Brain Region Structures and Functions…
What are the functions of the following structures?
 Forebrain structures - Cerebrum, Thalamus, Hypothalamus, Pituitary Gland, Limbic System, Olfactory Bulb
 Thalamus - ranging from relaying sensory and motor signals, as well as regulation of consciousness and alertness.
 Hypothalamus - is involved in different daily activities like eating or drinking, in the control of the body's temperature
and energy maintenance, and in the process of memorizing and in stress control. It also modulates the endocrine
system through its connections with the pituitary gland.
 Cerebral cortex - Frontal Lobe - Planning, decision making and speech / Parietal Lobe - Sensory / Temporal Lobe
- Auditory / Occipital Lobe - Visio
 Limbic system - Amygdala, Hippocampus, Thalamus, Hypothalamus: Feeding, Reproduction, Caring for young,
Fight and flight responses
Midbrain structures - The Colliculi, The Tegmentum, The Cerebral Peduncles
 Reticular formation and neuron receptors - Muscle control, consciousness, control of autonomic system and
control of endocrine system.
Hindbrain structures - Pons, Cerebellum, Medulla Oblongata
 Medulla - Controls autonomic functions / Helps to transfer messages from brain and spinal cord.
 Cerebellum - Anterior lobe - information from the spinal cord / Posterior lobe - information from the brain stem and
cerebral cortex / Flocculonodular lobe - information from the cranial nuclei of the vestibular nerve / Coordinate
information from the spinal cord and from different parts of the brain. Controls balance, movement, equilibrium and
offers animals a sense of body position.
 Pons - Breathing regulation, Sleep, Arousal, Relaying information between the cerebrum and cerebellum.
Sensory Organ Structures and Functions…
What are the functions of the following components?
Eye
 Cornea - It’s like a window that controls and focuses the entry of light into the eye.
 Pupil - Is to allow light to enter the eye so it can be focused on the retina to begin the process of sight.
 Iris - Helps regulate the amount of light entering the eye.
 Ciliary body - Includes the ring-shaped muscle that changes the size of the pupil and the shape of the lens when
the eye focuses, and it also makes the fluid that fills the eye.
 Lens - To focus light rays onto the retina.
 Retina (rod and cone cells) - Is to receive light that the lens has focused, convert the light into neural signals, and
send these signals on to the brain for visual recognition.
 Optic nerve - Is a special sensory nerve that carries information from the visual world to the brain.
Ear
 Pinna - Collects sound waves and channels them into the ear canal, where the sound is amplified.
 Auditory meatus - Provides a passage through which the vestibulocochlear nerve, the facial nerve, and the
labyrinthine artery can pass from inside the skull to structures of the inner ear and face.
 Tympanic membrane - It separates the outer ear from the middle ear. When sound waves reach, they cause it to
vibrate. The vibrations are then transferred to the tiny bones in the middle ear
 Stapes - The vibrations enter the inner ear, where they are processed into neural data to be transmitted to the brain
via the cochlear and the auditory nerve.
 Cochlea - Is to transform the vibrations of the liquids and associated structures into a neural signal.
 Cochlear nerve - Primarily responsible for transmitting the electrical impulses generated for hearing and localization
of sound.
 Semi- circular canals - Help you keep your balance.
Nose
 Nasal chambers - To humidify, warm, filter, and act as a conduit for inspired air, as well as protect the respiratory
tract through the use of the mucociliary system.
 Turbinates - Is to regulate airflow, and to warm and humidify the air you breathe in.
 Olfactory nerve - Is the first cranial nerve and conveys special sensory information related to smell
 Olfactory bulb - Where information about odours is processed.
Mouth
 Taste buds - Allow you to experience tastes that are sweet, salty, sour, and bitter.
 Soft palate - For swallowing and sucking
 Hard palate - Provides space for the tongue to move freely and supplies a rigid floor to the nasal cavity so that
pressures within the mouth do not close off the nasal passage.
