thin layer of light-sensitive rod cells and color-sensitive cone
Optic nerve – conveys nerve signals to brain; each contains one million cells located along the inside back of the eye
nerve fibers Tapetum – iridescent blue-green layer near the choroid that is found in
Vitreous body – cavity filled with fluid called vitreous humor many mammals but not humans; reflects excess light back through the
retina, increasing night vision
Pupil – hole in iris that becomes wider in dim light
Causes the green glow of animals’ eyes when
Iris – ring of muscle that changes size of pupil to regulate amount of light a light shines on them
entering eye Conversely, “red eye” seen in photographs
Ciliary muscle (body) – ring of muscle that alters lens shape of humans is caused by excess light reflecting
Lens – transparent disk that changes shape for near or far vision off the retina
Outer and Middle Ear Anatomy
Outer ear
o Pinna – ear flap
o Ear canal
Middle ear
o Contains the eardrum and
three ossicles— hammer,
anvil, and stirrup
o Connects to throat by the
Eustachian tube
Inner Ear Anatomy Today’s Assignments
Three semicircular canals – detect Observe as your lab instructor dissects a sheep heart.
the speed and direction of different Video: Sheep heart dissection
head movements – roll, pitch, and
yaw
Label the structures on the heart diagram.
Be able to identify parts of the heart on the quiz and exam.
Cochlea – fluid-filled, spiral shaped Four chambers
organ lined internally with cilia or Septum
hair cells that translate sound Aorta
waves into nerve signals Work with a partner to dissect a sheep eye.
Video: Sheep eye dissection
Auditory nerve – transfers signals Point out eye structures to your TA and obtain his/her initials!
from the cochlear hair cells to the
Label structures on the eye, inner ear, and brain diagrams.
brain
Be able to identify parts of the eye, ear, and brain on the quiz and
exam.