Skin
 Skin receptors - Glabrous skin and hairy skin contain a wide variety of sensory receptors for detecting mechanical,
thermal, or nociceptive (consciously perceived as painful) stimuli applied on the body surface. These receptors
include bare nerve endings (nociception, thermal sensation) and encapsulated endings.
 Structure of skin - The skin consists of two layers: the epidermis and the dermis. Beneath the dermis lies the
hypodermis or subcutaneous fatty tissue. The skin has three main functions: protection, regulation and sensation.
Specialised Senses
What specialised senses do these animals use and what specialised structures are involved?
 Bats & Dolphins - Echolocation - is a technique used by bats, dolphins and other animals to determine the location
of objects using reflected sound. This allows the animals to move around in pitch darkness, so they can navigate,
hunt, identify friends and enemies, and avoid obstacles.
 Snakes - Tactile organs - The tactile sense is one of the five traditional senses of the body. It is recognized by
the organs of touch which are found mainly in the skin. The sensitivity varies from one part of the skin to another.
The highly sensitive areas are the tactile sense on the forehead, temples, and the back of the forearm
 Whales - Electroreception - the capacity to detect external underwater electric fields with specialised receptors, is
a phylogenetically widespread sensory modality in fishes and amphibians
 Elephants - Taste and smell - Odors come from molecules in the air that stimulate receptors in the nose; if an
organism does not have a receptor for that particular odor molecule, for that organism, the odor has no smell. The
senses of smell and taste are directly related because they both use the same types of receptors.
Thermoregulation
Define and give species examples of each
 Endotherm - Endothermic animals are basically warm-blooded animals. They CAN maintain their body temperature
with that of the environment.
 Ectotherm - Ectothermic animals are basically cold-blooded animals. They CANNOT maintain their body
temperature with that of the environment.
Explain the process of thermoregulation via a negative feedback loop? (Consider receptors, control and
effectors.)
Nervous Control
List Structures in  Central Nervous System - the brain and spinal cord.
 Peripheral Nervous System - the somatic nervous system and the autonomic nervous system
Describe the Functions of the nerves listed above  Sensory Nerves - Sensory message to the brain
 Motor Nerves - Motor message from the brain
 Autonomic Nerves - Regulates internal body
Circulatory Systems
Describe the function of  Plasma - Liquid part of the blood - serum with dissolved substances such as carbon dioxide, amino acids, glucose
and fatty acids that also contains waste materials such as urea, hormones, enzymes and antibodies. Acts as a
buffer to maintain pH
 Erythrocytes (red blood cells) - Contain a protein called haemoglobin with Oxygen binds to. No nucleus or
mitochondria (rely on anaerobic metabolism) = space for more haemoglobin. Bi-concave shape = more surface
area. Much smaller than WBCs - can travel along capillaries
 Leucocytes (White Blood Cells) - Fight disease, destroy germs and remove dead tissue.
 Platelets (Thrombocytes) (no nucleus) - Formed from megakaryocytes in the bone marrow. Aid blood clot
formation during haemostasis. Function of clot is to prevent further blood loss and entry of infective agents. When
a blood vessel is damaged the platelets become sticky and form a platelet plug
What are the main blood vessels and describe their function  Arteries - carry oxygenated blood
 Capillaries - allow blood diffusion
 Veins - carry deoxygenated blood
Respiratory Systems
What are the functions of the following  Trachea - Airways are pipes that carry oxygen-rich air to your lungs.
 Bronchi - Bring Air In and Out of the Lungs.
 Bronchioles - Deliver air to the exchange surfaces of the lungs
 Alveoli - Are where the lungs and the blood exchange oxygen and carbon dioxide during the process of breathing
in and breathing out.
 Diaphragm - Upon inhalation, the diaphragm contracts and flattens and the chest cavity enlarges.
Describe how the diaphragm and intercostal muscles ventilate the lungs The diaphragm contracts and moves downwards. The intercostal muscles contract and move the ribs upwards and
outwards. This increases the size of the chest and decreases the air pressure inside it which sucks air into the lungs.
Reproductive Systems
Identify 4 components and describe their function in the FEMALE reproductive system  Vagina
 fallopian tubes
 Ovary
 Uterus
 Cervix
Identify 4 components and describe their function in the MALE reproductive system  Penis
 Epididymis
 Seminal vesicles
 Scrotum
 Vas deferens
 Testes
 Prostate
Outline the role of the reproductive hormones  Estrogen - helps control the menstrual cycle and is important for childbearing
 Progesterone - prepares the endometrium for the potential of pregnancy after ovulation
 Testosterone - to regulate sex drive (libido), bone mass, fat distribution, muscle mass and strength, and the
production of red blood cells and sperm.
 Follicle Stimulating Hormone - n sexual development and functioning. In women, Follicle Stimulating
Hormone helps control the menstrual cycle and stimulates the growth of eggs in the ovaries
 Luteinizing Hormone - in sexual development and functioning. In women, Luteinizing Hormone helps control the
menstrual cycle. It also triggers the release of an egg from the ovary.
Endocrine System
Define Endocrine vs Exocrine glands
 Endocrine - Endo = within, Crine = Secrete / Endocrine glands secrete hormones or other products directly into the
blood. / It maintains a stable environment for the body called ‘homeostasis’. /Without it there would be no life.
 Exocrine - These glands have ducts that carry the hormones from the gland to the target site. / These glands are
ductless and secrete hormones directly into the blood and the blood takes the hormones to the target site
What hormones do the following Endocrine Glands release?
 Thyroid – Thyroxine: Increase heart rate and oncrease respiratory rate / Triiodothyronine: Regulates protein
synthesis and Embryo development / Calcitonin: Regulates calcium levels in the blood
 Parathyroid  Pituitary - Growth Hormones / Endorphins – Feelings of well being / Prolactin – Stimulates milk production /
Oxytocin – Stimulates b
 Adrenal - Cortisol: Anti-stress and anti-inflammatory / Androgen: Developing male characteristics / Aldosterone:
Controls kidney function / Various steroids
 Pancreas - It has special cells known as the islets of Langerhans that produce hormones involved in regulating
sugar levels / Exocrine: secretes pancreatic juices into the gut / Endocrine: secretes insulin into the bloodstream
to control sugar levels
 Ovaries - oestrogen and progesterone, both important hormones in the menstrual cycle.
 Testes - Testosterone is secreted by cells that lie between the seminiferous tubules, known as the Leydig cells
Lymphatic System
List the roles of the Lymphatic System in the body  System of thin tubes that run throughout the body called - 'Lymph or Lymphatic vessels', that carry colourless fluid
called Lymph.
 As blood circulates, fluid/ 'plasma' leaks out from capillaries into tissues; carrying food and oxygen to the body
tissues and removes wastes from the body tissues into the blood.
 Some of the plasma that leaves the blood capillaries does not return to them and drains into the lymph vessels to
form lymph.
 It is drained away to prevent body tissues from becoming swollen by excess fluid. The water/proteins and plasma
are returned to the bloodstream.
 This network of vessels also prevents the backflow of lymph into the bodies tissues.
Describe the function of the following  Lymph Capillaries - Lymphatic capillaries collect lymph fluid from the tissues, which allows them to regulate the
pressure of interstitial fluid. This fluid is essentially plasma that leaks out of cardiovascular capillaries into the tissues
due to the forces of hydrostatic or oncotic pressure.
 Lymphatic Ducts - is to transport lymph back into the circulatory system.
 Lymph Nodes - filter out the damaged cells and cancer cells.
 Thoracic - The function of the thoracic duct is to transport lymph back into the circulatory system. Interstitial fluid is
collected by lymph capillaries from the interstitial space. Lymph then moves through lymphatic vessels to lymph
nodes. Lymphatic vessels merge to create the lymphatic ducts which drain into the venous system.
 Right Lymphatic Ducts - The right lymphatic duct is an important lymphatic vessel that drains the right upper
quadrant of the body. It forms various combinations with the right subclavian vein and rightinternal jugular vein.
 Subclavian Veins - The subclavian vein is a paired large vein, one on either side of the body, that is responsible
for draining blood from the upper extremities, allowing this blood to return to the heart.